| Abstract|| |
Hepatitis C virus (HCV) is the most common cause of chronic liver disease in patients with end-stage renal disease. It is more prevalent in hemodialysis (HD) patients than the general population but the exact routes of transmission are not clear. In this study, the current situation of HCV infection was assessed in eleven dialysis centers in Tehran, Iran. A total of 548 patients on maintenance HD with a mean age of 45.4 ± 16.8 years were studied. Most of the patients were dialysed 3 times/week, each session lasting 4 to 4.5 hours. About 15% of patients had a history of having received peritoneal dialysis prior to maintenance HD and 23.6 of patients had received blood transfusion(s). The most common cause of renal failure was hypertension in 29.7% followed by diabetes mellitus in 23.2%, failed renal transplant in 19.4% and glomerulonephritis in 9.7%. HCV antibodies were measured by ELISA-III. All positive sera were tested for HCV RNA by RT-PCR. Positive HCV antibody tests were present in 19.6% of patients. In these seropositive patients, 48.6% had detectable HCV RNA. Prevalence of HCV antibody seropositivity was not different in patients with or without history of blood transfusion. The prevalence of positive HCV antibody in this study was higher than reports from Europe but lower than other countries in the region. Only 48.6% of seropositive cases were confirmed by PCR, which is lower than expected values. It seems that nosocomial transmission is the main route of infection in Iran.
Keywords: End-stage renal disease, Hemodialysis, Hepatitis C virus, Tehran, Iran.
|How to cite this article:|
Broumand B, Shamshirsaz AA, Kamgar M, Hashemi R, Aiazi F, Bekheirnia M, Boozary N, Komeilian Z, Shamshirsaz AA, Tabatabaiee MR, Broumand V. Prevalence of Hepatitis C Infection and its Risk Factors in Hemodialysis Patients in Tehran: Preliminary Report from "The Effect of Dialysis Unit Isolation on the Incidence of Hepatitis C in Dialysis Patients" Project. Saudi J Kidney Dis Transpl 2002;13:467-72
|How to cite this URL:|
Broumand B, Shamshirsaz AA, Kamgar M, Hashemi R, Aiazi F, Bekheirnia M, Boozary N, Komeilian Z, Shamshirsaz AA, Tabatabaiee MR, Broumand V. Prevalence of Hepatitis C Infection and its Risk Factors in Hemodialysis Patients in Tehran: Preliminary Report from "The Effect of Dialysis Unit Isolation on the Incidence of Hepatitis C in Dialysis Patients" Project. Saudi J Kidney Dis Transpl [serial online] 2002 [cited 2022 Jan 18];13:467-72. Available from: https://www.sjkdt.org/text.asp?2002/13/4/467/33100
| Introduction|| |
Hepatitis C virus (HCV) is the most common cause of chronic liver disease in patients suffering from end-stage renal disease.  The prevalence of anti-HCV antibody among patients on dialysis is higher than in healthy populations; reports have shown prevalence from 17 to 51% in Asia, 8 to 36% in North America, and 1 to 54% in Europe.  The risk of mortality has been shown to be higher in dialysis patients with positive HCV antibody than those without such antibodies.  Although there is evidence to support nosocomial transmission, the exact mode of transmission of HCV in dialysis patients is unclear.  It is unlikely that blood transfusions are the only cause for recent infections.  Also, there are many HCVantibody positive patients who had not received any blood transfusion. 
Antibody detection by enzyme-linked immunosorbent assay (ELISA) and recombinant immunoblot assay (RIBA) are two major tests used to diagnose HCV infection. In patients with end-stage renal disease, however, partial immunosupression and poor antibody response may affect results.  HCV-RNA detection by polymerase chain reaction (PCR) is the gold standard for diagnosis in such cases. The RNA is detectable one to three weeks following exposure to the HCV virus. This study has been designed to evaluate prevalence of HCV infection and the effect on seroconversion rate by isolating patients who are HCV-Positive. This is the preliminary result of the project. We report the prevalence of HCV-antibody in dialysis units in Tehran.
| Materials and Methods|| |
Eleven in-hospital dialysis units with more than 20 patients in each, located in Tehran, were selected for the study. Altogether, 548 patients were dialyzed regularly in these 11 centers. All of these patients were enrolled after obtaining informed consent.
