Tacrolimus induced pseudogout following allogeneic hematopoietic cell transplant.

Introduction: Crystalline arthritis (CA), characterized by acute joint pain and erythema secondary to calcium pyrophosphate deposition (CPPD, or pseudogout) or monosodium urate crystals (gout), is a potentially underreported complication following allogeneic hematopoietic cell transplant (alloHCT). Graft-versus-host disease prophylaxis with calcineurin inhibitors (CNIs) causes hypomagnesemia and hyperuricemia, resulting in CA. CA related to tacrolimus has yet to be characterized following alloHCT.