Polyclonal immunoglobulin G ameliorates the course of progressive mesangioproliferative glomerulonephritis in rats

Intravenous immunoglobulins (IVIG) consist of polyvalent immunoglobulins (Ig), mainly IgG with varying amounts of other Ig depending on preparation. IVIG have renoprotective properties in diseases like lupus nephritis mostly due to their anti-inflammatory effects. The role of polyvalent IgG treatment during the course of experimental progressive mesangioproliferative nephritis is not yet known.

Progressive mesangioproliferative nephritis was induced in male Wistar rats by uninephrectomy and anti-Thy1.1 antibody injection. Rats were treated with either vehicle (phosphate-buffered saline; n = 10) or nonspecific human polyclonal IgG (IgG; n = 10) on days 3, 10 and 17 after disease induction and sacrificed on day 56.

During the experiment, IgG treatment prevented weight loss and had a beneficial effect on the rise in serum creatinine and the decline of creatinine clearance. At sacrifice, a significantly lower number of IgG-treated rats had tripled their creatinine or halved their creatinine clearance. Moreover, during the 56 days of follow-up, the IgG-treated group exhibited reduced mortality due to renal failure. At sacrifice, IgG-treated rats had reduced indices of renal fibrosis.

IgG treatment is an effective treatment approach in rats with progressive glomerulonephritis. Our data also indicate that studies using specific antibodies need to be controlled for nonspecific IgG effects.