Introduction: Cytomegalovirus (CMV) infection is the most common viral infection after orthotopic liver transplantation commonly occurs within 3 months after transplantation and may lead to severe CMV disease, which directly or indirectly reduces the graft and patient survival. There are two prophylaxis methods including universal prophylaxis and preemptive therapy. We conduct this study to find the prevalence of CMV infection in a group of Iranian liver recipients who received preemptive therapy and evaluate the effectiveness of this approach in prevention of CMV disease after liver transplantation. Besides, we are to find the risk factors associated with CMV infection after liver transplantation in our patients.

Materials and Methods: Patients who orthotopic liver transplantation in Imam Khomeini Hospital, Tehran University of Medical Sciences from 2006 to 2013 who survived for more than two weeks after liver transplantation were enrolled in the study. The data of recipients were recorded prospectively. After transplantation, all patients were examined for pp65-antigen weekly after liver transplantation until 90 days. CMV reactivation was concluded when a recipient had the PP65-antigenemia equal or greater than 1/50,000 leukocytes. In patients with CMV reactivation, preemptive therapy with intravenous Gancylovir 5 mg/kg twice a day was immediately started and continued for at least 21 days and until two consecutive CMV antigen became undetectable.

Results: From January 2006 until February 2013, 161 liver transplantations were performed in 155 patients. Ten patients who died in two weeks after liver transplantation were excluded. One-hundred and forty-five liver recipients were enrolled in the study. The overall mean age was 40±12.35 years (range=8-62) including 78 males (53.8%). The mean follow-up time was 27.1±19.7 months (range=5.2-80.6). Forty-six patients (31.7%) experienced CMV reactivation at mean of 56.4±67.3 days (range=12-445) post transplant. All CMV patients were sero-positive for CMV before transplant. The mean age of CMV Ag positive patients was 41.3±12 years (range=16-61) which was not significantly different compared with the control group (P=0.309). The number of females patients were significantly greater in the CMV Ag positive group compared with the control group (OR=2.3; P=0.02). The most common etiology of liver failure in the CMV group was autoimmune hepatitis following by cryptogenic and HBV related cirrhosis. There was no significant relationship between etiology of liver failure, pre and post transplant use of steroid, and rate of acute rejection and CMV reactivation (P=.357, P=.278, P=.595, and P=.297, respectively). Only one patient (2%) developed CMV disease at 22 days post transplant who was successfully treated. Six patients (13%) developed second episode of CMV reactivation at median of 43 days (range=10-176) after the first episode. All these six patients were also successfully with the same protocol.

Conclusions: The preemptive therapy with monitoring the PP65-antigenemia can be a safe and cost-effective approach against CMV in liver recipients. In our center, female patients are at the higher risk of developing CMV infection after liver transplantation.