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Papers by Annie Vereecken
RESULTS: Increasing disturbance of the lactobacillary flora (lactobacillary grades I, IIa, IIb, a... more RESULTS: Increasing disturbance of the lactobacillary flora (lactobacillary grades I, IIa, IIb, and III) was highly correlated with the presence of Gardnerella vaginalis, Trichomonas vaginalis, enterococci, group B streptococci, and Escherichia coli. Vaginal pH and interleukin 8 and interleukin 1β concentrations increased linearly with in- creasing lactobacillary grade, whereas lactate concentrations and the presence of epithelial cell lysis decreased. A
Journal of Clinical Pathology
Aim-The status of vaginal lactobacillary flora, an indicator of possible genital infection and pr... more Aim-The status of vaginal lactobacillary flora, an indicator of possible genital infection and pregnancy complications, can be assessed on wet mount or Gram stained specimens. The former is quick, the latter more routine. The accuracy of the two preparative techniques to detect normal vaginal lactobacillary microflora was compared for 646 patients. The eVect of delay in transport medium before Gram staining was also investigated.
Tijdschrift voor Geneeskunde, 2007
Het aanvragen van laboratoriumanalyses is voor veel artsen een dagelijkse routine. De kwaliteit d... more Het aanvragen van laboratoriumanalyses is voor veel artsen een dagelijkse routine. De kwaliteit die door de klinische laboratoria wordt geleverd, is het hoogst ten opzichte van alle andere medische disciplines (1). Dit is niet enkel te verklaren door de goed controleerbare omstandigheden waarin wordt gewerkt, maar ook door de toepassing van uitgebreide kwaliteitssystemen die in sommige laboratoria al meer dan vijftien jaar toegepast worden. Klinische laboratoria zijn op het gebied van kwaliteitszorg pioniers binnen de medische wereld. Desondanks weerspiegelen de bekomen resultaten niet altijd de klinische toestand van de patiënt.
The European journal of contraception & reproductive health care : the official journal of the European Society of Contraception, 1998
International clinical psychopharmacology, 1995
Two hundred hospitalized patients with DSM-III diagnosis of moderate to severe major depressive e... more Two hundred hospitalized patients with DSM-III diagnosis of moderate to severe major depressive episode were randomized to receive mirtazapine or trazodone for 6 weeks in a double-blind trial. The dosages were 24-72 mg/day for mirtazapine and 150-450 mg/day for trazodone. The improvement on all depression rating scales used was generally greater for mirtazapine, with statistically significant differences over trazodone in the Hamilton Psychiatric Rating Scale for Depression total score and two subscores (the Bech melancholia factor and retardation factor), the Brief Psychiatric Rating Scale total score, the General Psychiatric Impression Global Assessment Scale, the Beck score and responder rates. Mirtazapine was well tolerated, while the trazodone-treated patients experienced somnolence more frequently, particularly during the first 2 weeks of treatment. Furthermore, postural symptoms were a clinical problem in 6% of the trazodone-treated patients. In this trial, mirtazapine showed...
Journal of Medical Screening, 2006
Objectives To evaluate in fetal aneuploidy screening the desirability of using Fetal Medicine Fou... more Objectives To evaluate in fetal aneuploidy screening the desirability of using Fetal Medicine Foundation (FMF) normal medians of nuchal translucency thickness (NT) measurements or performerspecific medians, and whether the NT measurements should be expressed as Delta-NT or Log NT-MoM values. Settings First trimester-combined screening programme in a low risk population in Flanders, Belgium (Algemeen Medisch Laboratorium, Antwerp). Methods Pregnancies unaffected by trisomy 21 (T21) were screened by FMF-trained or other ultrasonographers. Performer-specific NT medians were established for FMF-trained and other ultrasonographers. NCSS Statistical Software was used to establish probability plots for Log NT-MoM and Delta-NT values, relative to performer-specific references or to the FMF-reference. Results A total of 16,096 pregnancies were evaluated. Six FMF-trainees and five other ultrasonographers each performed between 83 and 658 NT measurements. For the FMF-trainees, FMF-specific NT-MoM medians were close to one at a crown-rump length (CRL) between 50 and 80 mm, whereas the population-specific NT-MoM medians of the other ultrasonographers were close to one at a CRL between 40 and 80 mm. Performer-specific Delta-NT values fitted a Gaussian distribution between the 5th and 90th percentiles, while for the Log NT-MoM values this was between the 10th and 95th percentiles. Conclusion We conclude that (i) the use of screening would benefit from performer-specific NTmedians based on Log NT-MoM values; (ii) the use of Log NT-MoM values is marginally better than the use of delta-NT MoMs; and (iii) NT measurements are valid at about 10 weeks (crown-rump length 40-45 mm) as well as at 11-13 weeks.
The Open Infectious Diseases Journal, 2008
Objective: Can assessment of vaginal microbial flora at first prenatal visit predict the outcome ... more Objective: Can assessment of vaginal microbial flora at first prenatal visit predict the outcome of pregnancy?
