To study which clinical and immunological factors may be associated with low salivary and lacrimal flow in patients with primary Sjögren's syndrome (SS). Are the lacrimal and salivary flows influenced by age of the patient, age at diagnosis, disease duration, or findings in the biopsies of the minor salivary glands, or are immunological factors of importance for reduced flow rates?
In total 72 patients (mean age 57 yrs and disease duration 13.5 yrs) with primary SS diagnosed according to the European classification criteria were evaluated objectively by serological testing and by measures of exocrine gland function, such as unstimulated whole saliva collection (UWSC) and by Schirmer I test.
Salivary flow (UWSC) in 72 patients with primary SS correlated to the presence of antinuclear antibodies (ANA) (r = -0.32, p = 0.006) and to anti-SSA/SSB (r = -0.31, p = 0.010). No such correlation was seen for the lacrimal flow, and there was no mutual correlation between lacrimal and salivary flow. UWSC was significantly lower in patients with anti-SSA versus those without anti-SSA (1.63 ml vs 2.63 ml; p < 0.007), while such a significant difference was not observed in the presence versus absence of anti-SSB. The salivary and lacrimal flow was not significantly affected by age of the patient, and did not correlate to age at diagnosis, sex, disease duration, rheumatoid factor finding, or findings in minor salivary gland biopsies.
Salivary flow in patients with primary SS was negatively correlated with immunological factors such as ANA and anti-SSA/SSB, in contrast to low lacrimal flow, where no such correlation was seen. There was no association of lacrimal and salivary flow with age of patient, age at diagnosis, disease duration, and findings in minor salivary gland biopsies. The results indicate that reduced salivary flow is closely associated with immunological factors, and is not associated with the age of the patient or infiltration of lymphocytes in salivary glands.