A LONGITUDINAL-STUDY OF LUNG IMPAIRMENT IN PATIENTS WITH PRIMARY SJOGRENS-SYNDROME

Objective. A longitudinal evaluation of lung involvement in primary Sj ogren's syndrome (SS). Methods, Eighteen non-smoking women fulfilling the European criteria for primary SS were followed for 55 months (rang e 26-137 mos.). These were consecutive patients with exclusion for cur rent smokers and patients with lung diseases. Every patient underwent clinical examination, chest radiographs and lung function tests (spiro graphy, flow/volume loop and CO lung diffusing capacity measurements). No patient was given any immunosuppressive or mucolytic therapy. Resu lts. Cough, dyspnea on exertion and recurrent bronchitis were observed in 50, 40 and 20% of the patients respectively and their frequency di d not change with time. Chest radiographs were and remained normal. At presentation, lung volumes and diffusing capacity were in the normal range, whereas expiratory flows in the small airways tended to be in t he low range. With time, the peak expiratory flow (PEF) significantly increased (95.8 +/- 4.6 v 103.5 +/- 4.6, mean +/- SE, % of predicted, Wilcoxon, p < 0.05) whereas the lung transfer factor for CO (TLCO) and the transfer coefficient (KCO = TLCO/alveolar volume) decreased (92.9 +/- 4.0 v 87.0 +/- 4.0 and 89.7 +/- 2.4 v 84.2 +/- 2.6 respectively, p < 0.05 for both). The TLCO decrease, corrected for the duration of f ollow-up, correlated with the titers of IgA circulating immune complex es (CIC) at presentation and to a lesser extent with the occurrence of cough. Conclusion. During the follow-lip of these primary SS patients , respiratory, symptoms did not change, the recurrent respiratory infe ction rate was low and no cases of pulmonary hypertension or lymphoma was observed. The diffusion capacity decrease was associated with IgA CIC titers at presentation. This impairment could contribute to dyspne a during its evolution over a lifetime but is too slight to explain th e dyspnea on exertion seen in most of our patients.