Minor salivary gland biopsy in the diagnosis of definite ocular sarcoidosis in paediatric granulomatous uveitis.

Abstract

Background: Non-infectious paediatric granulomatous uveitis (PGU) is a rare disease that is idiopathic in more than half of affected children. The diagnosis of definite ocular sarcoidosis (OS) must be supported by the presence of non-caseating granulomas detected in biopsy, and is therefore a challenge in children with PGU. This study investigated the utility of minor salivary gland biopsy (MSGB) in the diagnosis of definite OS in PGU.

Methods: Twenty-six consecutive children with PGU diagnosed between 2018 and 2023 and with a systematically performed MSGB within 3 months of the diagnosis were enrolled.

Results: The median age at PGU diagnosis was 11.6 (4.2-16.5) years, and 54% of the children were boys. PGU consisted mainly of bilateral (92%) pan-uveitis (96%). MSGB detected non-caseating granulomas (MSGB+) in 12/26 (46%) children. In all, 13 of the 26 (50%) children were diagnosed with definite OS, and 8 (31%) had idiopathic uveitis. MSGB had a sensitivity of 92%, and a NPV of 93% in the diagnosis of definite OS in children with PGU. Compared to MSGB- children, those who were MSGB + were more frequently older than 10 years of age at diagnosis (p = 0.02), had a higher rate of general signs (p = 0.003), extra-ocular organ involvement (p = 0.005) and polyclonal hypergammaglobulinaemia (p = 0.03). The most frequent extra-ocular organ involvements at OS diagnosis were renal (46%) and thoracic (46%). First-line therapy was systemic corticosteroids in 88% of the children. During a median follow-up time of 3.1 (0.6-6.3) years after PGU diagnosis, 88% of the children needed methotrexate and/or anti-tumour necrosis factor-alpha therapy to achieve inactive uveitis.

Conclusions: MSGB is useful to improve the diagnosis of OS and to reduce the incidence of uveitis considered idiopathic in PGU. MSGB could be considered in PGU patients, particularly those > 10 years of age with general signs and/or hypergammaglobulinaemia.