Long-Term Outcomes of Reduced-Intensity Conditioning Hematopoietic Stem Cell Transplantation for Patients With Systemic Sclerosis With Impaired Cardiac Function.

Abstract

High-intensity conditioning autologous hematopoietic stem cell transplantation (AHSCT) is standard of care for patients with advanced systemic sclerosis (SSc). The role of reduced-intensity conditioning (RIC) before AHSCT in this population remains unclear. We conducted this study to determine the long-term outcomes of RIC AHSCT in patients with SSc and cardiac involvement. We evaluated 42 participants who sequentially underwent RIC AHSCT 5 years after the last participant was treated. Progression was defined as reinitiation of disease-modifying antirheumatic drugs or worsening end-organ failure. We determined overall survival (OS) and progression-free survival (PFS) by the Kaplan-Meier method and identified pretransplant characteristics associated with OS or PFS by multivariable Cox regression. All participants had evidence of SSc with cardiac involvement. Ninety-five percent of participants had interstitial lung disease. The median percent predicted forced vital capacity and diffusing capacity of the lungs for carbon monoxide was 62% and 45%, respectively. The 5-year OS was 75% (95% confidence interval [CI] 63%-90%), and 5-year PFS was 59% (95% CI 46%-76%). Pretransplant supplemental oxygen use (hazard ratio [HR] 7.88, P < 0.01) and elevated B-type natriuretic peptide (BNP; HR 1.005 per pg/mL, P < 0.01]) were associated with mortality. Anti-Scl-70 antibody positivity (HR 3.03, P = 0.02) was associated with progression. Twenty-four participants (57%) who did not use supplemental oxygen and had BNP <100 pg/mL pretransplant had a 5-year OS of 91% (95% CI 80%-100%). RIC AHSCT is safe for patients with severe manifestations from SSc. Supplemental oxygen use, elevated BNP, and anti-Scl-70 antibody positivity were risk factors for worse outcomes after RIC AHSCT.