The objective of this study was to document the occurrence and to correlate the prevalence of dif... more The objective of this study was to document the occurrence and to correlate the prevalence of different human papillomavirus (HPV) types with the cytological results on simultaneously performed thin-layer preparations in a large population of Flemish women. During 1 year, 69 290 thin-layer preparations were interpreted using the Bethesda classification system. Using an algorithm for HPV testing based on consensus primers and type-specific PCRs in combination with liquid-based cytology, we determined the occurrence and distribution of 14 different oncogenic HPV types (16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, 66 and 68). Reflex HPV testing was performed on cytologically abnormal samples and on an age matched randomly selected control group with normal cervical cytology (n=1351). Correlation between cytology, age and prevalence for the 14 different high-risk HPV types is given. There is a significant increase in predominance of high-risk HPV types, with increasing abnormal cytology. Coinfection with multiple HPV types also increased with cytological abnormalities, and was highest in HSIL (16.7%). In Flanders, HSIL was most often associated with HPV types 16, 33, 35, 31, 18 and 51. Using thin-layer liquid-based cytology and PCR to detect HPV, it is feasible to screen large numbers of women.
Ultrasound in Obstetrics and Gynecology, 2004
Prenatal Diagnosis, 2005
Objectives To evaluate the performance of a first-trimester fetal aneuploidy screening program, w... more Objectives To evaluate the performance of a first-trimester fetal aneuploidy screening program, with a documented underestimation of nuchal translucency thickness measurements (NT) compared to the Fetal Medicine Foundation (FMF) reference range.
PLoS ONE, 2013
Objective: Is Trichomonas vaginalis (TV) an inducing factor for the development of (pre-)cancerou... more Objective: Is Trichomonas vaginalis (TV) an inducing factor for the development of (pre-)cancerous lesions of the cervix?
Journal of Clinical Pathology, 2007
Despite many improvements, cervical cancer screening is still subject to shortcomings. Diagnostic... more Despite many improvements, cervical cancer screening is still subject to shortcomings. Diagnostic accuracy may improve by using molecular biological techniques, requiring RNA of superior quality. This study determined the effect of SurePath fixation on RNA integrity to assess the suitability of clinical samples collected in this medium for RNA-based molecular assays. RNA isolation was performed on fresh and fixed HeLa cells and exfoliated cervical cells fixed in SurePath. The RNA integrity was evaluated by analysis of ribosomal RNA as an indicator of quality. The effect of SurePath preservation on PCR amplification was evaluated by real-time reverse transcriptase (RT)-PCR. In contrast to unfixed cells, SurePath-fixed cells yielded less and severely degraded RNA, as shown by the absence of ribosomal RNA bands. RNA derived from SurePath-fixed cells showed poor real-time RT-PCR amplification characteristics, as evidenced by the absent correlation between threshold values and log cDNA concentration. Implementation of molecular biology in a clinical context is on the rise and may alleviate shortcomings in current screening and diagnostics. This study shows that SurePath fixation gives rise to highly fragmented RNA with insufficient quality for further reliable analysis by standard real-time RT-PCR applications. The increasing prominence of molecular screening stresses the importance of this finding, which must be considered in relation to choice of an appropriate liquid-based cytology system.
Journal of Clinical Pathology, 2006
Background: Human papillomavirus (HPV) plays a critical role in the carcinogenesis of squamous ce... more Background: Human papillomavirus (HPV) plays a critical role in the carcinogenesis of squamous cervical carcinoma. Integration of viral DNA into the host genome is a major contributing factor to malignant transformation. Viral load may influence integration. Aims: To compare HPV status (type, viral load, integration status) between normal samples, carcinoma in situ and invasive carcinoma in order to elucidate the role of HPV in progression to invasive lesions. Methods: The study population comprised 10 biopsy samples from each diagnostic group. Laminin-5 immunohistochemistry was performed to distinguish invasive carcinoma from non-invasive high-grade lesions. Real-time PCR was used to detect specific HPV types, viral load and integrated HPV, with quantification of viral E2 and E6 genes. Results: Invasive carcinomas contained a higher number of laminin-5 immunoreactive cells as compared to non-invasive lesions. Almost all samples contained HPV, with a higher viral load and copy number of HPV16 integrated in E2 in cases of laminin-5 immunoreactivity and cases of invasive carcinoma. High HPV16 viral load was associated with more integrated copies in E2. Conclusions: HPV is important in progression from carcinoma in situ to invasive carcinoma. Viral load and HPV integration influence the development of cervical cancer towards invasiveness. Overall HPV status may be more predictive of patient outcome and may influence patient management.
