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Öğe Co-existing mild Haemophilia A with Mild Type 1 Von Willebrand Disease: Case Report(Akad Doktorlar Yayinevi, 2011) Akin, Mehmet; Karapinar, Deniz Yilmaz; Balkan, Can; Ay, Yilmaz; Kavakli, KaanVon Willebrand disease and haemophilia A are the two most common inherited bleeding disorders. Despite the relatively high frequency of those two bleeding disorders in the general population, reports of their coexistence together or of combined coagulopathies in general are rare. We describe a 1-year-old male with confirmed mild haemophilia A co-existing with mild type 1 VWD. The 1- year old male was admitted to our hospital with a history of excessive bleeding following circumcision. Initial laboratory evaluation revealed a prolonged activated partial thromboplastin time (APTT) of 46.2 s (normal range 23.2-34.7), and low FVIII activity level of 5.5% of normal. His subsequent evaluation, was also consistent with mild type 1 VWD with a decreased VWF antigen (VWF:Ag) of 50%, decreased ristocetin cofactor activity (VWF:RCo) of 44%. The DNA testing detected a C2 domain R2304H mutation of the FVIII gene.Öğe A Common VWF Exon 28 Haplotype in the Turkish Population(Sage Publications Inc, 2013) Berber, Ergul; Pehlevan, Funda; Akin, Mehmet; Capan, Ozlem Yalcin; Kavakli, Kaan; Caglayan, S. HandeAn increasing number of mutations and polymorphisms have been identified in the von Willebrand factor (VWF) gene of patients with von Willebrand disease (VWD). Most of the sequence alterations are within exon 28, duplicated in the VWF pseudogene on chromosome 22. Genetic recombination causing the gene conversion between the VWF gene and its pseudogene is associated with multiple substitutions in the VWF gene and with VWD. In the present study, VWF gene exon 28 was analyzed in 33 patients with VWD by DNA sequencing. A total of 73% of the patients were heterozygous for p.D1472H, p.V1485L, p.1500A, p.1501F, p.L1503P, and p.S1506L single-nucleotide polymorphisms. Family analysis revealed that the gene conversion occurred between the VWF gene and its pseudogene in 3 patients. Case-control association analysis by Haploview 4.2 did not show an association between the haplotype and VWD. In conclusion, a common exon 28 haplotype in the Turkish population, which might have arisen from the gene conversion events in the founder population, was identified.Öğe An Evaluation of the DDAVP Infusion Test With PFA-100 and vWF Activity Assays to Distinguish vWD Types in Children(Sage Publications Inc, 2011) Akin, Mehmet; Karapinar, Deniz Yilmaz; Balkan, Can; Yilmaz, A. Y.; Kavakli, Kaanvon Willebrand disease (vWD) is classified into partial (type 1), qualitative (type 2), and total deficiency (type 3). The aims of the study were to evaluate prospectively the potency of the DDAVP infusion test together with von Willebrand factor (vWF) ristocetin cofactor (vWF:RCo), vWF antigen (vWF:Ag), factor VIII coagulant activity (FVIII:C), and platelet function analyzer (PFA)-100 to distinguish vWD types. Genetic analysis and multimeric analysis of vWF was not applied. We classified the 112 patients and 47 healthy children phenotypically according to the laboratory test results and bleeding severity score. PFA-100 closure times (CT), FVIII:C, vWF:RCo, vWF:Ag, ristocetin-induced platelet aggregation (RIPA), and the response of FVIII: C and vWF parameters to desmopressin (DDAVP) were used to define types 1, 2, and 3 vWD. Type 1 vWD is mild in 34 cases (vWF:RCo % 40-55), moderate in 29 (vWF:RCo % 27-40), severe type 1 vWD or nonclassical type 2 vWD in 12 cases (vWF:RCo % 4-16), and type 2 vWD in 23 cases (vWF:RCo % 4-38). The response to DDAVP of vWF parameters is normal in all patients with mild/moderate type 1 vWD, 6 patients with severe type 1 vWD or nonclassical type 2 vWD and 11 patients with type 2 vWD. In conclusion, this study showed that measurement of vWF:RCo, vWF:Ag, FVIII:C, and PFA-100 parameters can differentiate vWD types but not severe type 1 vWD or nonclassical type 2 vWD. In the differentiation of severe type 1 vWD and nonclassical type 2 vWD, DDAVP response may be used.