Successful use of split-dose intravenous daratumumab in a multiple myeloma patient after a first-dose life-threatening infusion-related reaction.

INTRODUCTION: Daratumumab is a humanized IgG1 kappa monoclonal antibody directed against CD38 used to treat myeloma. The recommended dose of daratumumab is 16 mg/kg, with no lower or upper threshold. Here, we present the first split-dose daratumumab infusion experience in a myeloma patient with morbid obesity in whom daratumumab was interrupted because of grade 3 infusion-related reaction. CASE REPORT: A female myeloma patient with morbid obesity received a combination of chemotherapy with daratumumab because of disease relapse. The calculated dose for the first intravenous daratumumab infusion was 1840 mg/day based on the weight of the patient, which was measured as 115 kilograms. Daratumumab infusion was initiated as appropriate but needed to be stopped because of a severe sudden presentation of shortness of breath and hypoxemia. MANAGEMENT AND OUTCOME: After daratumumab was stopped, premedication was repeated, and oxygen, intravenous and inhaler steroids, inhaler ß2 agonists and intravenous diphenhydramine were given in repeated doses. She was monitored and followed up in the emergency critical care unit. Daratumumab treatment with a split-dose schedule was planned after she fully recovered from all signs and symptoms. The total dose was divided into two doses and was given without any complications on two consecutive days. After that, she was also able to tolerate once a week 1840 mg of daratumumab in a single day. DISCUSSION: There is a paucity of data regarding the best practice for instituting intravenous daratumumab in patients with morbid obesity regarding the infusion rate and duration, optimal dosing, and ideal way to cope with infusion-related reactions. Our case suggests a potential role for a split-dose schedule for patients with obesity and potential dose reductions and infusion-related reactions.

Glofitamab in relapsed/refractory diffuse large B-cell lymphoma: Real-world data.

Glofitamab is a CD3xCD20 bi-specific antibody with two fragments directed to the CD20 antigen and a single CD3-binding fragment. Encouraging response and survival rates were recently reported in a pivotal phase II expansion trial conducted in patients with relapsed/refractory (R/R) B-cell lymphoma. However, the real-world data of patients of all ages with no strict selection criteria are still lacking. Herein, this retrospective study aimed to evaluate the outcomes of diffuse large B-cell lymphoma (DLBCL) patients who received glofitamab via compassionate use in Turkey. Forty-three patients from 20 centers who received at least one dose of the treatment were included in this study. The median age was 54 years. The median number of previous therapies was 4, and 23 patients were refractory to first-line treatment. Twenty patients had previously undergone autologous stem cell transplantation. The median follow-up time was 5.7 months. In efficacy-evaluable patients, 21% and 16% of them achieved complete response and partial response, respectively. The median response duration was 6.3 months. The median progression-free survival (PFS) and overall survival (OS) was 3.3 and 8.8 months, respectively. None of the treatment-responsive patients progressed during the study period, and their estimated 1-year PFS and OS rate was 83%. The most frequently reported toxicity was hematological toxicity. Sixteen patients survived, while 27 died at the time of the analysis. The most common cause of death was disease progression. One patient died of cytokine release syndrome during the first cycle after receiving the first dose of glofitamab. Meanwhile, two patients died due to glofitamab-related febrile neutropenia. This is the largest real-world study on the effectiveness and toxicity of glofitamab treatment in R/R DLBCL patients. The median OS of 9 months seems promising in this heavily pretreated group. The toxicity related mortality rates were the primary concerns in this study.

Prospective registry of adult patients receiving therapeutic plasma exchange with a presumptive diagnosis of thrombotic microangiopathy (TMA): The Turkish hematology research and education group (ThREG)-TMA02 study.

