Factors that determi̇ned the graft survival and mortality in renal transplantation patients

Two billion people worldwide have serologic evidence of past or present hepatitis B virus (HBV) infection, and 350 million are chronically infected and at risk of developing HBV-related liver disease. Some 15–40% of chronically infected patients will progress to develop cirrhosis, progressing to liver failure and/or HCC. HBV infection and its clinical outcomes account for 500.000–1.200.000 deaths each year. The prevalence of HBV varies markedly between different regions of the world and is largely related to age at the start of the infection. The chance that acute infection will become chronic is 70–90% for perinatally acquired (vertical) infection and 20–50% for (horizontal) infections acquired during early childhood (under the age of 5 years). In our study we determined to show the impact of HBV infection on the graft and patient survival and to evaluate the impact of the anti-viral and the immunsupressive treatment regimes on viral replication. The demographic data, serologic markers and the laboratory tests were analyzed in a retrospective cohort. A total of 106 subjects of whom; 32 were renal transplant recipients with HBV infection and 74 were regarded as a control group (HBV negative renal transplant recipients). Compared to the control group, HBV infected renal transplant recipient patient group had a graft survival span significantly (p= 0.007) longer. Although another parameter that may affect the graft survival is diabetes mellitus (DM), we found no significant difference between groups. We also evaluated the effects of immunesupressive agents in study groups. Tacrolimus and pulse steroid-based regimens were found to be less preferred choices in HBV infected group. The use of immunesupressive drugs (particularly cyclosporin and tacrolimus) indirectly enhances viral replication which may accelerate the rise of liver enzyme (ALT,AST) levels particularly in HBsAg positive renal transplant recipients. Based on these findings; our study revealed no deaths due to the liver failure (acute or chronic) but we determined increased liver enzyme (ALT,AST,GGT) (P=0.02, P=0.017, P=0.024) levels in HBsAg positive patients group. We also compared the relation between the use of immunsupressive regimens and HBV-DNA titers among HBsAg positive renal transplant recipients and control group. In our study we categorized the patients according to antiviral therapy responses; group A: pretransplanation HBsAg positive but HBV-DNA negative patients who began to receive prophylactic antiviral therapy prior to transplantation and posttransplantation follow-up HBV-DNA titers never became positive. Group B symbolizes patients whose pretransplantation HBsAg and HBV-DNA levels were positive but with prophlyactic regimens lost HBV-DNA positivity. Group C symbolizes patients whose pre-transplant HBsAg and HBV-DNA titers positive ( similar as group B) and the positivity remains stable post-transplantation. Group D : pretransplantation HBsAg and HBV-DNA negative but post-transplant HBV-DNA titers are positive. Group 1 consist of A and B , group 2 consist of C and D. Our study revealed that In Group 1 (A+B), tacrolimus regimen is found to be more effective than cyclosporin regimen in suppressing HBV-DNA titers. As a result, the development and increasing use of the anti-viral agents has a significant impact on the graft and the patient survival among the renal transplant recipients with HBV infection. Although our study has a retrospective design, with a small number of HBsAg positive renal transplant recipients; it has shown that the use of different immunsuppresive regimens have had different outcomes on renal graft survival. Also, for the purpose of screening the disease progress, especially for the renal transplantation patients; serum biochemical markers as well as HBV-DNA titers are again shown to be inferior to the liver biopsy.