Change in Antinuclear Antibodies After Lung Transplantation in Patients with Systemic Sclerosis

Objectives: Lung transplantation (LT) is a rescue therapy for end-stage pulmonary diseases, including systemic autoimmune diseases. The aim of this study was to analyse the evolution of patients with systemic sclerosis (SSc) who, after undergoing LT, become negative for antinuclear antibodies (ANA) and to assess whether they have different clinical and prognostic characteristics than patients who do not become negative. Material and Methods: A retrospective, descriptive analysis was performed over a cohort of patients with a diagnosis of SSc, who underwent unilateral or bilateral LT between 2006 and 2021 at the Vall d'Hebron University Hospital. Clinical and analytical data were obtained from these patients by reviewing their electronic medical records. Two groups of patients were compared: those who tested negative for ANA after LT and those who did not. Statistical analysis was performed with SPSS Statistics 20.0. Results: Eighteen patients were included. The most frequent indication for LT was interstitial lung disease (ILD) combined with pulmonary hypertension (PH), in 13 (72%) patients. All had ANA before the LT (n = 18), and regarding specific SSc autoantibodies, anti-topoisomerase I was presented in 44% (n = 8), anti-U11/U12RNP in 17% (n = 3), anti-RNA Polymerase III in 11.1% (n = 2), anti-Ro52 in 11% (n = 2) and anti-centromere in 6% of individuals (n = 1). 39% (n = 7) of the patients had negative post-LT ANA, 44% (n = 8) had declining titres, and 17% (n = 3) had stable ANA titres. Titres did not increase in any case after LT. Those patients who became ANA-negative after LT were those who had significantly lower titres before LT. No statistically significant differences between groups were found related to pre-LT clinical characteristics, immunosuppressive regimen applied after LT, or in post-LT outcomes. A non-significant trend towards better survival was observed in patients who became ANA negative, with a cumulative survival at 5 years of 85.7% compared to 72.7% among those who remained ANA-positive. Conclusions: Most patients with SSc clear ANA or reduce their levels after LT. A trend towards better survival was observed in this group, compared to the group of transplanted patients who remained positive.