Fluorocytometric analysis of anti-HLA class 2 autoantibodies in patients with lupus nephritis.
Systemic lupus erythematosus (SLE) patients are known to produce a variety of autoantibodies (AAb), some of which may be directed against immunocompetent cells. Anti-B cell autoimmunity may encompass reactivity against HLA-class 2 molecules, which are also expressed on kidney tissue. We studied 15 patients with moderate to severe renal involvement and 5 lupus patients with no clinical renal disease, in order to detect the presence of anti-HLA class 2 AAb. Flow cytometry was employed in an inhibitory assay using patient sera, autologous cells and two anti-class 2 monoclonals, to establish the specificity of anti-B cell AAb. Seven out of 15 nephritis patients had detectable anti-class 2 AAb with an epitopic heterogeneity, as demonstrated by different degrees of inhibition on the binding of non-overlapping monoclonals. The specificity of the reaction was confirmed by the lack of inhibition of non-class 2 antibody binding. The presence of such AAb was not correlated with disease activity but with the presence of a diffuse proliferative glomerulonephritis on renal biopsy. Anti-class 2 AAb may be a marker of SLE diffuse proliferative nephritis.
Brunati
C
C
Division of Nephrology and Dialysis, Niguarda-Cà Granda Hospital, Milano, Italy.
Brando
B
B
Traballi
G
G
Canesi
B
B
Busnach
G
G
Inzaghi
A
A
Minetti
L
L
D000293:Adolescent; D000328:Adult; D000911:Antibodies, Monoclonal; D001323:Autoantibodies / Q000032:analysis*; D001706:Biopsy; D005260:Female; D005434:Flow Cytometry; D015235:HLA-B Antigens / Q000032:analysis*; D006801:Humans; D007678:Kidney Glomerulus / Q000276:immunology; D008181:Lupus Nephritis / Q000276:immunology* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D013601:T-Lymphocytes / Q000276:immunology
D000911:Antibodies, Monoclonal; D001323:Autoantibodies; D015235:HLA-B Antigens