Quinine-Induced Thrombotic Microangiopathy: A Report of 19 Patients.

Background: Quinine can cause diverse and severe immune-mediated adverse reactions, including thrombotic microangiopathy (TMA). Our objective was to describe the presenting features and long-term outcomes of patients with quinine-induced TMA.

Study Design: A case series of 19 patients with quinine-induced TMA treated with plasma exchange.

Setting & Participants: Patients with quinine-induced TMA initially suspected of having thrombotic thrombocytopenic purpura (TTP) were identified among patients enrolled in the Oklahoma TTP-Hemolytic Uremic Syndrome Registry.

Outcomes: The clinical course of the initial episode and morbidity and mortality following recovery.

Measurements: The diagnosis of quinine-induced TMA was confirmed by documentation of quinine-dependent antibodies reactive with platelets or neutrophils and/or by previous quinine-associated systemic symptoms. Clinical data from the initial episode and long-term follow-up were described, focusing on kidney function.

Results: 19 of the 509 patients enrolled in the registry in 1989 to 2015 had quinine-induced TMA. 18 patients had quinine-dependent antibodies reactive with platelets and/or neutrophils (1 patient died before testing); 8 patients had a history of quinine-associated systemic symptoms. All patients were white; 18 were women. Quinine exposure was in pill form for 18 patients and as tonic water for 1. All patients had microangiopathic hemolytic anemia, thrombocytopenia, and acute kidney injury. All were initially misdiagnosed as having TTP or hemolytic uremic syndrome, and adverse reactions to quinine were not initially suspected. 1 patient died before treatment began; 17 of the 18 surviving patients required dialysis. 14 patients developed chronic kidney disease, 3 of whom developed end-stage renal disease. 8 patients died.

Limitations: Patients for whom plasma exchange was not requested were not identified.

Conclusions: Quinine-induced TMA causes severe acute kidney injury that commonly results in chronic kidney disease.