Analysis of anti-U1 RNA antibodies in patients with connective tissue disease. Association with HLA and clinical manifestations of disease.
OBJECTIVE
To determine the prevalence of anti-U1 RNA antibodies in connective tissue disease (CTD) patients and evaluate immunogenetic and clinical features of patients possessing these antibodies.


METHODS
RNA immunoprecipitation was used to analyze patient and healthy control sera for the presence of anti-R1 RNA antibodies. Enzyme-linked immunosorbent assay and immunoblotting were used to determine small nuclear RNP (snRNP) polypeptide antibodies. HLA polymorphisms were determined by microcytotoxicity and DNA typing.


RESULTS
Anti-U1 RNA IgM and IgG antibodies were found in 60% of anti-RNP positive patients. All of the anti-U1 RNA positive patients had anti-70K, and most had anti-A, (U1)snRNP polypeptide antibodies. HLA-DR2/DR4, as well as Raynaud's phenomenon and synovitis, were significantly increased in the anti-U1 RNA positive group.


CONCLUSIONS
The presence of anti-U1 RNA antibodies correlates with anti-70K and anti-A polypeptide antibodies. In addition, the anti-U1 RNA positive CTD patient group is immunogenetically and clinically distinctive from the anti-U1 RNA negative patient group.
Hoffman
R W
RW
University of Missouri-Columbia School of Medicine, USA.
Sharp
G C
GC
Deutscher
S L
SL
D000293:Adolescent; D000328:Adult; D000368:Aged; D000974:Antibodies, Antinuclear / Q000378:metabolism; D001323:Autoantibodies / Q000378:metabolism*; D002648:Child; D003240:Connective Tissue Diseases / Q000150:complications / Q000235:genetics / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006680:HLA Antigens / Q000378:metabolism*; D015802:HLA-DR2 Antigen / Q000378:metabolism; D015804:HLA-DR4 Antigen / Q000378:metabolism; D006801:Humans; D007074:Immunoglobulin G / Q000378:metabolism; D007075:Immunoglobulin M / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D011233:Precipitin Tests; D012313:RNA / Q000276:immunology*; D011928:Raynaud Disease / Q000209:etiology; D017412:Ribonucleoprotein, U1 Small Nuclear / Q000235:genetics* / Q000276:immunology; D013585:Synovitis / Q000209:etiology
D000974:Antibodies, Antinuclear; D001323:Autoantibodies; D006680:HLA Antigens; D015802:HLA-DR2 Antigen; D015804:HLA-DR4 Antigen; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D017412:Ribonucleoprotein, U1 Small Nuclear; D012313:RNA