Renal dysfunction occurs in up to one-half of patients with multiple myeloma (MM). Crystalline nephropathy refers to renal parenchymal deposition of crystals leading to kidney damage. The most common forms of crystalline nephropathy encountered in renal pathology are nephrocalcinosis and oxalate nephropathy. Less frequent types include urate nephropathy, cystinosis, dihydroxyadeninuria, and drug-induced crystalline nephropathy (e.g., caused by indinavir or triamterene).
Monoclonal proteins can also deposit in the kidney as crystals and cause tissue damage. This occurs in conditions such as light chain proximal tubulopathy, crystal-storing histiocytosis, and crystalglobulinemia. The latter is a rare complication of MM that results from crystallization of monoclonal proteins in the systemic vasculature, leading to vascular injury, thrombosis, and occlusion.
In the Journal of the American Society of Nephrology, Mayo Clinic researchers, first author Samih Nasr, M.D., Consultant, Division of Anatomic Pathology, and Associate Professor of Laboratory Medicine and Pathology, describe a case of crystalglobulin-induced nephropathy and discuss its pathophysiology and the differential diagnosis of paraprotein-induced crystalline nephropathy.
Crystalglobulin-induced nephropathy is characterized by large extracellular crystals within the lumen of arterioles, arteries, and/or glomerular capillaries with or without secondary vascular thrombosis. Rare crystals may also be seen within Bowman’s capsule and tubular lumina.
Read the full case to for clinical details and diagnosis.