Soluble HLA-I in rheumatic diseases.
OBJECTIVE
To study serum levels of Class I soluble HLA (sHLA-I) in patients with systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), polymyositis or dermatomyositis (PM/DM) or scleroderma and to assess the possible influence of ethnic factors on concentration in each disease group.


METHODS
Solid-phase enzyme linked immunoassay was used to measure sHLA-I in the serum of 385 patients with varied ethnic backgrounds (American-Caucasians, African-Americans, Georgian-Caucasians) with rheumatic diseases. Studies on patients were compared to similar measurements of 189 healthy individuals.


RESULTS
Mean sHLA-I levels were significantly higher in patients with SLE than those observed in healthy individuals or other rheumatic diseases. Highest concentrations were present in Georgian-Caucasian patients with SLE. American-Caucasian patients with RA or scleroderma had higher sHLA-I levels than normal Caucasian individuals. The majority of patients with PM/DM in all ethnic subgroups were low secretors of sHLA-I.


CONCLUSIONS
Mechanisms underlying the secretion of sHLA-I appear to differ among the rheumatic diseases studied and various ethnic groups. These genetic differences in sHLA-I secretion could be associated with ethnic and pathophysiologic differences among these rheumatic diseases.
Department of Medicine, Louisiana State University Medical Center, Shreveport 71130-3932, USA.
R E
RE
Wolf
I M
IM
Adamashvili
F B
FB
Gelder
V C
VC
Hall
P A
PA
Fraser
J C
JC
McDonald
D001172:Arthritis, Rheumatoid / Q000097:blood / Q000208:ethnology / Q000276:immunology; D044383:Black People; D005846:Georgia (Republic); D006680:HLA Antigens / Q000097:blood*; D015395:Histocompatibility Antigens Class I / Q000097:blood*; D006801:Humans; D008145:Louisiana; D008180:Lupus Erythematosus, Systemic / Q000097:blood / Q000208:ethnology / Q000276:immunology; D009220:Myositis / Q000097:blood / Q000208:ethnology / Q000276:immunology; D012216:Rheumatic Diseases / Q000097:blood / Q000208:ethnology* / Q000276:immunology*; D012595:Scleroderma, Systemic / Q000097:blood / Q000208:ethnology / Q000276:immunology; D012995:Solubility; D014900:West Indies / Q000208:ethnology; D044465:White People; D001741:Black or African American
D006680:HLA Antigens; D015395:Histocompatibility Antigens Class I