M. Ertem - Academia.edu (original) (raw)

Papers by M. Ertem

41st Annual Meeting of the European-Society-for-Blood-and-Marrow-Transplantation -- MAR 22-25, 20... more 41st Annual Meeting of the European-Society-for-Blood-and-Marrow-Transplantation -- MAR 22-25, 2015 -- Istanbul, TURKEYWOS: 000351632902302European Soc Blood & Marrow Transplanta

Nature Publishing Group, 2015

41st Annual Meeting of the European-Society-for-Blood-and-Marrow-Transplantation -- MAR 22-25, 20... more 41st Annual Meeting of the European-Society-for-Blood-and-Marrow-Transplantation -- MAR 22-25, 2015 -- Istanbul, TURKEYWOS: 000351632902206European Soc Blood & Marrow Transplanta

Turkish journal of haematology : official journal of Turkish Society of Haematology, Jan 5, 2007

Autoimmune lymphoproliferative syndrome (ALPS) is a rare childhood disorder characterized by chro... more Autoimmune lymphoproliferative syndrome (ALPS) is a rare childhood disorder characterized by chronic non-malignant lymphoproliferation and autoimmunity. Patients with ALPS frequently exhibit episodic and intermittent, severe autoimmune- induced hemolytic anemia, thrombocytopenia or combined cytopenias. The co-occurrence of immune-mediated cytopenias, autoimmune thrombocytopenia and autoimmune hemolytic anemia is also known as Evans syndrome. This report describes a child who presented with Evans syndrome symptoms and who, after the detection of increased percentage of double negative T cell population in the peripheral blood, was diagnosed as ALPS. He received several courses of treatment including glucocorticoids, cyclosporine A (Cs A), and intravenous immunoglobulin (IVIG) without any clinical benefit and was treated with the antimalarial drug Fansidar®. With administration of Fansidar® (half tablet per week; containing 250 mg of pyrimethamine and 12.5 mg of sulfadoxine) combined ...

Turkish journal of haematology : official journal of Turkish Society of Haematology, Jan 5, 2010

Stable mixed chimerism (MC) may result in cure for thalassemia major patients following hematopoi... more Stable mixed chimerism (MC) may result in cure for thalassemia major patients following hematopoietic stem cell transplantation (HSCT), but rejection can occur. Twenty-eight HSCTs for thalassemia major were reviewed retrospectively to evaluate the clinical course of MC with possible risk factors and predictors of outcome, with a median follow-up of 1669 days (811-3576 days). Chimerism was detected by fluorescence in situ hybridization (FISH) or multiplex polymerase chain reaction depending on the sex match between the donor and the recipient. Primary rejection, stable MC and full donor chimerism was detected in 3.6%, 17.8% and 78.6% of patients, respectively. Clinically, 4/5 patients with stable MC had thalassemia trait with donor chimerism as low as 14%. One patient was started on pRBC transfusions at 2.5 years postHSCT. Stable MC can result in cure for thalassemia major patients. The clinical picture remains as the best guide for intervention until a more reliable predictor is ava...

Journal of Pediatric Hematology/oncology, 1999

Transfusion Science, 1998

The Journal of Trace Elements in Experimental Medicine, 2000

ABSTRACT

Pediatric Hematology-Oncology, 2000

Hereditary multiple exostoses (HME) is an autosomal dominant disorder characterized by the presen... more Hereditary multiple exostoses (HME) is an autosomal dominant disorder characterized by the presence of multiple exostoses. Three genetic loci have been identified, of which two (EXT1 and EXT2) have tumor suppressor activity. HME greatly increases the risk to develop sarcoma in the dysplastic tissue. The authors report an 8-year-old girl with HME who developed acute myeloblastic leukemia.

