Spontaneous glomerular mesangial lesions in common marmoset monkeys (Callithrix jacchus): a benign non-progressive glomerulopathy.

BACKGROUND

Common marmosets are known to develop an IgM glomerulopathy, which has been linked with 'wasting marmoset' syndrome. This study investigated renal pathology in a colony of marmosets, with and without weight loss.

METHODS

Renal histology, immunofluorescence, and electron microscopy were performed on marmosets euthanized for research or for weight loss. Serum and urine biochemistry were measured during life and at euthanasia.

RESULTS

Histology from 25 adult marmosets (19 research and 6 weight loss) showed mesangial expansion in the majority of glomeruli. Mesangial changes correlated with electron-dense deposits and IgM deposition by immunofluorescence; negligible other pathology was seen. Glomerular basement membrane thickness appeared increased compared to reported human measurements. Low-grade proteinuria was present in all animals, but did not progress. Renal function was normal in all animals.

CONCLUSIONS

Marmosets develop a glomerulopathy characterized by mesangial expansion, IgM deposition, and proteinuria. This is a benign occurrence and not specifically associated with weight loss.