Elevated Allele Frequency and Male-Predominance of a Common LAG3 Germline Variant in Multiple Myeloma

The incidence of multiple myeloma is higher in males. The underlying mechanisms may be related to differences in immune system orchestration in males and females. LAG3 and CTLA4 are immune checkpoint proteins and inhibitory regulators of T cells. Here, we analyzed the prevalence of the common <i>LAG3</i> gene variant rs870849 and the common <i>CTLA4</i> gene variant rs231775 in myeloma patients eligible for autologous stem cell transplantation. <i>CTLA4</i> rs231775 was prevalent at normal allele frequencies. In contrast, <i>LAG3</i> rs870849 was prevalent at elevated allele frequencies in myeloma patients, with allele frequency 0.61 in male and 0.53 in female patients compared to 0.39 in the European population. The gene risk analysis of rs870849 indicated an odds ratio 6.8 in male and 3.6 in female patients. Moreover, treatment outcomes differed in the three genetic <i>LAG3</i> subgroups with median progression-free survival of 2.6, 3.3 and 3.4 and median overall survival of 7, 15 and 18 years in the I455hom, I455Thet and T455hom subgroups, respectively. <i>LAG3</i> rs870849 may affect survival and treatment outcome after autologous stem cell transplantation in myeloma patients with favorable outcomes in rs870849 carriers.