False positive and false negative reactions in HLA B-27 antigen testing.
The recent commercial availability of HLA B-27 antiserum now enables laboratories without prior experience in HLA typing to test for this antigen. False positive and false negative reactions frequently occur and require judicious interpretation. In our laboratory, 30 of 100 specimens were positive for B-27 and 70 were negative. Of the 30 positive, 10 (33%) failed to react against every antiserum tested. Twenty-nine of the 70 negative specimens (41%) reacted falsely with one or more B-27 antisera. A significant cause of false positive reactions was cross-reaction of the B-7 antigen with B-27 antisera (13 of 15 B-7 positive, B-27 negative specimens). For valid B-27 testing, use of more than one B-27 antiserum is included.
D005188:False Negative Reactions; D005189:False Positive Reactions; D006649:Histocompatibility Antigens; D006801:Humans
D006649:Histocompatibility Antigens