Journal of Clinical Pathology, 2008
Aims: Cervical cytology biobanking is a feasible concept in cervical pathology and could be an in... more Aims: Cervical cytology biobanking is a feasible concept in cervical pathology and could be an indispensable tool for fundamental and applied molecular biological research. PCR is a powerful molecular technique that can be performed on a variety of cervical sample types including Pap-stained cervical smears. However, since the quality of DNA from such specimens is inferior to that from fresh tissue, the correct processing methods are required. This study evaluates three commercial isolation methods and one digestion procedure for their ability to obtain DNA suitable for PCR from fixed and stained Pap smears. Methods: The High Pure PCR Template Preparation kit, the NucliSENS easyMAG system, the QIAamp DNA Mini Kit and crude proteinase K digestion were used to obtain DNA for subsequent PCR applications. Amplification of bglobin was performed to verify the presence and integrity of target DNA. The influence of PCR inhibitors and extent of DNA fragmentation were analysed. Results: All commercial DNA isolation techniques provided DNA suitable for PCR amplification, and DNA isolated from 10-year-old archival smears yielded amplicons up to 400 base pairs. Conversely, crude proteinase K digestion limited the amplicon size to 300 bp and did not consistently yield amplifiable digests, as these were contaminated with PCR-inhibiting factors and debris. Conclusion: The study indicates that commercial DNA isolation techniques are suitable for PCR amplification of DNA isolated from archival smears, yielding amplicons up to 400 base pairs. Proteinase K digestion is not suitable to obtain amplifiable DNA from fixed and stained Pap-stained smears.
Journal of Clinical Pathology, 2003
Aims: To test the ability of Ki-67 to detect cytological lesions in a screening setting and its u... more Aims: To test the ability of Ki-67 to detect cytological lesions in a screening setting and its use as a surrogate marker of human papillomavirus (HPV) infection. Methods: A study of liquid based cytology, HPV DNA testing by MY09/MY11 consensus polymerase chain reaction (PCR), type specific PCRs, and Ki-67 immunocytochemistry on a randomly selected series of 147 patients. Results: Comparison of the number of Ki-67 immunoreactive cells/1000 cells in the different cytological groups showed that the HSIL group yielded a significantly higher mean count than did the other groups. The number of Ki-67 immunoreactive cells/1000 cells was significantly higher in HPV-16 positive samples than in samples containing infections with other high risk types. Receiver operating characteristic curves indicated a test accuracy (area under curve) of 0.68, 0.72, and 0.86 for atypical squamous cells of undetermined significance (ASCUS), low grade squamous intraepithelial lesions (LSIL), and high grade squamous intraepithelial lesions (HSIL), respectively. Thresholds for 95% sensitivity were 0.07, 0.08, and 0.15 Ki-67 immunopositive cells/1000 cells for ASCUS, LSIL and HSIL, respectively. The threshold for 95% specificity was 1.9 Ki-67 immunopositive cells/1000 cells. Conclusions: Ki-67 immunocytochemistry can be applied to liquid based cytology. The accuracy and diagnostic indices of the test are good when compared with those of other techniques. As part of a panel of screening procedures, it could be used as an adjunct to liquid based cytology to identify HSIL, and as a surrogate marker of HPV-16 infection.
International Journal of Cancer, 2004
Cytological screening for cervical cancer is hampered by high false negative rates. Inter-observe... more Cytological screening for cervical cancer is hampered by high false negative rates. Inter-observer reproducibility needs optimizing. The potential of p16 INK4a as a biomarker for cervical lesions was examined in a study of liquid-based cytology (LBC), HPV DNA testing by MY09/MY11 consensus PCR and type-specific PCRs and p16 INK4a immunocytochemistry on a series of 291 patients selected from routine screening. Comparison of the number of p16 INK4a immunoreactive cells/1,000 cells exhibited a significantly higher mean count in HSIL (8.80 ؎ 1.13) than other cytological groups. The mean count of LSIL (1.09 ؎ 0.18) was significantly higher than that of the negative group (0.82 ؎ 0.40). ASC-H and HSIL combined showed a significantly higher mean count (6.46 ؎ 1.17) than negative, ASC, ASC-US and LSIL. The mean count of immunoreactive cells/1,000 cells was significantly higher in HPV16 positive samples (3.22 ؎ 0.72) than in samples containing infections with types of unknown malignant potential (0.83 ؎ 0.26) or HPV negative samples (1.17 ؎ 0.41). The mean count in infections with other high-risk HPV types (2.55 ؎ 0.52) was significantly higher than that in HPV negative samples. Receiver-operating characteristic curves yielded a test accuracy (area under curve) of 0.76, 0.79, 0.88 and 0.95 for ASCUS, LSIL, ASC-H/HSIL and HSIL, respectively. Thresholds for 95% sensitivity were at 0.005, 0.007, 0.098 and 0.445 immunopositive cells/1,000 cells for ASCUS, LSIL, ASC-H/HSIL and HSIL, respectively. The 95% specificity threshold for the detection of HSIL was at 1.87 immunopositive cells/1,000 cells. P16 INK4a immunocytochemistry can be used as an adjunct to LBC in cervical screening, because it has a good diagnostic accuracy to discriminate HSIL and ASC-H from other lesions. It could be used as a surrogate marker of high-risk HPV infections.
