Mesangiocapillary Nephritis, Partial Lipodystrophy, and Hypocomplementæmia

Metabolic Studies of the Third Component of Complement and the Glycine-Rich Beta Glycoprotein in Patients with Hypocomplementemia

“…No correlation was observed (r =-0.428, P> 0.05). However, Our results show that hypercatabolism and depressed C3 synthesis occur together in patients with hypocomplementemia, either when complement is activated by the classical pathway (involving C1, C4, and C2) or when activation is known to be independent of these components, as occurs in MCGN (6) and in PLD (5). Depressed C3 synthesis has also been reported in hypocomplementemic SLE by Sliwinski and Zvaifler (26).…”

“…Of special interest has been the finding of a circulating C3 activator-the so-called C3 nephritic factor (C3NeF) -in the serum of patients with MCGN (1-3). More recently hypocomplementemia and a factor closely resembling C3NeF have been demonstrated in the serum of patients, with partial lipodystrophy (PLD) (4,5).…”

Nephritic factor (NeF) of alternate pathway (NeFA) and of classical pathway (NeFc).

“…The same factor was found in sera from partial lipodystrophy with the same complement profile without nephritis, but thereafter the patients developed membranoproliferative glomerulonephritis (MPGN) (Peters et al 1973). These reports were of interest, because there appeared to be the relation between the presence of NeF and the pathogenesis of glomerulonephritis.…”

Spectrum of Renal Diseases Associated with Extreme Forms of Insulin Resistance

“…Patients often have compensatory hypertrophy of their lower extremity adipose tissue and typically have normal serum lipids and glucose. Although the cause is unknown, this disorder often is associated with low C3 and elevated C3NeF, the latter of which has been implicated as a possible cause for the lipodystrophy (17,18). C3NeF, an IgG autoantibody, dysregulates the alternative pathway, contributing to the consumption of C3, and may also lead to adipocyte lysis (19).…”