Anti-CCP positivity in Sjögren’s syndrome without articular manifestations: a case report

Anti-cyclic citrullinated peptide (anti-CCP) antibodies are highly specific biomarkers for rheumatoid arthritis (RA) and strongly predict future development of inflammatory arthritis. Their presence in patients with sicca symptoms without articular manifestations presents diagnostic and prognostic challenges, as an isolated anti-CCP positivity is uncommon in primary Sjögren’s syndrome. A 46-year-old man presented with a three-year history of progressive dry eyes and dry mouth without musculoskeletal symptoms. Examination revealed dry oral mucosa, reduced salivary pooling, abnormal Schirmer’s test ≤5 mm/5 min), and decreased unstimulated whole salivary flow rate (≤ 0.1 mL/minute). Serologic testing showed markedly elevated anti-CCP (> 1000 U/mL) and mildly elevated rheumatoid factor (26.4 IU/mL), with negative anti-SSA and anti-SSB antibodies. Musculoskeletal ultrasound demonstrated no synovitis or erosions. Pathology result of minor salivary gland biopsy taken a year after the initial evaluation showed results suggestive of Focal Lymphocytic Sialadenitis(FLS). The patient fulfilled criteria for Sjögren’s syndrome and was treated with chloroquine and other symptomatic treatment, resulting in improvement of sicca symptoms. During four years of follow-up, he remained free of joint symptoms and imaging abnormalities despite persistently elevated anti-CCP levels. This case demonstrates that markedly elevated anti-CCP antibodies may occur in primary Sjögren’s syndrome without clinical evidence of rheumatoid arthritis, highlighting the need for long-term clinical monitoring.