Abstract
Purpose:
Graft rejection greatly influences the prognosis of corneal transplantation. There is no quantitative method of predicting signs of rejection at present. Cytokines in tear fluid over time were investigated and the correlation with the occurrence of rejection was investigated.
Methods:
This is a prospective study. All patients underwent keratoplasties from August, 2011 to May, 2012 in Fukuoka University Hospital were included in the study. There were 6 cases of penetrating keratoplasty (PKP) and 2 cases of lamellar keratoplasty (LKP). Eighteen normal subjects were used as controls. All operations were conducted by the same surgeon. Tear fluid was extracted by the Schirmer method on preoperative day, on postoperative day 1, day 7, first month, third month, and sixth month respectively. Control subjects were healthy individuals without ocular or systemic infections or allergies. Tear fluid extraction was performed by adding 0.01M phosphate buffer pH7.2. Measurement of cytokines was carried out by the BDTM Cytometric Beads Array system (CBA) and BDTM FACS Canto II according to the manufacturer’s instructions. The concentrations of seven inflammatory cytokines (IL-2, IL-4, IL-6, IL-10, TNF, IFN-γ, and IL-17A) were measured.
Results:
The concentration of IL-6 was significantly higher in the cases of PKP (p = 0.03 ) and LKP on postoperative day 1. There was no increased in levels of other cytokines. Concentration of IL-6 was lowered to the preoperative level at first month. However concentration of IL-6 was increased again in the rejection group. Three rejection cases occurred after PKP (2 in the third month, and 1 in the sixth month). All concentrations of cytokines increased in the acute period of rejection. Only IL-10 was remarkably decreased in the chronic phase.
Conclusions:
The concentration of IL-6 was significantly higher on the postoperative day 1, and it took one month until the level normalized. IL-6 level increased at the time of rejection and IL-10 level decreased at the same time. IL-6 and IL-10 could be used as markers for keratoplasty rejection in human tears. However, more cases should be required to confirm the efficiency of cytokine measurement in tear fluids as a predictor of clinical status.
Keywords: 490 cytokines/chemokines •
462 clinical (human) or epidemiologic studies: outcomes/complications •
479 cornea: clinical science