J. de Monchy - Academia.edu (original) (raw)

Papers by J. de Monchy

Objective: We aimed to assess dust exposure among different wheat exposed workers and to study th... more Objective: We aimed to assess dust exposure among different wheat exposed workers and to study their risk for sensitization. Methods: About 520 measures of inhalable dust and wheat allergens were performed among 270 individuals from four sectors of industry. Data on sensitization to wheat and common allergens (atopy) was also available. Using mixed effects models, we estimated exposure levels according to sector, job title and tasks. The shape of the relationship between sensitization and exposure was studied using a 2-stage modeling approach: a semi-parametric generalized additive model and consequently a parametric logistic model. To avoid possible risk estimate attenuation, we modeled variance weighted estimate (VWE) of exposure in addition to the actual exposure. Results: The effect of exposure to both inhalable dust and to wheat allergens on sensitization was found to be a quadratic relationship. The probability of sensitization increased with exposure up to ~2.7 mg/m3 for inha...

Nederlands Tijdschrift Voor Geneeskunde, 1996

Item does not contain fulltext2 p

Journal of investigational allergology & clinical immunology, 2012

Allergy Living and Learning (ALL) is a European initiative designed to increase knowledge and und... more Allergy Living and Learning (ALL) is a European initiative designed to increase knowledge and understanding of people living with allergies in order to improve respiratory allergy care. To investigate diagnostic and treatment patterns associated with respiratory allergies, patients' perception of their treatment, and restrictions on daily activities. Using a telephone-based randomized screening method, we recruited and analyzed 7004 patients (aged 16-60 years) with self-reported respiratory allergic disease from 10 European countries. Patients answered questions assessing their knowledge, experience, and perception of their condition and its treatment. Data analyses were descriptive. The most prevalent conditions were allergic rhinitis (66%) and asthma (26%), and the average duration of the symptoms of respiratory allergy was 14.5 years. Over 30% of patients had never had a specific diagnostic test. About 80% of patients used medication for their respiratory allergy, and 10% of ...

Clinical and experimental immunology, 1983

Circulating immune complexes after a test meal were measured with three methods (PEG precipitatio... more Circulating immune complexes after a test meal were measured with three methods (PEG precipitation, Clq-ELISA and the indirect granulocyte phagocytosis test) in 10 controls, two symptomless persons with selective IgA deficiency and 14 patients with various types of glomerulonephritis, of which two patients (with idiopathic membranous glomerulopathy and local focal glomerulonephritis) also had selective IgA deficiency. The PEG and Clq-ELISA test did not show significant differences between the groups. In the two symptomless persons with selective IgA deficiency and in the patient with local focal glomerulonephritis and selective IgA deficiency the indirect granulocyte phagocytosis test (IGFT) showed a reproducible increase in IgG, IgM and complement containing immune complexes. In the last patient multiple food antigens were probably responsible for this phenomenon, a rapid amelioration of kidney function could be induced three times by giving an antigen free diet.

Scandinavian Journal of Work, Environment & Health, 2005

Objectives Dust and wheat-allergen exposure were assessed among bakers, flour millers, and bakery... more Objectives Dust and wheat-allergen exposure were assessed among bakers, flour millers, and bakeryingredient producers, and the risk for sensitization was studied. Methods About 520 inhalable dust and wheat-allergen measurements were made among 270 Dutch workers. Data on sensitization to wheat and common allergens (atopy) were also available. Exposure was estimated according to the sector of industry, job title, and tasks. The shape of the relationship between sensitization and exposure was studied using a two-stage modeling approach: semi-parametric generalized additive modeling and, consequently, a simple description of the relationship using a parametric logistic model. To reduce the effect of exposure measurement errors (attenuation), a combination of the actual measured exposure and variance-weighted estimates of exposure was used. Results The effect of exposure to both inhalable dust and wheat allergens on sensitization was described best by a linear relationship in three industries and a quadratic relationship in one industry. The relation for the whole study population was best described as quadratic, and the probability of sensitization increased with exposure up to ∼2.7 mg/m 3 for inhalable dust and ∼25.7 µg EQ/m 3 for wheat allergens. The risk decreased at higher exposures (P=0.0121 and P=0.0731 for dust and wheat, respectively). Atopy and sector of industry modified the sensitization risk significantly in all the analyses. Using a variant-weighted estimator to calculate exposures corrected for the bias and resulted in almost the same point risk estimators. Conclusions Exposure-response relationships for allergens may be nonlinear and differ between industries. A threshold is not indicated on which to base occupational exposure standards; alternatively, other approaches, such as benchmarking, seem warranted.

