Frequency of Hematologic and Solid Malignancies in the Family History of Patients with Myeloid Neoplasms

Background: Studies demonstrated that there are several germline mutations that lead to a familial predisposition for acute myeloid leukemia and Myelodysplastic syndrome. According to the American Society of Clinical Oncology, the minimum cancer family history was defined as including first- and second-degree family history, type of primary cancer, and age at diagnosis. The current study aimed to estimate the frequency of positive family history for hematologic and solid malignancies in patients with Myeloid Neoplasms / Aplastic anemia. Patients and Methods: A cross-section study was carried out at the Center of Blood Diseases, Medical City Campus during the period from March-December 2020. A purposeful sample of all adult patients with Myeloid Neoplasms [Acute Myeloid Leukemia, Myelodysplastic Syndrome, Chronic Myeloid Leukemia, and Aplastic Anemia] was included in the study. A data collection form was prepared, based on the Hereditary Hematopoietic Malignancies Screening form adopted by the University of Chicago, and modified by the researchers; The data were collected by direct interview with the patients. Patients with hematologic malignancy and one or more first-degree relatives, or ≥2 second-degree relatives, with hematologic malignancies and individuals with Myelodysplastic Syndrome or Acute Myeloid Leukemia and two first or second-degree relatives with a diagnosis of solid tumor malignancy, were considered potential carriers of such genetic predisposition. Results: A total of 153 patients were included; males were nearly equal to females with a male to female ratio of nearly 1:1. Acute Myeloid Leukemia was found in 57.5%, Aplastic Anemia was found in 19%, Chronic Myeloid Leukemia in 17% and only four patients (6.5%) were known cases of Myelodysplastic Syndrome. Nine patients (5.9%) reported a family history of hematological malignancies, 29 (19.0%) reported a family history of solid malignancies and only one patient reported a family history of both hematological and solid malignancies. Regarding the official medical reports of the patients, no patient had been interviewed properly about this crucial point. Conclusion: Positive family history for hematological and solid malignancies in Iraqi patients with myeloid neoplasms is prevalent. Our current approach to this critical issue in Iraq needs to be re-considered.

Multi-Omics Profiling Identifies Pathways Associated With CD8+ T-Cell Activation in Severe Aplastic Anemia

Severe aplastic anemia (SAA) is an autoimmune disease characterized by immune-mediated destruction of hematopoietic stem and progenitor cells. Autoreactive CD8+ T cells have been reported as the effector cells; however, the mechanisms regulating their cell activation in SAA remain largely unknown. Here, we performed proteomics and metabolomics analyses of plasma and bone marrow supernatant, together with transcriptional analysis of CD8+ T cells from SAA patients and healthy donors, to find key pathways that are involved in pathogenic CD8+ T-cell activation. We identified 21 differential proteins and 50 differential metabolites in SAA patients that were mainly involved in energy metabolism, complement and coagulation cascades, and HIF-1α signaling pathways. Interestingly, we found that these pathways are also enriched in T cells from SAA patients by analyzing available single-cell RNA sequencing data. Moreover, CD8+ T cells from SAA patients contain a highly activated CD38+ subset, which was increased in the bone marrow of SAA patients and a murine model of SAA. This subset presented enriched genes associated with the glycolysis or gluconeogenesis pathway, HIF-1α signaling pathway, and complement associated pathways, all of which were of importance in T-cell activation. In conclusion, our study reveals new pathways that may regulate CD8+ T-cell activation in SAA patients and provides potential therapeutic targets for SAA treatment.

Single-Cell RNA-Seq of Bone Marrow Cells in Aplastic Anemia

Aplastic anemia (AA) is an autoimmune disease characterized by peripheral blood pancytopenia and bone marrow failure. Recently, a research study verified bone marrow failure of AA patients resulting from hematopoietic stem and progenitor cell (HSPC) attack by active T cells. Nonetheless, whether B cells, as one of the important immune cells, destruct the hematopoiesis is still unclear. Here, a large-scale single-cell transcriptomic sequencing of 20,000 bone marrow cells from AA patients and healthy donors was performed. A total of 17 clusters and differentially expressed genes were identified in each cluster relative to other clusters, which were considered potential marker genes in each cluster. The top differentially expressed genes in HSPCs (S100A8, RETN, and TNFAIP3), monocytes (CXCL8, JUN, and IL1B), and neutrophils and granulocytes (CXCL8, NFKBIA, and MT-CYB) were related to immune and inflammatory injury. Then, the B-cell receptor (BCR) diversities and pairing frequencies of V and J genes were analyzed. The highest pairing frequencies in AA patients were IGHV3-20-IGKJ2, IGHV3-20-IGKJ4, and IGHV3-20-IGHLJ2. Meanwhile, there were 3 V genes, including IGHV3-7, IGHV3-33, and IGLV2-11, with elevated expression in B cells from AA patients. Cell type–specific ligand–receptor was further identified in B-cell interaction with hematopoietic cells in the bone marrow. The changed ligand–receptor pairs involved antigen presentation, inflammation, apoptosis, and proliferation of B cells. These data showed the transcriptomic landscape of hematopoiesis in AA at single-cell resolution, providing new insights into hematopoiesis failure related with aberrance of B cells, and provide available targets of treatment for AA.