Human Herpesvirus 8 Infection in Hemodialysis Patients

Human Herpesvirus 8 Infection in Hemodialysis Patients Assimina Zavitsanou, MSc, Vana Sypsa, PhD, Maria Petrodaskalaki, MSc, Mina Psichogiou, MD, PhD, Antigoni Katsoulidou, PhD, John Boletis, MD, PhD, Valsamakis Hadjiconstantinou, MD, PhD, Dimitris Karalis, MD, PhD, Victoria Kalapothaki, MD, PhD, and Angelos Hatzakis, MD, PhD ● Background: The aim of the present study was to evaluate human herpesvirus 8 (HHV-8) seroprevalence in Greek hemodialysis patients. Patterns of change in HHV-8 serostatus (seroconversions and seroreversions) over time were also evaluated. Methods: Serum samples obtained from a cohort of 485 Greek hemodialysis patients were tested for antibodies to HHV-8 by whole virus lysate enzyme-linked immunosorbent assay, and reactive samples were confirmed by means of the orf-73 enzyme-linked immunosorbent assay. HHV-8 seroprevalence at study entry and the incidence of seroreversions and seroconversions per 100 person-years were estimated. Results: The prevalence of HHV-8 antibodies in Greek hemodialysis patients at enrollment was 7.2%. No univariate associations were established between HHV-8 serostatus and patients’ characteristics. Incidences of seroreversions and seroconversions were 16.4/100 person-years (95% confidence interval, 7.1 to 32.3) and 0.28/100 person-years (95% confidence interval, 0.03 to 1.02), respectively. Patients 50 years and younger had an increased probability for seroreversion to HHV-8 antibodies than patients older than 50 years (log-rank test, P ⴝ 0.018). Conclusion: We observed a fair number of seroreversions and a low incidence of seroconversion to HHV-8 infection in hemodialysis patients in Greece. Our data provide indirect evidence that HHV-8 transmission in the hemodialysis setting is uncommon. Am J Kidney Dis 47:167-170. © 2005 by the National Kidney Foundation, Inc. INDEX WORDS: Human herpesvirus 8; hemodialysis (HD); cohort; seroconversion; seroreversion.

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UMAN HERPESVIRUS 8 (HHV-8) was identified in 1994 as a new gammaherpesvirus, closely related to Epstein-Barr virus.1 HHV-8 infection is now considered the etiologic agent of Kaposi sarcoma (KS), and its DNA sequences have been detected in all forms of KS, including sporadic (classic), endemic (African), epidemic (acquired immunodeficiency syndrome related), and iatrogenic (ie, posttransplantation).1-5 A strict association was clearly shown between HHV-8 and the development of KS in transplant recipients. In particular, the incidence of KS was documented to be 400 to 500 times greater in renal transplant recipients compared with controls of the same ethnic origin.6 KS occurs in 0.1% to 5% of renal transplant recipients7 and is associated with substantial morbidity and mortality.6,8 The virus, as with other members of the Herpesviridae family, is characterized by its ability to remain latent within the host after primary infection, and it may be reactivated during states of relative immune dysregulation. It still is not clear whether posttransplantation KS is caused by reactivation of HHV-8 as a result of the immunosuppressive treatment, or by a primary HHV-8 infection transmitted through organ transplantation. Although it was documented that the virus can be transmitted through renal allo-

grafts,9 the majority of posttransplantation KS is caused by HHV-8 reactivation.10 It still is unclear whether hemodialysis or the uremic state is associated with an increased frequency of HHV-8 infection. Results of early epidemiological studies are controversial. A casecontrol study conducted in hemodialysis patients from Taiwan concluded that the prevalence of HHV-8 antibodies in hemodialysis patients was greater than that in healthy blood donors.11 Conversely, another case-control study performed in hemodialysis patients from northern Italy, a geographic area with a relatively high prevalence of HHV-8 in blood donors, indicated that uremia and hemodialysis procedures are not associ-

From the Department of Hygiene and Epidemiology, Athens University Medical School; Laiko General Hospital; and Amalia Fleming Hospital, Athens, Greece. Received July 14, 2005; accepted in revised form September 20, 2005. Originally published online as doi:10.1053/j.ajkd.2005.09.019 on November 7, 2005. Potential conflicts of interest: None. Address reprint requests to Angelos Hatzakis, MD, PhD, Department of Hygiene and Epidemiology, Athens University Medical School, 75 Mikras Asias St, GR-11527 Athens, Greece. E-mail: [email protected] © 2005 by the National Kidney Foundation, Inc. 0272-6386/05/4701-0020$30.00/0 doi:10.1053/j.ajkd.2005.09.019

