Identification of the molecular etiology in rare congenital hemolytic anemias using next-generation sequencing with exome-based copy number variant analysis.

OBJECTIVES: In congenital hemolytic anemias (CHA), it is not always possible to determine the specific diagnosis by evaluating clinical findings and conventional laboratory tests. The aim of this study is to evaluate the utility of next-generation sequencing (NGS) and clinical-exome-based copy number variant (CNV) analysis in patients with CHA. METHODS: One hundred and forty-three CHA cases from 115 unrelated families referred for molecular analysis were enrolled in the study. Molecular analysis was performed using two different clinical exome panels in 130 patients, and whole-exome sequencing in nine patients. Exome-based CNV calling was incorporated into the traditional single-nucleotide variant and small insertion/deletion analysis pipeline for NGS data in 92 cases. In four patients from the same family, the PK Gypsy variant was investigated using long-range polymerase chain reaction. RESULTS: Molecular diagnosis was established in 86% of the study group. The most frequently mutated genes were SPTB (31.7%) and PKLR (28.5%). CNV analysis of 92 cases revealed that three patients had different sizes of large deletions in the SPTB and six patients had a deletion in the PKLR. CONCLUSIONS: In this study, NGS provided a high molecular diagnostic rate in cases with rare CHA. Analysis of the CNVs contributed to the diagnostic success.

A Rare Inherited Bone Marrow Failure Syndrome Disclosed by Reanalysis of the Exome Data of a Patient Evaluated for Cytopenia and Dysmorphic Features.

BACKGROUND: Multisystemic findings of inherited bone marrow failure syndromes may cause difficulty in diagnosis. Exome sequencing (ES) helps to define the etiology of rare diseases and reanalysis offers a valuable new diagnostic approach. Herein, we present the clinical and molecular characteristics of a girl who was referred for cytopenia and frequent infections. CASE REPORT: A 5-year-old girl with cytopenia, dysmorphism, short stature, developmental delay, and myopia was referred for genetic counseling. Reanalysis of the ES data revealed a homozygous splice-site variant in the DNAJC21 (NM_001012339.3:c.983+1G>A), causing Shwachman-Diamond Syndrome (SDS). It was shown by the RNA sequencing that exon 7 was skipped, causing an 88-nucleotide deletion. CONCLUSIONS: Precise genetic diagnosis enables genetic counseling and improves patient management by avoiding inappropriate treatment and unnecessary testing. This report would contribute to the clinical and molecular understanding of this rare type of SDS caused by DNAJC21 variants and expand the phenotypic features of this condition.

Central nervous system thrombosis in pediatric acute lymphoblastic leukemia in Turkey: A multicenter study.

BACKGROUND: In patients with acute lymphoblastic leukemia (ALL), the risk of thromboembolism increases due to hemostatic changes secondary to the primary disease and due to treatment-related factors. In this multicenter study, we aimed to research the frequency of central nervous system (CNS) thrombosis occurring during treatment, hereditary and acquired risk factors, clinical and laboratory features of patients with thrombosis, treatment approaches, and thrombosis-related mortality and morbidity rates in pediatric ALL patients. PROCEDURE: Pediatric patients who developed CNS thrombosis during ALL treatment from 2010 to 2021 were analyzed retrospectively in 25 different Pediatric Hematology Oncology centers in Türkiye. The demographic characteristics of the patients, symptoms associated with thrombosis, the stage of the leukemia treatment during thrombosis, the anticoagulant therapy applied for thrombosis, and the final status of the patients recorded through electronic medical records were determined. RESULTS: Data from 70 patients with CNS thrombosis during treatment, out of 3968 pediatric patients with ALL, were reviewed. The incidence of CNS thrombosis was 1.8% (venous: 1.5 %; arterial: 0.03%). Among patients with CNS thrombosis, 47 had the event in the first 2 months. Low molecular weight heparin (LMWH) was the most commonly used treatment with a median of 6 months (min-max: 3-28 months). No treatment-related complications occurred. Chronic thrombosis findings occurred in four patients (6%). In five (7%) patients who developed cerebral vein thrombosis, neurological sequelae (epilepsy and neurological deficit) remained. One patient died related to thrombosis, and the mortality rate was 1.4%. CONCLUSION: Cerebral venous thrombosis and, less frequently, cerebral arterial thrombosis may develop in patients with ALL. The incidence of CNS thrombosis is higher during induction therapy than during other courses of treatment. Therefore, patients receiving induction therapy should be monitored carefully for clinical findings suggestive of CNS thrombosis.