Serum was prepared immediately from the samples drawn, and the tests were performed at the Iranian Blood Transfusion Organization and the Iranian Pasteur Institute. 317 (58%) of the patients were males and 231 (42%) were females. The mean age of patients was 45.4 ± 16.82 years. The dialysis centers were divided into two groups: "isolation centers" were centers which used separate units for HCV-positive patients. "Nonisolation" centers did not use separate units.
The ELISAIII method was used to detect HCV antibodies. This test uses three recombinant antigens (c22-3, C 200, NSS) and was used and interpreted according to the manufacturer's instructions.
A simple reverse transcriptase (RT)-PCR, based on combined transcription-amplification reaction and non-isotopic hybridization was used. RT-PCR was performed on all sera which had a positive antibody based on ELISAIII test. Viral RNA was extracted from 250 µL of serum by the trizol 750 µL after chloroform extraction. RNA precipitated with iso-propanol. Pellets were washed with 70% ethanol and resuspended in 20 µL of DEPC water. The cDNA was synthesized with primer and amplified by nested PCR in a single tube. 5µL of RNA solution was denatured at 70 o C for 10 minutes with 20 pmol of primer and 5µL DEPC water. cDNA synthesis was carried out at 42 o C, 50 minutes with 25 micron of expanded reverse transcriptase in 7µL reactive volume, containing 10x PCR buffer, 50µL/mol Mg Cl2, 10 mmol DNTP, 0.1 mol DTT and DEPC water. cDNA was stored at -20 o C. One fifth of the cDNA was subjected to nested PCR in a single tube with the lower mixed containing 20 pmol of each external primer in the presence of 2.5 units of taq DNA polymerase. This was covered with 30 µL of high- density oil, and the upper mixed containing 20 pmol of each internal primer after a first amplification of 35 cycles and then a second amplification of 30 cycles. The PCR product was examined on 2% agarose gel.
| Statistical Analysis|| |
Data were entered into the designed database, and analysed by SPSS for windows V.10 (SPSS Inc). Descriptive results were presented as mean ± SD or percentage. The relationships between HCV infection and categorical variables were analyzed by chisquare test. Those of HCV infection and quantitative variables (such as years on dialysis) were analysed by Student's T test.
| Results|| |
A total of 548 patients from 11 dialysis units in Tehran were studied. Most of the patients (81%) were dialyzed three times a week. In 18.1%, the number of dialysis sessions was twice a week and in 0.9% once a week. Treatment with hemodialysis was started at a mean age of 45.4 ± 16.8 years, the youngest being five at the onset and the oldest 81 years old. Seventy seven percent of the patients had an average of 4hour dialysis sessions while 2.2% had an average of 3.5 hour dialysis sessions. On an average, 68.7% of patients received dialysis treatment 12 hours per week. The mean dialysis time during the week was 11.4 ± 1.7 hours. A history of surgical operation was present in 1.7%, and 15.2% had undergone peritoneal dialysis prior to maintenance hemodialysis. Seventeen percent had renal transplantation once prior to maintenance hemodialysis and 2.4% were transplanted twice. [Figure - 1] shows the causes of renal failure in the patients. The most common etiology for renal failure was hypertension, followed by diabetes mellitus. Only 23.6% had a positive history of blood transfusion, and 18.2% reported a history of HCV infection. The mean time from the probable onset of hepatitis infection was 28.7 ± 19.7 months, and the last hepatitis test was done 2.4 ± 2.7 months before the study.
Overall, 19.6% (105) of the dialysis patients had positive serologic (ELISA) tests for HCV antibody. All the patients with positive serologic tests were again tested for HCV RNA by RT-PCR. HCV-RNA was detected in 48.6% of these patients.
