Fas mRNA expression in blood is reduced during episodes of human corneal graft rejection

Our purpose is to examine levels of Fas mRNA expression in blood during human corneal transplant rejection. Fas mRNA expression was detected by reverse transcription-PCR in blood from normal controls, corneal recipients at the time of transplantation and during episodes of rejection. Samples taken at the time of a corneal rejection episode showed Fas mRNA levels were significantly lower in these patients than either normal controls (P = 0.017) or corneal transplant recipients not undergoing graft rejection (P = 0.00052). Serial samples from five patients who suffered an episode of rejection showed that the level of Fas mRNA is reduced during the rejection episode and subsequently recovers. These results indicate low levels of Fas mRNA in blood may have a role in corneal transplant rejection.