Objective: Based on the immunophenotype, acute lymphoblastic leukemia (ALL) can be categorized into B-cell or T-cell lineages. B-cell precursor ALL (BCP-ALL) cases show various genetic/molecular abnormalities, and varying frequencies of chimeric fusion transcripts in BCP-ALL cases are reported from different parts of the world. We studied the immunophenotypic aberrancy profiles of a large number of BCP-ALL cases with respect to various common chimeric fusion transcripts.
Materials and Methods: Flow cytometric immunophenotyping and multiplex reverse-transcription polymerase chain reaction assays were performed for 986 BCP-ALL cases.
Results: Among 986 BCP-ALL cases, the incidence of various fusion transcripts was 38.36% in adult cases and 20.68% in pediatric cases. Adult BCP-ALL patients with t(9;22)(BCR-ABL1) fusion transcripts and expression of aberrant myeloid markers were significantly older at presentation (p=0.0218) with male preponderance (p=0.0246) compared to those without aberrant myeloid expression. In pediatric patients with the t(12;21)(ETV6-RUNX1) chimeric fusion transcript, aberrant expression of CD13 was observed in 39.13%, CD33 in 36.95%, and CD117 in 8.69% of patients, respectively. Pediatric BCPALL patients with the ETV6-RUNX1 fusion transcript and expression of aberrant myeloid markers were not significantly different compared to those without with respect to demographic and clinical/hematological characteristics (p=0.5955). Aberrant myeloid markers were rarely or never expressed in pediatric and adult BCP-ALL patients with the t(4;11)(KTM2A-AF4) and t(1;19)(TCF3-PBX1) fusion transcripts.
Conclusion: Aberrant myeloid markers were frequently expressed among BCP-ALL patients with the t(9;22)(BCR-ABL1) and t(12;21) (ETV6-RUNX1) fusion transcripts. However, BCP-ALL patients with the t(4;11)(KTM2A-AF4) and t(1;19)(TCF3-PBX1) fusion transcripts rarely or never expressed aberrant myeloid markers. Aberrant myeloid CD markers can be used in predicting chimeric fusion transcripts at baseline so as to plan appropriate tyrosine kinase inhibitor therapy in cases of BCP-ALL with specific chimeric fusion transcripts. This study has delineated the relationship of chimeric fusion transcripts with the aberrant expression of myeloid markers in a large cohort of BCP-ALL cases.

Objective: Philadelphia chromosome-negative myeloproliferative neoplasms (MPNs) have a high propensity for thrombosis, which has been attributed to increased blood counts, endothelial cell (EC) dysfunction, and inflammation. The presence of the JAK2V617F mutation in the ECs of MPN patients has been confirmed, but the consequences of EC involvement by JAK2V617F in the pathogenesis of thrombosis are unclear. Endothelial microparticles (EMPs) released from ECs play an important role in endothelial dysfunction and also in the intercellular exchange of biological signals and information. Several studies have revealed that patients with JAK2V617F and a thrombosis history have increased numbers of MPs in their circulation.
Materials and Methods: The current study utilized a lentiviral transduction model of JAK2 wild type (JAK2wt) or JAK2V617F encoding green fluorescent protein (GFP) into human umbilical vein ECs to determine the effect of JAK2V617F on ECs. EC infected with JAK2V617F, JAK2WT, and only-GFP were tested after two days of culture.
Results: The proteins of ECs that potentially play a role in the development of thrombosis, including endothelial protein C receptor, thrombomodulin, and tissue factor, were detected by flow cytometry analysis with no statistical significance. Increased annexin-V uptake of JAK2V617F and JAK2wt ECs compared to GFP-alone ECs was detected. The EMP production in the supernatants of the EC culture was investigated. Genotyping of the EMPs revealed the presence of genomic DNA and RNA fragments in EMP cargos. JAK2V617F-positive DNA was detected in EMPs released from JAK2V617F-infected ECs and EMPs were shown to carry the genotype of the cell of origin.
Conclusion: JAK2V617F-positive EMPs were shown for the first time in the literature. This novel research provides the first evidence that EMPs might regulate neighboring and distant cells via their cargo materials. Thus, the direct effect of JAK2V617F on ECs and their functions suggests that different mechanisms might play a role in the pathogenesis of thrombosis in MPNs.