Thrombotic microanjiopathy (TMA) is a pathological diagnosis characterized by abnormalities of small vessels leading to microvascular thrombosis of arterioles and capillaries. The current prospective, non-interventional, multicenter study aimed to define the distribution of different TMA forms in adult Turkish patients who were referred for therapeutic plasma exchange (TPE) for presumptive diagnosis of TMA. Patients with serum ADAMTS13 activity <5% were diagnosed as having acquired thrombotic thrombocytopenic purpura (aTTP). Patients presenting with ADAMTS13 activity 6-10 % / normal renal function and patients with ADAMTS13 activity >10 %, normal renal function and no secondary TMA were treated as unclassified TMA. The study included a total of 80 patients (women: 50; man: 30) with a median age of 48 (20-74). Detailed evaluation at 1 month after hospital admission revealed aTTP, secondary TMA, infection/complement-associated hemolytic uremic syndrome and unclassified TMA in 29 (36.2 %), 22 (27.5 %), 23 (28.8 %) and 6 (7.5 %) patients respectively. As subclassification of various TMAs will dictate specific therapy, proper diagnosis in a timely manner is of utmost clinical significance.

Clinical characteristics and therapeutic outcomes of paroxysmal nocturnal hemoglobinuria patients in Turkey: a multicenter experience.

The aim of this study is to collect paroxysmal nocturnal hemoglobinuria (PNH) patient data from hematology centers all over Turkey in order to identify clinical features and management of PNH patients. Patients with PNH were evaluated by a retrospective review of medical records from 19 different institutions around Turkey. Patient demographics, medical history, laboratory findings, and PNH-specific information, including symptoms at the diagnosis, complications, erythrocyte, and granulocyte clone size, treatment, and causes of death were recorded. Sixty patients (28 males, 32 females) were identified. The median age was 33 (range; 17-77) years. Forty-six patients were diagnosed as classic PNH and 14 as secondary PNH. Fatigue and abdominal pain were the most frequent presenting symptoms. After eculizumab became available in Turkey, most of the patients (n = 31/46, 67.4%) were switched to eculizumab. Three patients with classic PNH underwent stem cell transplantation. The median survival time was 42 (range; 7-183 months) months. This study is the first and most comprehensive review of PNH cases in Turkey. It provided us useful information to find out the differences between our patients and literature, which may help us understand the disease.

Prospective registry of adult patients receiving therapeutic plasma exchange with a presumptive diagnosis of thrombotic microangiopathy (TMA): The Turkish hematology research and education group (ThREG)-TMA02 study.

Thrombotic microangiopathy(TMA) is a pathological diagnosis characterized by abnormalities of small vessels leading to microvascular thrombosis of arterioles and capillaries. The current prospective, non-interventional, multicenter (n:18) study aimed to define distribution of different TMA forms in adult Turkish patients who were referred for therapeutic plasma exchange (TPE) for a presumptive diagnosis of TMA. Patients with serum ADAMTS13 activity <5% were diagnosed as acquired thrombotic thrombocytopenic purpura (aTTP). Patients presenting with ADAMTS13 activity 6-10 % / normal renal function and patients with ADAMTS13 activity >10 %, normal renal function and no secondary TMA were treated as unclassified TMA. The study included a total of 97 patients (female: 60; male: 30) with a median age of 48 (18-74). Detailed evaluation at 1 month after hospital admission revealed aTTP, secondary TMA, infection/complement-associated hemolytic uremic syndrome and unclassified TMA in 32 (33 %), 33 (34 %), 26 (27 %) and 6 (6%) patients respectively. As subclassification of various TMAs will dictate specific therapy, proper diagnosis in a timely manner is of utmost clinical significance.

