Hepatitis C virus infection in Saudi Arabian recipients of renal transplantation

Hepatitis C virus infection in Saudi Arabian recipients of renal transplantation AyoolaE. A. , Srinivas KV , Gadour M O EH 3 Abstract Background: Studies of recipients most of whom had been infected prior to transplantation, had yielded conflicting conclusions in regard to the clinical impact of hepatitis C virus [HCV] infection. We determined the frequency of new HCV infection and assessed its effect on patient – and graft – survival and occurrence of chronic hepatitis in renal transplant recipients. Methods: We studied 54 Saudi recipients [37 males and 17 females; mean age (SD); 38.2(17.1) years] they were anti-HCV negative at the time of transplantation and followed for 3 to 19 years [mean = 8.1]. The prevalence of anti-HCV at the time of censorship was compared with the rates in 99 hemodialyzed patients, 400 healthy volunteers and 113 hospitalized patients. Results: The period prevalence of anti-HCV in recipients was 37% [20 of 54], compared to hemodialyzed patients [17.1%], hospital patients [1.8%] and healthy volunteers [2.3%]. [P < 0.01]. Seroconversion to anti-HCV positivity occurring from 2 to 11 years [mean =7.8] after transplantation and was not influenced by age, gender or source of donor kidney. Cumulative frequency of HBsAg was 14.8%. Graft loss occurred in 1 HCV positive recipient. Serum aminotransferase was abnormal [>2 – fold elevation] in 2 anti-HCV positive recipients transiently. No deaths occurred among the recipients. Conclusion: The acquisition of new HCV infections had a relatively high frequency among renal transplant recipients in the study. The course of the infection was benign in the medium term, with no discernible progression to clinically recognized chronic liver disease. Further studies are required to determine costbenefit of antiviral therapy in such patients.


Introduction
Hepatitis C virus (HCV) infection is frequent in renal transplant recipients among whom it has a variable prevalence of between 6.2% and 65.8% [1][2][3][4][5] .Studies of recipients, the majority of whom had been HCV-infected prior to transplantation, produced conflicting conclusions in regard to the incidence of graft loss, patient survival and occurrence of liver diseases [1][2] .In some reports, HCV infection was associated with deleterious effects that included higher frequency of graft loss and patient mortality [6][7][8][9][10][11] .Others reported low frequencies of HCV-induced chronic hepatitis 12 and insignificant impact on the survival of patients or grafts 13 Information is scant on the natural history and clinical significance of HCV infection that was acquired after transplantation 14 .We analyzed renal transplant recipients that were followed in a tertiary hospital in Saudi Arabia in order to determine the incidence of HCV infection correspondence to: Prof. E. Ayobanji.Ayoola.E-mail: bayoola@aol.com, bayoola@yahoo.com after transplantation and its relationship to graft survival, the development of chronic liver disease and patient-survival.We report the periodprevalence and, the cumulative incidence of anti-HCV in a cohort of renal transplant recipients who were followed in a tertiary regional hospital in Saudi Arabia.The effects of newly acquired HCV infection on graft survival, patient mortality and occurrence of chronic liver disease were evaluated.

Materials and Methods
The subjects were 54 renal transplant recipients [37 males and 17 females] who were HCV negative at the time of transplantation and were followed for 3 to 19 years [up to June 2002]  in the Nephrology unit [ Ninety-nine patients of 146 hemodialyzed patients, who were negative on entry to the dialysis program and had been followed for 3 to 19 years during the same period as the renal transplant recipients, were enrolled and their data were analyzed.They had been re-tested for HBsAg, anti HCV at intervals ranging from 3 to 6 months.
The remaining 47  15 For comparison of prevalence rates, 2 groups served as controls [Table 1].One group comprised 400 apparently healthy volunteers who were recruited from among the residents of the same locality as the patients 15 .None had any history or clinical evidence of hepatobiliary disease, previous blood transfusion or history of commercial blood donation.The subjects in the other group were 113 hospital patients with various chronic illnesses requiring frequent clinic visits and occasional admissions as previously described 15 .The periods of follow-up prior to the inclusion in the study varied from 3 to 10 years and the various diagnoses in these patients are summarized in table 2.
Data obtained from the subjects and the respective medical records included age, gender, history of jaundice, blood transfusions, and episodes of clinically -recognized hepatitis, jaundice or elevated serum ALT and history of travel or blood transfusions.Complete blood count (CBC), electrolytes, urea, creatinine and calcium alanine aminotransferase (ALT), aspartate aminotransferase (AST), total bilirubin, alkaline phosphatase, and albumin were estimated at each clinic visit.Serum ALT level higher than 2 times the upper limit of normal Protocol liver biopsies were obtained in all patients who were considered for transplantation and as part of the policy, only those who had normal histology were transplanted.Liver biopsy was done in hemodialysis patients or in the posttransplantation period only when clinical, laboratory and ultrasonographic assessment indicated the presence of liver disease.