International Journal of Cancer, 2006
Cytological screening for cervical cancer is hampered by imperfect sensitivity and low inter-obse... more Cytological screening for cervical cancer is hampered by imperfect sensitivity and low inter-observer reproducibility. Human papillomavirus (HPV) testing lacks specificity as a primary screening method. Studies indicate that immunocytochemical detection of alterations caused by HPV in the host cells can optimise screening. Here, the potential of p16 INK4a (cyclin-dependent kinase inhibitor p16) and MIB-1 (Ki-67 proliferation marker) as adjunct molecular markers for cervical lesions was investigated in a prospective, cross-sectional study of 500 samples in the framework of opportunistic screening in Flanders, Belgium. A consecutive series of 200 samples and 100 samples from the cytological categories ASC, LSIL and HSIL were investigated. Surepath samples were interpreted according to the Bethesda 2001 reporting system. HPV testing was done with MY09/MY11 consensus PCR. Immunocytochemistry for p16 INK4a and MIB-1 was performed with an automated staining protocol. The number of immunoreactive cells/1,000 cervical cells was assessed. There was a higher mean number of p16 INK4A and MIB-1 immunoreactive cells/1,000 cells in HSIL (4.06 6 1.93 and 11.13 6 2.83, respectively) compared to other cytological categories. Both markers showed a large spread in counts, for all categories. In cases of HSIL without immunoreactive cells for either marker, low cellularity and longterm storage in water were often the cause of false negativity. This study confirms that positive staining for p16 INK4a and MIB-1 is highly correlated with presence of high-grade lesions. These markers could be used as adjuncts to increase the sensitivity of cytological screening as well as the specificity of the HPV test. However, clear methodological standards are needed for optimal performance of immunocytochemistry in a clinical setting. ' 2005 Wiley-Liss, Inc.
International Journal of Andrology, 2002
The present study was undertaken to assess the relationship between the results of conventional s... more The present study was undertaken to assess the relationship between the results of conventional semen analysis and the sperm motility index (SMI) as measured by the sperm quality analyser (SQA), and to evaluate these in relation to the fertilization and/or pregnancy outcome of assisted reproduction. SMI determinations and conventional semen analyses were performed on 223 samples from subfertile men in two laboratories in Leuven (n = 136) and Antwerp (n = 87), and on spermatozoa prepared on a Percoll gradient (n = 136) used for treatment of male factor infertility in 57 cycles of intrauterine insemination (IUI), 44 attempts at in vitro fertilization (IVF) and 31 attempts at intracytoplasmic sperm injection (ICSI). SMI values for native semen correlated significantly with sperm concentration, motility and morphology. Multiple regression analysis revealed sperm concentration after preparation, and the concentration of motile spermatozoa with normal morphology and SMI (before preparation) to be the independent determinants for SMI after preparation. SMI values were significantly higher after, than before, preparation (p < 0.0001). In regular IVF (n = 44) the percentage of fertilized oocytes correlated significantly (p < 0.05) with sperm motility (A + B%, r = 0.33), with the percentage of spermatozoa with normal morphology (r = 0.46) before preparation, with the values of SMI both before and after preparation (r = 0.54, r = 0.48), with sperm concentration (r = 0.34) and with the motile sperm concentration (r = 0.29) after preparation. For the occurrence of pregnancy (all treatment methods), comparison of areas under ROC curves (AURC) indicated motile sperm concentration after preparation, as well as SMI both before and after preparation, to have the highest AURC, with no significant difference between these values as far as predictive power was concerned. These results indicate that the SQA allows for rapid evaluation of sperm characteristics and of the effectiveness of sperm preparation techniques. However, it is not superior to conventional semen analysis in predicting the outcome of assisted reproduction.
International Journal of Andrology, 1998
This prospective study compared the diagnostic and predictive potential of sperm morphology asses... more This prospective study compared the diagnostic and predictive potential of sperm morphology assessments in a fertile vs. a subfertile population, evaluated in three different laboratories. The fertile population included 144 men who had recently fertilized their partners. As subfertile controls, 136 men with a history of subfertility for more than 12 months were used. All semen samples (280) were evaluated in three different centres in a blind fashion, without any patient information. The evaluation of sperm morphology was performed according to the criteria normally used in the different laboratories: WHO (1992) criteria for laboratory A, and Tygerberg strict criteria for laboratories B and C. Using ROC analysis, the predictive power of sperm morphology turned out to be different in the three laboratories (area under ROC curve: 69% for lab A, 72% for lab B and 78% for lab C). Using percentile 10 of the fertile population as the cut-off value for normality, we obtained the following results: 2, 1 and 5% for laboratories A, B and C, respectively. Using ROC analysis cut-off values with optimal specificity and sensitivity were 6, 1 and 10%, respectively. Although our data highlight a reasonable predictive power of sperm morphology in centres using different or the same criteria, cut-off values for normality were different, even when the same criteria were applied. These results stress the importance of standardization in sperm morphology evaluation and the need for examining a reference population in estimating the real threshold value in different laboratories.