Molecular Immunology, 1998

Bone Marrow Transplantation, 2009

Loss of specific immunity after hematopoietic SCT (HSCT) is well documented for polio, measles, m... more Loss of specific immunity after hematopoietic SCT (HSCT) is well documented for polio, measles, mumps and tetanus. There are limited studies reporting the loss of Hepatitis A virus immunity and no reports evaluating the effect of donor immunity on Hepatitis A virus (HAV) immunity loss after HSCT. A total of 49 of the 81 patients who received HSCT at the Ankara University Pediatric HSCT Unit from January 1997 to December 2006 had HAV serology tested before HSCT and were evaluated for seroprevalence, and 30 of 49 patients were evaluated for the loss of Ab and for the effect of donor immunity on the loss of HAV Abs. The seroprevalence before HSCT was 75.5%. Loss of Ab was detected in 43.5% (10/23) of the patients. The median time to loss of Ab was 12 months (12-32 months), and 60% of these patients were seronegative at 12 months after HSCT. After HSCT, 46.7% of the patients were seronegative. Loss of Ab was higher in the seronegative donor group (75 vs 26%). The loss of HAV Ab is high after allogeneic HSCT for pediatric patients. Reimmunization should be considered for the continuation of individual and community immunity. Further studies with larger study groups are warranted to clarify the role of donor immunity on the loss of HAV immunity.

Nature Publishing Group, 2015

41st Annual Meeting of the European-Society-for-Blood-and-Marrow-Transplantation -- MAR 22-25, 20... more 41st Annual Meeting of the European-Society-for-Blood-and-Marrow-Transplantation -- MAR 22-25, 2015 -- Istanbul, TURKEYWOS: 000351632903148…European Soc Blood & Marrow Transplanta

Turkish journal of haematology : official journal of Turkish Society of Haematology, Jan 5, 2006

Development of factor VIII inhibitors remains the most serious and life-threatening complication ... more Development of factor VIII inhibitors remains the most serious and life-threatening complication of hemophilia therapy. The aim of this study was to determine the prevalence of inhibitor development in Turkish patients with hemophilia. Totally 1226 patients were screened [HA: 1057, HB: 105, von Willebrand's disease (vWD): 64]. Ages ranged from 1 to 55 years (mean: 16.5 years). Sixty-two percent of patients (657/1057) were severe hemophilia. This study showed that inhibitor prevalence in Turkish hemophiliacs exposed to factor concentrates and fresh frozen plasma (FFP) is 11.2% for all HA and 15.8% for severe HA versus 1.9% for HB after eliminating transient inhibitors. Totally 122 patients were found inhibitor positive [high responder (HR) inhibitor= 60 and low responder (LR) inhibitor= 59 for HA/2 LR for HB/1 LR for vWD]. Thanks to this project, patients with inhibitor development can be treated with specific products such as recombinant factor VIIa or activated protrombin compl...

Medical and pediatric oncology, 1999

Pediatric Transplantation, 2009

Eight children with FA underwent allogeneic HSCT without using irradiation for the conditioning r... more Eight children with FA underwent allogeneic HSCT without using irradiation for the conditioning regimen. Patients received two different conditioning regimens: first two patients received BU 1.5 mg/ kg/day for four days and CY 10 mg/kg/day for four days and the other regimen was: Flu 30 mg/m 2 /day for five days, CY 10 mg/kg/day for two days, and ATG-Fresenius 9-10 mg/kg/day for four days. GVHD prophylaxis consisted of CsA + MTX for the first two patients and only CsA for the others. All patients received HLA-identical stem cells from related donors. Primary engraftment was demonstrated in all patients. No patient developed acute GVHD and one patient had chronic GVHD. Only one patient who received BU based regimen died because of VOD. Overall, seven patients (87.5%) are alive with stable full donor chimerism at a median follow-up time of 2.5 yr (range: 1.7-8.9 yr). None of the patients developed secondary malignancy. Based on our data, we conclude that Flu-based, non-irradiation conditioning regimen was safe with low organ toxicity and stable engraftment in FA patients undergoing HSCT from matched related donors.

Pediatric Neurology, 2009

There are few reports on valproic acid related to thrombophilia. Thrombophilic risk factors were ... more There are few reports on valproic acid related to thrombophilia. Thrombophilic risk factors were investigated in 21 children (age range, 1-13 years) diagnosed with epilepsy and newly treated with valproic acid monotherapy. None of the children had been previously treated with any anticonvulsant agent. Before starting valproic acid therapy, homocysteine, lipoprotein(a), factor VIII, factor IX, protein C, protein S, antithrombin III levels, and activated protein C resistance levels were evaluated in all patients, with repeat evaluation after 9 months or 1 year of the therapy. Thrombosis gene mutations (factor V Leiden and prothrombin G20210A) were also evaluated in all patients before therapy. There was statistically significant elevation in lipoprotein(a) levels and reduction in fibrinogen levels after treatment. Reduction in protein C levels and elevation in homocysteine levels were also observed, but without statistical significance. Before therapy, no thrombotic event had occurred, despite thrombotic risk factors in some patients. Valproic acid can increase lipoprotein(a) and decrease fibrinogen, which may increase the risk of stroke or other thrombotic events. No clinical adverse effects resulted from changes in the levels or activity of thrombophilic factors associated with valproic acid treatment. Thus, routine investigation of factors implicated in thrombosis prior to initiation of valproic acid is not warranted for all patients. Nonetheless, caution is advised when initiating valproic acid treatment in children who have had prior stroke or thrombotic events.