Respiratory Medicine, 2004

Background: Many epidemiological studies have assessed the prevalence of respiratory allergic dis... more Background: Many epidemiological studies have assessed the prevalence of respiratory allergic disorders in confined geographical locations. However, no study has yet established nationally prevalence data in a uniform manner representing whole countries and, thus, enabling cross-national comparisons. Methods: In 10 European countries, screening of random, representative samples of telephone numbers identified the target population aged 16-60. The inclusion criteria were a positive reporting of respiratory allergy to named allergens and, concomitantly, an unassisted description of appropriate symptoms. To obtain a truly representative, national prevalence of each country, the data were weighted against the actual sex and age composition. Results: 31,065 screening interviews were performed. The nationally balanced prevalence varied significantly among the 10 countries (Po0:001) from 11.7% in Spain to 33.6% in Italy. The overall weighted prevalence for Europe was 24.4%. Comparing males and females, overall, the odds-ratio was 0.874 (Po0:001). For age intervals of 16-29, 30-49, and 50-60 years, the odds-ratios for males were 1.104 (Po0:088), 0.827 (Po0:001), and 0.658 (Po0:001), respectively. The prevalence correlated inversely with age. Conclusions: Respiratory allergic disorders constitute a huge health problem in Europe, and the impact may be increasing as the prevalence is highest among young people.

Occupational and Environmental Medicine, 2007

Neurology, 1981

Many organophosphorus compounds, including the organophosphate insecticides, may cause polyneurop... more Many organophosphorus compounds, including the organophosphate insecticides, may cause polyneuropathy of delayed onset. An exception is parathion, which has been considered the prototype of nonneurotoxic cholinesterase inhibitors. Nevertheless, we describe a patient with delayed polyneuropathy after suicidal ingestion of parathion.

Journal of Clinical Epidemiology, 2010

Objectives: To develop and validate a prediction model to detect sensitization to wheat allergens... more Objectives: To develop and validate a prediction model to detect sensitization to wheat allergens in bakery workers. Study Design and Setting: The prediction model was developed in 867 Dutch bakery workers (development set, prevalence of sensitization 13%) and included questionnaire items (candidate predictors). First, principal component analysis was used to reduce the number of candidate predictors. Then, multivariable logistic regression analysis was used to develop the model. Internal validation and extent of optimism was assessed with bootstrapping. External validation was studied in 390 independent Dutch bakery workers (validation set, prevalence of sensitization 20%). Results: The prediction model contained the predictors nasoconjunctival symptoms, asthma symptoms, shortness of breath and wheeze, work-related upper and lower respiratory symptoms, and traditional bakery. The model showed good discrimination with an area under the receiver operating characteristic (ROC) curve area of 0.76 (and 0.75 after internal validation). Application of the model in the validation set gave a reasonable discrimination (ROC area 5 0.69) and good calibration after a small adjustment of the model intercept. Conclusion: A simple model with questionnaire items only can be used to stratify bakers according to their risk of sensitization to wheat allergens. Its use may increase the cost-effectiveness of (subsequent) medical surveillance.

