To report the clinical characteristics of primary Sjögren’s syndrome (pSS) in a teenage male whose initial and prominent manifestation was heart valve involvement, and to highlight the diagnostic value of autoimmune evaluation in patients with atypical cardiac presentations.

The clinical history, physical findings, laboratory data, imaging studies, salivary gland pathology, and treatment response of one patient were retrospectively analyzed. The case was summarized together with the disease characteristics discussed in the original manuscript, with emphasis on the relationship between valvular involvement and pSS.

A 19-year-old male was admitted because of recurrent nail cyanosis that had been present intermittently for several years. He did not complain of classic sicca symptoms such as dry mouth or dry eyes, and he had no history of rash, fever, arthralgia, oral ulcers, genital ulcers, or uveitis. Routine examination identified mitral valve prolapse, and further rheumatologic evaluation showed a positive speckled antinuclear antibody at a titer of 1:320, together with positive anti-SSA/Ro and anti-SSB/La antibodies at a titer of 1:320. Labial salivary gland biopsy demonstrated typical focal lymphocytic infiltration consistent with pSS. Complement levels and a broad panel of autoantibodies, including rheumatoid factor, anti-CCP, anti-RNP, anti-Sm, anti-dsDNA, and ANCA, were negative. Chest CT, CTPA, abdominal ultrasonography, serial electrocardiography, and most routine laboratory tests were unremarkable. Echocardiography revealed prolapse of the A2 area of the anterior mitral valve with slight mitral regurgitation. Schirmer’s test was negative. According to the 2012 American College of Rheumatology classification criteria, the diagnosis of pSS was established on the basis of autoantibody positivity and characteristic salivary gland pathology. After treatment with hydroxychloroquine, the patient’s cyanosis improved. This case shows that valvular disease may precede glandular symptoms and may be the major clue leading to the diagnosis in unusual demographic groups such as adolescent or young adult males.

Primary Sjögren’s syndrome can rarely present with heart valve involvement as the initial and prominent manifestation, even in the absence of overt sicca symptoms. For patients with unexplained valvular abnormalities accompanied by positive autoimmune serology, especially anti-SSA/Ro and anti-SSB/La antibodies, pSS should be considered. Early immunologic workup and salivary gland biopsy may help avoid missed or delayed diagnosis.