Pediatric Hematology-Oncology, 1999

The complications of right atrial catheters (RACs) in pediatric oncology patients are unknown for... more The complications of right atrial catheters (RACs) in pediatric oncology patients are unknown for centers in developing countries. This study examined the complications of RACs at Ankara University Medical School, Turkey. A total of 90 RACs were placed in 61 children for long-term chemotherapy with a total experience of 15,536 catheter days. The rate of catheter-related sepsis was 4.9 episodes per 1000 catheter days. Coagulase-negative staphylococci and Candida species were the most common organisms, accounting for 25.0 and 13.1% of all organisms, respectively. The most common reasons for the removal of the RACs were infection (42.4%) and dislodgement (32.2%). The rates of complications were significantly higher in this study than in western studies. This increase could be explained by the differences in catheter care practices in the Turkish center. In conclusion, the use of RACs in a developing country necessitates an appraisal of the benefits and risks for each patient and improvement of catheter care procedures.

Pediatric Hematology-Oncology, 2002

Antiphospholipid antibody syndrome (APS) is characterized by the association of recurrent arteria... more Antiphospholipid antibody syndrome (APS) is characterized by the association of recurrent arterial or venous thrombosis or recurrent fetal wastage and the presence of circulating antiphospholipid antibodies, detected as anticardiolipin antibodies or lupus anticoagulant. The authors report an 8-year-old girl, who presented with central retinal artery occlusion and live do reticularis and was diagnosed as APS. Despite the proper anticoagulant treatment she had several cerebral ischemic events and died 29 months after the diagnosis. A larger number of pediatric case investigations will be required for better understanding and treating this rare thrombotic disorder.

41st Annual Meeting of the European-Society-for-Blood-and-Marrow-Transplantation -- MAR 22-25, 20... more 41st Annual Meeting of the European-Society-for-Blood-and-Marrow-Transplantation -- MAR 22-25, 2015 -- Istanbul, TURKEYWOS: 000351632902302European Soc Blood & Marrow Transplanta

Nature Publishing Group, 2015

41st Annual Meeting of the European-Society-for-Blood-and-Marrow-Transplantation -- MAR 22-25, 20... more 41st Annual Meeting of the European-Society-for-Blood-and-Marrow-Transplantation -- MAR 22-25, 2015 -- Istanbul, TURKEYWOS: 000351632902206European Soc Blood & Marrow Transplanta

Turkish journal of haematology : official journal of Turkish Society of Haematology, Jan 5, 2007

Autoimmune lymphoproliferative syndrome (ALPS) is a rare childhood disorder characterized by chro... more Autoimmune lymphoproliferative syndrome (ALPS) is a rare childhood disorder characterized by chronic non-malignant lymphoproliferation and autoimmunity. Patients with ALPS frequently exhibit episodic and intermittent, severe autoimmune- induced hemolytic anemia, thrombocytopenia or combined cytopenias. The co-occurrence of immune-mediated cytopenias, autoimmune thrombocytopenia and autoimmune hemolytic anemia is also known as Evans syndrome. This report describes a child who presented with Evans syndrome symptoms and who, after the detection of increased percentage of double negative T cell population in the peripheral blood, was diagnosed as ALPS. He received several courses of treatment including glucocorticoids, cyclosporine A (Cs A), and intravenous immunoglobulin (IVIG) without any clinical benefit and was treated with the antimalarial drug Fansidar®. With administration of Fansidar® (half tablet per week; containing 250 mg of pyrimethamine and 12.5 mg of sulfadoxine) combined ...