Journal of Allergy and Clinical Immunology, 2010

Background: Venom immunotherapy (VIT) enables longtime prevention of insect venom allergy in the ... more Background: Venom immunotherapy (VIT) enables longtime prevention of insect venom allergy in the majority of patients. However, in some, the risk of a resystemic reaction increases after completion of treatment. No reliable factors predicting individual lack of efficacy of VIT are currently available. Objective: To determine the use of gene expression profiles to predict the long-term effect of VIT. Methods: Whole genome gene expression analysis was performed on RNA samples from 46 patients treated with VIT divided into 3 groups: (1) patients who achieved and maintained long-term protection after VIT, (2) patients in whom insect venom allergy relapsed, and (3) patients still in the maintenance phase of VIT. Results: Among the 48.071 transcripts analyzed, 1401 showed a >2 fold difference in gene expression (P < .05); 658 genes (47%) were upregulated and 743 (53%) downregulated. Fortythree transcripts still show significant differences in expression after correction for multiple testing; 12 of 43 genes (28%) were upregulated and 31 of 43 genes (72%) downregulated. A naive Bayes prediction model demonstrated a gene expression pattern characteristic of effective VIT that was present in all patients with successful VIT but absent in all subjects with failure of VIT. The same gene expression profile was present in 88% of patients in the maintenance phase of VIT. Conclusion: Gene expression profiling might be a useful tool to assess the long-term effectiveness of VIT. The analysis of differently expressed genes confirms the involvement of immunologic pathways described previously but also indicates novel factors that might be relevant for allergen tolerance.

Clinical Immunology, 2012

From 1997, plasma-derived C1-inhibitor concentrate (Cetor®) has been available to HAE and AAE pat... more From 1997, plasma-derived C1-inhibitor concentrate (Cetor®) has been available to HAE and AAE patients. Recently, a virus reducing 15 nm nanofiltration step has been introduced in the production process. A randomized, double-blind controlled cross-over study was performed to compare the pharmacokinetics (PK) of nanofiltered (C1-INH-NF) with conventional C1-inhibitor (C1-INH). Efficacy and safety were investigated in an open-label, on-demand and a prophylactic study. No differences in pharmacokinetic parameters between C1-INH and C1-INH-NF were found (13 non-symptomatic HAE patients). Both C1-inhibitor products equally increased plasma C4 levels. In the on-demand study, 14 acute angioedema attacks in 8 patients were analyzed. In the prophylactic study, 1 AAE and 5 HAE patients experienced in total 31 attacks during 748 observation days. In total 180,000 units of C1-INH-NF were administered. No product-related adverse events occurred, and no anti-C1-antibodies were induced. Nanofiltration in the production process of C1-inhibitor did not affect the pharmacokinetics, efficacy, and safety.

Clinical <html_ent glyph="@amp;" ascii="&"/> Experimental Allergy, 1984

Cutaneous reactions associated with captopril treatment occurred in fifteen out of eighty-nine pa... more Cutaneous reactions associated with captopril treatment occurred in fifteen out of eighty-nine patients (17%). Dose reduction invariably led to improvement of the reaction but later recurrences were frequent (six patients). In four out of the fifteen patients captopril withdrawal ultimately was necessary. Skin tests and in vitro lymphocyte transformation tests with captopril were performed in these fifteen patients and also in nine captopril-treated control patients without adverse reactions. Positive epicutaneous skin tests were observed in five out of the fifteen patients including the four in whom captopril had to be withdrawn, but in none of the controls. Intracutaneous skin tests were positive in ten of the patients with cutaneous reactions and in two control patients. Captopril-induced in vitro lymphocyte transformation occurred in most patients with cutaneous reactions whereas in control patients captopril suppressed the in vitro lymphocyte proliferative response. Skin biopsies revealed histologic changes consistent with lymphocytic vasculitis. We conclude that epicutaneous skin tests with captopril are helpful in predicting the necessity of captopril withdrawal.

