[Detection of anti-Ro(SS-A) by using immunoimprint. Comparison with double diffusion in agar. Apropos of a series of 63 primary Gougerot-Sjögren syndromes].

Among soluble anti-nuclear antigen auto-antibodies, anti-Ro(SS-A) were, for unknown reasons, difficult to detect by immunoimprint (II). The aim of this study was the development of a method of preparation of Ro(SS-A) antigen enabling greater sensitivity in the detection by II of the corresponding antibodies, then application of this method in a series of 63 cases of primary Sjögren's syndrome in order to study the clinical significance of anti-Ro(SS-A) antibodies. Ro(SS-A) antigen was prepared from human spleen and partially purified on DE-52 resin. The protein extract prepared reacted in II with reference anti-Ro(SS-A) and anti-La(SS-B) antibodies. The series of 63 cases of primary Sjögren's syndrome (57 F, 6M) included 50 of extraglandular primary Sjögren's syndrome and 13 of isolated glandular primary Sjögren's syndrome. Twenty two cases of primary Sjögren's syndrome had anti-Ro(SS-A) (35%). Twenty patients had anti-Ro(SS-A) by II (32%) and 17 by double diffusion in agar (27%) (p = NS). Among 7 discordant sera, 2 were not detected by II. The incidence of anti-Ro did not differ statistically between the extraglandular (40%) and glandular (15%) primary Sjögren's syndrome groups. Patients were divided into two groups according to whether they did (n = 22) or did not (n = 41) produce anti-Ro(SS-A).(ABSTRACT TRUNCATED AT 250 WORDS)