A Case Series Describing Response to Rabbit Anti-thymocyte Globulin for the Treatment of Bronchiolitis Obliterans Syndrome in Patients With Chronic Lung Allograft Dysfunction
Recommended Citation
Fitzmaurice M, Franco-Palacios DJ, Henderson R, Olexsey K, Pinto Corrales J, Poparad-Stezar A, Stagner LD, Allenspach L. A Case Series Describing Response to Rabbit Anti-thymocyte Globulin for the Treatment of Bronchiolitis Obliterans Syndrome in Patients With Chronic Lung Allograft Dysfunction. Am J Respir Crit Care Med 2024; 209:A3733.
Document Type
Conference Proceeding
Publication Date
6-1-2024
Publication Title
Am J Respir Crit Care Med
Abstract
Background: Chronic allograft dysfunction (CLAD) is a frequent complication and main reason for morbidity and decreased survival after lung transplant. Besides augmented immunosuppression and azithromycin, few other salvage therapies exist. Anti-thymocyte globulin therapy (ATG) is commonly offered to patients. The goal is to attenuate the rate of disease progression, stabilize or improve forced expiratory volume in 1 second (FEV1). Few centers have reported their treatment response with thymoglobulin and with varying doses. Methods: We reviewed all patients treated at our center with ATG for CLAD from 2015 to 2023. Their treatment response and side effects are described in 16 patients (BOS in 14, BOS + RAS in 2). Results: Median age 61, 81% were men, 15 patients underwent bilateral lung transplant. Most common indication was pulmonary fibrosis (6/16, 37%), followed by emphysema, cystic fibrosis and sarcoidosis. All patients received standard induction. Triple maintenance immunosuppression with calcineurin and cell cycle inhibitors and steroids were used in 68% of patients. Most patients (14/16, 87%) were taking azithromycin 250 mg three times weekly. The median cumulative ATG dose was 2.25 mg/kg with a median of 2 doses per course. Median time from transplant to BOS development was 24 months. Most patients (80%) had BOS stages 3 (9/16; 56%) and 4 (3/16, 18%). The median rate of FEV1 decline was - 142 mL/month. Eight patients had follow-up spirometry at 6 months post ATG. All eight (8/16, 50%) had attenuated decline or improvement in FEV1 in 4 and 4 patients, respectively. Four patients with shorter follow-up post ATG (2 to 4.5 months) have also responded to ATG (1 unchanged, 2 improved and 1 attenuated decline in FEV1). At the time of data censoring, responders had a median survival of 11 months. Baseline FEV1 was lower in non-responders. Five of them declined rapidly and died. Serum sickness was diagnosed in one patient post ATG. Three patients required dose reductions or slower infusion rate due to tolerability. Conclusions: Attenuated decline, stabilization, or improvement in FEV1 was seen in 68% (11/16) of patients at any time post ATG. Four patients with early BOS (stages 1 and 2) had improved FEV1 after ATG. Even in patients with late CLAD (BOS s-3 and 4, or on chronic oxygen therapy) ATG was of some benefit (partial response in 6/12, 50%). Our outcomes are consistent with previous reports and suggest that ATG at lower cumulative doses could benefit patients with CLAD.
Volume
209
First Page
A3733
