Collapsing glomerulopathy in a patient with mixed connective tissue disease.

Collapsing glomerulopathy (CG) is a distinct podocytopathy characterized by the global or segmental collapse of glomerular capillary tuft with overlying podocyte hypertrophy and hyperplasia. CG has been associated with numerous etiologies, including infections, autoimmune disorders, drugs, and malignancies. Anecdotal reports of CG in patients with mixed connective tissue disease (MCTD) have been reported in the literature. We report a case of a 53-year-old female who presented to us with acute kidney injury and proteinuria. The patient underwent renal biopsy for further evaluation of her proteinuria, and was diagnosed to have collapsing glomerulopathy. The patient was subsequently diagnosed with MCTD, given her constellation of symptoms and serology titers. The patient was started on prednisone with subsequent stabilization of renal function and reduction of proteinuria and continues to be in remission. We report our case to highlight the association between collapsing glomerulopathy and MCTD and the potential role of steroids as first-line therapy in such cases.