Efficacy and safety of ruxolitinib in patients with myelofibrosis: a retrospective and multicenter experience in Turkey

Background/aim: The aim of this study is to assess the efficacy and safety of ruxolitinib in patients with myelofibrosis. Materials and methods: From 15 centers, 176 patients (53.4% male, 46.6% female) were retrospectively evaluated. Results: The median age at ruxolitinib initiation was 62 (28­87) and 100 (56.8%) of all were diagnosed as PMF. Constitutional symptoms were observed in 84.7%. The median initiation dose of ruxolitinib was 30 mg (10­40). Dose change was made in 69 (39.2%) patients. Forty seven (35.6%) and 20 (15.2%) of 132 patients had hematological and nonhematological adverse events, respectively. The mean spleen sizes before and after ruxolitinib treatment were 219.67 ± 46.79 mm versus 199.49 ± 40.95 mm, respectively (p < 0.001). There was no correlation between baseline features and subsequent spleen response. Overall survival at 1-year was 89.5% and the median follow up was 10 (1­55) months. We could not show any relationship between survival and reduction in spleen size (p = 0.73). Conclusion: We found ruxolitinib to be safe, well tolerated, and effective in real-life clinical practice in Turkey. Ruxolitinib dose titration can provide better responses in terms of not only clinical benefit but also for long term of ruxolitinib treatment.

Thrombotic thrombocytopenic purpura associated with pesticides: A report of 4 cases and literature review.

Thrombotic thrombocytopenic purpura (TTP) is a disease characterized by the presence of microangiopathic hemolytic anemia (MAHA) and thrombocytopenia, caused by the congenital or acquired decrease of the enzyme activity which degrades unusual large vWF multimers. There is no identifiable cause in half of the acquired TTP cases. Herein, we report four possible pesticide-related cases with decreased ADAMTS13 enzyme activity, increased titer of ADAMTS13 inhibitor and typical clinical and laboratory presentation.

ß2-Microglobulin, Neutrophil Gelatinase-Associated Lipocalin, and Endocan Values in Evaluating Renal Functions in Patients with ß-Thalassemia Major.

Chronic anemia, transfusion-associated iron deposition, and chelating agents lead to renal impairment in ß-thalassemia (ß-thal) patients. The present study aimed to determine the most reliable and practical method in assessing and predicting renal injury in ß-thal major (ß-TM) patients. Therefore, we assessed the predictive values of urine ß2-microglobulin (ß2-MG) and neutrophil gelatinase-associated lipocalin (NGAL) levels, their ratios to urine creatinine, and serum endocan level. Sixty ß-TM patients and 30 healthy controls were included. Renal functions of the patients and controls were evaluated by means of urine protein/creatinine ratio, urine ß2-MG, urine NGAL, and serum endocan level. The ß-TM and control groups were comparable in terms of the demographic characteristics. Of the ß-TM patients, 26.7% had glomerular hyperfiltration and 41.7% had proteinuria. Compared with the control group, the ß-TM group had significantly higher levels of urine protein/creatinine, urine ß2-MG, urine ß2-MG/creatinine, urine NGAL, urine NGAL/creatinine, and serum endocan. These parameters did not differ between the chelating agent subgroups in the patient group. Urine ß2-MG/creatinine and NGAL/creatinine ratios were the parameters with high specificity in predicting proteinuria. There were significant correlations of urine ß2-MG, urine NGAL, and serum endocan levels with serum ferritin concentration. Urine ß2-MG/creatinine, NGAL/creatinine, and protein/creatinine ratios were correlated with each other in the patient group. Positive correlations of urine ß2-MG, urine NGAL, and serum endocan levels with serum ferritin concentration indicated that iron deposition was associated with endothelial damage and renal injury.

Acquired hemophilia A in chronic lymphocytic leukemia: A case report.

Acquired hemophilia A, due to spontaneous autoantibody against FVIII, is a rare hemorrhagic disorder with an incidence of about 1 per million population per year. If unrecognized and untreated, it is associated with a high morbidly and mortality rate of 8-12%. Autoantibody against coagulation factor VIII neutralizes procoagulant activity. We report herein is such a rare case of acquired hemophilia in a patient with CLL.

The Turkish experience with therapeutic plasma exchange: A national survey.

