Prevalence of 60 kDa and 52 kDa Ro/SS-A Autoantibodies in Anti-Ro Positive Thai Sera in Siriraj Hospital
Ronnachai Viriyataveekul MD*, Saikhwun Srijumroon Cert MST*, Chaicharoen Tantanate MD*, Tanawan Kummalue MD*, Nisarat Opartkiattikul MD*
Affiliation : * Department of Clinical Pathology, Faculty of Medicine, Siriraj Hospital, Mahidol University
Background : Anti-Ro antibody may directly react against either Ro60 or Ro52 or both antigens. To be more
applicable for routine laboratory practice, the specific antigen type for antibody detection should be identi-
fied before test application.
Objective : Investigate the prevalence of 60 kDa and 52 kDa Ro/SS-A antibodies in Thai patients’ sera in
Siriraj Hospital.
Materials and Methods : Specimens for anti-Ro were requested between June and December 2005. They were
tested with EUROLINE test kit for prevalence determination. The principle of the test is a qualitative in-vitro-
assay that contains test strips coated with parallel lines of 14 highly purified antigens. Of 84 specimens
requested for anti-Ro antibody, 76 were collected and tested with the EUROLINE test kits and eight were
excluded due to inadequacy.
Results : The prevalence of anti-Ro60 and anti-Ro52 of all sera tested for anti-Ro by EUROLINE test kit were
30% (95%CI: 20-40%) and 26% (95%CI: 16-36%), respectively; and, those in anti-Ro positive Thai sera
were 82% (95%CI: 68-96%) and 71% (95%CI: 54-88%), respectively. The prevalence of anti-Ro52 alone in
anti-Ro positive Thai sera and all specimens requested for anti-Ro was about 18% (95%CI: 4-32%) and 7%
(95%CI: 1-13%), respectively. The agreement and Kappa value between the two methods were 0.9 and 0.77,
respectively. The study suggests that the test for anti-Ro detection should provide both Ro 60 and Ro 52
antigens.
Conclusion : The prevalence of both anti-Ro 60 and anti-Ro 52 were quite common, therefore, the test for this
specific antibody should provide both antigens for antibody detection.
Keywords : Prevalence, Anti-Ro, Anti-Ro 60, Anti-Ro 52
