A case of membranous nephropathy associated with thyroid antigens

A 54-year-old woman who had proteinuria due to stage II membranous nephropathy is reported. She was treated with indomethacin for proteinuria and developed drug-induced hepatitis four months later. Liver dysfunction gradually recovered, but hormonal studies revealed abrupt fall of T3 and T4 and concomitant elevation of TSH levels within a month. Pathological findings of thyroid specimen and positive antithyroglobulin and antimicrosomal antibodies were compatible to chronic thyroiditis. In the second renal biopsy, glomerular deposits of thyroglobulin, thyroid microsomal antigens and IgG were demonstrated by immunofluorescence. Therefore, membranous nephropathy in this patient is presumed to be caused by immune complexes mediated by thyroid constituents. We believe that this is a precious case because continuous changes in T3, T4 and TSH were followed in a course of chronic thyroiditis, especially in the stage of progress to hypothyroidism, and the chronic thyroiditis was shown to be involved in the membranous nephropathy.