Pulmonary arterial hypertension in autoimmune diseases: an analysis of 19 cases from a medical center in northern Taiwan.

BACKGROUND AND PURPOSE: Pulmonary arterial hypertension (PAH), a serious complication of autoimmune diseases, has rarely been reported in Taiwan.

METHODS

Nineteen patients with various autoimmune diseases diagnosed with PAH at Taipei Veterans General Hospital from 2002 to 2004 were enrolled; the underlying autoimmune diseases included systemic lupus erythematosus (n = 6), primary Sjögren's syndrome (n = 5), systemic sclerosis (n = 4), adult-onset Still's disease (n = 2), and mixed connective tissue disease (n = 2). The characteristic manifestations of underlying autoimmune diseases and the clinical features of PAH were analyzed.

RESULTS

There were 16 female and 3 male patients. The median age at onset of PAH was 44 years and the mean right ventricular systolic pressure (RVSP) was 67.9 mm Hg. Patients without pneumonitis had a significantly higher RVSP value than those with pneumonitis (77.5 +/- 24.3 vs 54.8 +/- 18.4 mm Hg, p=0.041). Four out of 7 patients (57.1%) with RVSP >or=80 mm Hg and 1 out of 12 patients (8.3%) with RVSP <80 mm Hg died. In all of the 19 patients, the severity of RVSP was significantly correlated with serum uric acid (UA) level (r = 0.686, p=0.001). Among the PAH patients without pneumonitis, the severity of RVSP inversely correlated with the diffusion capacity of the lung for carbon monoxide (DLCO) [r = -0.856, p=0.003]. The characteristic manifestations of underlying autoimmune diseases included a high incidence of Raynaud's phenomenon (15/19, 78.9%), a high titer of antinuclear antibody (13/17, 76.5%), positive anti-ribonucleoprotein antibody (8/15, 53.3%), hypergammaglobulinemia (15/19, 78.9%), hyperuricemia (13/19, 68.4%), and less renal involvement.

CONCLUSIONS

PAH in autoimmune diseases could be potentially fatal with characteristic manifestations. Moreover, RVSP correlated directly with serum UA level and inversely with DLCO.