Bronchoalveolar lavage cellular profiles in patients with systemic sclerosis-associated interstitial lung disease are not predictive of disease progression

Abstract

Objective: To evaluate the prognostic value of bronchoalveolar lavage (BAL) cellular profiles in patients with systemic sclerosis-associated interstitial lung disease (SSc-ILD).

Methods: BAL cellularity was examined in relation to mortality (n = 141), serial pulmonary function findings (n = 134), and "progression-free survival" (n = 134), by proportional hazards analysis. Baseline severity was quantified according to the extent of disease on high-resolution computed tomography, the diffusing capacity for carbon monoxide, and the presence or absence of pulmonary hypertension. Mortality was subclassified into overall mortality (during 10 years of followup), early mortality (occurring within 2 years of presentation), and late mortality (occurring 2-10 years after presentation).

Results: Overall mortality was associated with neutrophilia on BAL (hazard ratio 2.23 [95% confidence interval 1.20-4.14], P = 0.01), but this effect was lost when disease severity was taken into account. Early mortality was associated with neutrophilia on BAL (hazard ratio 8.40 [95% confidence interval 1.91-36.95], P = 0.005), independent of disease severity. Late mortality was not associated with neutrophilia on BAL. The presence of neutrophilia on BAL was not associated with time to decline in pulmonary function or progression-free survival. Neither eosinophilia nor lymphocytosis on BAL was associated with mortality, rapidity of functional deterioration, or progression-free survival. These findings were unaltered when treatment status was taken into account.

Conclusion: BAL findings provide only limited prognostic information in SSc-ILD. Neutrophilia on BAL is linked to early mortality, but BAL findings are not linked to long-term survival or the rapidity of progression of lung disease. The usefulness of BAL to define alveolitis in SSc is questionable.