Evolution of Systemic Sclerosis-Associated Interstitial Lung Disease One Year After Hematopoietic Stem Cell Transplantation or Cyclophosphamide

Abstract

Objective: Hematopoietic stem cell transplantation (HSCT) and cyclophosphamide (CYC) are treatment options for progressive systemic sclerosis associated with interstitial lung disease (SSc-ILD). The aims of our retrospective observational study were to evaluate: 1) the evolution of SSc-ILD in SSc patients treated with HSCT (assessed by high-resolution computed tomography [HRCT]; a group of patients treated with CYC was included as frame of reference); 2) how results of pulmonary function tests (PFTs) are associated with HRCT findings; and 3) which factors predict ILD reduction.

Methods: We semiquantitatively scored total ILD extent, reticulations, and ground-glass opacities (GGO) scores at baseline and at the 1-year HRCTs of SSc patients treated with HSCT or CYC. Linear association between changes in HRCT scores and PFT results and predictors of ILD improvement were studied.

Results: We included 51 patients (those treated with HSCT [n = 20] and those treated with CYC [n = 31]). The mean change in total ILD score was -5.1% (95% confidence interval [95% CI] -10.2, 0.0) in the HSCT treatment group (P = 0.050), and -1.0% (95% CI -4.3, 2.3) in the CYC treatment group (P = 0.535). For all patients, the evolution of HRCT scores was weakly associated with relative changes in PFT results. In univariate logistic regression, higher ground-glass opacities, higher total ILD, and lower single-breath diffusing capacity for carbon monoxide scores at baseline predicted improvement of ILD extent after treatment, but a multivariable model could not be built to assess independency of predictors.

Conclusion: One year after treatment with HSCT, a nonsignificant but clear reduction of SSc-ILD extent was observed. Changes in PFT results were associated with changes in HRCT scores but the correlation was weak and cannot be considered conclusive.

Figure 1

Proportion of improved, stable, or progressed patients 1 year after treatment with hematopoietic stem cell transplantation (HSCT) or cyclophosphamide (CYC). Improvement or progression were defined as absolute changes >5% in total interstitial lung disease (ILD) score, while stability identified patients with no more than 5% ILD extent modification at follow‐up.

Figure 2

Evolution of high‐resolution computed tomography scores 1 year after treatment shown in descending order from maximum improvement to maximum progression of interstitial lung disease (ILD) score. Individual changes from baseline to follow‐up of total (ILD) score (A), ground‐glass opacities (GGOs) score (B), and reticular pattern (RET) score (C) are shown. Bars represent individual patients. HSCT = hematopoietic stem cell transplantation; CYC = intravenous cyclophosphamide.

Figure 3

Correlations between evolution of interstitial lung disease (ILD) and changes in pulmonary function tests. Scatter plots of bivariate correlation, in the combined population, between changes in total ILD and relative changes in forced vital capacity (FVC) (A) or single‐breath diffusing capacity for carbon monoxide (DLco) (B). At follow‐up compared with baseline, changes in total ILD score were calculated as absolute differences, and changes in FVC and DLco were calculated as relative changes.