Objective: Low glutamine levels have been shown in tumor environments for several cancer subtypes. Therefore, it has been suggested that cancer cells rewire their metabolism to adopt low nutrient levels for survival and proliferation. Although glutamine is a non-essential amino acid and can be synthesized de novo, many cancer cells including malignant hematopoietic cells have been indicated to be addicted to glutamine. This study aimed to investigate the proliferation of leukemia cell lines in glutamine-deprived conditions.
Materials and Methods: Cell proliferation of K562, NB-4, and HL-60 cells was determined by calculating cell numbers in normal vs. low glutamine media. Changes in mRNA expressions were investigated using qRT-PCR. The glutamine synthetase (GS)-encoding GLUL gene was knocked out (KO) in HL-60 cells using the CRISPR/Cas9 method and protein expression was evaluated with immunoblotting.
Results: The proliferation of all cell lines was decreased in glutaminedeprived medium. GS protein expression was increased in glutaminelimited medium although the mRNA level did not change. Increased protein expression was confirmed with inhibition of new protein synthesis by treating cells with cycloheximide. To further investigate the role of GS protein, the GS-encoding GLUL gene was KO in HL-60 cells using the CRISPR/Cas9 method. GS KO cells proliferated less compared to control cells in glutamine-limited medium.
Conclusion: Our results indicate that upregulated GS protein expression is responsible for glutamine addiction of leukemia cell lines. Exploiting the genetic and metabolic mechanisms responsible for GS protein expression could lead to the identification of new anticancer drug targets.

Objective: The present study investigated immune disorders and chemokine C receptor 7 (CCR7) expression in primary immune thrombocytopenia (ITP) patients and analyzed their changes and clinical significance before and after treatments.
Materials and Methods: Flow cytometry was used to detect the proportion of different immune cell subsets in the peripheral blood of 42 patients with ITP and 20 healthy controls at different time points. Treatments included first-line drugs, such as glucocorticoids and intravenous immunoglobulin, and second-line therapy, such as interleukin-11 and thrombopoietin receptor agonists.
Results: An elevated CD4/CD8 ratio and decreased natural killer (NK) cells and CD4+CD25+CD127low regulatory T-cells (Tregs) were found in pretreatment ITP patients compared to healthy controls. The newly diagnosed group had a higher CD4/CD8 ratio and more NK cells than the relapsed group. Treg levels of the remission group were higher than those of the recurrence group. The CD4+CCR7+, CD8+CCR7+, and CCR7+ subsets of B cells and NK cells showed higher increases in the newly diagnosed and relapsed group compared to controls and the remission group. The values for the CD4+CCR7+ and CD8+CCR7+ subsets in the relapsed group were slightly higher than those in the newly diagnosed group. The CCR7+ subsets of CD4+ T-cells, CD8+ T-cells, NK cells, and B cells had lower values in the remission group compared to the relapsed group. Higher levels of the CD8+CCR7+ subset and lower levels of NK cells were found in the remission group compared to the controls. The ratio between the CD4+CCR7+ subset and CD8+CCR7+ subset was lower in ITP patients than in healthy controls. There was a negative correlation between the CD8+CCR7+ subset and platelet count in the ITP patients.
Conclusion: ITP patients with CCR7 had immune disorders and high heterogeneity, and CCR7 was found to be involved in the pathogenesis of ITP. Further studies are needed to investigate effective treatments for ITP by targeted regulation of CCR7.

