Autoantibodies against glomerular mesangial cells and their target antigens in lupus nephritis.
Mesangial proliferation and deposition of immunoglobulins and complement components within glomerular mesangium was one of the important pathological features of lupus nephritis. Autoantibodies against human mesangial cells could be detected in the sera of patients with IgA nephropathy (IgAN) and Henoch-Schöenlein nephritis. We speculated that autoantibodies against human glomerular mesangial cells might play a role in the development of lupus nephritis.


OBJECTIVE
To screen autoantibodies against human glomerular mesangial cells in sera from patients with lupus nephritis and to identify their target antigens.


METHODS
Sera were collected from 96 patients with lupus nephritis as well as 25 patients with IgAN and 20 patients with idiopathic membranous nephropathy (IMN). Cell lysates of in vitro cultured human glomerular mesangial cells were used as antigens in Western-blot analysis to detect autoantibodies against human mesangial cells in sera from patients with lupus nephritis as well as IgAN and IMN. The clinical and pathological significance of the autoantibodies were further investigated.


RESULTS
Autoantibodies against human mesangial cells could be detected in 94/96 (97.9%) of the sera from patients with lupus nephritis in Western-blot analysis. Twelve protein bands could be blotted by the sera from patients with lupus nephritis. The prevalence of autoantibodies against human mesangial cells in IgAN was 14/25 (56.0%) and only seven protein bands could be blotted. Five autoantibodies (anti-18, 24, 36, 46, and 91 kD) could be detected only in sera from patients with lupus nephritis. In patients with lupus nephritis, some autoantibodies might have some relationship with gender, hematuria, ANA, anti-dsDNA or anti-ENA antibodies.


CONCLUSIONS
There are autoantibodies directly against heterogeneous antigens of human glomerular mesangial cells in sera from patients with lupus nephritis, and some of them might be associated with different clinical manifestations.
Chen
Min
M
Renal Division, Institute of Nephrology, Peking University First Hospital, Beijing, P.R. China.
Wang
Ying-Yu
YY
Zhao
Ming-Hui
MH
Zhang
You-Kang
YK
Wang
Hai-Yan
HY
D000293:Adolescent; D000328:Adult; D001323:Autoantibodies / Q000276:immunology*; D001324:Autoantigens / Q000276:immunology*; D015415:Biomarkers / Q000097:blood; D015153:Blotting, Western; D016022:Case-Control Studies; D002478:Cells, Cultured; D005260:Female; D005920:Glomerular Mesangium / Q000166:cytology*; D006801:Humans; D008181:Lupus Nephritis / Q000097:blood / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index
D001323:Autoantibodies; D001324:Autoantigens; D015415:Biomarkers