International Congress Series, 2005
ABSTRACT
RESULTS: Increasing disturbance of the lactobacillary flora (lactobacillary grades I, IIa, IIb, a... more RESULTS: Increasing disturbance of the lactobacillary flora (lactobacillary grades I, IIa, IIb, and III) was highly correlated with the presence of Gardnerella vaginalis, Trichomonas vaginalis, enterococci, group B streptococci, and Escherichia coli. Vaginal pH and interleukin 8 and interleukin 1β concentrations increased linearly with in- creasing lactobacillary grade, whereas lactate concentrations and the presence of epithelial cell lysis decreased. A
Journal of Clinical Pathology
Aim-The status of vaginal lactobacillary flora, an indicator of possible genital infection and pr... more Aim-The status of vaginal lactobacillary flora, an indicator of possible genital infection and pregnancy complications, can be assessed on wet mount or Gram stained specimens. The former is quick, the latter more routine. The accuracy of the two preparative techniques to detect normal vaginal lactobacillary microflora was compared for 646 patients. The eVect of delay in transport medium before Gram staining was also investigated.
Tijdschrift voor Geneeskunde, 2007
Het aanvragen van laboratoriumanalyses is voor veel artsen een dagelijkse routine. De kwaliteit d... more Het aanvragen van laboratoriumanalyses is voor veel artsen een dagelijkse routine. De kwaliteit die door de klinische laboratoria wordt geleverd, is het hoogst ten opzichte van alle andere medische disciplines (1). Dit is niet enkel te verklaren door de goed controleerbare omstandigheden waarin wordt gewerkt, maar ook door de toepassing van uitgebreide kwaliteitssystemen die in sommige laboratoria al meer dan vijftien jaar toegepast worden. Klinische laboratoria zijn op het gebied van kwaliteitszorg pioniers binnen de medische wereld. Desondanks weerspiegelen de bekomen resultaten niet altijd de klinische toestand van de patiënt.
The European journal of contraception & reproductive health care : the official journal of the European Society of Contraception, 1998
International clinical psychopharmacology, 1995
Two hundred hospitalized patients with DSM-III diagnosis of moderate to severe major depressive e... more Two hundred hospitalized patients with DSM-III diagnosis of moderate to severe major depressive episode were randomized to receive mirtazapine or trazodone for 6 weeks in a double-blind trial. The dosages were 24-72 mg/day for mirtazapine and 150-450 mg/day for trazodone. The improvement on all depression rating scales used was generally greater for mirtazapine, with statistically significant differences over trazodone in the Hamilton Psychiatric Rating Scale for Depression total score and two subscores (the Bech melancholia factor and retardation factor), the Brief Psychiatric Rating Scale total score, the General Psychiatric Impression Global Assessment Scale, the Beck score and responder rates. Mirtazapine was well tolerated, while the trazodone-treated patients experienced somnolence more frequently, particularly during the first 2 weeks of treatment. Furthermore, postural symptoms were a clinical problem in 6% of the trazodone-treated patients. In this trial, mirtazapine showed...
Journal of Medical Screening, 2006
Objectives To evaluate in fetal aneuploidy screening the desirability of using Fetal Medicine Fou... more Objectives To evaluate in fetal aneuploidy screening the desirability of using Fetal Medicine Foundation (FMF) normal medians of nuchal translucency thickness (NT) measurements or performerspecific medians, and whether the NT measurements should be expressed as Delta-NT or Log NT-MoM values. Settings First trimester-combined screening programme in a low risk population in Flanders, Belgium (Algemeen Medisch Laboratorium, Antwerp). Methods Pregnancies unaffected by trisomy 21 (T21) were screened by FMF-trained or other ultrasonographers. Performer-specific NT medians were established for FMF-trained and other ultrasonographers. NCSS Statistical Software was used to establish probability plots for Log NT-MoM and Delta-NT values, relative to performer-specific references or to the FMF-reference. Results A total of 16,096 pregnancies were evaluated. Six FMF-trainees and five other ultrasonographers each performed between 83 and 658 NT measurements. For the FMF-trainees, FMF-specific NT-MoM medians were close to one at a crown-rump length (CRL) between 50 and 80 mm, whereas the population-specific NT-MoM medians of the other ultrasonographers were close to one at a CRL between 40 and 80 mm. Performer-specific Delta-NT values fitted a Gaussian distribution between the 5th and 90th percentiles, while for the Log NT-MoM values this was between the 10th and 95th percentiles. Conclusion We conclude that (i) the use of screening would benefit from performer-specific NTmedians based on Log NT-MoM values; (ii) the use of Log NT-MoM values is marginally better than the use of delta-NT MoMs; and (iii) NT measurements are valid at about 10 weeks (crown-rump length 40-45 mm) as well as at 11-13 weeks.
The Open Infectious Diseases Journal, 2008
Objective: Can assessment of vaginal microbial flora at first prenatal visit predict the outcome ... more Objective: Can assessment of vaginal microbial flora at first prenatal visit predict the outcome of pregnancy?