Central Nervous System Fungal Infections in Children With Leukemia and Undergoing Hematopoietic Stem Cell Transplantation: A Retrospective Multicenter Study.

BACKGROUND: Central nervous system fungal infections (CNSFI) are seen in patients with hematologic malignancies and have high morbidity and mortality. Because of their rarity, there is limited data on CNSFI in children with no established treatment protocols or guidelines. MATERIALS AND METHODS: In this multicenter retrospective study, 51 pediatric patients with leukemia, 6 of whom had undergone bone marrow transplantation, with proven or probable CNSFI were evaluated. Fungal infections were defined as proven or probable based on European Organisation for Research and Treatment of Cancer criteria. Proven CNSFI was diagnosed by appropriate central nervous system (CNS) imaging or tissue sample findings in combination with positive microbiological results of cerebrospinal fluid. A positive culture, microscopic evidence of hyphae, a positive result of the galactomannan assays are defined as positive microbiological evidence. Probable CNSFI was defined as appropriate CNS imaging findings together with proven or probable invasive fungal infections at another focus without CNS when there is no other explanatory condition. Data was collected by using the questionnaire form (Supplemental Digital Content 1, http://links.lww.com/JPHO/A541 ). RESULTS: Seventeen patients had proven, 34 patients had probable CNSFI. Headaches and seizures were the most common clinical findings. The median time between the onset of fever and diagnosis was 5 days. The most common fungal agent identified was Aspergillus . Sixteen patients received single-agent, 35 received combination antifungal therapy. Surgery was performed in 23 patients. Twenty-two patients (43%) died, 29 of the CNSFI episodes recovered with a 20% neurological sequelae. CONCLUSION: CNSFIs should be considered in the differential diagnosis in patients with leukemia and refractory/recurrent fever, headache, neurologicalocular symptoms, and a radiologic-serological evaluation should be performed immediately. Early diagnosis and prompt management, both medical and surgical, are essential for improving clinical outcomes.

Results of multicenter registry for patients with inherited factor VII deficiency in Turkey.

INTRODUCTION: Inherited factor VII (FVII) deficiency (FVIID) is the most common of inherited rare bleeding disorders. Other determinants of clinical severity apart from FVII level (FVIIL) include genetic and environmental factors. We aimed to identify the cut-off FVIILs for general and severe bleedings in patients with FVIID by using an online national registry system including clinical, laboratory, and demographic characteristics of patients. METHODS: Demographic, clinical, and laboratory data of patients with FVIID extracted from the national database, constituted by the Turkish Society of Hematology, were examined. Bleeding phenotypes, general characteristics, and laboratory features were assessed in terms of FVIILs. Bleeding rates and prophylaxis during special procedures/interventions were also recorded. RESULTS: Data from 197 patients showed that 46.2% of patients had FVIIL< 10%. Most bleeds were of mucosal origin (67.7%), and severe bleeds tended to occur in younger patients (median age: 15 (IQR:6-29)). Cut-off FVIILs for all and severe bleeds were 16.5% and 7.5%, respectively. The major reason for long-term prophylaxis was observed as central nervous system bleeding (80%). CONCLUSION: Our data are consistent with most of the published literature in terms of cut-off FVIIL for bleeding, as well as reasons for prophylaxis, showing both an increased severity of bleeding and younger age at diagnosis with decreasing FVIIL. However, in order to offer a classification similar to that in Hemophilia A or B, data of a larger cohort with information about environmental and genetic factors are required.

Mixed Langerhans Cell Histiocytosis and Erdheim-Chester Disease in a Girl: A Rare and Puzzling Diagnosis.

OBJECTIVE: The objective of this study was to report the case of a girl diagnosed as suffering from multisystem, BRAF V600E-positive refractory Langerhans cell histiocytosis (LCH) and coexistent Erdheim-Chester disease (ECD) with perirenal, intracranial involvement and the dramatic response to clofarabine treatment. OBSERVATIONS: Histiocytoses are rare diseases with a broad clinical spectrum. Recent evidence supports a molecular and clinical overlap between LCH and ECD, and mixed LCH/ECD is now a separate entity. However, only a few pediatric cases of mixed disease have been reported in the literature. CONCLUSIONS: In a child with refractory, multisystem histiocytosis and atypical presentations, mixed LCH/ECD should be suspected in the differential diagnosis.

Congenital Factor XIII Deficiency With the Presence of Inhibitor: A Case Study.

