Serum 1,25(OH)2 Vitamin D and 25(OH) Vitamin D Ratio for the Diagnosis of Sarcoidosis-Related Uveitis

ABSTRACTPurpose: The diagnostic workup of uveitis is challenging, with 30 to 50% of cases remaining of undetermined etiology despite multiple investigations. Sarcoid granuloma-related increase of 1,25(OH)2D levels could be helpful for the diagnosis of ocular sarcoidosis.Methods: Monocentric retrospective cohort study of patients for whom serum 25(OH)D and 1,25(OH)2D levels were measured during the etiologic workup of unexplained uveitis in a tertiary referral center. The diagnoses of uveitis’ underlying diseases were established according to international diagnostic criteria.Results: Fifty-nine patients were included. The diagnosis of defined, presumed or probable sarcoidosis was made in 37% of patients while 41% of cases remained of undetermined origin. The median serum levels of 25(OH)D in patients with ocular sarcoidosis and in those with uveitis due to another cause were 34.50 [21.2–40.8] and 43.20 [32.2–58.3] nmol/L (P=0.02), respectively. In the same subgroups of patients, the median serum levels of...