SelfHLA

SelfHLA refers to the set of human leukocyte antigen alleles that an individual expresses as part of their own immune system. The term is used in immunogenetics and transplantation to distinguish a person’s inherited HLA repertoire from donor or foreign HLA.

The HLA system includes class I molecules (HLA-A, -B, -C) that present endogenous peptides to CD8+ T cells, and class II molecules (HLA-DR, -DQ, -DP) that present exogenous peptides to CD4+ T cells. Each person inherits a pair of HLA haplotypes from their parents, forming a unique selfHLA profile. HLA expression is widespread on nucleated cells for class I, while class II is typically restricted to antigen-presenting cells but can be induced in other cells during inflammation.

SelfHLA alleles influence immune recognition and tolerance. In normal immunity, self-derived peptides bound to selfHLA contribute to central and peripheral tolerance, helping to eliminate or regulate self-reactive T cells. Disruptions in selfHLA presentation can contribute to autoimmunity, where the immune system misidentifies self as foreign.

In transplantation, knowledge of an individual’s selfHLA is critical for matching with donors. Mismatches between donor and recipient HLA alleles can provoke alloimmune responses, increasing the risk of graft rejection in solid organ transplantation or graft-versus-host disease in hematopoietic stem cell transplantation. High-resolution typing of selfHLA improves compatibility assessment and outcomes.

Certain selfHLA alleles or haplotypes associate with disease susceptibility or protection, informing risk assessment and research. Examples include associations between specific HLA variants and autoimmune diseases.

HLA typing uses serology and molecular methods such as PCR-based typing and sequencing to determine an individual’s selfHLA profile. This information is central to transplantation, allergy and infection research, and personalized medicine.