Objective: Eltrombopag remains a prominent option in the treatment of steroid-dependent or steroid-refractory immune thrombocytopenia (ITP) patients. Unfortunately, not all patients respond to eltrombopag. Antinuclear antibody (ANA) positivity can be seen at rates of up to 30% in ITP patients. Despite being widely used, more markers to predict the response to eltrombopag are still needed. In the present study, we aimed to show the association between ANA positivity and eltrombopag response in ITP patients.
Materials and Methods: Patients who were diagnosed with ITP in the Trakya University Faculty of Medicine’s Department of Hematology and who underwent eltrombopag treatment due to their resistance to steroids and other treatments were included in our study. ANA measurement was performed by indirect fluorescent antibody method and titers of 1: 160 and above were considered positive. ANA measurements were made before starting eltrombopag.
Results: Forty-five patients were included in our study, 33 being women and 12 men. The mean age of the patients was 45.73 years. There were 14 patients with ANA positivity and 31 patients were found to be ANA-negative. Response rates were higher in ANA-negative patients compared to ANA-positive patients in the 1st and 6th months of eltrombopag treatment (p<0.05).
Conclusion: ANA positivity in ITP may indicate unresponsiveness to eltrombopag treatment, a finding that should be further supported by prospective studies involving more patients.

Objective: Patients with solid malignancies are more vulnerable to severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection than the healthy population. The outcome of SARS-CoV-2 infection in highly immunosuppressed populations, such as in patients with hematological malignancies, is a point of interest. We aimed to analyze the symptoms, complications, intensive care unit admissions, and mortality rates of patients with hematological malignancies infected with SARS-CoV-2 in Turkey.
Materials and Methods: In this multicenter study, we included 340 adult and pediatric patients diagnosed with SARS-CoV-2 from March to November 2020. Diagnosis and status of primary disease, treatment schedules for hematological malignancies, time from last treatment, life expectancy related to the hematological disease, and comorbidities were recorded, together with data regarding symptoms, treatment, and outcome of SARS-CoV-2 infection.
Results: Forty four patients were asymptomatic at diagnosis of SARSCoV- 2 infection. Among symptomatic patients, fever, cough, and dyspnea were observed in 62.6%, 48.8%, and 41.8%, respectively. Sixtynine (20%) patients had mild SARS-CoV-2 disease, whereas moderate, severe, and critical disease was reported in 101 (29%), 71 (20%), and 55 (16%) patients, respectively. Of the entire cohort, 251 (73.8%) patients were hospitalized for SARS-CoV-2. Mortality related to SARS-CoV-2 infection was 26.5% in the entire cohort; this comprised 4.4% of those patients with mild disease, 12.4% of those with moderate disease, and 83% of those with severe or critical disease. Active hematological disease, lower life expectancy related to primary hematological disease, neutropenia at diagnosis of SARS-CoV-2, ICU admission, and first-line therapy used for coronavirus disease-2019 treatment were found to be related to higher mortality rates. Treatments with hydroxychloroquine alone or in combination with azithromycin were associated with a higher rate of mortality in comparison to favipiravir use.
Conclusion: Patients with hematological malignancy infected with SARS-CoV-2 have an increased risk of severe disease and mortality.

Hematologists often encounter transfusion problems, one of which is crossmatch incompatibility. In many countries, transfusion medicine is not a recognized specialty, there are no reference immunohematology laboratories, and most blood banks can only perform “type and screen” and crossmatch analyses. Therefore, hematologists should have basic knowledge about blood banking procedures and how to use them. This review aims to provide hematologists who do not have access to advanced blood bank laboratories some practical tips for handling problems in pretransfusion testing.

Objective: Angiogenic factors (AFs) released under endothelial stress are reflective of tissue healing, while some may also contribute to tissue damage/inflammation. We investigated whether alterations in the pre-transplant levels of AFs were associated with the risk of acute graft-versus-host disease (aGvHD).
Materials and Methods: The pre-conditioning plasma levels of angiopoietin-2 (Ang2), endoglin, and follistatin were measured for 37 patients together with inflammatory markers. The index values defined were evaluated to better identify the alterations.
Results: The patients had higher pre-conditioning levels of Ang2, endoglin, and follistatin compared to controls. The patients with aGvHD had higher Ang2 index and lower albumin index scores in comparison to those without aGvHD. Multivariate analysis revealed that the pre-transplant Ang2 index was an independent risk factor for aGvHD development.
Conclusion: Pre-transplant evaluation of plasma Ang2 levels along with inflammatory status even before conditioning is associated with endothelial vulnerability. The pre-transplant Ang2 index could be a promising candidate to estimate the risk of aGvHD.