Clinical characteristics, treatments, and outcomes of interferon-beta-induced thrombotic microangiopathy: a literature-based retrospective analysis

Background: Thrombotic microangiopathy (TMA) is a rare side effect of interferon-beta (IFN-β) therapy. The clinical characteristics of IFN-β-induced TMA are unknown. Objectives: To explore the clinical characteristics of IFN-β-induced TMA and provide reference for the prevention of TMA. Design: Articles on IFN-β-induced TMA were collected by searching the literature in relevant Chinese and English databases from inception to 31 July 2023. Methods: Data in the articles were extracted and analyzed retrospectively. Results: Forty-seven patients, with a median age of 41 years (range 22, 66), were included in the analysis. The median time to the diagnosis of IFN-β-induced TMA was 8 years (range 0.1-30) after administration. The main clinical symptoms were neurological symptoms (51.1%), hypertension (78.7%), dyspnea (19.1%), edema (19.1%), asthenia/fatigue (19.1%), and digestive symptoms (17.0%). Most patients presented with hemolytic anemia (76.6%), thrombocytopenia (63.8%), and acute kidney injury (70.2%). All patients stopped IFN-β and received plasma exchange therapy (53.2%), systemic steroids (46.8%), antihypertensive therapy (46.8%), eculizumab (12.8%), and rituximab (12.8%). Kidney damage was not completely reversible; 40.4% of patients achieved renal function and hematology remission, 27.7% developed chronic kidney disease, 25.5% developed end-stage renal disease, and 2.1% died. Conclusion: IFN-β-induced TMA is a rare but serious complication that can be life-threatening. It may occur after many years of IFN-β therapy, and patients taking IFN-β should be monitored for symptoms such as headache and hypertension.