Therapeutic plasma exchange (TPE) is used to treat more than 60 diseases worldwide and has drawn growing interest. Little is known about the current situation of TPE activity in Turkey, so we developed a survey to obtain information about this timely topic. We collected data on TPE from 28 apheresis units throughout Turkey. We performed a total of 24,912 TPE procedures with 3203 patients over the past decade. Twenty years ago, the majority of procedures were performed for neurological and hematological disorders, and today, most TPE procedures are done for the same reasons. The only historical change has been an increase in TPE procedures in renal conditions. Currently, renal conditions were more frequently an indication for TPE than rheumatic conditions. Fresh frozen plasma was the most frequently used replacement fluid, followed by 5% albumin, used in 57.9% and 34.6% of procedures, respectively. The most frequently used anticoagulants in TPE were ACD-A and heparin/ACD-A, used with 1671 (52.2%) and 1164 (36.4%) patients, respectively. The frequency of adverse events (AEs) was 12.6%. The most common AEs were hypocalcemia-related symptoms, hypotension, and urticaria. We encountered no severe AEs that led to severe morbidity and mortality. Overall, more than two thirds of the patients showed improvement in the underlying disease. Here, we report on a nationwide survey on TPE activity in Turkey. We conclude that there has been a great increase in apheresis science, and the number of TPE procedures conducted in Turkey has increased steadily over time. Finally, we would like to point out that our past experiences and published international guidelines were the most important tools in gaining expertise regarding TPE.

Matrix metalloproteinase-9, 10, and stress hyperglycaemia in acute kidney injury.

BACKGROUND: This study investigated the effect of matrix metalloproteinase (MMP)-9 and 10, and stress hyperglycaemia on the necessity of emergency renal replacement therapy (RRT) and mortality in nondiabetic geriatric patients with acute kidney injury (AKI). MATERIALS AND METHODS: The present observational and longitudinal study included 101 nondiabetic geriatric patients (age >65 years) with AKI. The serum levels of MMP-9 and MMP-10 were evaluated in these patients. Serum glucose level >140 mg/dL at the time of admission was accepted as stress hyperglycaemia. RESULTS: The average age of patients was 81 ± 7.1 years. Stress hyperglycaemia was diagnosed in 34.6% of the cases; the majority of these cases were patients with high-serum urea, CRP, and chronic kidney disease. The average levels of MMP-9 and MMP-10 were found to be 199 ± 38 and 16.5 ± 7.5 ng/mL, respectively. Thirty-one cases (30.6%) mortality during hospitalization and 20 cases (20%) underwent emergency RRT. Multiregression analysis showed the serum urea (P < .001) and stress hyperglycaemia (P = .03) to be independently associated with mortality. Also, serum urea (P = .01), potassium level (P = .03), and MMP-10 levels (P = .03) were independently associated with the necessity of the emergency RRT. The MMP-9 levels exhibited no relation with the necessity of emergency RRT and mortality. CONCLUSION: Stress hyperglycaemia is a common condition among nondiabetic geriatric patients with AKI and is related to mortality. Serum MMP-10 levels serve as an important predictor of the necessity of emergency RRT in these patients.

A multicenter experience of thrombotic microangiopathies in Turkey: The Turkish Hematology Research and Education Group (ThREG)-TMA01 study.

Thrombotic microangiopathies (TMAs) are rare, but life-threatening disorders characterized by microangiopathic hemolytic anemia and thrombocytopenia (MAHAT) associated with multiorgan dysfunction as a result of microvascular thrombosis and tissue ischemia. The differentiation of the etiology is of utmost importance as the pathophysiological basis will dictate the choice of appropriate treatment. We retrospectively evaluated 154 (99 females and 55 males) patients who received therapeutic plasma exchange (TPE) due to a presumptive diagnosis of TMA, who had serum ADAMTS13 activity/anti-ADAMTS13 antibody analysis at the time of hospital admission. The median age of the study cohort was 36 (14-84). 67 (43.5%), 32 (20.8%), 27 (17.5%) and 28 (18.2%) patients were diagnosed as thrombotic thrombocytopenic purpura (TTP), infection/complement-associated hemolytic uremic syndrome (IA/CA-HUS), secondary TMA and TMA-not otherwise specified (TMA-NOS), respectively. Patients received a median of 18 (1-75) plasma volume exchanges for 14 (153) days. 81 (52.6%) patients received concomitant steroid therapy with TPE. Treatment responses could be evaluated in 137 patients. 90 patients (65.7%) achieved clinical remission following TPE, while 47 (34.3%) patients had non-responsive disease. 25 (18.2%) non-responsive patients died during follow-up. Our study present real-life data on the distribution and follow-up of patients with TMAs who were referred to therapeutic apheresis centers for the application of TPE.

