Outcomes Following ATG Therapy for Chronic Lung Allograft Dysfunction

Area of Science:

• Immunology
• Transplantation Medicine
• Pulmonology

Background:

• Chronic lung allograft dysfunction (CLAD) is a primary cause of mortality after lung transplantation (LTx).
• Effective therapeutic options for CLAD are limited, necessitating research into novel treatments.

Purpose of the Study:

• To evaluate the efficacy of antithymocyte globulin (ATG) as a second-line therapy for CLAD.
• To identify predictors of response to ATG in lung transplant recipients with CLAD.

Main Methods:

• A retrospective analysis of 76 lung transplant recipients treated with ATG for CLAD.
• Calculation of forced expiratory volume in 1 second (FEV1) decline rate before and after ATG treatment.
• Definition of partial response (≥20% improvement in FEV1 decline rate) and complete response (absolute FEV1 improvement or stability).

Main Results:

• 23% of patients achieved complete response and 40% achieved partial response to ATG.
• Patients with CLAD stage 2 or 3 and younger age were more likely to respond to ATG.
• Partial responders had a 65% lower risk of death or retransplant, while complete responders had a 70% lower risk.

Conclusions:

• Antithymocyte globulin (ATG) can stabilize or improve lung function decline in CLAD, potentially enhancing retransplant-free survival.
• Younger age and later CLAD stages (2-3) may predict response to ATG.
• Multicenter randomized controlled trials are needed to confirm these findings and identify definitive predictors of ATG response in CLAD.