American Journal of Kidney Diseases, Vol 47, No 1 (January), 2006: pp 167-170

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ated with an increased frequency of HHV-8 infection.12 The objective of the present study is to evaluate HHV-8 seroprevalence and seroincidence in a cohort of Greek hemodialysis patients. We also evaluated the pattern of change in HHV-8 serostatus (seroconversions and seroreversions) over time. METHODS Four hundred eighty-five consecutive hemodialysis patients from the Multicenter Haemodialysis Cohort Study on Viral Hepatitis were included in this study.13-15 Median time on dialysis therapy of the study population was 4.4 years (25th, 75th: 2.5, 7.3 years), 57.1% were men, and 42.9% were women. Thirty-nine patients (8%) had a history of renal transplantation. Subjects were former renal transplant recipients who lost allograft function and returned to hemodialysis treatment. Descriptive characteristics of the study population at the beginning of follow-up are listed in Table 1. All patients were followed up for a median of 1.4 years (25th, 75th: 0.9, 2.3 years), and several serum samples per case were collected. For all patients, at least 2 serum samples (at the beginning and end of follow-up) were tested for immunoglobulin G antibodies to HHV-8. For hemodialysis patients who seroconverted or seroreverted to anti–HHV-8, intermediate serum samples, collected during follow-up, were tested. We evaluated the prevalence of HHV-8 antibodies at the beginning of follow-up. Screening for HHV-8 infection was conducted by using a commercially available enzyme-linked immunosorbent assay kit, based on whole virus lysate (Advanced Biotechnologies, Columbia, MD).16 Reactive samples were confirmed by using a second enzyme-linked immunosorbent assay that detects antibodies to LANA, the orf-73 encoded HHV-8 latent nuclear antigen (Advanced Biotechnologies).17 Only samples reactive by both assays were considered positive. Univariate analysis using chi-square test and t-test, as appropriate, was performed to examine the presence of associations between HHV-8 serostatus and variables determined at enrollment. A multivariate logistic regression model18 was used to identify risk factors independently associated with the presence of HHV-8 antibodies. Rate of change in HHV-8 serostatus over time was estimated by calculating the incidence of seroreversions and seroconversions per 100 person-years. Log-rank test was performed to establish whether patients’ characteristics were associated with an increased rate of seroconversion or seroreversion.

RESULTS

Of 485 participants, 35 were reactive for anti– HHV-8 antibodies at study entry. Therefore, the prevalence of HHV-8 antibodies in hemodialysis patients at the beginning of follow-up was 7.2% (95% confidence interval, 5.1% to 9.9%).

Table 1. Descriptive Characteristics of the Study Population at the Beginning of Follow-Up and Univariate Associations Among HHV-8 Seroprevalence at Study Entry and Potential Risk Factors in 485 Greek Hemodialysis Patients

Characteristic

Age (y) ⱕ50 ⬎50 Sex Male Female Duration of hemodialysis (y) ⱕ10 ⬎10 Unit of hemodialysis 1 2 3 4 5 History of transfusion No Yes History of renal transplantation No Yes Anti-HCV Positive Negative History of acute hepatitis No Yes Long-term alanine aminotransferase elevation No Yes Hepatomegaly No Yes Splenomegaly No Yes Hepatomegaly/splenomegaly None At least 1

HHV-8 Seropositivity No. of at Study Patients Entry

P

130 329

6 (4.6) 26 (7.9)

0.213

277 208

21 (7.6) 14 (6.7)

0.720

362 58

24 (6.6) 0.141 7 (12.1)

46 132 76 43 188

6 (13.0) 11 (8.3) 1 (1.3) 0.074 1 (2.3) 16 (8.5)

83 402

77 (93.3) 0.996 373 (92.8)

446 39

32 (7.2) 3 (7.7)

0.905

121 364

13 (10.7) 0.083 22 (6.0)

466 19

33 (7.1) 0.569 2 (10.5)

415 70

33 (7.9) 2 (2.9)

453 32

30 (6.6) 0.057 5 (15.6)

474 11

33 (7.0) 0.155 2 (18.2)

450 35

30 (6.7) 0.093 5 (14.3)

0.128

NOTE. Values expressed as number (percent).

