Glomerulopathy in spontaneously obese rhesus monkeys with type 2 diabetes: a stereological study.

BACKGROUND: Animal models could provide insights into the diabetic nephropathy pathogenesis; however, available rodent models do not mirror the heterogeneity of lesions in type 2 diabetic patients, and do not progress to end-stage renal disease. Previous studies showed that spontaneously obese type 2 diabetic rhesus monkeys develop many of the features of human diabetic glomerulopathy, and may progress to end-stage renal disease. Here, in order to further characterize diabetic glomerulopathy in this model, we used electron microscopic stereology. METHODS: Renal biopsies from 17 diabetic, 17 pre-diabetic/metabolic syndrome and 11 non-diabetic monkeys were studied. Fractional volumes of mesangium [Vv(Mes/glom)], mesangial matrix [Vv(MM/glom)] and mesangial cells [Vv(MC/glom)], glomerular basement membrane width and peripheral glomerular basement membrane surface density per glomerulus [Sv(PGBM/glom)] were estimated. Glomerular filtration and albumin excretion rates were measured in a limited number of animals. Glomerular structural and biochemical/metabolic data were compared among the groups. RESULTS: Compared to non-diabetic monkeys, diabetic rhesus monkeys showed classic diabetic nephropathy changes, including glomerular basement membrane thickening (p = 0.001), increased fractional volumes of mesangium (p = 0.02), and reduced peripheral glomerular basement membrane surface density per glomerulus (p = 0.03) compared to non-diabetic monkeys. Increased fractional volumes of mesangium was primarily due to increased mesangial matrix (p = 0.03). Glomerular structural parameter inter-relationships in diabetic monkeys mirrored those of human diabetic glomerulopathy. Albumin excretion rate was greater (p = 0.03) in diabetic vs. non-diabetic monkeys. There was trend for a positive correlation between albumin excretion rate and fractional volumes of mesangium. CONCLUSIONS: This rhesus primate model shares many features of human diabetic glomerulopathy. Mesangial expansion in this model, similar to human diabetic nephropathy and different from available rodent models of the disease, is primarily due to increased mesangial matrix.

Autoimmune Diabetes and Thyroiditis Complicating Treatment with Nivolumab.

Programmed cell death-1 (PD-1) ligand inhibitors have gained popularity in the treatment of advanced non-small-cell lung cancer. The immune system is regulated by stimulatory and inhibitory signaling and aims to achieve the balance between activation and inhibition. Treatment with immune checkpoint inhibitors enhances immune response, but is also known to diminish immune tolerance and increase autoimmune toxicity. Here we present a case of a patient with advanced squamous cell lung cancer who developed type I diabetes and thyroiditis after treatment with PD-1 checkpoint inhibitor nivolumab. The presence of autoimmune diabetes mellitus and thyroiditis were confirmed by markedly elevated titers of the glutamic acid decarboxylase autoantibody and thyroid peroxidase antibody, respectively. This report serves to heighten awareness of potential autoimmune toxicities related to anti-PD-1 therapy, especially as these toxicities are manageable if identified in a timely manner.