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 mu L 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.