The objective of this study was to document the occurrence and to correlate the prevalence of dif... more The objective of this study was to document the occurrence and to correlate the prevalence of different human papillomavirus (HPV) types with the cytological results on simultaneously performed thin-layer preparations in a large population of Flemish women. During 1 year, 69 290 thin-layer preparations were interpreted using the Bethesda classification system. Using an algorithm for HPV testing based on consensus primers and type-specific PCRs in combination with liquid-based cytology, we determined the occurrence and distribution of 14 different oncogenic HPV types (16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, 66 and 68). Reflex HPV testing was performed on cytologically abnormal samples and on an age matched randomly selected control group with normal cervical cytology (n=1351). Correlation between cytology, age and prevalence for the 14 different high-risk HPV types is given. There is a significant increase in predominance of high-risk HPV types, with increasing abnormal cytology. Coinfection with multiple HPV types also increased with cytological abnormalities, and was highest in HSIL (16.7%). In Flanders, HSIL was most often associated with HPV types 16, 33, 35, 31, 18 and 51. Using thin-layer liquid-based cytology and PCR to detect HPV, it is feasible to screen large numbers of women.
Ultrasound in Obstetrics and Gynecology, 2004
Prenatal Diagnosis, 2005
Objectives To evaluate the performance of a first-trimester fetal aneuploidy screening program, w... more Objectives To evaluate the performance of a first-trimester fetal aneuploidy screening program, with a documented underestimation of nuchal translucency thickness measurements (NT) compared to the Fetal Medicine Foundation (FMF) reference range.
PLoS ONE, 2013
Objective: Is Trichomonas vaginalis (TV) an inducing factor for the development of (pre-)cancerou... more Objective: Is Trichomonas vaginalis (TV) an inducing factor for the development of (pre-)cancerous lesions of the cervix?
Journal of Clinical Pathology, 2007
Despite many improvements, cervical cancer screening is still subject to shortcomings. Diagnostic... more Despite many improvements, cervical cancer screening is still subject to shortcomings. Diagnostic accuracy may improve by using molecular biological techniques, requiring RNA of superior quality. This study determined the effect of SurePath fixation on RNA integrity to assess the suitability of clinical samples collected in this medium for RNA-based molecular assays. RNA isolation was performed on fresh and fixed HeLa cells and exfoliated cervical cells fixed in SurePath. The RNA integrity was evaluated by analysis of ribosomal RNA as an indicator of quality. The effect of SurePath preservation on PCR amplification was evaluated by real-time reverse transcriptase (RT)-PCR. In contrast to unfixed cells, SurePath-fixed cells yielded less and severely degraded RNA, as shown by the absence of ribosomal RNA bands. RNA derived from SurePath-fixed cells showed poor real-time RT-PCR amplification characteristics, as evidenced by the absent correlation between threshold values and log cDNA concentration. Implementation of molecular biology in a clinical context is on the rise and may alleviate shortcomings in current screening and diagnostics. This study shows that SurePath fixation gives rise to highly fragmented RNA with insufficient quality for further reliable analysis by standard real-time RT-PCR applications. The increasing prominence of molecular screening stresses the importance of this finding, which must be considered in relation to choice of an appropriate liquid-based cytology system.
Journal of Clinical Pathology, 2006
Background: Human papillomavirus (HPV) plays a critical role in the carcinogenesis of squamous ce... more Background: Human papillomavirus (HPV) plays a critical role in the carcinogenesis of squamous cervical carcinoma. Integration of viral DNA into the host genome is a major contributing factor to malignant transformation. Viral load may influence integration. Aims: To compare HPV status (type, viral load, integration status) between normal samples, carcinoma in situ and invasive carcinoma in order to elucidate the role of HPV in progression to invasive lesions. Methods: The study population comprised 10 biopsy samples from each diagnostic group. Laminin-5 immunohistochemistry was performed to distinguish invasive carcinoma from non-invasive high-grade lesions. Real-time PCR was used to detect specific HPV types, viral load and integrated HPV, with quantification of viral E2 and E6 genes. Results: Invasive carcinomas contained a higher number of laminin-5 immunoreactive cells as compared to non-invasive lesions. Almost all samples contained HPV, with a higher viral load and copy number of HPV16 integrated in E2 in cases of laminin-5 immunoreactivity and cases of invasive carcinoma. High HPV16 viral load was associated with more integrated copies in E2. Conclusions: HPV is important in progression from carcinoma in situ to invasive carcinoma. Viral load and HPV integration influence the development of cervical cancer towards invasiveness. Overall HPV status may be more predictive of patient outcome and may influence patient management.
