Two sisters producing anti-U1RNP exhibit serological concordance and clinical discordance.
Two sisters had autoimmune responses to the U1RNP particle that were quantitatively similar and/or identical in molecular characteristics. No other autoantibodies were demonstrable. Both sisters immunoprecipitated only U1RNA, had a reaction of identity in gel diffusion, bound the 68-kDa band in HeLa cell extract in Western blot, and reacted almost equally to a rabbit anti-idiotypic reagent made against either sister's isolated anti-U1RNP Fab fragments. They both carried a DR4 allele, which has been associated with anti-U1RNP production in several studies. While the sisters both had Raynaud's phenomenon, their clinical pictures were otherwise dissimilar. One had a seizure disorder (Ju); the other had polymyositis and features of scleroderma (Je). In sister Ju, Raynaud's phenomenon was manifest for the first time in association with the appearance of precipitating anti-U1RNP.
Reichlin
M
M
Department of Medicine, Oklahoma University Health Sciences Center, Oklahoma Medical Research Foundation, Oklahoma City 73104.
Abumohor
P
P
Itoh
Y
Y
D000328:Adult; D000974:Antibodies, Antinuclear / Q000097:blood*; D001324:Autoantigens; D005260:Female; D015804:HLA-DR4 Antigen / Q000235:genetics; D006801:Humans; D008947:Mixed Connective Tissue Disease / Q000150:complications / Q000235:genetics / Q000276:immunology; D017285:Polymyositis / Q000150:complications / Q000235:genetics / Q000276:immunology; D011928:Raynaud Disease / Q000150:complications / Q000235:genetics / Q000276:immunology*; D017412:Ribonucleoprotein, U1 Small Nuclear / Q000276:immunology*; D012595:Scleroderma, Systemic / Q000150:complications / Q000235:genetics / Q000276:immunology; D012640:Seizures / Q000150:complications; D055517:snRNP Core Proteins
D000974:Antibodies, Antinuclear; D001324:Autoantigens; D015804:HLA-DR4 Antigen; D017412:Ribonucleoprotein, U1 Small Nuclear; D055517:snRNP Core Proteins