Usual interstitial pneumonia is the predominant histopathology in patients with systemic sclerosis receiving a lung transplant

Studies identifying nonspecific interstitial pneumonia (NSIP) as the predominant histopathology in systemic sclerosis-associated interstitial lung disease (SSc-ILD) have primarily utilised surgical lung biopsies in early disease. These case series may only reflect the histopathology of early disease and differ from the histopathology of advanced disease in those with respiratory failure.Patients receiving a lung transplant for a diagnosis of SSc at a single centre from 2000-2021 were included for retrospective analysis. All explanted lungs underwent histopathology review as part of routine care.127 patients with SSc received a native lung transplant during the study period. Usual interstitial pneumonia (UIP) was identified in 111 explants (87.4%), NSIP in 45 (35.4%) explants, organising pneumonia in 11 explants (8.7%), and lymphocytic bronchitis in 2 explants (1.6%). Areas of both UIP and NSIP were identified in 37 explants (29.1%), with only 9 explants (7.1%) showing neither UIP nor NSIP. Aspiration was identified on histology in 49 (38.6%) explants. Pathology results were available from a prior surgical lung biopsy for 19 patients, with 11 patients maintaining the same primary pathology on biopsy and explant (2 NSIP, 9 UIP) and 8 patients showing different pathology at the timepoints, all of whom had UIP on explant. Most patients (101, 79.5%) had evidence of pulmonary hypertension and vasculopathy on explant.UIP is the predominant histopathology in patients with SSc receiving a lung transplant, with many patients concurrently having both NSIP and UIP or showing progression from NSIP to UIP over time before transplant.