[Table - 1] shows the results of RT-PCR seropositive patients from isolated and nonisolated dialysis centers. Chi square test did not reveal any significant difference between these two groups. The prevalence of HCV infection was not significantly different between patients with a history of blood transfusion and those without such history. Also, no relationship was present between HCV infection and a previous surgical operation, a positive family history of hepatitis C, having a high-risk occupation, or the number of weekly dialysis hours. Prevalence of HCV infection significantly increased with the number of years on dialysis (P=0.01).
| Discussion|| |
Seroprevalence of HCV in our hemodialysis patients was 19.6%. This is much lower than the results from other neighboring countries in the region, such as Saudi Arabia where the prevalence of positive anti-HCV antibodies has been reported to be 68%,  15.5%,  45.5%  and 50%  in different surveys. In the latter study, like the present report, systemic hypertension was the most common cause of ESRD.  Fujiyama and colleagues  reported a seroprevalence of more than 20% in Japan. In one study in France,  32.5% of patients had HCV antibodies. It seems that the figures are much lower in northwestern Europe with 2-6% of patients on dialysis having been reported to have HCV antibodies in the region, and a National Survey in the Netherlands has shown the figure to be as low as 3.5%.  Nevertheless these antibodies are more prevalent in hemodialysis patients than in healthy blood donors. 
While the above-mentioned national survey in The Netherlands was performed on 2653 patients which constitute about 68% of all Dutch dialysis patients, our study involved about 25% of Tehran's and 8% of the country's dialysis patients. In Washington, Stehman-Breen and colleagues 1 studied 200 patients on hemodialysis, and found HCV antibodies in 22% of them.
It is generally believed that partial immunosupression and poor antibody response are present in dialysis patients  and HCV infection might aggravate the situation. The prevalence of cryoglobulinemia, for example, has been shown to be higher in HCV infection.  Use of third-generation assays (ELISAIII) can clarify uncertain results of second-generation tests and increase the rate of antibody detection.  About 48% of seropositive patients in our study had HCVRNA detected by RT-PCR. In other studies, this rate is generally higher. In The Netherlands' national survey, for instance, 72% of seropositive patients had detectable HCV-RNA.  In another study in the United States, this rate was 77%. It seems that, although ELISA tests in our study were performed at a standard reference laboratory, the Iranian Blood Transfusion Organization, they are not accurate enough, and more care should be taken in order to avoid unnecessary distress to patients, due to false positive HCV-antibody detection.
In some studies, anti-HCV positive hemodialysis patients were reported to have received transfusion of blood products more than anti-HCV negative patients.  Olmer  has also considered blood transfusion and duration on hemodialysis as risk factors for HCV infection. On the other hand, some reports do not agree with these findings. A study in Spain  found no relationship between HCV infection and blood transfusion, and concluded that nosocomial transmission was the main mechanism of infection in dialysis patients. Simon and colleagues  showed that 36.5% of their HCV-positive dialysis patients had not received any blood transfusion at all. Our findings also show that only 23.6% of patients on dialysis had a history of blood product transfusion, and HCV seropositivity was not more prevalent in this group. It seems that screening for HCV in blood donors has been very effective in preventing transmission by this route,  and may have reduced the importance of blood transfusion as a risk factor.  We also found that the duration on dialysis was an important risk factor as described in previous studies. 
It seems that peritoneal dialysis carries a lower risk of HCV infection.  While HCV infection was present in 3.5% of hemodialysis patients, only 1.3% of those on chronic Ambulatory Peritoneal Dialysis (CAPD) were infected in The Netherlands. 
Stehman-Breen and colleagues  also reported that they had seen no HCV RNA positive case among patients on peritoneal dialysis or home hemodialysis. In Iran, peritoneal dialysis is not common. It seems rational to encourage the use of peritoneal dialysis in our patients.
In conclusion, the prevalence of HCV antibodies is relatively high in Iran, but false positive results are more than expected. Nosocomial transmission seems to be the main route. We plan to follow-up the patients for one year and determine the rate of seroconversion in centers that practice isolation of HCV patients and also in the nonisolation-policy centers. During this period, in the isolation-policy centers, patients will be screened for HCV antibodies every three months and those who become antibodypositive will be transferred to a special unit for HCV-infected patients.
| Acknowledgments|| |
This study was supported by a research grant from Charity Foundation for Special Diseases (CFSD). The authors thank the Iran's Pasteur Institute for their cooperation and performing RT-PCR tests.
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Professor of Medicine, University of Medical Sciences, P.O. Box 15115-454, Tehran
[Figure - 1]
[Table - 1]