Are salivary flow rates associated with histopathologic aspects in patients with rheumatoid arthritis?

The aim of this retrospective cross-sectional study was to verify the association between salivary flow rates (SFR) and the histopathologic aspects of labial salivary glands (LSG) in patients with rheumatoid arthritis (RA). Patients presenting rheumatologic diseases referred for oral evaluation were included in the study if they had RA and had SFR measured and LSG biopsy performed. Patients were excluded if they had systemic conditions that affect SFR or if they were being treated for hyposalivation. Cases without enough material for histopathologic analysis were also excluded. Data were collected through questionnaires, oral examination, resting and stimulated SFR, and LSG biopsies. A histopathologic reevaluation was carried out in order to seek for additional histopathologic aspects. Fifty-one patients met the inclusion criteria. The mean age was 53.5 years (25-77), and 94.1% were women. The median resting and stimulated SFRs were 0.24 mL/min and 1.02 mL/min, respectively. The presence of lymphocytic focus and fibrosis were significantly associated with stimulated SFR, but not with resting SFR. The odds ratio of patients who had hyposalivation for presenting a positive lymphocytic focus was 7.33 (confidence interval CI: 1.53-35.23) by the stimulated technique, and 2.56 (CI: 0.57-11.40) in resting SFR. In the medical records, 14 (31.80%) patients had been diagnosed with secondary Sjögren's syndrome. In conclusion, stimulated SFR represent a good screening test to predict lymphocytic focus in LSG in patients with RA, which represents the most specific test to diagnose Sjögren's syndrome.