Journal of Clinical Pathology, 2008
Aims: Cervical cytology biobanking is a feasible concept in cervical pathology and could be an in... more Aims: Cervical cytology biobanking is a feasible concept in cervical pathology and could be an indispensable tool for fundamental and applied molecular biological research. PCR is a powerful molecular technique that can be performed on a variety of cervical sample types including Pap-stained cervical smears. However, since the quality of DNA from such specimens is inferior to that from fresh tissue, the correct processing methods are required. This study evaluates three commercial isolation methods and one digestion procedure for their ability to obtain DNA suitable for PCR from fixed and stained Pap smears. Methods: The High Pure PCR Template Preparation kit, the NucliSENS easyMAG system, the QIAamp DNA Mini Kit and crude proteinase K digestion were used to obtain DNA for subsequent PCR applications. Amplification of bglobin was performed to verify the presence and integrity of target DNA. The influence of PCR inhibitors and extent of DNA fragmentation were analysed. Results: All commercial DNA isolation techniques provided DNA suitable for PCR amplification, and DNA isolated from 10-year-old archival smears yielded amplicons up to 400 base pairs. Conversely, crude proteinase K digestion limited the amplicon size to 300 bp and did not consistently yield amplifiable digests, as these were contaminated with PCR-inhibiting factors and debris. Conclusion: The study indicates that commercial DNA isolation techniques are suitable for PCR amplification of DNA isolated from archival smears, yielding amplicons up to 400 base pairs. Proteinase K digestion is not suitable to obtain amplifiable DNA from fixed and stained Pap-stained smears.
Journal of Clinical Pathology, 2003
Aims: To test the ability of Ki-67 to detect cytological lesions in a screening setting and its u... more Aims: To test the ability of Ki-67 to detect cytological lesions in a screening setting and its use as a surrogate marker of human papillomavirus (HPV) infection. Methods: A study of liquid based cytology, HPV DNA testing by MY09/MY11 consensus polymerase chain reaction (PCR), type specific PCRs, and Ki-67 immunocytochemistry on a randomly selected series of 147 patients. Results: Comparison of the number of Ki-67 immunoreactive cells/1000 cells in the different cytological groups showed that the HSIL group yielded a significantly higher mean count than did the other groups. The number of Ki-67 immunoreactive cells/1000 cells was significantly higher in HPV-16 positive samples than in samples containing infections with other high risk types. Receiver operating characteristic curves indicated a test accuracy (area under curve) of 0.68, 0.72, and 0.86 for atypical squamous cells of undetermined significance (ASCUS), low grade squamous intraepithelial lesions (LSIL), and high grade squamous intraepithelial lesions (HSIL), respectively. Thresholds for 95% sensitivity were 0.07, 0.08, and 0.15 Ki-67 immunopositive cells/1000 cells for ASCUS, LSIL and HSIL, respectively. The threshold for 95% specificity was 1.9 Ki-67 immunopositive cells/1000 cells. Conclusions: Ki-67 immunocytochemistry can be applied to liquid based cytology. The accuracy and diagnostic indices of the test are good when compared with those of other techniques. As part of a panel of screening procedures, it could be used as an adjunct to liquid based cytology to identify HSIL, and as a surrogate marker of HPV-16 infection.
International Journal of Cancer, 2004
Cytological screening for cervical cancer is hampered by high false negative rates. Inter-observe... more Cytological screening for cervical cancer is hampered by high false negative rates. Inter-observer reproducibility needs optimizing. The potential of p16 INK4a as a biomarker for cervical lesions was examined in a study of liquid-based cytology (LBC), HPV DNA testing by MY09/MY11 consensus PCR and type-specific PCRs and p16 INK4a immunocytochemistry on a series of 291 patients selected from routine screening. Comparison of the number of p16 INK4a immunoreactive cells/1,000 cells exhibited a significantly higher mean count in HSIL (8.80 ؎ 1.13) than other cytological groups. The mean count of LSIL (1.09 ؎ 0.18) was significantly higher than that of the negative group (0.82 ؎ 0.40). ASC-H and HSIL combined showed a significantly higher mean count (6.46 ؎ 1.17) than negative, ASC, ASC-US and LSIL. The mean count of immunoreactive cells/1,000 cells was significantly higher in HPV16 positive samples (3.22 ؎ 0.72) than in samples containing infections with types of unknown malignant potential (0.83 ؎ 0.26) or HPV negative samples (1.17 ؎ 0.41). The mean count in infections with other high-risk HPV types (2.55 ؎ 0.52) was significantly higher than that in HPV negative samples. Receiver-operating characteristic curves yielded a test accuracy (area under curve) of 0.76, 0.79, 0.88 and 0.95 for ASCUS, LSIL, ASC-H/HSIL and HSIL, respectively. Thresholds for 95% sensitivity were at 0.005, 0.007, 0.098 and 0.445 immunopositive cells/1,000 cells for ASCUS, LSIL, ASC-H/HSIL and HSIL, respectively. The 95% specificity threshold for the detection of HSIL was at 1.87 immunopositive cells/1,000 cells. P16 INK4a immunocytochemistry can be used as an adjunct to LBC in cervical screening, because it has a good diagnostic accuracy to discriminate HSIL and ASC-H from other lesions. It could be used as a surrogate marker of high-risk HPV infections.
