Bucillamine-induced membranous nephropathy with crescent formation in a patient with rheumatoid arthritis: case report and literature review

Abstract

Bucillamine is a disease-modifying antirheumatic drug that is structurally similar to D-penicillamine. The major renal side effect of bucillamine and D-penicillamine is proteinuria caused by membranous nephropathy (MN). In addition to MN, combined crescent formation has been occasionally reported in D-penicillamine-induced MN, while crescent formation has been rarely reported in bucillamine-treated cases. Here, we describe a 76-year-old female who presented with nephrotic syndrome and rapidly progressive glomerulonephritis. She was receiving bucillamine as initial treatment for recently diagnosed rheumatoid arthritis, and renal biopsy showed MN with crescent formation. To the best of our knowledge, this is the first report of bucillamine-induced MN with crescent formation in the English literature.

Keywords: Bucillamine; Crescent formation; Membranous nephropathy; Nephrotic syndrome; Rapidly progressive glomerulonephritis; Rheumatoid arthritis.

Fig. 1

Clinical course after the initiation of bucillamine therapy.

Fig. 2

Light microscopy findings of the renal biopsy. a Mild intracapillary proliferation and small cellular crescents. Periodic acid Schiff staining. ×40. b Global cellular crescent. Periodic acid methenamine silver staining. ×100. IF findings: fine granular staining of IgG (c), IgG1 (d), IgG2 (e), IgG3 (f), and IgG4 (g) on the glomerular capillary loop.

Fig. 3

EM findings. a Subepithelial electron-dense deposits (white arrow heads). Original magnification ×6,000. b Extensive foot process effacement, microvillus transformation, and vacuolar degeneration of podocytes. Original magnification ×2,000.