Study objective: To evaluate pulmonary findings in patients with prima
ry Sjogren's syndrome (SS). Design: Prospective data collection. Patie
nts: Seventeen consecutive nonsmoking patients with primary SS. Measur
ements and results: Mild radiologic parenchymal changes were seen in t
wo patients, Pulmonary hyperinflation (residual volume/total lung capa
city [RV/TLC] percent ratio measured minus [-] RV/TLC percent ratio pr
edicted greater than or equal to 8) was observed in 9 (53%) patients,
whereas obstructive and restrictive changes were infrequently found in
ordinary spirometry (FVC, FEV(1), FEV%) (none and two cases, respecti
vely). Patients with SS with hyperinflation had significantly lower ma
ximal expiratory flow MEF50 (<0.05), MEF25 (p<0.05), and higher total
lung capacity (p<0.05) and FRC (p<0.05) values as compared with those
patients with SS without hyperinflation, They were also more frequentl
y dyspnoeic (six vs none, p<0.02) and had higher mean serum B-2-microg
lobulin levels (3.6+/-1.0 mg/L vs 2.6+/-0.7 mg/L, p<0.025). The levels
of serum beta(2)-microglobulin correlated inversely with FVC (r=-0.58
3, p<0.01), FEV(1) (r=-0.533, p<0.05), diffusing capacity for carbon m
onoxide (r=-0.580, p<0.01); its correlation with RV/TLC percent ratio
was positive and relatively significant (r=0.447, 0.05< p<0.10). Concl
usions: Pulmonary hyperinflation associated with diminished peripheral
spirometric flow values is frequently found in patients with primary
SS, This together with the correlation of disturbed lung function para
meters to elevated serum Pz-microglobulin levels suggests that lungs a
nd especially small airways may be an usual target organ in primary SS
.