Ten year follow up of pulmonary function in patients with primary Sjogren's syndrome

Objectives-To follow up a previous report on the lung function of patients with primary Sjogren's syndrome (SS), and describe the findings having foll owed up this cohort for a median duration of 10 years (range 8-12 years). Methods-30 patients fulfilling Fox's criteria for definite or probable prim ary SS were assessed within six months of diagnosis and after a median dura tion of four and then 10 years by a clinical examination, chest radiograph, and lung function studies (FEV1, FVC, TLCO, and KCO). Results-At baseline, symptomatic dyspnoea was a common finding, reported by 13/30 patients, of whom two had evidence of fibrosing alveolitis on plain chest radiograph. Five patients had a carbon monoxide transfer factor (TLCO ) more than two standardised residuals below the predicted value. After fou r years' follow up two further patients developed radiological fibrotic cha nges and there were significant reductions in TLCO (p<0.02) and transfer co efficient (KCO) (p<0.02) compared with the baseline measurements. At 10 yea rs follow up four patients had died and four were lost to follow up. One pa tient with fibrosing alveolitis had died from chest disease. There were no further cases of pulmonary fibrosis identified on plain chest radiograph. T he lung function studies showed no further deterioration from the results f ound at year four with significant improvements in both TLCO (p<0.001) and KCO (p<0.001). Those patients who were anti-Re antibody positive had signif icantly lower transfer factors than patients with primary SS without this s erological marker (p<0.02). Conclusion-This long term follow up of lung disease in primary SS is reassu ring, and suggests that most patients do not develop progressive lung disea se. Pulmonary disease occurs predominantly in anti-Re antibody positive pat ients and presents early in the course of the disease.