The salivary concentrations of
immunoglobulins and total
proteins and the salivary flow rate (measured by the method of Deniker et al.) were determined in 29 patients with
keratoconjunctivitis sicca and
xerostomia and in 11 healthy subjects. According to Fox criteria the group pf 29 patients was divided into two groups: 14 patients with primary Sjögren's syndrome (pSS) and 15 patients with
sicca syndrome (SS). The
IgA salivary levels were significantly higher in the patients with pSS than in the patients with SS (p < 0.05) and in the healthy subjects (p < 0.001). Moreover the
IgG and
IgM salivary levels in the first group of patients were higher than in the group of patients suffering from
sicca syndrome (p < 0.05) and in the control group (p < 0.02). The salivary flow rate of the patients with pSS and
sicca syndrome was lower when compared with the control group (p < 0.005). No significant correlation was found between the salivary flow rate and the
immunoglobulins in the three groups of patients. The salivary flow was inversely correlated (p < 0.01) only with the
IgA levels in all 40 subjects. The salivary total
proteins were significantly elevated in pSS patients when compared with the SS patients (p < 0.04) and with the control group (p < 0.01). The
immunoglobulins/total
proteins ratios in saliva were significantly higher in the first group than in the other groups (p < 0.005) for the
IgG and in the first group than in the SS patients (p < 0.05) for the
IgM; no significant differences were noted for the
IgA. The bioptic focus scores, graded according Greenspan's criteria, of minor salivary glands of 20 patients with pSS or
sicca syndrome were directly correlated with a high significance (p < 0.001) to
IgG salivary levels and with a lower significance (p < 0.05) with
IgM salivary levels. No significant correlation was found between the bioptic focus scores and the
IgA levels. The present results demonstrated a high specificity (100%) and a good sensitivity (86%) of the assessment of salivary
IgG for the diagnosis of pSS. The sensitivity of the salivary levels of
IgA was higher than that of
IgG (93%) but the specificity was low (50%); on the contrary the specificity of the assessment of salivary
IgM was good (92%) but the sensitivity was low (60%). This study therefore indicated that the assessment of salivary
IgG has a great value for the diagnosis of pSS because
IgG levels are related to the amount of lymphoplasmocytic infiltration.(ABSTRACT TRUNCATED AT 400 WORDS)