Increased level of soluble HLA class I antigens in systemic lupus erythematosus: correlation with anti-DNA antibodies and leukopenia.
The concentration of soluble HLA class I (sHLA-I) was measured by ELISA in serum samples from 30 well-characterised SLE patients at high and low disease activity states and from 100 healthy controls. HLA-A allotypes in the patients were analysed by a PCR-based typing technique. A higher level of sHLA-I was found in SLE patient sera both at high and low disease activity than in controls (P< 0.001). The sHLA-I level was further increased during active disease (P< 0.01). Concentrations of sHLA-I correlated with anti-dsDNA antibodies at high disease activity, but not with disease activity as analysed by a modified SLEDAI. Numbers of leukocytes and lymphocytes, as well as levels of C1q and C3 correlated inversely with sHLA-I concentration. In five serial samples from ten patients the sHLA-I level co-varied with disease activity. Presence of HLA allotype A9 was associated with higher sHLA-I levels in both patients (P< 0.001) and controls (P< 0.001). We conclude that the increased sHLA-I concentration in SLE patients was related to several laboratory parameters reflecting disease activity suggesting that sHLA-I molecules are connected with the disease process. Increased sHLA-I level due to HLA-A allotype was not a disease susceptibility factor for SLE.
Kippner
L
L
Department of Laboratory Medicine, Section of M.I.G., Lund University, Sweden.
Klint
C
C
Sturfelt
G
G
Bengtsson
A A
AA
Eriksson
H
H
Truedsson
L
L
D000328:Adult; D000368:Aged; D000974:Antibodies, Antinuclear / Q000097:blood* / Q000276:immunology; D015415:Biomarkers; D015922:Complement C1q / Q000032:analysis; D003176:Complement C3 / Q000032:analysis; D003181:Complement C4 / Q000032:analysis; D005260:Female; D015234:HLA-A Antigens / Q000235:genetics; D015395:Histocompatibility Antigens Class I / Q000097:blood* / Q000235:genetics; D006801:Humans; D007126:Immunoglobulin Allotypes; D007970:Leukopenia / Q000276:immunology*; D008180:Lupus Erythematosus, Systemic / Q000097:blood / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D012995:Solubility
D000974:Antibodies, Antinuclear; D015415:Biomarkers; D003176:Complement C3; D003181:Complement C4; D015234:HLA-A Antigens; D015395:Histocompatibility Antigens Class I; D007126:Immunoglobulin Allotypes; D015922:Complement C1q