Öğe Feasibility of Using Thrombin Generation Assay (TGA) for Monitoring Bypassing Agent Therapy in Patients With Hemophilia Having Inhibitors(Sage Publications Inc, 2013) Ay, Yilmaz; Balkan, Can; Karapinar, Deniz Yilmaz; Akin, Mehmet; Bilenoglu, Basri; Kavakli, KaanBackground: Monitoring bypassing agent therapy and observing concordance with clinical hemostasis is crucial in vital hemorrhages and major surgeries in patients with hemophilia having inhibitor. Objective: We aimed to investigate the value of the thrombin generation assay (TGA) and thromboelastography (TEG) for monitoring hemostasis in patients with hemophilia having inhibitor, during supplementation therapy with bypassing agents. Patients and Methods: The study group consisted of 7 patients with hemophilia having factor VIII inhibitor. All patients were male. The median age of the participants was 10 years. Age range was 6 to 32 years. The median inhibitor level was 10 Bethesda units (BU), with a range of 5 to 32 BU. A total of 17 bleeding episodes were evaluated. Both TEG and TGA tests were assessed in addition to clinical responses. Assessments were made prior to bypass agent therapy such as recombinant factor VIIa (rFVIIa) or activated prothrombin complex concentrate (aPCC) for bleeding episodes, during the first hour and 24 hours after either intervention in patients. Results: No relation between clinical response and TGA or TEG parameters was found in patients. There was no difference between clinical responses after rFVIIa and aPCC treatments. However, after aPCC treatment, endogenous thrombin potential and peak thrombin levels and also TEG R, K, and alpha angle degrees were significantly higher. Conclusions: In conclusion, we found that the clinical effectiveness of bypass therapy in hemophilia cannot be assessed by TGA and TEG.Öğe Laboratory Diagnosis and Management of von Willebrand Disease in Turkey: Izmir Experience(Thieme Medical Publ Inc, 2011) Akin, Mehmet; Kavakli, Kaanvon Willebrand disease (VWD) is caused by a deficiency or dysfunction of von Willebrand factor (VWF). The pathophysiology, classification, diagnosis, and management of VWD are relatively complex, but their understanding is important for proper diagnosis and management of patients with VWD. There are inherent difficulties in both the identification and classification of VWD because of clinical uncertainty and the limitations in the test processes and test panels typically used by laboratories. The most common test panel employed by laboratories, particularly in the geographic regions covered by the mutational studies, would comprise factor VIII coagulant (FVIII:C), VWF protein (antigen; VWF:Ag), and ristocetin cofactor (VWF:RCo). In our center, use of a desmopressin challenge with our core four-test panel (i.e., VWF:Ag, VWF:RCo, FVIII:C, and PFA-100) is expected to further assist laboratory diagnosis of VWD in Turkey. Molecular genetics is a rather new approach for Turkey, with gene analyses related to VWD being initiated in one center and the results used for confirmation of diagnosis in limited cases.Öğe A National Registry of Thalassemia in Turkey: Demographic and Disease Characteristics of Patients, Achievements, and Challenges in Prevention(Galenos Yayincilik, 2018) Aydinok, Yesim; Oymak, Yesim; Atabay, Berna; Aydogan, Gonul; Yesilipek, Akif; Unal, Selma; Kilinc, Yurdanur; Oflaz, Banu; Akin, Mehmet; Vergin, Canan; Evim, Melike Sezgin; Caliskan, Umran; Unal, Sule; Bay, Ali; Kazanci, Elif; Ileri, Talia; Atay, Didem; Patiroglu, Turkan; Kahraman, Selda; Soker, Murat; Akcan, Mediha; Akdeniz, Aydan; Buyukavci, Mustafa; Alanoglu, Guchan; Bor, Ozcan; Soyer, Nur; Karadas, Nihal Ozdemir; Uysalol, Ezgi; Turker, Meral; Akcay, Arzu; Ocak, Suheyla; Gunes, Adalet Meral; Tokgoz, Huseyin; Unal, Elif; Tiftik, Naci; Karakas, ZeynepObjective: The Turkish Society of Pediatric Hematology set up a National Hemoglobinopathy Registry to demonstrate the demographic and disease characteristics of patients and assess the efficacy of a hemoglobinopathy control program (HCP) over 10 years in Turkey. Materials and Methods: A total of 2046 patients from 27 thalassemia centers were registered, of which 1988 were eligible for analysis. This cohort mainly comprised patients with beta-thalassemia major (n = 1658, 83.4%) and intermedia (n = 215, 10.8%). Results: The majority of patients were from the coastal areas of Turkey. The high number of patients in Southeastern Anatolia was due to that area having the highest rates of consanguineous marriage and fertility. The most common 11 mutations represented 90% of all beta-thalassemia alleles and 47% of those were IVS1-110(G->A) mutations. The probability of undergoing splenectomy within the first 10 years of life was 20%, a rate unchanged since the 1980s. Iron chelators were administered as monotherapy regimens in 95% of patients and deferasirox was prescribed in 81.3% of those cases. Deferasirox