The SARS-CoV-2 spike protein mRNA-based vaccines have prevented countless mortality and morbidity, and have an excellent risk/benefit ratio. However, various adverse events may rarely occur after the BNT162b2 vaccine, like any other medical intervention. The COVID-19 itself and the spike protein produced endogenously by mRNA vaccines may have immunological, microenvironmental, prothrombotic, and neoplastic effects. As a contribution to the published report, we would like to share our experience regarding four cases in which myeloid neoplasms emerged following the vaccination. Conclusions: There is no doubt that vaccination could continue along the lines of established universal recommendations. Meanwhile, all hematological adverse events must be closely monitored and reported. Further efforts should be focused on the probable pathobiological mechanisms and causalities of spike protein-related toxicity and clonal myeloid disorders.

The disease caused by SARS-CoV-2 was named as COVID-19. There is as yet insufficient information about the effects of HSCT on the clinical course of COVID-19. In the present study, we aimed to investigate the clinical course of COVID-19 in patients who had undergone HSCT. We analyzed baseline characteristics, clinical course and findings of COVID-19, hospitalization and death rates, overall survival and case fatality rates of HSCT recipients diagnosed with COVID-19 retrospectively. 57.6% of the patients underwent AHSCT, and 42.4% underwent allo-HSCT. 60.6%, 27.3%, and 12.1% of the patients had mild, moderate and severe COVID-19 or critical illness, respectively. 45.5% were hospitalized, and 12.1% required intensive care. 9.1% necessitated invasive mechanical ventilation. The total CFR was 9.1% in HSCT recipients, 22.2% in patients with active hematologic malignancy and 4.2% in patients without active hematologic malignancy. It can be concluded that mortality of HSCT recipients is lower in patients whose primary disease is in remission compared to ones that are not in remission. Further studies with larger group patients are needed in order to delineate the effects of COVID-19 on HSCT patients.

To evaluate the incidence, clinical features, risk factors, and prognosis of central nervous system (CNS) involvement in patients with acute myeloid leukemia (AML). All AML patients who were admitted to Hacettepe University hospital between 2000 and 2021 were evaluated. The medical records of 548 AML cases were retrospectively analyzed. The frequency of CNS involvement was 2.4% (n=13) at diagnosis and 4.6% (n= 25) at diagnosis or during follow-up. Parenchymal involvement was seen in 5 patients, leptomeningeal involvement was seen in 11 patients. Three patients had both leptomeningeal and parenchymal involvements and 6 patients had optic nerve or ocular involvement. In univariate analysis; younger age and extramedullary involvement at diagnosis were associated with CNS disease at diagnosis and extramedullary involvement at diagnosis was associated with CNS disease during follow-up. In multivariate analysis; younger age and extramedullary involvement at diagnosis were associated with CNS disease at diagnosis and during follow-up respectively. Median overall survival was 5.4 months in patients with CNS disease at diagnosis and 16.9 months in patients with CNS disease during follow-up and 16.2 months in patients with no CNS disease. CNS disease is a rare complication of AML. Younger age and extramedullary involvement at diagnosis are risk factors for CNS involvement.

Background/aim: Thrombocytopenia is a common complication following hematopoietic stem cell transplantation (HSCT). Eltrombopag has been used in thrombocytopenia treatment after HSCT in recent years. Herein, we present our experience of 25 patients treated with eltrombopag for post-HSCT thrombocytopenia. Materials and methods: Fifteen autologous hematopoietic stem cell transplantation (AHSCT) and 10 allogenic hematopoietic stem cell transplantation (allo-HSCT) recipients treated with eltrombopag for treatment of prolonged isolated thrombocytopenia (PIT) or secondary failure of platelet recovery (SFPR) in the stem cell transplantation unit of Hacettepe University Hematology Department between 2017 and 2021 were included in the study. The primary endpoint of this study is eltrombopag response in patients diagnosed with PIT or SFPR. Platelet count above 50,000/mm3 for five consecutive days without platelet transfusion was considered as eltrombopag response. Overall survival (OS) analyses were calculated based on the time between HSCT and death from any cause. The patients who were alive at the last follow-up were censored at this time for calculation of OS analyses. Results: AHSCT (66.7% (10/15)) and allo-HSCT (50% (5/10)) recipients responded to eltrombopag for the treatment of post-HSCT thrombocytopenia. There was no excess toxicity related to the eltrombopag use. The median response duration of allo-HSCT recipients and AHSCT recipients were 41 (13-104) days and 50 (7-342) days, respectively. There was a statistically significant OS duration difference between the responders and nonresponders in allo-HSCT and AHSCT recipients with p values of 0.005 and 0.02, respectively. Conclusion: Eltrombopag is promising for the treatment of thrombocytopenia after AHSCT and allo-HSCT in terms of efficacy and safety