Systemic lupus erythematosus in a multiethnic US Cohort LUMINA XLVIII: factors predictive of pulmonary damage

Abstract

The objective of this study was to determine the factors predictive of time to the occurrence of pulmonary damage in systemic lupus erythematosus (SLE). Six-hundred and twenty-six SLE patients from a multiethnic (Hispanics, African Americans and Caucasians) longitudinal study of outcome were studied. Pulmonary damage was defined as per the Systemic Lupus International Collaborating Clinics Damage Index. Socioeconomic-demographic, clinical, genetic, serological features, pharmacologic treatments, behavioural, psychological and disease activity [as per the Systemic Lupus Activity Measure-Revised (SLAM-R)] were examined. Factors associated with time to the occurrence of pulmonary damage were examined by Cox proportional hazards regressions. A Kaplan-Meier survival curve was also examined. Forty-six (7.3%) patients had pulmonary damage after a mean (SD) total disease duration of 5.3 (3.6) years. Among those patients, 25 had pulmonary fibrosis, 12 pulmonary hypertension, eight pleural fibrosis, four pulmonary infarction and four shrinking lung syndrome. Seven patients had more than one type of lung damage. Cumulative rates of pulmonary damage at five and 10 years were 7.6% and 11.6%, respectively. In the multivariable analyses, age (HR = 1.033, 95% CI 1.006-1.060; P = 0.0170), pneumonitis (HR = 2.307, 95% CI 1.123-4.739; P = 0.0229) and anti-RNP antibodies (HR = 2.344, 95% CI 1.190-4.618; P = 0.0138) were associated with a shorter time to the occurrence of pulmonary damage while photosensitivity (HR = 0.388, 95% CI 0.184-0.818; P = 0.0128) and oral ulcers (HR = 0.466, 95% CI 0.230-0.942; P = 0.0335) with a longer time. Pulmonary damage is relatively common in SLE. Age, pneumonitis and anti-RNP antibodies were associated with a shorter time to the development of permanent lung disease.