administration was the highest (93.6%) in patients aged <10 years. Of the thalassemia major patients, 5.8% had match-related hemopoietic stem cell transplantation with a success rate of 77%. Cardiac disease was detected as a major cause of death and did not show a decreasing trend in 5-year cohorts since 1999. Conclusion: While the HCP has been implemented since 2003, the affected births have shown a consistent decrease only after 2009, being at lowest 34 cases per year. This program failure resulted from a lack of premarital screening in the majority of cases. Additional problems were unawareness of the risk and misinformation of the at-risk couples. In addition, prenatal diagnosis was either not offered to or was not accepted by the at-risk families. This study indicated that a continuous effort is needed for optimizing the management of thalassemia and the development of strategies is essential for further achievements in the HCP in Turkey.Öğe Prospective Evaluation of Chromosomal Breakages in Hemophiliac Children after Radioisotope Synovectomy with Yttrium(90) and Rhenium(186).(Amer Soc Hematology, 2008) Kavakli, Kaan; Cogulu, Ozgur; Aydogdu, Semih; Ozkilic, Hayal; Durmaz, Burak; Kirbiyik, Ozgur; Özkınay, Ferda; Balkan, Can; Karapinar, Deniz Yilmaz; Ay, Yilmaz; Akin, MehmetÖğe Rabbit Antithymocyte Globulin Treatment in Childhood Acquired Severe Aplastic Anemia(Taylor & Francis Inc, 2014) Karapinar, Deniz Yilmaz; Karadas, Nihal; Ay, Yilmaz; Akin, Mehmet; Balkan, Can; Aydinok, Yesim; Kavakli, KaanAcquired severe aplastic anemia (SAA) is a life threatening bone marrow failure characterized by pancytopenia and hypocellular bone marrow. Matched sibling donor is not available for majority of the patients and many children receive immunosuppressive therapy (IST). Although horse antithymocyte globuline (ATG) is the preferred option, our patients received rabbit ATG; since horse ATG is not available in Turkey. We reviewed the medical records of children with SAA who were treated with rabbit ATG, cyclosporine, and granulocyte colony stimulating factor (GCSF) between 2006 and 2012. Fifteen children with SAA aged between 1.5 and 17 years received rabbit ATG as first line treatment. Only two of them showed partial response and the others did not give any response at 3rd, 6th, and 12th months after the first course of IST. The second course of ATG was given to 8 of the patients; Rabbit ATG at the same dosage was used for 3 of them, and others were given horse ATG. None of the patients responded to the second course of ATG. Invasive fungal infection (IFI) which was seen in 80% of the patients was the most significant problem. Overall survival rate was 60%. The median time between the diagnosis and initiation of IST was 57 (range; 29-144) days. This delay might be significantly contributed to unresponsiveness. In our series, the use of rabbit ATG was not effective for these patients as first line treatment modality. Response rate was very low and the incidence of fungal infections was very high in the SAA patients who received rabbit ATG.Öğe A rescue therapy with a combination of caspofungin and liposomal amphotericin B or voriconazole in children with haematological malignancy and refractory invasive fungal infections(Wiley-Blackwell, 2011) Yilmaz, Deniz; Balkan, Can; Ay, Yilmaz; Akin, Mehmet; Karapinar, Bulent; Kavakli, KaanP>Combination treatment of paediatric invasive fungal infections (IFIs) has rarely been reported. A total of 17 children with 19 IFI episodes were enrolled in the study. The median age of the patients was 5.3 (range 0.5-17) years. IFI was classified as proven in 4, probable in 12 and possible in 3 episodes. These patients received empiric antifungal treatment, which consisted of liposomal amphotericin B (LAmB) monotherapy for a median duration of 12 days (range 3-69 days). All patients were refractory to LAmB; therefore, caspofungin was added to the therapy in 11 patients. In the remaining six patients, LAmB was ceased and a combination of caspofungin and voriconazole was started. Among the patients who received caspofungin + LAmB, four did not show favourable response and the combination was switched to caspofungin + voriconazole. The median (range) and total duration of the therapy were 7 (3-14) days and 91 patient days for LAmB + caspofungin combination and 49 (7-126) days and 516 patient days for caspofungin + voriconazole combination. We found a favourable response rate of 68.4% in 16 proven or probable IFI episodes. Twelve-week survival rate of these patients was 75%. No serious side effect was observed among the patients. Our data suggest that combination antifungal therapy is safe and effective in children with haematological malignancies.