Turkish journal of haematology : official journal of Turkish Society of Haematology, Jan 5, 2010

Stable mixed chimerism (MC) may result in cure for thalassemia major patients following hematopoi... more Stable mixed chimerism (MC) may result in cure for thalassemia major patients following hematopoietic stem cell transplantation (HSCT), but rejection can occur. Twenty-eight HSCTs for thalassemia major were reviewed retrospectively to evaluate the clinical course of MC with possible risk factors and predictors of outcome, with a median follow-up of 1669 days (811-3576 days). Chimerism was detected by fluorescence in situ hybridization (FISH) or multiplex polymerase chain reaction depending on the sex match between the donor and the recipient. Primary rejection, stable MC and full donor chimerism was detected in 3.6%, 17.8% and 78.6% of patients, respectively. Clinically, 4/5 patients with stable MC had thalassemia trait with donor chimerism as low as 14%. One patient was started on pRBC transfusions at 2.5 years postHSCT. Stable MC can result in cure for thalassemia major patients. The clinical picture remains as the best guide for intervention until a more reliable predictor is ava...

Journal of Pediatric Hematology/oncology, 1999

Transfusion Science, 1998

The Journal of Trace Elements in Experimental Medicine, 2000

ABSTRACT

Pediatric Hematology-Oncology, 2000

Hereditary multiple exostoses (HME) is an autosomal dominant disorder characterized by the presen... more Hereditary multiple exostoses (HME) is an autosomal dominant disorder characterized by the presence of multiple exostoses. Three genetic loci have been identified, of which two (EXT1 and EXT2) have tumor suppressor activity. HME greatly increases the risk to develop sarcoma in the dysplastic tissue. The authors report an 8-year-old girl with HME who developed acute myeloblastic leukemia.

Molecular Immunology, 1998

Bone Marrow Transplantation, 2009

Loss of specific immunity after hematopoietic SCT (HSCT) is well documented for polio, measles, m... more Loss of specific immunity after hematopoietic SCT (HSCT) is well documented for polio, measles, mumps and tetanus. There are limited studies reporting the loss of Hepatitis A virus immunity and no reports evaluating the effect of donor immunity on Hepatitis A virus (HAV) immunity loss after HSCT. A total of 49 of the 81 patients who received HSCT at the Ankara University Pediatric HSCT Unit from January 1997 to December 2006 had HAV serology tested before HSCT and were evaluated for seroprevalence, and 30 of 49 patients were evaluated for the loss of Ab and for the effect of donor immunity on the loss of HAV Abs. The seroprevalence before HSCT was 75.5%. Loss of Ab was detected in 43.5% (10/23) of the patients. The median time to loss of Ab was 12 months (12-32 months), and 60% of these patients were seronegative at 12 months after HSCT. After HSCT, 46.7% of the patients were seronegative. Loss of Ab was higher in the seronegative donor group (75 vs 26%). The loss of HAV Ab is high after allogeneic HSCT for pediatric patients. Reimmunization should be considered for the continuation of individual and community immunity. Further studies with larger study groups are warranted to clarify the role of donor immunity on the loss of HAV immunity.

Nature Publishing Group, 2015

41st Annual Meeting of the European-Society-for-Blood-and-Marrow-Transplantation -- MAR 22-25, 20... more 41st Annual Meeting of the European-Society-for-Blood-and-Marrow-Transplantation -- MAR 22-25, 2015 -- Istanbul, TURKEYWOS: 000351632903148…European Soc Blood & Marrow Transplanta

Turkish journal of haematology : official journal of Turkish Society of Haematology, Jan 5, 2006

Development of factor VIII inhibitors remains the most serious and life-threatening complication ... more Development of factor VIII inhibitors remains the most serious and life-threatening complication of hemophilia therapy. The aim of this study was to determine the prevalence of inhibitor development in Turkish patients with hemophilia. Totally 1226 patients were screened [HA: 1057, HB: 105, von Willebrand's disease (vWD): 64]. Ages ranged from 1 to 55 years (mean: 16.5 years). Sixty-two percent of patients (657/1057) were severe hemophilia. This study showed that inhibitor prevalence in Turkish hemophiliacs exposed to factor concentrates and fresh frozen plasma (FFP) is 11.2% for all HA and 15.8% for severe HA versus 1.9% for HB after eliminating transient inhibitors. Totally 122 patients were found inhibitor positive [high responder (HR) inhibitor= 60 and low responder (LR) inhibitor= 59 for HA/2 LR for HB/1 LR for vWD]. Thanks to this project, patients with inhibitor development can be treated with specific products such as recombinant factor VIIa or activated protrombin compl...