Statistical analysis
The respective numbers of patients who were positive for anti-HCV at the end of the designated study period [June 2002] were used to calculate the prevalence among renal transplant recipients and hemodialysis patients.For the apparently healthy volunteers and hospitalized patients, the prevalence rates of HCV or HBV were determined from a single blood test during the survey.Data were presented as means and standard deviations for continuous variables that are approximately normally distributed, as medians for skewed variables and as percentages for discrete or categorical variables.Comparisons of data in proportions were performed with the X 2 test or Fisher's exact test.Differences between mean values were determined using Student t-test and Mann-Whitney U-test.Where applicable, the odds ratios [OR] with the 95% confidence intervals [95% CI] were calculated.A p value of less than 0.05 was considered as significant.

Results
The recipients had been followed for an average period of 11.The prevalence rates of anti-HCV and markers of HBV at the time of censorship, are summarized in table 1.A statistically significant difference [OR = 2.84; 95% CI of 1.24 -6.51; p = 0.01] was found between the prevalence of anti -HCV in the transplant recipients [37%; 95% CI, 24.3 -51.3] and the rate [17.1%; 95% CI, 10.3 -26.1] in hemodialysis patients The prevalence in recipients was significantly higher than the rate in the group of healthy persons [37% vs.2.3%; OR =25.56; 95% CI of 10.07 -66.35, p = 0.000]; and the rate in hospital patients [37% vs.1.8%;OR = 32.65;95% 6.82 -213.52;p= 0.000] Among the 20 recipients who became positive for anti-HCV in the post transplantation period 7 of 8 serum samples tested for HCV RNA were positive.As summarized in table 3, comparison of recipients who acquired HCV and those who remained HCV-negative revealed no statistically significant differences in relation to gender, age, source of donor kidneys and follow-up period.HBsAg was positive in 1 of 20 HCV-positive and 7 of 34 HCV-negative patients.
Recipients who became positive for anti HCV or HBsAg were compared to those who remained negative for both markers during the follow-up period [Table 4].No significant differences were found in relation to the peak ALT levels, duration of follow up, and the intervals from transplantation to sero -conversion.Most of the new HCV infections [13 of 20; 65%] occurred within 2 years of transplantation [Table 4].The peak ALT ranged from 15 to 195 iu/l [median = 32] in the recipients.Serum ALT was abnormal [> 2 fold increase] at least once during the follow up in 2 of the 20 HCV-positive recipients [peak values of 129, and 195 iu/l] and in 2 of 34 HCV-negative recipients [peak values of 118 and156] but these abnormal levels were not sustained or persistent.Serum albumin levels were normal in all of the patients.None showed clinical features or ultrasonographic evidence of chronic liver disease, and the abnormalities of aminotransferase levels were transient.
Graft failure occurred in only 1 patient, a 62-year-old male who was transplanted in India 14 years before inclusion in the study became HCV-positive five years after the transplantation, and was re-grafted two years thereafter.No death occurred among the recipients during the followup period.

