Further description of early clinically silent lupus nephritis.

ABSTRACT

Thirty silent lupus nephritis (SLN) patients were compared to 16 individuals bearing overt lupus nephritis (OLN). Results included years of systemic lupus erythematosus (SLE) diagnosis were significantly earlier (4.6 +/- 2.8 years) in SLN than in OLN (7.18 +/- 3.61) (P < 0.05). Neurological compromise, hypertension, normocitic anemia and lymphopenia were significantly prevalent in OLN than in SLN (P < 0.05). Beside normal urinary sediment and renal function tests, the SLN group showed a moderate increase of both activity (AI) and chronicity (CI) renal pathology index when compared to highly increased AI and CI in OLN (P < 0.05). Seventy percent of SLN patients were ISN/RPS Classes I (6.6%) and II (63.3%) while 81% of OLN cases were Classes III, IV (37.5%) and V. IgG, IgA, IgM, lambda chain, C3 and fibrinogen immune deposits were found in 90% or over in both SLN and OLN individuals while in 60% or over, both groups also showed kappa chain, Clq and C4 deposits. While prevalence of ANA, anti-dsDNA and anti-C1q antibodies were similar in both groups, anti-histone, anti-RNP, CIC and CH50 serum levels were significantly different in OLN versus SLN (P < 0.05). We strongly suggest that indeed SLN is the earliest stage in the natural history of lupus nephritis.