Background/Purpose: Lung transplantation is a potentially life-saving treatment for patients with systemic sclerosis (SSc) who have developed end-stage lung disease due to interstitial lung disease and/or pulmonary hypertension. However, many transplant programs are hesitant to offer lung transplantation (LTx) to those with SSc due to concerns about extra-pulmonary involvement that might affect short- and long-term survival. However, survival data for lung transplantation in SSc are sparse. The primary aim of this study was to determine whether adults with SSc have higher 1-year mortality rates after LTx compared to those with interstitial lung disease (ILD) or pulmonary arterial hypertension (PAH) not due to SSc. We hypothesized that adults with SSc would have higher 1-year mortality rates after LTx than those with ILD or PAH not due to SSc.

Methods: We performed a retrospective cohort study of adults who underwent double or single LTx in the United States between May 4, 2005 (the date of implementation of the lung allocation score) and September 14, 2012. Data were provided by the United Network for Organ Sharing, a non-profit organization that records data on all solid organ transplants performed in the US. Subjects were included if they were at least 18 years of age at the time of LTx; had a diagnosis of SSc, ILD, or PAH; and were transplanted at a center that has performed at least 1 LTx for SSc. Subjects were excluded if they had received a heart-lung transplant; if they received a LTx from a living donor; or if they had missing data on survival time. We modeled diagnosis (SSc) as the independent binary variable of interest in stratified Cox regression models where survival time was the dependent variable, adjusting for recipient, donor, and procedural factors (Table 1). We used multiple imputation to account for missing covariate data.

Results: A total of 3763 adults were transplanted during the study period and met inclusion criteria: 229 with SSc, 201 with PAH, and 3333 with ILD (Table 1). The 1-year unadjusted mortality rate following LTx per 100 person-years was 21.4 among adults with SSc, 19.0 among adults with PAH, and 17.8 among adults with ILD. A diagnosis of SSc was associated with a multivariable-adjusted 48% relative increase in the 1-year mortality rate compared to a diagnosis of ILD (HR 1.48, 95% CI 1.01-2.17). However, a diagnosis of SSc was not associated with a relative increase in the 1-year mortality rate compared to a diagnosis of PAH (HR 0.85, 95% CI 0.50-1.44).

Conclusion: Adults with SSc had a 48% increased risk of death at 1 year following LTx compared to adults with ILD, but no increase in risk of death at 1 year compared to adults with PAH. Rather than denying SSc patients LTx because of their SSc diagnosis, variables need to be identified that will enable risk stratification of these patients prior to LTx, with particular attention to modifiable risk factors.