Univariate associations between HHV-8 serostatus and patients’ characteristics at enrollment are listed in Table 1. At study entry, no significant associations were observed between

HUMAN HERPESVIRUS 8 INFECTION IN HEMODIALYSIS

HHV-8 infection and age group, sex, duration or unit of hemodialysis, history of transfusion, history of renal transplantation, hepatitis C virus (HCV) infection, history of acute hepatitis, longterm alanine aminotransferase level elevation, hepatomegaly, and/or splenomegaly. Seroprevalence tended to be greater in individuals presenting with hepatomegaly (P ⫽ 0.057). There was considerable variability in HHV-8 seroprevalence among different hemodialysis units, and this finding was marginally statistically significant (P ⫽ 0.074). No independent associations were identified between these factors and HHV-8 serostatus in the multiple logistic regression model (data not shown). Of 485 participants included in this study, 450 were negative for HHV-8 antibodies at study entry. Only 2 of these participants developed antibodies to HHV-8 infection during follow-up. The corresponding incidence rate was 0.28 seroconvesions/100 person-years (95% confidence interval, 0.03 to 1.02). Of 35 patients positive at enrollment, 8 patients experienced seroreversion of HHV-8 antibodies. The incidence of seroreversions was 16.4 seroreversions/100 person-years (95% confidence interval, 7.1 to 32.3). We observed that patients 50 years and younger had an increased probability to experience seroreversion of HHV-8 antibodies than those older than 50 years. Twentyfive percent of patients older than 50 years were estimated to experience seroreversion during the first 3 years after study entry, whereas the corresponding estimate for subjects 50 years and younger was 7 months (log-rank test, P ⫽ 0.018). Additionally, no patient developed KS in this cohort. Characteristics of the 2 patients who experienced seroconversion are described in the following paragraphs. Case 1 A 73-year-old Greek woman with chronic renal failure caused by nephrosclerosis was on hemodialysis therapy for 5 consecutive years in hemodialysis unit 1. She was followed up for 68 weeks. The patient presented with hepatomegaly and splenomegaly and was anti-HCV positive. She had no history of renal transplantation. At the beginning of follow-up, the participant was negative for HHV-8 infection and re-

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mained negative for 60 weeks. On the 61st week of follow-up, she underwent blood transfusion, and on the 68th week, she presented with immunoglobulin G antibodies to HHV-8. Case 2 A 59-year-old Greek woman was undergoing hemodialysis for 10 successive years in hemodialysis unit 2. The patient was followed up for 108 weeks. Chronic renal failure of unknown origin was diagnosed. She had no history of renal transplantation and had never received a blood transfusion. Moreover, she was anti-HCV negative. Furthermore, the patient did not present with hepatomegaly and/or splenomegaly. At the beginning of follow-up, the participant was negative for HHV-8 antibodies, and she experienced seroconversion after week 92 of follow-up. The patient remained positive to the viral infection until the end of follow-up. DISCUSSION

This study reports on HHV-8 seropositivity in a cohort of 485 hemodialysis patients. HHV-8 seroprevalence at study entry was 7.2%. A similar seroprevalence rate (9.2%) is reported in hemodialysis patients from northern Italy,12 whereas HHV-8 prevalence in hemodialysis patients from Taiwan is reported to be 19.5%.11 Only 2 patients converted to seropositive HHV-8 status during follow-up, suggesting that seroconversion caused by hemodialysis procedures is relatively uncommon. Patients in this cohort were part of the Multicenter Haemodialysis Cohort Study on Viral Hepatitis.13,14 These studies showed a relatively high HCV incidence, and nosocomial practices seemed to be the predominant mechanism of HCV transmission in this cohort of patients.14 The low incidence of HHV-8 infection in this cohort of hemodialysis patients, in which other blood-borne agents were horizontally readily transmitted, suggests that horizontal nosocomial transmission of HHV-8 is a rare event. Blood transfusion apparently was implicated in 1 of the 2 HHV-8 seroconversions. Whether HHV-8 is transmitted through transfusions of blood or blood products still is an unresolved issue. Several studies reported an association between HHV-8 seroprevalence and intravenous drug use, suggesting possible bloodborne transmission.19,20 Nevertheless, results of

