To investigate serum and salivary neopterin and interferon-gamma as possible markers of immune system activation in primary Sjögren's Syndrome (pSS).
Serum and salivary neopterin and interferon-gamma concentrations were determined in 30 untreated patients with pSS and matched with several other clinical and laboratory parameters.
The mean concentration of neopterin was significantly higher in pSS patients (8.12+/- 3.36 nmol/L in serum and 9.50 +/-7.61 nmol/L in saliva) than in normal controls (p<0.05). Significant correlations were found between serum neopterin and beta2-microglobulin, serum IgG as well as lip biopsy score. Salivary neopterin concentration was inversely related to Shirmer-I test, tear break-up time and stimulated salivary flow rate. Serum and salivary levels of interferon-gamma were normal and no correlation with the other parameters was found.
In pSS patients serum neopterin may represent a useful marker of cell-mediated immunity. On the other hand, salivary neopterin seems to reflect theglandular damage.