Significance Our analysis shows that sex can be associated with the degree to which HLA molecules propagate selection and expansion of T cells as characterized by their T cell receptor variable beta chain (TCRBV). Furthermore, CD8 T cells, especially in men with autoimmune diseases such as multiple sclerosis or rheumatoid arthritis, are capable of expanding in unison with other CD8 T cells, even without expressing TCRBVs with biochemical similarity in pivotal HLA-binding regions. Our findings add to the understanding of sex bias in diseases with immune system involvement: autoimmunity, infection, and cancer. These results also reveal pathology-associated TCRBVs of interest for future studies and support the argument for sex-separated analysis of HLA disease associations in general.