Serologic profile and clinical markers of Sjögren syndrome in patients with rheumatoid arthritis.

OBJECTIVE: The aim of this study was to evaluate the clinical relevance of rheumatoid factor (RF) and antibodies against cyclic citrullinated peptides (anti-CCP) in patients with Sjögren syndrome (SS) secondary to rheumatoid arthritis (RA).

METHODS: The study included 118 individuals, and the subjects were divided into three groups: rheumatoid arthritis (RA; n = 46), RA with secondary Sjögren syndrome (RA/SS; n = 20) and healthy controls (C; n = 52). Clinical and laboratory characteristics, including ocular, oral, and serum markers, anti-CCP, and rheumatoid factor (RF), were compared in addition to biopsy of labial minor salivary glands.

RESULTS: The RA group exhibited unstimulated salivary flow rate, and Schirmer test results were similar to those for C and higher than those for RA/SS (P < .05). Furthermore, the frequency of xerophthalmia and xerostomia was similar among the RA and C groups, and much higher in the RA/SS group (P < .05). Anti-CCP positivity and serum levels were similar in both RA groups, irrespective of SS diagnosis (RA × RA/SS; P > .05). RF presented a similar frequency and serum level between the RA and RA/SS groups (P > .05).

CONCLUSIONS: Secondary SS seems to be a cluster of oral and ocular symptoms among patients with RA. Anti-CCP and RF are not relevant to evaluate the presence of SS among these patients.