Clinical characteristics and prognosis of pulmonary renal syndrome in West China.

Pulmonary renal syndrome (PRS) is a rare and life-threatening syndrome. Interstitial lung disease (ILD) has been recently considered another phenotype of lung dysfunction in patients with PRS, but there are very limited data. The characteristics of fifty PRS patients were retrospectively reviewed after a 3-year follow-up, and the differences between PRS patients whose lung dysfunction presented as diffuse alveolar hemorrhage (DAH group) and those with interstitial lung disease (ILD group) were also analyzed. The median age at diagnosis of PRS patients was 50.78 ± 17.88 years, and the main symptoms at disease onset were proteinuria (94.00%), hemoptysis (68.00%), dyspnea (32.00%) and fever (12.00%). DAH patients were younger and had significantly lower hemoglobin levels, a higher incidence of hemoptysis, and higher serum creatinine levels at onset than ILD patients. Univariate analyses of PRS patients showed that respiratory failure and the initiation of mechanical ventilation predicted patient death and that the initiation of hemodialysis and higher serum creatinine levels at onset predicted ESRD. Multivariate analyses showed that respiratory failure and anti-GBM antibody positivity could independently predict patient death. Survival analyses showed that 1- and 3-year patient survival rates and ESRD-free survival rate were not significantly different between the two groups. ILD was another important phenotype of lung dysfunction in patients with PRS. Poor outcomes were observed in PRS patients with ILD and in PRS patients with DAH.