Crystalglobulin-Induced Nephropathy and Keratopathy

Crystalglobulinemia, a rare manifestation of monoclonal gammopathy, results from vascular deposition of crystallized monoclonal proteins leading to tissue injury. A 56-year-old man initially presented several years earlier with migratory polyarthralgias and blurry vision with no unifying diagnosis. Following an acute episode of malignant hypertension and rapidly progressive kidney failure, kidney biopsy was performed and was interpreted as idiopathic thrombotic microangiopathy. Further evaluation revealed an underlying monoclonal protein disorder. Slit-lamp biomicroscopy evaluation showed crystalline keratopathy. Re-evaluation of the kidney biopsy material with pronase staining confirmed crystalglobulin-induced nephropathy. The patient was initially treated with cyclophosphamide, bortezomib, and dexamethasone with partial response, followed by autologous stem cell transplantation with normalization of monoclonal protein studies, improvement in kidney function and joint symptoms, and decreased corneal deposits. His disease recurred but did not require additional treatment 1 year later. This case exemplifies the unique systemic presentation of diseases in the monoclonal gammopathy spectrum and emphasizes the need for a multidisciplinary approach when caring for these patients.