Discussion
This study showed that 37% of the recipients who were negative at the time of transplantation became positive for anti-HCV during the follow-up period, indicating a relatively high prevalence in the studied cohort.A similar survey among Korean recipients reported that 19.6% persons acquired anti-HCV after transplantation 14 .In a study from Hong Kong, the incidence of new HCV infection was 0.45% per patient-year in 185 recipients who were followed for 24 months 3 .
The exact timing and mode of infection are often unknown but it is probable that the HCV infection occurring in previously negative recipients might have been transmitted through blood transfusion before or at the time of operation.However, it would be difficult to exclude acquisition of HCV from the community through unknown modes in those who became positive several years after the respective transplantation.None of the factors that were assessed [namely, gender of the recipients, the age at the time of transplantation and, source of the donor kidneys] separated those who became infected from those who remained negative for anti-HCV.There are conflicting data with regard to the clinical outcome of HCV infection acquired prior to transplantation and thus, the higher incidence of liver diseases and related deaths among HCVpositive recipients that was reported by some authors 7,9,11 and was not supported by other investigators 1,2,13 .The heterogeneity of patient characteristics in those studies, the timing of infection in individual cases and, the slow evolution of disease in HCV infection may be responsible for the discordant results.Therefore, the increased incidence of liver diseases and mortality among recipients who acquired HCV before treatment but not among those who were infected at the time of treatment is probably a consequence of a longer duration of HCV infection 17 .
The natural history of HCV infection that is acquired in the post-transplantation period is not well understood, but an accelerated and sometimes aggressive course of HCV related hepatitis after renal transplantation has been reported 18 .However, our study in which abnormal levels of aminotransferases [> 2 fold elevation] occurred in only two of the anti-HCV-positive patients transiently, and in which none of the recipients developed clinical evidence of chronic liver disease is in agreement with the observations of a relatively benign clinical course in recipients infected by HCV alone 5,7,14 .It was estimated that 30-60 % of HCV-positive recipients have persistently normal ALT serum levels 2,9 .
Although serum aminotransferase levels have been generally accepted and used as a reliable index of inflammatory activity or necrosis, it is uncertain whether ALT levels may accurately indicate the presence or extent of liver damage in those being treated with immunosuppressive drugs 3,4 .In uremic patients with chronic hepatitis, aminotransferase levels may be normal or minimally elevated 19 The prevalence of dual infections by HCV and HBV vary from 2.5% to 9% and may lead to aggressive liver disease among transplant recipients 7,9,20 .For example, the incidence of chronic hepatitis as defined by > two-fold increase in ALT for more than 6 months was 40%; compared with the rates in those patients infected by HCV [24.4%] or HBV alone [25%] 20 .Only one of our patients had dual infections and had no clinical or laboratory evidence of liver disease.
Information on histological changes caused by HCV in recipients is scanty and is often limited to those who were infected before transplantation 1 .The findings vary from normal pattern or mild non-specific changes in patients with persistently normal liver enzymes, to fibrosing cholestatic hepatitis, with progression to cirrhosis and liver failure, in patients with persistently elevated ALT or AST 21 ..Most reports suggested a benign effect of infection on graft survival 1,3,7 , while others reported increased incidence rates of graft loss in recipients with HCV infection, compared to those who were negative.The low incidence of graft rejection, occurring in only one HCV-positive recipients indicated the lack of significant impact of HCV infection on graft survival in those who were infected after transplantation.None of the studied recipients had died by the time of censorship.The impact of HCV on the mortality among recipients remains controversial.A study involving a large number of recipients concluded that recipients who are anti-HCV positive do not have an increased risk of death after transplantation compared with hepatitis C-negative recipients 1 .However, some reports have shown an increased mortality among those who acquired HCV before transplantation; but not among those who acquire the infection after transplantation, indicating a major influence of the duration of infection 4,17 .Some reports indicated that the deaths in HCV-positive patients that are more often unrelated to liver diseases had lower rates than in recipients who are HBV-positive 2,12 .
It remains unclear whether anti-viral therapy is indicated, safe or beneficial in recipients who are infected by HCV after transplantation.Major concerns about toxicity and renal impairment have limited the use or the success of interferon treatment among patients with functioning grafts [27][28][29] .For example, 6 of 16 recipients with functioning grafts who were treated with interferon, developed renal impairment 28 .Theret et al 30 treated 13 post transplantation patients with interferon and therapy had to be suspended in 7 patients because of adverse effects.The decision to treat should be weighed carefully against the potential risks of therapy.
It is concluded that the incidental rate of new HCV infection after transplantation is high among recipients and is higher than the seroconversion rate in hemodialyzed patients.On the short term, post-transplantation HCV infection had a benign clinical course that was not associated with clinically recognized chronic hepatitis, increased incidence of graft loss or patient fatality in the recipients who were followed in a regional hospital in Saudi Arabia.A study with a larger number of HCV-positive recipients and a longer period of follow-up will provide firmer conclusions on the natural history of HCV infection after transplantation.
[2XULN; normal up to 65 iu/l] was considered abnormal.Antibodies to hepatitis C virus [anti -HCV] were detected using a third generation enzyme immunoassay [Murex III].All positive anti -HCV antibody tests were confirmed by positive immunoblot assays [HCV Blot 3.0 Genelabs Diagnostics and Ortho Diagnostics Systems Raritan NJ].Serum samples obtained from anti -HCV-positive recipients [n = 8], hemodialyzed patients [n=7], healthy volunteers [n=5] and hospital patients [n=2] were tested for HCV -RNA by reverse transcriptionpolymerase chain reaction [RT-PCR using specific primers from the 5'-UTR, [Amplicor, Roche Diagnostic systems 16 Hepatitis B surface antigen [HBsAg], total antibody to hepatitis B core antigen [anti-HBc], antibody to HBsAg [anti-HBs], total antibody to hepatitis A virus [anti-HAV], were detected by using commercial enzyme immunoassays [EIA] kits [Abbott Laboratories Chicago II.].
4 years [556 person-years].The duration of post-transplantation follow-up was 4 years [in 1 recipient], 6-10 years [in 21 recipients], 11-15 years [in 27 recipients] and more than 16 years [in 5 recipients].The proportion of females in the group of hemodialyzed patients was significantly higher than in other groups; [p = 0.002].

Table 1 :
Demographic data and prevalence of anti -HCV and HBsAg in renal transplantation recipients, hemodialyzed patients and control groups

Table 2 :
Diagnoses in 113 patients tested as controls

Table 4 : Follow-up duration and intervals between transplantation and conversion to positive anti -HCV or HBsAg in renal transplant recipients
d Median {range} follow up in years after seroconversion ; e Highest ALT (iu/l) in each patient during the follow -up period ; ALT normal to 65 iu/l; AST normal to 50iu/l ; No = number of patients Hepatitis C Virus Infection in Saudi Arabian Recipients of Renal Transplantation Ayoola E A et al © Sudan JMS Vol. 2, -o. 1, Mar 2007