Complement C5 inhibition reverses bleomycin-induced thrombotic microangiopathy.

Area of Science:

• Oncology
• Nephrology
• Pulmonology

Background:

• Chemotherapy-induced thrombotic microangiopathy (TMA) is a rare but serious complication.
• Bleomycin is known to cause lung fibrosis, but rarely TMA.
• The efficacy of C5 complement pathway inhibition in chemotherapy-induced TMA is not well-established.

Observation:

• A patient receiving bleomycin, cisplatin, and etoposide developed acute respiratory distress syndrome and TMA.
• Plasma exchange was ineffective, leading to the use of eculizumab as salvage therapy.
• Eculizumab rapidly resolved the TMA within two days.

Findings:

• Eculizumab effectively treated the thrombotic microangiopathy (TMA).
• Despite TMA remission, the patient's lung fibrosis progressed, leading to refractory respiratory failure.
• This suggests distinct pathophysiological pathways for bleomycin-induced lung injury and TMA.

Implications:

• Complement C5 inhibition may be a viable treatment for chemotherapy-induced TMA.
• Targeting the C5 pathway may not prevent or treat bleomycin-induced lung fibrosis.
• Further research is needed to elucidate the differing mechanisms of bleomycin-related lung toxicities.