Heart Rate Recovery as a Novel Test for Predicting Cardiac Involvement in Beta-Thalassemia Major.

BACKGROUND: Abnormal heart rate recovery (HRR) is predictive of cardiac mortality. Autonomic abnormalities in beta-thalassemia major (TM) patients have been reported in previous studies. However, the importance of low HRR in exercise stress test in TM patients has not yet been ascertained. Therefore, this study will be the first of its kind in the literature. METHODS: Exercise stress test was performed on 56 TM patients who were being treated at the Thalassemia Center of our hospital, along with 46 non-TM iron deficiency anemia (IDA) patients as a control group. Values for HHR were recorded at 1, 2, 3, 4 and 5 min, and HRR was calculated by the difference of heart rate at peak exercise and at a specific time interval following the onset of recovery. RESULTS: All HRR values were found to be lower in TM patients compared to those in the IDA group. Exercise capacity [metabolic equivalents (METs)] was also found to be low in these patients (p < 0.001) as well. Total exercise time was significantly lower in the TM group compared to the IDA group (8.40 ± 1.7 min vs. 11.17 ± 1.51 min, p < 0.001). Exercise capacity (METs) was also lower in the TM group compared to the IDA group. Mean T2* value was 28.3 ± 13.7 ms in TM patients on magnetic resonance imaging (MRI). In addition, there are 18 TM patients with T2* value was < 20 ms. CONCLUSIONS: This study found that TM was independently associated with low HRR. Such a condition is an indicator of autonomic dysfunction in TM patients, since abnormal HRR is related to impaired autonomic response. In addition, impaired HRR may be a marker of early cardiac involvement in patients, whose T2* value is high on MRI. Modifying HRR with a cardiac rehabilitation program in TM patients with impaired HRR is a field open for further investigation.

ß-Thalassemia gene mutations in Antalya, Turkey: results from a single centre study.

ß-Thalassemia (ß-thal) is a common autosomal recessive disorder resulting from over 300 different mutations of the ß-globin genes. Our aim was to create a mutation map of ß-thal in the province of Antalya, Turkey. In this study, mutation analysis of a total 146 of ß-thal patients followed at the Thalassemia Center of the Antalya Education and Research Hospital, Antalya, Turkey, were included. Direct DNA sequence analysis was performed for mutation scanning of the ß-globin gene. One hundred and forty-six patients with ß-thal including all types were analyzed, and 14 different ß-thal mutations were detected. The most frequently seen mutation was HBB: c.93 - 21G > A [IVS-I-110 (G > A)] (52.7%), followed by HBB: .c.92 + 6T > C [IVS-I-6 (T > C)] (14.4%), HBB: c.-80T > A [-30 (T > A)] (8.2%), HBB: c.315 + 1G > A [IVS-II-1 (G > A)] (8.2%), which made up 83.1% of the observed mutations. Our results indicate the importance of micromapping and epidemiology studies of thalassemia, which will assist in establishing the national prevention and control program in Turkey.

The Association between Serum Ferritin Level, Tissue Doppler Echocardiography, Cardiac T2* MRI, and Heart Rate Recovery in Patients with Beta Thalassemia Major.

