IL-10 Measurement in Aqueous Humor for Screening Patients with Suspicion of Primary Intraocular Lymphoma

PURPOSE: To determine the value of IL-10 measurement in aqueous humor (AH) for screening in primary intraocular lymphoma (PIOL). METHODS: One hundred consecutive diagnostic or therapeutic vitrectomies were performed in patients with uveitis. During surgery, 100 microL of both AH and pure vitreous was taken. IL-10 levels were determined with a standard quantitative sandwich enzyme immunoassay technique. Patients were distributed in two groups: 51 patients with proven PIOL, 108 patients with uveitis divided into 74 with uveitis of proven etiology and 34 with idiopathic uveitis. Groups were compared by ANOVA and the Tukey-Kramer test or nonparametric Wilcoxon test. Distributions were compared by using the chi(2) test. Segmentation was derived from the ROC curves by choosing a tradeoff between sensitivity and specificity. RESULTS: In patients with PIOL, IL-10 mean values were 2205.5 pg/mL (median: 1467 pg/mL) in the vitreous and 543.4 pg/mL (median: 424 pg/mL) in AH. In patients with uveitis (idiopathic and diagnostic uveitis), mean values were 26.6 pg/mL (median: 8 pg/mL) in the vitreous, and 21.9 pg/mL (median: 8 pg/mL) in AH. IL-10 mean values were significantly different between patients with PIOL and patients with uveitis (P < 10(-3)). The areas under the curves were 0.989 and 0.962 for vitreous and AH, respectively. A cutoff of 50 pg/mL in the AH was associated with a sensitivity of 0.89 and a specificity of 0.93. In the vitreous, a cutoff value of 400 pg/mL yielded a specificity of 0.99 and a sensitivity of 0.8. CONCLUSIONS: Diagnosis of PIOL is often made months or years after the initial onset of ocular symptoms. Cytology remains the gold standard for diagnosis. However, measurement of IL-10 in the AH is a good screening test to reduce diagnostic delays.