histokompatibiliteedist

Histokompatibiliteedist is a term used in transplantation medicine to describe the study and assessment of histocompatibility between donor and recipient. The aim is to minimize immune incompatibility that can trigger graft rejection, graft-versus-host disease, or poor graft function. The central element is the human leukocyte antigen (HLA) system, a set of genes within the major histocompatibility complex (MHC) on chromosome 6. Matching donor and recipient for key HLA loci (most importantly HLA-A, HLA-B, HLA-C and HLA-DR, with additional consideration of HLA-DQ and sometimes HLA-DP) improves graft survival in solid organ transplantation and reduces complications in hematopoietic stem cell transplantation. ABO compatibility is also relevant in many settings.

Histokompatibiliteedist relies on both serological and molecular approaches. Traditional serology used antibodies to detect HLA antigens, while modern typing relies on molecular methods including sequence-based typing (SBT), sequence-specific primer (SSP) or sequence-specific oligonucleotide (SSOP) methods, and increasingly next-generation sequencing (NGS). Crossmatching assesses whether recipient antibodies react with donor cells, with flow cytometry crossmatch and complement-dependent cytotoxicity crossmatch being common techniques. Panel reactive antibody (PRA) testing estimates preformed sensitization and influences donor selection. Virtual crossmatching combines donor HLA data with the recipient’s antibody profile to predict compatibility.

Clinically, high-resolution HLA matching is most critical for hematopoietic stem cell transplantation, while for solid organs the balance between waiting time and match quality shapes practice. Ongoing research seeks to refine matching algorithms and immunosuppressive strategies to improve outcomes.