International Journal of Cancer, 2006
Cytological screening for cervical cancer is hampered by imperfect sensitivity and low inter-obse... more Cytological screening for cervical cancer is hampered by imperfect sensitivity and low inter-observer reproducibility. Human papillomavirus (HPV) testing lacks specificity as a primary screening method. Studies indicate that immunocytochemical detection of alterations caused by HPV in the host cells can optimise screening. Here, the potential of p16 INK4a (cyclin-dependent kinase inhibitor p16) and MIB-1 (Ki-67 proliferation marker) as adjunct molecular markers for cervical lesions was investigated in a prospective, cross-sectional study of 500 samples in the framework of opportunistic screening in Flanders, Belgium. A consecutive series of 200 samples and 100 samples from the cytological categories ASC, LSIL and HSIL were investigated. Surepath samples were interpreted according to the Bethesda 2001 reporting system. HPV testing was done with MY09/MY11 consensus PCR. Immunocytochemistry for p16 INK4a and MIB-1 was performed with an automated staining protocol. The number of immunoreactive cells/1,000 cervical cells was assessed. There was a higher mean number of p16 INK4A and MIB-1 immunoreactive cells/1,000 cells in HSIL (4.06 6 1.93 and 11.13 6 2.83, respectively) compared to other cytological categories. Both markers showed a large spread in counts, for all categories. In cases of HSIL without immunoreactive cells for either marker, low cellularity and longterm storage in water were often the cause of false negativity. This study confirms that positive staining for p16 INK4a and MIB-1 is highly correlated with presence of high-grade lesions. These markers could be used as adjuncts to increase the sensitivity of cytological screening as well as the specificity of the HPV test. However, clear methodological standards are needed for optimal performance of immunocytochemistry in a clinical setting. ' 2005 Wiley-Liss, Inc.
International Journal of Andrology, 2002
The present study was undertaken to assess the relationship between the results of conventional s... more The present study was undertaken to assess the relationship between the results of conventional semen analysis and the sperm motility index (SMI) as measured by the sperm quality analyser (SQA), and to evaluate these in relation to the fertilization and/or pregnancy outcome of assisted reproduction. SMI determinations and conventional semen analyses were performed on 223 samples from subfertile men in two laboratories in Leuven (n = 136) and Antwerp (n = 87), and on spermatozoa prepared on a Percoll gradient (n = 136) used for treatment of male factor infertility in 57 cycles of intrauterine insemination (IUI), 44 attempts at in vitro fertilization (IVF) and 31 attempts at intracytoplasmic sperm injection (ICSI). SMI values for native semen correlated significantly with sperm concentration, motility and morphology. Multiple regression analysis revealed sperm concentration after preparation, and the concentration of motile spermatozoa with normal morphology and SMI (before preparation) to be the independent determinants for SMI after preparation. SMI values were significantly higher after, than before, preparation (p < 0.0001). In regular IVF (n = 44) the percentage of fertilized oocytes correlated significantly (p < 0.05) with sperm motility (A + B%, r = 0.33), with the percentage of spermatozoa with normal morphology (r = 0.46) before preparation, with the values of SMI both before and after preparation (r = 0.54, r = 0.48), with sperm concentration (r = 0.34) and with the motile sperm concentration (r = 0.29) after preparation. For the occurrence of pregnancy (all treatment methods), comparison of areas under ROC curves (AURC) indicated motile sperm concentration after preparation, as well as SMI both before and after preparation, to have the highest AURC, with no significant difference between these values as far as predictive power was concerned. These results indicate that the SQA allows for rapid evaluation of sperm characteristics and of the effectiveness of sperm preparation techniques. However, it is not superior to conventional semen analysis in predicting the outcome of assisted reproduction.
International Journal of Andrology, 1998
This prospective study compared the diagnostic and predictive potential of sperm morphology asses... more This prospective study compared the diagnostic and predictive potential of sperm morphology assessments in a fertile vs. a subfertile population, evaluated in three different laboratories. The fertile population included 144 men who had recently fertilized their partners. As subfertile controls, 136 men with a history of subfertility for more than 12 months were used. All semen samples (280) were evaluated in three different centres in a blind fashion, without any patient information. The evaluation of sperm morphology was performed according to the criteria normally used in the different laboratories: WHO (1992) criteria for laboratory A, and Tygerberg strict criteria for laboratories B and C. Using ROC analysis, the predictive power of sperm morphology turned out to be different in the three laboratories (area under ROC curve: 69% for lab A, 72% for lab B and 78% for lab C). Using percentile 10 of the fertile population as the cut-off value for normality, we obtained the following results: 2, 1 and 5% for laboratories A, B and C, respectively. Using ROC analysis cut-off values with optimal specificity and sensitivity were 6, 1 and 10%, respectively. Although our data highlight a reasonable predictive power of sperm morphology in centres using different or the same criteria, cut-off values for normality were different, even when the same criteria were applied. These results stress the importance of standardization in sperm morphology evaluation and the need for examining a reference population in estimating the real threshold value in different laboratories.
International Congress Series, 2005
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