Coagulation factor XIII (FXIII) is a fibrin-stabilizing factor with additional roles in wound healing and interactions between the decidua and fetus. Congenital FXIII deficiency is rare bleeding disorder. Inhibitor development against FXIII in inherited FXIII deficency is also uncommon, but may cause severe, life-threatening bleeding. FXIII is the last step in the coagulation cascade with normal coagulation paramaters (PT, aPTT), the detection of inhibitor to FXIII is quite difficult. The treatment of inhibitor-positive congenital FXIII deficiency is challenging due to the lack of a role of by-pass agents such as FVII. The best known ways of treatment in these cases are the use of high-dose FXIII concentrates and immunosuppression. Herein, we report the management of postoperative bleeding diathesis in a patient with FXIII deficiency who developed inhibitors, and to follow the clinical course of the disease with FXIII concentrate and immunosuppression.

Evaluation of Chromogenic Factor VIII Assay Compared with One-Stage Clotting Assay.

BACKGROUND: Congenital factor VIII (FVIII) deficiency causes hemophilia A due to different types of defects in the FVIII gene. Although the chromogenic measurement is the reference method and shows less variability, a one-stage assay is the most commonly preferred method for measurement of FVIII. In this study, we aimed to evaluate the analytical performances of chromogenic and one-stage assays, and compare the results prior to introduction of newly developed extended half-life recombinant FVIII products. METHODS: Sixty-six blood samples from residual material of Istanbul Faculty of Medicine, Central Laboratory workflow comprised the study group. Samples were classified; plasma FVIII > 40 IU and FVIII < 40 IU. FVIII activities were measured using one-stage clotting and chromogenic assays on a CS-2500 analyzer. Analytical performances were determined through precision, linearity, carryover, and comparability studies. RESULTS: The within-run CV% of the one-stage assay on the CS-2500 had 1.6%, 2.6%, the between day CV% were 8.5%, 4.9 % for low and high controls, respectively. The within-run CV% of chromogenic method had 1.2% and 0.9%. Both methods demonstrated good linearity (R2 > 0.998), and the comparisons of both assays exhibited good agreement with minor bias for FVIII activity > 40 IU. However, a significant bias was obtained for FVIII activity < 40 IU. CONCLUSIONS: We obtained higher results using the one-stage assay compared with the chromogenic assay, and a significant bias was found for the samples lower than 40 IU. The discrepancy can explained by the presence of a weak agreement for samples lower than 10 IU due to the lower detection limit of the chromogenic assay used in this study (1.5%).

Age-Related Co-Expression of BCOR and BCORL1 mRNA in Acute Myeloid Leukemia.

BACKGROUND: Acute myeloid leukemia (AML) is an aggressive hematological malignancy caused by a variety of genetic abnormalities and epigenetic dysregulation. The incidence of AML is strongly related to age, with the highest incidence rates being in older adults. The loss of function mutations in BCOR and BCORL1 genes have been identified in AML. BCL6 corepressor (BCOR) and BCL6 corepressor like 1 (BCORL1) are important epigenetic regu-lators as a member of Polycomb repressive complex 1 (PRC1.1), involved in histone modification processes. METHODS: We analyzed the BCOR and BCORL1 mRNA expression in 74 adult and 22 pediatric patients with AML by Real-Time quantitative PCR in this study. RESULTS: Our results indicated that both BCOR and BCORL1 mRNA expressions decrease with age (p = 0.009 and p = 0.008, respectively) and there is a positive correlation between BCOR and BCORL1 mRNA expression (p < 0.001). BCOR and BCORL1 mRNA expressions were not significantly different in both adult and pediatric patients with AML compared to control (p > 0.05). CONCLUSIONS: Our findings indicate that expression of BCOR and BCORL1 mRNA are down-regulated with age. The increase in AML incidence with age suggests that age-associated BCOR and BCORL1 down-regulation might potentially contribute to age-related epigenetic alterations and form a predisposing condition for the development of elderly AML.

Upregulation of SPINK2 in acute myeloid leukemia.