BACKGROUND: It is generally well-understood that iron-mediated cardiomyopathy is the major complication that can arise from beta thalassemia major (TM). Therefore, early diagnosis, risk stratification, and the effective treatment of beta TM patients are clinically important to optimize long-term positive outcomes. METHODS: This study included 57 beta TM patients with a mean age of 25 ± 7 years. We determined the serum ferritin level, echocardiography, heart rate recovery (HRR), and cardiac magnetic resonance (CMR) T2* in all patients. CMR T2* findings were categorized as normal myocardium (T2* > 20 ms), and myocardial involvement (T2* ≤ 20 ms). HRR values at 1-5 min (HRR1-5) were recorded; Subsequently. HRR was calculated by subtracting the heart rate at each time point from the heart rate at peak exercise. RESULTS: There was a significant negative correlation between the serum ferritin level and the cardiac T2* MRI findings (r = -0.34, p = 0.009). A similar result was found in the negative correlation between serum ferritin and all heart rate recovery values. There was a significant positive correlation between HRR1, HRR2, and HRR3 values, and CMR T2* (T2* heart rate recovery (HRR)1: r = 0.51, p < 0.001; T2* HRR2: r = 0.48, p < 0.001; T2* HRR3: r = 0.47, p < 0.001, respectively). CONCLUSIONS: The serum ferritin level and echocardiography can be used to predict the presence of myocardial iron load in beta TM patients. Therefore, HRR can be used to screen beta TM patients, and the clinical use of HRR can be a predictive marker for autonomic dysfunction in beta TM patients. KEY WORDS: Beta thalassemia major • Cardiac magnetic resonance T2* • Heart rate recovery • Iron overload • Serum ferritin level • Tissue Doppler imaging.

Evaluation of bone marrow findings in hemodialysis patients with erythropoietin-resistant anemia.

INTRODUCTION: Treatment with erythropoietin-stimulating agents (ESAs) is widely used in anemia of chronic kidney disease (CKD). Acquired ESA resistance is an important problem. The aim of this study is to examine the bone marrow findings in hemodialysis patients with ESA-resistant anemia. METHODS: The data of 210 patients with acquired ESA resistance were reviewed retrospectively. The patients were divided into groups according to having diagnosis of dysplasia and hematological disease, and survival analysis was performed. RESULTS: A total of 26 patients were included in the study. While dysplasia was present in 10 (38.5%) patients, five of them were diagnosed hematologically. When survival analysis was performed between those with and without a hematological diagnosis, a difference in survival was observed against the group with the diagnosis (24.4 vs. 72 months, p = 0.045). CONCLUSION: Unresponsiveness to ESA treatment in CKD patients or a decrease in one of the other cell lines along with hemoglobin, it would be appropriate to perform early bone marrow examination.

Real-life experience with plasmapheresis in newly diagnosed multiple myeloma accompanied by acute kidney injury.

OBJECTIVES: The aim of this study was to retrospectively evaluate the effect of plasmapheresis treatment concomitant with chemotherapy and the number of sessions on renal improvement and survival in patients with newly diagnosed multiple myeloma (MM) presenting with acute kidney injury (AKI). MATERIAL AND METHODS: Retrospective analysis was performed on 55 newly diagnosed MM patients who were presented with AKI to the Hematology Clinic of University of the Health Sciences Antalya Training and Research Hospital between 2013 and 2021. RESULTS: The study included 55 patients between 39 and 91 years of age and comprised 22 (40%) women and 33 (60%) men. Forty-eight (87.3%) patients were treated with plasmapheresis and chemotherapy. Based on the median number of plasmapheresis sessions, the patients were grouped as ≤ 3 and > 3. A significant difference was observed in both groups between the mean values of repeated measurements at the time of diagnosis, after completion of plasmapheresis treatment, and at 1 month of plasmapheresis, when statistics of differences were evaluated for urea, creatinine, estimated glomerular filtration rate (eGFR) (ml/min), total protein, albumin, and globulin (p < 0.05); however, there was no difference between these parameters and the number of plasmapheresis sessions. The 1.16 (0.56-2.38) fold higher risk of ex found in patients with ≤ 3 plasmapheresis sessions compared to those with > 3 was not statistically significant (p > 0.05). CONCLUSION: It was observed that plasmapheresis is beneficial in the short term for renal recovery in the treatment of MM with AKI and that > 3 plasmapheresis sessions have no superior effectiveness in renal improvement or survival.

