A pilot study on the infiltrating cells and cytokine levels in the tear of fungal keratitis patients

Abstract

Aim: To determine the cellular profile and cytokine levels in the tear fluid of fungal keratitis patients. Materials and Methods: Tear samples were collected from six fungal keratitis patients (Group I) from active stages of the disease up to resolution. Tears collected from the following served as controls: uninfected fellow eye (Group II A) of Group I, patients undergoing cataract surgery (Group II B) and acute conjunctivitis (Group II C). The cellular profile was evaluated. Interleukines (IL-6, IL-8 and IL-1β) were estimated using sandwich enzyme immunoassay. Statistical analysis was carried out using nonparametric two-sample median test. Results: Polymorphonuclear leukocytes (PMN) were the predominant infiltrating cells in Group I. During the initial stages of fungal infection, levels of IL-6 and IL-8 in the tear samples were found to be significantly increased when compared with Group II A ( P = 0.019 for IL-6, P < 0.001 for IL-8). This was also true for IL -8 ( P = 0.008) levels in Group I and Group II B). While IL-6 levels decreased significantly towards healing, IL-8 remained slightly elevated even after healing. These cytokines were at the base level in Group II A. Lymphocytes and PMN were present in equal proportions in Group II C, which showed elevated levels of cytokines but not to the extent of Group I. Conclusion: This horizontal study indicates that understanding the nature of the inflammatory response in the tears of fungal keratitis patients is of considerable interest and warrants further investigations.