Evaluation of a Korean HLA-B27 typing tray

Park, Pil Whan; Kim, Think You; Hwang, Se Jin

Abstract

BACKGROUND
Routine typing for HLA-B27 has been usually accomplished by the microcytotoxicity assay in Korea because it does not require special equipment and is easily reproducible. Recently, an immunofluorescence method and the polymerase chain reaction have also been applied for HLA-B27 testing. However, the current economic crisis in Korea have led domestic manufacturers to develop a Korean HLA-B27 typing kit. The aim of this study was to assess the advantages and disadvantages of this kit and to assess the possibility of replacing the currently used foreign-made kits with this domestic one.
METHODS
HLA-B27 testing by the microcytotoxicity test was performed on 116 patients during a period of 3 months in 1998. The Biotest typing tray and the Chongkundang typing tray were tested simultaneously.
Results
There was no difference in results in 116 samples (positive: 39, negative: 77). The Korean typing tray showed high false positivity of the negative control well (8 point: 1 case, 6 point: 33 cases, 4 point: 47 cases, 2 point: 17 cases, 1 point: 18 cases) and 6 of the HLA-B27 negative cases showed false positivity in one of the four HLA-B27 wells. Typing of HLA-Bw4 and Bw6 revealed an inconsistency in five and six cases, respectively.
CONCLUSIONS
Despite of the false positivity of the negative control in Korean panel, we believe that Korean typing tray can replace the foreign-made tray due to its low cost and adequate performance. Because placenta of Korean multiparous women was used for the kit, Chongkundang typing tray seems to correlate better with Korean HLA-B27 subtypes.