Soluble HLA antigens and ELISA--a new technology for crossmatch testing

Area of Science:

• Immunology
• Transplantation Immunology
• Clinical Chemistry

Background:

• Detection of donor-specific anti-HLA antibodies is crucial for successful kidney transplantation.
• Microlymphocytotoxicity assays are the standard but can have limitations in reproducibility and sensitivity.
• Development of alternative, more reliable methods is needed to improve transplant outcomes.

Purpose of the Study:

• To develop and validate a soluble HLA ELISA for detecting donor-specific anti-HLA class I IgG antibodies.
• To compare the performance of the developed ELISA with standard microlymphocytotoxicity testing.
• To assess the interlaboratory reproducibility and sensitivity of the ELISA method.

Main Methods:

• A soluble HLA ELISA was developed using monoclonal antibody-coated plates to capture donor HLA.
• Serum samples from kidney transplant candidates were tested using both ELISA and microlymphocytotoxicity (AHG protocol).
• Interlaboratory reproducibility and sensitivity were evaluated across four different laboratories.

Main Results:

• The ELISA demonstrated high concordance (99%) with microlymphocytotoxicity crossmatch results.
• Interlaboratory reproducibility for ELISA was significantly higher (99%) compared to microlymphocytotoxicity (78%).
• ELISA showed equivalent sensitivity to AHG lymphocytotoxicity and similar sensitivity to flow cytometry crossmatch.

Conclusions:

• The developed soluble HLA ELISA is a reliable and reproducible method for detecting donor-specific anti-HLA class I IgG antibodies.
• ELISA offers a valuable alternative to microlymphocytotoxicity testing, potentially improving pre-transplant crossmatching accuracy.
• This advancement could contribute to better patient selection and reduced risk of antibody-mediated rejection in kidney transplantation.