Objectives: Acute myeloid leukemia (AML) is a highly heterogeneous disease. Although patients can be classified into risk groups based on their genetic changes, the prognosis of disease within these categories varies widely. This situation raises the need to search for new molecular markers related to AML. Serine peptidase inhibitor Kazal type 2 (SPINK2) has recently been reported to be upregulated in AML and associated with poor outcomes by meta-analysis and in a limited number of AML patients. Methods: We analyzed SPINK2 mRNA expression in 62 patients (45 adult and 17 pediatric) with AML and 11 cell lines using quantitative Real-Time PCR (qRT-PCR). SPINK2 protein level was determined using ELISA in cell lines. Results: We found that the expression of SPINK2 mRNA and protein levels in AML cell lines (HL60 and NB4) have increased compared to other cell lines (K562, Jurkat and NALM6, MCF7, HeLa, HUVEC, hFOB, 293T, U87). SPINK2 mRNA expression was upregulated in patients with AML compared to controls (p=0.004) and significantly lower in t(8;21)-positive patients compared to negative patients (p=0.0006). Conclusions: Our results suggest that SPINK2 serves an important role in AML development. Further studies are needed to evaluate SPINK2 expression in AML patients with t(8.21) and investigate to clarify its prognostic value in various subgroups of AML.

Mediastinal masses in children: experience with 120 cases.

Primary mediastinal malignancies are rare tumors and can originate from any mediastinal organ or tissue such as thymic, neurogenic, lymphatic, germinal, or mesenchymal. The authors reviewed all cases of primary pediatric mediastinal masses diagnosed over a 25-year period to determine the pattern of presentation, the histology, and the outcome of the surgical treatment. In this study, 120 primary pediatric mediastinal mass cases diagnosed between 1985 and 2011 are retrospectively evaluated according to their age, sex, symptoms, anatomical location, surgical treatment, and histopathological evaluation. The median age of the patients was 5.8 years. There were 34 benign and 86 malign tumors. Thirty patients were asymptomatic. Common symptoms in the patients were cough, dyspnea, fatigue, fever, abdomen pain, back pain, and neurological symptoms. According to their origins, they were presented as neurogenic tumors (38.3%), lymphomas (18.3%), undifferentiated sarcomas (15%), germ cell tumors (7.5%), and the other tumors (22%) thymic pathologies, lymphangiomas, rhabdomyosarcomas, lipomas, hemangiomas, and Wilms' tumor. Complete resection of the tumor was performed in 86 patients, partial resection of the tumor was the intervention in 11 patients. In 23 patients, biopsy was undertaken. Because of the high incidence of asymptomatic or nonspecific presentation such as the upper airway disease, the presentation of a mediastinal mass in children may be challenging. Neurogenic tumors or lymphomas are indicating surgery, if possible complete resection, for both benign and malignant conditions. Although surgery is the mainstay of therapy for most mediastinal tumors, an experienced multidisciplinary approach is necessary.

Rare coagulation disorders: a retrospective analysis of 156 patients in Turkey.

OBJECTIVE: To retrospectively evaluate the clinical findings, laboratory data, management, and outcome in a group ofTurkish children diagnosed with rare coagulation deficiencies (RCDs) between January 1999 and June 2009. MATERIAL AND METHODS: The Turkish Society of Pediatric Hematology-Hemophilia-Thrombosis-Hemostasissubcommittee designed a Microsoft Excel-based questionnaire for standardized data collection and sent it to participatinginstitutions. RESULTS: In total, 156 patients from 12 pediatric referral centers were included in the study. The cost common RCDswere as follows: FVII (n = 53 [34%]), FV (n = 24 [15.4%]), and FX (n = 23 [14.7%]) deficiency. The most common initialfinding in the patients was epistaxis, followed by ecchymosis, and gingival bleeding. CONCLUSION: Initial symptoms were mucosal bleeding, and fresh frozen plasma (FFP) and tranexamic acid werethe most commonly used treatments. We think that prophylactic treatment used for hemophilia patients should beconsidered as an initial therapeutic option for patients with rare factor deficiencies and a severe clinical course, and forthose with a factor deficiency that can lead to severe bleeding.

Analysis of Chromosomal Aberrations and FLT3 gene Mutations in Childhood Acute Myelogenous Leukemia Patients.

OBJECTIVE: To identify the well-known common translocations and FLT3 mutations in childhood acute myelogenousleukemia (AML) patients in Turkey. MATERIAL AND METHODS: The study included 50 newly diagnosed patients in which t(15;17), t(8;21), and inv(16)chromosomal translocations were identified using real-time PCR and FLT3 gene mutations were identified via direct PCR amplification PCR-RE analysis. RESULTS: In all, t(15;17) chromosomal aberrations were observed in 4 patients (8.0%), t(8;21) chromosomal aberrationswere observed in 12 patients (24.0%), inv(16) chromosomal aberrations were observed in 3 patients (6.0%), and FLT3-ITD mutations were observed in 2 patients (4.0%); FLT3-D835 point mutation heterozygosity was observed in only 1patient (2.0%) patient. CONCLUSION: Despite of the known literature, a patient with FLT3-ITD and FLT3-D835 double mutation shows a bettersurvival and this might be due to the complementation effect of the t(15;17) translocation. The reportedmutation ratein this article (4%) of FLT3 gene seems to be one of the first results for Turkish population.