Clinical & Experimental Allergy, 1993

Standardization of allergen provocation tests ofthe airways requires standardization of eaeh ofth... more Standardization of allergen provocation tests ofthe airways requires standardization of eaeh ofthe steps involved, including standardization ofthe extracts used. The value of international standards is emphasized and so is the determination ofa clinically relevant potency. The allergen extracts used for bronchial provocation tests must be compared with qualitatively and quantitatively clinically relevant standards using complementary immunoehemical and biological methods. Ideally the same extracts should be used for diagnosis (skin test, specific IgE determinations, provocations) and treatment (immunotherapy). The importance ofthe biological compared with the non-biological methods is that the biological methods are established in allergenic patients in order to select a clinically relevant potency of the allergen in question, and this potency ought to be confirmed in clinical trials. Once established the biological potency of an in-house preparation can be reproduced by supplementary in vitro methods. Very few commercial allergen preparations are available which fulfil the above-mentioned criteria.

Allergy, 2012

We have read with interest the article entitled ‘Tryptase and histamine metabolites as diagnostic... more We have read with interest the article entitled ‘Tryptase and histamine metabolites as diagnostic indicators of indolent systemic mastocytosis without skin lesions’ by Doormaal et al. (1). Results of this study related to the higher risk for systemic mastocytosis (SM) conferred by male gender, insectinduced anaphylaxis and tryptase levels support previous findings from our group, based on which we have proposed a score to predict for SM in patients with mast cell (MC) activation symptoms without skin lesions (2), such score being further validated (3) in the largest cohort of SM patients without urticaria pigmentosa (UP) (n = 80) published so far. On the basis of our findings in both studies, which Doormal et al. failed to cite, we would like to comment on some of the specific methods used by the authors to rule out/diagnose SM that may impact their results and conclusions. It is well established that indolent SM (ISM) patients without UP typically display a low MC burden, which translates into a substantial proportion of cases lacking bone marrow (BM) MC aggregates (2). Consequently, highly sensitive diagnostic methods including multiparameter flow cytometry immunophenotyping for the identification of BMMC down to frequencies as low as <10 4 to 10 , and the KIT mutation analysis of highly purified BMMC (4), should be routinely applied in these patients to avoid false-negative results. In fact, 10% of our ISM patients without UP showed <0.01% [the detection limit reported by the authors (1)] immunophenotypically aberrant BMMC (3), and even higher frequencies (18%) have been reported by Bonadonna et al. (5) in a series of 17 ISM patients without UP presenting with insect venom anaphylaxis. In addition, 11/78 patients (14%) from our series showed KIT-mutated BMMC in the absence of criteria for SM, which currently leads to the diagnosis of the socalled clonal MC activation syndrome (c-MCAS) or monoclonal MC activation syndrome (MMAS) (2,6); noteworthy, more than half (6/11) of these patients showed <0.01% of BMMC by flow cytometry. Investigation of the KIT mutation in whole (unfractionated) BM samples, specifically for the identification of the D816V KIT mutation without investigating other exon 17 mutations, as conducted by Doormaal et al. (1) may lead to a lower rate of detection of mutated BMMC as previously demonstrated (4). In fact, in their study, Doormaal et al. (1) reported an overall frequency of KIT mutation of 85% among the SM group, a frequency significantly lower than that found in our series where molecular studies were performed in highly purified BMMC: overall frequency of KIT mutation among evaluable cases of 98%, including 7% of cases with KIT mutations involving exon 17 other than the D816V KIT mutation (3), supporting the need to screen for mutations in the entire exon 17 of KIT in cases lacking the classical D816V KIT mutation. Finally, we would also like to support the authors’ conclusion that serum tryptase levels <20 lg/l exclude neither SM nor MMAS and that such cut-off could be lowered (5). However, caution should be taken in systematically refraining from BM examination in suspected patients with serum tryptase <10 lg/l, as proposed by the authors. In fact, 4/14 (28%) patients who presented with MC mediator release symptoms without UP and tryptase <10 lg/l referred to our centre were finally diagnosed with SM (n = 2) and MMAS (n = 2), when the above-described diagnostic methods were followed (3). Consequently, neither SM nor MMAS can be ruled out, as proposed by the authors, based exclusively on both normal histology and cytology, and we strongly recommend that such BM studies are performed in experienced reference centres where the most sensitive diagnostic procedures available nowadays are routinely applied.