To determine the frequency and relative risk of bronchial hyperreactivity to methacholine in systemic sclerosis patients with or without associated Sjögren's syndrome.
A prospective study of 56 patients with systemic sclerosis (42 with the diffuse and 14 with the limited variant; 24 with associated Sjögren's syndrome), 57 with primary Sjögren's syndrome, and 61 healthy controls.
Bronchial hyperreactivity (BH) was present in 6.5% of the healthy controls, 25% of the systemic sclerosis patients without associated Sjögren's syndrome, 42.2% of those with primary Sjögren's syndrome, and in 50% of those with systemic sclerosis with associated Sjögren's syndrome. The presence of BH did not correlate with age, disease duration, chest radiograph abnormalities, respiratory, and immunological data. The subgroup of subjects with the limited variant of systemic sclerosis more frequently had associated BH than did those with the diffuse variant of the disease; coexisting Sjögren's syndrome further increased this frequency.
In agreement with previous studies, we have confirmed the high prevalence of bronchial hyperreactivity in primary Sjögren's syndrome; systemic sclerosis likewise appears to be associated with an increased frequency of bronchial hyperreactivity compared with healthy control subjects. There is evidence also that the coexistence of Sjögren's syndrome and systemic sclerosis further increases the frequency and the calculated relative risk of developing bronchial hyperreactivity.