Bladder granulocytic sarcoma in a child: case report and literature review.

BACKGROUND: Granulocytic sarcoma (GS) is an extramedullary solid tumor composed of immature myeloid cells. GS has been associated with acute myeloid leukemia (AML), myelodysplastic syndromes or myeloproliferative diseases. Although GS can affect various tissues of the human body, it has rarely been reported in other soft tissues such as the breast, gastrointestinal, respiratory and genitourinary tracts. We report a pediatric case diagnosed with granulocytic sarcoma of the bladder and concomitant AML. CASE: A twelve-year-old previously healthy girl was admitted to the pediatric urology clinic with a ten-day history of hematuria and pollakiuria. Laboratory examinations revealed anemia, thrombocytopenia and neutrophilic leukocytosis. Bone marrow aspiration results were consistent with acute myeloid leukemia -FAB subtype M2-. Abdominal magnetic resonance imaging (MRI) showed an irregularly bounded 12 cm mass on the right side of the bladder. Transurethral resection (TUR) pathology was consistent with granulocytic sarcoma. After a multimodal treatment approach, complete remission was achieved. CONCLUSIONS: Malignant bladder masses are rare causes of macroscopic hematuria in childhood. The diagnostic spectrum is wide, ranging from rhabdomyosarcoma to leukemia involvement. The bladder is a rare site of extramedullary involvement in pediatric patients with AML. Multimodal treatment should be considered on a per-patient basis.

Human herpes virus type 8-associated Kaposi sarcoma in a pediatric liver transplant recipient.

Development of KS in pediatric liver transplant recipients is a rare entity and has dismal prognosis. Latent HHV-8 infection, immunosuppression, and genetic predisposition are possible etiological factors. Decreasing the dose or cessation of immunosuppressive drugs, switching to sirolimus with antiproliferative and antitumor properties, and different chemotherapeutic regimens are the current therapeutic strategies. We herein report a pediatric liver transplant recipient who developed generalized KS at post-transplant fifth month. The disease had an aggressive course despite the highly toxic chemotherapy. On the other hand, a prompt and durable response was provided by paclitaxel with tolerable side effects. The patient is now free of disease for at least 24 months and healthy with good graft function under sirolimus therapy as maintenance immunosuppression. Instead of highly toxic chemotherapy, paclitaxel can be used as therapeutic option in cases with generalized disease and in those who are unresponsive to conventional chemotherapy. However, new studies are needed to assess the efficacy of the paclitaxel therapy in KS in the liver transplant recipients.

Hepatitis B Vaccination in Children With Ongoing Cancer Treatment: A Safety and Efficacy Study of Super-Accelerated Vaccination Scheme.

OBJECTIVE: Children with cancer have an increased risk for hepatitis B virus (HBV) infections due to chemotherapy-induced secondary immunodeficiency and frequent blood transfusions. The aim of this study is to evaluate the efficacy and safety of hepatitis B vaccination during the intensive induction chemotherapy in children with cancer found to be seronegative for hepatitis B on admission. MATERIALS AND METHODS: Children newly diagnosed with cancer were evaluated for the presence of hepatitis B surface antigen (HBsAg) and antibody on admission. The children negative for both were included in the study. A super-accelerated vaccination scheme (3 booster doses at days 1-5, 8-12, and 28-33) was administered to these seronegative children concurrently with induction chemotherapy. Antibody response was checked 4-8 weeks after the last vaccination and 6 months after the end of the treatment. RESULTS: Eleven out of 122 children were seronegative for hepatitis B on admission (9%). Acute lymphoblastic leukemia, lymphoma, and solid tumors were diagnosed in 5, 4, and 2 children, respectively. Complete seroconversion was achieved in 4-8 weeks after the last vaccination with high titers of anti-HBs antibody, and all patients remained antibody-positive until 6 months after the completion of chemotherapy. CONCLUSION: The risk of transfusion-related infections increases with a number of transfused products and donor exposures, and it is more significant for immunosuppressed children with hematologic and oncologic malignancies. Hepatitis B vaccination could safely be applied with brisk and sustained responses in this vulnerable population, based on the local epidemiological data.

