Cyclophosphamide for Refractory Acute Cellular Rejection After Lung Transplantation

Area of Science:

• Transplantation immunology
• Pulmonary medicine

Background:

• Acute cellular rejection (ACR) is a primary driver of chronic lung allograft dysfunction post-transplant.
• Recurrent or refractory ACR often fails to respond to standard immunosuppression, necessitating alternative therapies.
• Limited treatment options exist for persistent and difficult-to-treat ACR cases.

Purpose of the Study:

• To evaluate the efficacy of cyclophosphamide in treating recurrent and refractory acute cellular rejection (ACR) in lung transplant recipients.
• To assess the safety and tolerability of cyclophosphamide in this patient population.

Main Methods:

• A series of six lung transplant recipients with recurrent or refractory ACR were treated with cyclophosphamide.
• Primary outcomes included ACR score improvement and changes in forced expiratory volume at 1 second (FEV1).
• Secondary outcomes monitored adverse drug events, including bone marrow suppression, gastrointestinal issues, and infections.

Main Results:

• Five out of six patients achieved complete ACR resolution on follow-up biopsies.
• A statistically significant improvement in ACR scores was observed post-cyclophosphamide treatment (P = 0.03).
• No patients experienced high-grade ACR (≥A3) within three months of treatment; FEV1 and bronchiolitis obliterans scores remained unaffected. Patients tolerated cyclophosphamide with minor side effects.

Conclusions:

• Cyclophosphamide represents a viable therapeutic option for lung transplant recipients with recurrent or refractory ACR who have not responded to conventional treatments.
• The treatment was generally well-tolerated, with no serious adverse drug events reported.