Medical and pediatric oncology, 1999

Pediatric Transplantation, 2009

Eight children with FA underwent allogeneic HSCT without using irradiation for the conditioning r... more Eight children with FA underwent allogeneic HSCT without using irradiation for the conditioning regimen. Patients received two different conditioning regimens: first two patients received BU 1.5 mg/ kg/day for four days and CY 10 mg/kg/day for four days and the other regimen was: Flu 30 mg/m 2 /day for five days, CY 10 mg/kg/day for two days, and ATG-Fresenius 9-10 mg/kg/day for four days. GVHD prophylaxis consisted of CsA + MTX for the first two patients and only CsA for the others. All patients received HLA-identical stem cells from related donors. Primary engraftment was demonstrated in all patients. No patient developed acute GVHD and one patient had chronic GVHD. Only one patient who received BU based regimen died because of VOD. Overall, seven patients (87.5%) are alive with stable full donor chimerism at a median follow-up time of 2.5 yr (range: 1.7-8.9 yr). None of the patients developed secondary malignancy. Based on our data, we conclude that Flu-based, non-irradiation conditioning regimen was safe with low organ toxicity and stable engraftment in FA patients undergoing HSCT from matched related donors.

Pediatric Neurology, 2009

There are few reports on valproic acid related to thrombophilia. Thrombophilic risk factors were ... more There are few reports on valproic acid related to thrombophilia. Thrombophilic risk factors were investigated in 21 children (age range, 1-13 years) diagnosed with epilepsy and newly treated with valproic acid monotherapy. None of the children had been previously treated with any anticonvulsant agent. Before starting valproic acid therapy, homocysteine, lipoprotein(a), factor VIII, factor IX, protein C, protein S, antithrombin III levels, and activated protein C resistance levels were evaluated in all patients, with repeat evaluation after 9 months or 1 year of the therapy. Thrombosis gene mutations (factor V Leiden and prothrombin G20210A) were also evaluated in all patients before therapy. There was statistically significant elevation in lipoprotein(a) levels and reduction in fibrinogen levels after treatment. Reduction in protein C levels and elevation in homocysteine levels were also observed, but without statistical significance. Before therapy, no thrombotic event had occurred, despite thrombotic risk factors in some patients. Valproic acid can increase lipoprotein(a) and decrease fibrinogen, which may increase the risk of stroke or other thrombotic events. No clinical adverse effects resulted from changes in the levels or activity of thrombophilic factors associated with valproic acid treatment. Thus, routine investigation of factors implicated in thrombosis prior to initiation of valproic acid is not warranted for all patients. Nonetheless, caution is advised when initiating valproic acid treatment in children who have had prior stroke or thrombotic events.

Pediatric Hematology-Oncology, 1999

The complications of right atrial catheters (RACs) in pediatric oncology patients are unknown for... more The complications of right atrial catheters (RACs) in pediatric oncology patients are unknown for centers in developing countries. This study examined the complications of RACs at Ankara University Medical School, Turkey. A total of 90 RACs were placed in 61 children for long-term chemotherapy with a total experience of 15,536 catheter days. The rate of catheter-related sepsis was 4.9 episodes per 1000 catheter days. Coagulase-negative staphylococci and Candida species were the most common organisms, accounting for 25.0 and 13.1% of all organisms, respectively. The most common reasons for the removal of the RACs were infection (42.4%) and dislodgement (32.2%). The rates of complications were significantly higher in this study than in western studies. This increase could be explained by the differences in catheter care practices in the Turkish center. In conclusion, the use of RACs in a developing country necessitates an appraisal of the benefits and risks for each patient and improvement of catheter care procedures.

Pediatric Hematology-Oncology, 2002

Antiphospholipid antibody syndrome (APS) is characterized by the association of recurrent arteria... more Antiphospholipid antibody syndrome (APS) is characterized by the association of recurrent arterial or venous thrombosis or recurrent fetal wastage and the presence of circulating antiphospholipid antibodies, detected as anticardiolipin antibodies or lupus anticoagulant. The authors report an 8-year-old girl, who presented with central retinal artery occlusion and live do reticularis and was diagnosed as APS. Despite the proper anticoagulant treatment she had several cerebral ischemic events and died 29 months after the diagnosis. A larger number of pediatric case investigations will be required for better understanding and treating this rare thrombotic disorder.