How to manage an unresectable or recurrent sialoblastoma.

Only 2-5% of all salivary gland tumors occur in children. Sialoblastoma is an extremely rare salivary gland tumor diagnosed at birth or shortly thereafter with significant variability in histological range and clinical course, so that it may be difficult to predict the most appropriate therapy. In cases where surgical removal is not curative or technically feasible, chemotherapy may be attempted. We report herein a patient with progression of a huge partially resected sialoblastoma who was successfully treated with chemotherapy. Systemic chemotherapy with vincristine, actinomycin D, and cyclophosphamide (VAC) seems to be an effective adjuvant or neoadjuvant treatment option for unresectable or recurrent sialoblastoma.

Li-Fraumeni syndrome in a Turkish family.

Li-Fraumeni syndrome (LFS) is one of the familial cancers characterized by different tumors and hereditary TP53 mutations. The adrenocortical carcinoma (ACC) association with acute leukemia is unusual in childhood, even in LFS. The authors here present a family with pR337P mutation in TP53 gene who had a child with acute lymphoblastic leukemia (ALL) and associated adrenocortical carcinoma as a case 1 and his cousin with brain tumor as a case 2. A hereditary TP53 mutation supported the diagnosis of LFS in this family. The patients had many difficulties in treatment strategies and succumbed to death. The availability of a reliable molecular marker to detect the R337P TP53 mutation allows the rapid identification of carriers in families that have a child with ACC. Once identified, carriers could be screened for early detection of ACC by imaging and endocrine studies and should be given psychological support to prevent anxiety for death. Whether early detection of ACC will reduce the mortality in these patients remains to be determined.

PTEN and AKT1 Variations in Childhood T-Cell Acute Lymphoblastic Leukemia

Objective: PTEN/AKT pathway deregulations have been reported to be associated with treatment response in acute leukemia. This study examined pediatric T-cell acute lymphoblastic leukemia (T-ALL) samples for PTEN and AKT1 gene variations and evaluated the clinical findings. Materials and Methods: Fifty diagnostic bone marrow samples of childhood T-ALL cases were investigated for the hotspot regions of the PTEN and AKT1 genes by targeted next-generation sequencing. Results: A total of five PTEN variations were found in three of the 50 T-ALL cases (6%). Three of the PTEN variations were first reported in this study. Furthermore, one patient clearly had two different mutant clones for PTEN. Two intronic single-nucleotide variations were found in AKT1 and none of the patients carried pathogenic AKT1 variations. Conclusion: Targeted deep sequencing allowed us to detect both low-level variations and clonal diversity. Low-level PTEN/AKT1 variation frequency makes it harder to investigate the clinical associations of the variants. On the other hand, characterization of the PTEN/AKT signaling members is important for improving case-specific therapeutic strategies.

Outcomes of Eltrombopag Treatment and Development of Iron Deficiency in Children with Immune Thrombocytopenia in Turkey

Objective: Immune thrombocytopenia (ITP) is a rare autoimmune disease and hematologic disorder characterized by reduced platelet counts that can result in significant symptoms, such as bleeding, bruising, epistaxis, or petechiae. The thrombopoietin receptor agonist eltrombopag (EPAG) is a second-line agent used to treat chronic ITP purpura in adults and children. Materials and Methods: The present retrospective study evaluated the efficacy, safety, and side effects of EPAG treatment in pediatric patients with acute refractory and chronic immune thrombocytopenia, particularly focusing on iron-deficiency anemia. Results: The diagnosis was chronic ITP in 89 patients and acute refractory ITP in 16 patients. The mean age of patients was 9.5±4.5 years (minimum-maximum: 1.2-18 years) at the beginning of EPAG treatment. The overall response rate was 74.3% (n=78). The mean time for platelet count of ≥50x109/L was 11.6±8 weeks (range: 1-34 weeks). The treatment was stopped for 27 patients (25.7%) at an average of 6.8±9 months (range: 1-38 months). The reason for discontinuation was lack of response in 18 patients, nonadherence in 4 patients, and hepatotoxicity in 2 patients. Response to treatment continued for an average of 4 months after cessation of EPAG in 3 patients. Conclusion: Results of the current study imply that EPAG is an effective therapeutic option in pediatric patients with acute refractory and chronic ITP. However, patients must be closely monitored for response and side effects during treatment, and especially for iron deficiency.