[HLA-DR typing by standard serology and PCR-amplification with sequence-specific primers: a comparative study]

DNA typing for HLA-DR by polymerase chain reaction with sequence-specific primers (PCR-SSP) compared with standard serology to evaluate the reliability and clinical practicability.

Double-blind typing for HLA-DR alleles was carried out using DNA typing by PCR-SSP and standard serology by microlymphocytotoxicity technique in 61 donors and 101 recipients of cadaveric transplantation. Matching time, sensitivity, specificity and clinical practicability were compared according to typing results by both methods.

All 162 samples were able to be typed by PCR-SSP. A total of 308 alleles were detected (16 DR "blank"). The results of matching were confirmed by analysis with restriction endonucleases and Southern hybridization. The specificity and reproducibility were 100%. HLA-DR typing was performed in 5 hours by PCR-SSP or 20 hours by serology. The discrepancy rate between PCR-SSP and serological HLA-DR typing was 30.2% (35.6% for kidney recipients, 21.3% for donors). The discrepancies consisted of 8 loci being doubtful, 29 antigens being incorrectly interpreted by serology and 20 of serological "blanks" turning out to be definable alleles by the DNA method.

Genotyping for HLA-DR by PCR-SSP offers the advantages of better reagent and sample availability, more rapid and greater accuracy, all of which would warrant that this approach was suitable for clinical practice in organ transplantation.