Autoantibodies and Relapse of Systemic Sclerosis After Autologous Hematopoietic Cell Transplantation.

OBJECTIVE

Autologous hematopoietic cell transplantation (HCT) is an effective treatment for a subset of patients with systemic sclerosis (SSc). Unfortunately, relapse is a significant problem, with no available tests to predict relapse. We studied whether relapse is associated with pre- or post-HCT serum levels of SSc-related autoantibodies.

METHODS

The cohort comprised 38 consecutive evaluable patients with SSc who underwent HCT at a single center and were followed for a median of 33 months. Sixteen patients (42%) relapsed at a median of 14 months post-HCT. Autoantibody levels were determined by immunoassays.

RESULTS

Regarding pre-HCT autoantibodies, in univariate analyses, the cumulative incidence of relapse (CIR) was lower in anti-RNA polymerase III (ARA)-positive than ARA-negative patients (hazard ratio [HR] 0.21, P = 0.04). Conversely, the CIR was higher among patients with positive anti-Ro52, although this difference was not statistically significant (HR 2.90, P = 0.053). The CIR was similar in patients positive and negative for antitopoisomerase antibody (ATA; ie, Scl-70) or antinuclear antibody (ANA). In bivariate analyses that included older age as a risk factor for relapse, pre-HCT ARA was still associated with relapse (HR 0.21, P = 0.04). This was not the case for Ro52 (HR 2.21, P = 0.16). Regarding post-HCT autoantibody level trajectory, there was no significant difference between patients with vs without relapse.

CONCLUSION

Positive ARA pre-HCT is associated with reduced relapse risk, and post-HCT autoantibodies do not appear to be associated with relapse risk.