Extended loci histocompatibility matching in HSCT-Going beyond classical HLA

Area of Science:

• Immunogenetics
• Hematology
• Transplantation immunology

Background:

• Unrelated hematopoietic stem cell transplantation (HSCT) is a curative option for hematologic malignancies.
• Advances in histocompatibility testing have improved HSCT protocols.
• Human Leukocyte Antigen (HLA) matching remains critical for donor selection in unrelated HSCT.

Purpose of the Study:

• To review the clinical evidence for the role of nonclassical HLA antigens (HLA-E, HLA-F, HLA-G) and HLA-like molecules (MICA, MICB) in unrelated HSCT.
• To explore potential immune system modulating factors beyond traditional HLA matching in HSCT.

Main Methods:

• Literature review of current clinical evidence.
• Analysis of studies investigating nonclassical HLA antigens and HLA-like molecules in HSCT.

Main Results:

• Nonclassical HLA antigens and HLA-like molecules are implicated as potential modulators of HSCT outcomes.
• These factors may contribute to HSCT-related complications despite optimal HLA matching.

Conclusions:

• Nonclassical HLA antigens and HLA-like molecules warrant further investigation in unrelated HSCT.
• Considering these additional immune factors may improve donor selection and patient outcomes in HSCT.