Roles of ghrelin, hepcidin and HIF-2α in iron metabolism in iron deficiency anemia.

OBJECTIVES: This study investigates the roles of HIF-2α, hepcidin, and ghrelin in iron deficiency anemia (IDA), the most widespread nutritional disorder globally. MATERIAL AND METHODS: Fifty IDA patients (18-50 years, BMI 19-25) and 40 healthy volunteers were studied. Hemoglobin, ferritin, hepcidin, HIF-2α, and ghrelin levels were analyzed. RESULTS: IDA patients showed lower hemoglobin, ferritin, hepcidin, and ghrelin levels than the control group, but HIF-2α levels were similar. Positive correlations were observed in both groups between hepcidin and HIF-2α (p < 0.001), hepcidin and ghrelin (p < 0.001), and HIF-2α and ghrelin (p < 0.001). Hemoglobin was correlated positively with HIF-2α, and ferritin was correlated positively with HIF-2α in the patient group. CONCLUSION: The study suggests that the low hepcidin levels in IDA patients enhance iron absorption. The lack of significant HIF-2α level differences may be due to the absence of chronic hypoxia in current hemoglobin levels of IDA patients. Moreover, the low ghrelin levels in patients and the correlations between ghrelin, hepcidin, and HIF-2α in both groups indicate their involvement in iron metabolism.

Eltrombopag treatment in thrombocytopenia following hematopoietic stem cell transplantation: A multicenter real-world experience.

INTRODUCTION: Thrombocytopenia is among the most common complications following hematopoietic stem cell transplantation and is associated with increased mortality and morbidity with no standard treatment yet. In this multicenter and retrospective study, we aim to present our multi-center experience of Eltrombopag treatment in patients with isolated thrombocytopenia following HSCT. MATERIAL-METHOD: A total of 73 patients from 5 centers who underwent autologous or allogeneic stem cell transplantation, had no primary disease relapse, all of whom had neutrophil engraftment, complete chimerism, and who were diagnosed with Prolonged Isolated Thrombocytopenia (PIT) or Secondary Failure Of Platelet Recovery (SFPR) were included in the study. The patients were initiated on Eltrombopag at a dose of 50-150 mg. Complete response was defined as a platelet count >50×109/L for 7 consecutive days with no transfusion support. RESULTS: A total of 50.3% of the patients underwent Autologous and 49.7% Allogeneic Stem Cell Transplantation, 54.8% were diagnosed with PIT, and 45.2% were diagnosed with SFPR, and the treatment with 50-150 mg/day Eltrombopag was initiated on the median day +42. Complete response was achieved in 71.2% of these patients on the median day 23 of the treatment. No significant effects of the initial dose (50-150 mg/day) were detected in the Complete Response in the multivariate analysis on response. An insufficient number of Megakaryocytes in the bone marrow before Eltrombopag treatment was determined as an independent risk factor in determining the response (OR 3.57, 95% CI 1.21-10.55). The overall survival of the patients who did not respond to Eltrombopag was found to be significantly worse than that of patients who responded (p=0.022, HR:2.74, 95% CI 1.12-6.54). CONCLUSION: As a result of the present study, Eltrombopag treatment was found to be effective and safe in thrombocytopenia that develops following hematopoietic stem cell transplantation. It was concluded that its use may be more effective in patients with sufficient bone marrow megakaryocytes before the treatment and an initial dose of 50 mg/day may be appropriate in terms of cost, effectiveness, and toxicity. Large-scale randomized and controlled prospective studies are needed to determine the roles of Eltrombopag treatment in patients with post-transplant PIT and SFPR.