Vital prognosis in intrathoracic sarcoidosis with special reference to pulmonary function and radiological stage

Abstract

A follow-up of 254 patients with intrathoracic sarcoidosis has been carried out after a median of 27 yrs from the diagnostic admission. All patients could be traced. At the end of follow-up there was no excess mortality (80 deaths observed versus 65.5 expected). However, during the first 20 yrs of follow-up a slight excess mortality was seen. Thirty three out of the 80 deaths were related to sarcoidosis. No excess number of deaths from lung cancer or lymphoma was observed. Erythema nodosum was of no prognostic significance concerning survival. X-ray stage was related to survival with a significant excess mortality for stage 3. Early clearing of X-ray changes gave a favourable vital prognosis. Survival was related to lung function, and for forced expiratory volume in one second (FEV1), FEV1/forced vital capacity (FVC) index and total lung capacity (TLC) this relationship reached levels of statistical significance. In multivariate Cox regression models, with age and sex entered as covariates, the same parameters were found to be significant predictors of mortality. Patients with FEV1 < or = 50% predicted had an increased mortality risk of 4.2 (95% confidence interval 1.8-9.6) when compared to patients with FEV1 > 80% predicted. Likewise, patients with TLC < or = 80% predicted had a mortality risk of 2.6 (1.5-4.5) when compared to patients with TLC > 80% predicted. In conclusion, a modest excess mortality was observed during the first 20 yrs of follow-up. Furthermore, both X-ray staging and lung function at the time of diagnosis influenced long-term mortality in patients with intrathoracic sarcoidosis.