A case of autoimmune thyroiditis and membranoproliferative glomerulonephritis

Thyroid hormones play an important role in the growth of the kidney and maintenance of its functions. Prolonged hypothyroidism is known to be accompanied by changes in renal morphology such as thickening of the glomerular and tubular basement membranes as well as increased mesangial matrix. Increased transcapillary leakage of plasma proteins leading to proteinuria and generalized edema is also a known complication of hypothyroidism. In particular, autoimmune thyroiditis is associated with proteinuria. Most previous reports of autoimmune thyroiditis with nephrotic syndrome have demonstrated mixed pathological morphology marked by predominant membranous glomerulopathy. Here we present a patient whose initial presentation with profound hypothyroidism and autoimmune thyroiditis was dominated by nephrotic syndrome secondary to type 1 membranoproliferative glomerulonephritis (MPGN). The association of MPGN and autoimmune thyroiditis is very rare.