Interferon induced thrombotic microangiopathy (TMA): Analysis and concise review

Area of Science:

• Hematology
• Oncology
• Immunology

Background:

• Interferon (IFN) therapy is linked to thrombotic microangiopathy (TMA), encompassing thrombotic thrombocytopenic purpura (TTP) and hemolytic uremic syndrome (HUS).
• A comprehensive literature review identified 68 cases of IFN-associated TMA from 1993 to 2016.

Purpose of the Study:

• To analyze the characteristics, treatment durations, and outcomes of thrombotic microangiopathy (TMA) associated with interferon (IFN) therapy.
• To identify risk factors and clinical features distinguishing different types of TMA induced by IFN.

Main Methods:

• Systematic literature review of reported cases of TMA associated with IFN therapy.
• Data analysis included patient demographics, indications for IFN treatment, duration of therapy, clinical presentation, laboratory findings (including ADAMTS13 levels), and treatment outcomes.

Main Results:

• The mean age of diagnosis was 47 years, with most cases linked to IFN treatment for chronic myelogenous leukemia (CML), multiple sclerosis (MS), and hepatitis C virus (HCV) infection.
• TMA developed after a median of 40.4 months of IFN treatment, with MS patients requiring the longest exposure (68.6 months).
• Confirmed TTP cases showed inhibitor presence and severe thrombocytopenia; outcomes included remission (40%), chronic kidney disease (42%), and fatality (18%), with corticosteroids, plasma exchange, and rituximab yielding durable responses.

Conclusions:

• Interferon-induced TMA is a significant complication, particularly in patients with CML, MS, and HCV.
• Early recognition and prompt treatment with agents like corticosteroids, plasma exchange, and rituximab are crucial for improving outcomes in IFN-associated TMA.