Öğe Resemblance to vWD Types and Laboratory Diagnosis of Obligatory Carriers of Type 3 von Willebrand Disease(Sage Publications Inc, 2011) Akin, Mehmet; Karapinar, Deniz Yilmaz; Balkan, Can; Ay, Yilmaz; Kavakli, KaanObjectives: It is important to diagnose obligatory carrier (OC) type 3 von Willebrand Disease (vWD) in countries, such as Turkey, where marriages between relatives is common. However, mild bleeding or no bleeding in such patients complicates the diagnosis of the disease. It is not clear how the diagnosis of OC type 3 vWD will be made based on FVIII:C (Factor VIII activity), vWF:Ag (von Willebrand factor antigen), vWF:RCo (von Willebrand factor ristocetin cofactor activity), and PFA (platelet function analyzer)-100 parameters. Therefore, the purpose of the study is to investigate how OC type 3 vWD diagnoses may be established by studying laboratory phenotypes of close relatives of patients with diagnosed 3 vWD. Patients and Methods: 8 patients with type 3 vWD (index cases) and 20 patients who were defined as OCs type 3 vWD were enrolled into the study. Result: 10 cases had similarity with mild type VWD, 4 cases had similarity with moderate type 1 vWD, 4 other cases had type 1 or 2 vWD similarities, 1 case had similarity with severe type 1 vWD, and 1 case also had similarity with severe type 1 or type 2 vWD; regarding their laboratory phenotypic characteristics. Conclusion: we identified that OC type 3 vWD is similar specifically to type 1 vWD in terms of laboratory phenotypic character, and we suggest that it may be used with PFA-100 as an easy and fast method in screening relatives.Öğe An unusual cause of multiple organ dysfunction syndrome in the pediatric intensive care unit: Hemophagocytic lymphohistiocytosis(Lippincott Williams & Wilkins, 2009) Karapinar, Buelent; Yilmaz, Deniz; Balkan, Can; Akin, Mehmet; Ay, Yilmaz; Kvakli, KaanObjective: To report our experience in children with primary or secondary hemophagocytic lymphohistiocytosis (HLH) presented with multiple organ dysfunction syndrome (MODS) in pediatric intensive care unit (PICU). Design: The records of patients with a diagnosis of HLH and MODS between January 2005 and January 2008 were reviewed. The patients' characteristics, treatment modalities, and outcomes were assessed. Setting: PICU of Ege University Hospital. Patients/Subjects: Twelve children who were hospitalized in the PICU met the diagnostic criteria for HLH, and presented with MODS were entered into the study. Results: The median age of the patients was 3 years (range, 2 months-15.5 years). Six patients had a history of parental consanguinity and two had an affected sibling. Five of the patients were classified as primary HLH. All of the patients had hepatosplenomegaly, elevated ferritin levels, hypofibrinogenemia, anemia, thrombocytopenia, and hemophagocytosis in bone marrow examination at presentation. The median Pediatric Logistic Organ Dysfunction score of the patients at onset was 51 (range, 12-62). Four patients had six, four had five, two had four, and the remaining two had three organ dysfunctions. Organ dysfunction, other than hematologic dysfunction which was present in all patients, was most commonly seen in hepatic (n = 11, 91.7%), respiratory (n = 11, 91.7%), and cardiovascular systems (n = 10, 83.3%). Although nine patients showed neurologic dysfunction including convulsion and coma, renal failure was detected in five patients. Eleven patients were supported with mechanical ventilation and four patients required hemodialysis. Eight patients were treated according to the HLH 2004 treatment protocol, consisting of cyclosporine A, etoposide, and dexamethasone. The remaining four patients received only intravenous immunoglobulin and supportive treatment. Seven of the patients died. Conclusion: HLH is a frequently lethal disease and with a clinical presentation similar to severe sepsis, MODS, disseminated intravascular coagulation, or septic shock, which are frequent diagnoses in the PICU. In the PICU, HLH should be considered in the case of prolonged fever, splenomegaly, cytopenia, and MODS. It is important for pediatricians and particularly pediatric intensivists to know the diagnostic criteria and possible clinical presentations of HLH so treatment is initiated promptly. (Pediatr Crit Care Med 2009; 10:285-290)