Elevated Allele Frequency of a Common Germline LAG3 Variant Associated with Anemia, Thrombocytopenia and Peripheral Blast Percentage in Acute Myeloid Leukemia

Background: Lymphocyte-activation gene 3 (LAG3) and cytotoxic T-lymphocyte-associated protein 4 (CTLA4) are immune checkpoint receptors and inhibitory regulators of T-cells. Methods: Here, we analyzed the prevalence and potential impact of the LAG3 gene variant rs870849 and the CTLA4 gene variant rs231775 in AML patients eligible for autologous stem cell transplantation. Results: While CTLA4 rs231775 was prevalent at reduced minor allele frequencies (MAF 0.33), LAG3 rs870849 was prevalent at elevated minor allele frequencies (MAF 0.58) in AML patients, compared to the allele frequencies in the European population (MAF 0.37 and MAF 0.39). The gene risk analysis indicated a dose-dependent risk of AML disease associated with LAG3 rs870849, but no risk associated with CTLA4 rs231775. Baseline blood count profiles differed across LAG3 genotypes, suggesting a link between LAG3 rs870849 and disease-associated levels of anemia, thrombocytopenia and peripheral blast percentage. Conslusions: The germline LAG3 variant rs870849 may be associated with AML disease risk and specific hematological disease features.