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another study support that blood-borne HHV-8 transmission, if it exists, is rare.21 Eight patients experienced seroreversion to HHV-8 antibodies during follow-up. Patients 50 years and younger had an increased probability to experience seroreversion to HHV-8 antibodies than patients older than 50 years, and this finding is statistically significant. This could be attributed to the impaired defense mechanisms of middle-aged and elderly patients with renal failure, particularly related to the combined effect of advancing age, uremia, and hemodialysis treatment.22,23 Furthermore, it was reported elsewhere for other high-risk groups that titers and epitope recognition increase over time from HHV-8 infection.24 These investigators support that the greater prevalence at older ages could be related to easier recognition of infection with advancing age. In conclusion, we observed a low incidence of seroconversion to HHV-8 infection in hemodialysis patients in Greece. These data provide indirect evidence that primary HHV-8 infection in this group of patients is relatively rare. Additional follow-up studies of a larger sample of individuals are needed to confirm whether longterm hemodialysis treatment is a possible transmission route of HHV-8 infection. REFERENCES 1. Chang Y, Cesarman E, Pessin MS, et al: Identification of herpesvirus-like DNA sequences in AIDS-associated Kaposi’s sarcoma. Science 266:1865-1869, 1994 2. Schalling M, Ekman M, Kaaya EE, Linde A, Biberfeld P: A role for a new herpes virus (KSHV) in different forms of Kaposi’s sarcoma. Nat Med 1:707-708, 1995 3. Moore PS, Chang Y: Detection of herpesvirus-like DNA sequences in Kaposi’s sarcoma in patients with and without HIV infection. N Engl J Med 332:1181-1185, 1995 4. Cathomas G, McGandy CE, Terracciano LM, Itin PH, De Rosa G, Gutdat F: Detection of herpesvirus-like DNA by nested PCR on archival skin biopsy specimens of various forms of Kaposi sarcoma. J Clin Pathol 49:631-633, 1996 5. Rady PL, Hodak E, Yen A, et al: Detection of human herpesvirus 8 DNA in Kaposi’s sarcomas from iatrogenically immunosuppressed patients. J Am Acad Dermatol 38:429-437, 1998 6. Penn I: Why do immunosuppressed patients develop cancer? in Penn I, Pimental E (eds): CRC Critical Reviews in Oncogenesis. Boca Raton, FL, CRC, 1989, pp 27-52 7. Francès C: Kaposi’s sarcoma after renal transplantation. Nephrol Dial Transplant 13:2768-2773, 1998 8. Francès C, Mouquet C, Marcelin AG, et al: Outcome of kidney transplant recipients with previous human herpesvirus-8 infection. Transplantation 69:1776-1779, 2000

9. Regamey N, Tamm M, Wernli M, et al: Transmission of human herpesvirus 8 infection from renal transplant donors to recipients. N Engl J Med 339:1358-1363, 1998 10. Andreoni M, Goletti D, Pezzotti P, et al: Prevalence, incidence and correlates of HHV-8/KSHV infection and Kaposi’s sarcoma in renal and liver transplant recipients. J Infect 43:195-199, 2001 11. Hsu YH, Lin DY, Liou HH: Human herpesvirus-8 infection in hemodialysis patients from eastern TaiwanHualien. Kaohsiung J Med Sci 18:393-396, 2002 12. Luppi M, Vandelli L, Whitby D: Human herpesvirus-8 infection in haemodialysis patients from northern Italy. Kidney Int 55:340, 1999 13. Sypsa V, Psichogiou M, Katsoulidou A, et al: Incidence and patterns of hepatitis C virus seroconversion in a cohort of hemodialysis patients. Am J Kidney Dis 45:334343, 2005 14. Katsoulidou A, Paraskevis D, Kalapothaki V, et al: Molecular epidemiology of a hepatitis C virus outbreak in a haemodialysis unit. Multicenter Haemodialysis Cohort Study on Viral Hepatitis. Nephrol Dial Transplant 14:1188-1194, 1999 15. Psichogiou M, Vaindirli E, Tzala E, et al: Hepatitis E virus (HEV) infection in haemodialysis patients. The Multicentre Haemodialysis Cohort Study on Viral Hepatitis. Nephrol Dial Transplant 11:1093-1095, 1996 16. Chatlynne LG, Lapps W, Handy M, et al: Detection and titration of human-herpesvirus-8 specific antibodies in sera from blood donors, acquired immunodeficiency syndrome patients, and Kaposi sarcoma patients using a whole virus enzyme-linked immunosorbent assay. Blood 92:53-58, 1998 17. Zhu L, Wang R, Sweat A, et al: Comparison of human sera reactivities in immunoblots with recombinant human herpesvirus (HHV-8) proteins associated with the latent (ORF73) and lytic (ORFs 65, K8.1A, and K8.1B) replicative cycles and in immunofluorescence assays with HHV-8infected BCBL-1 cells. Virology 256:381-392, 1999 18. Hosmer DW, Lemeshow S: Applied Logistic Regression. New York, NY, Wiley, 1989 19. Cannon MJ, Dollard SC, Smith DK, et al: Bloodborne and sexual transmission of human herpesvirus 8 in women with or at risk for human immunodeficiency virus infection. N Engl J Med 344:637-643, 2001 20. Atkinson J, Edlin BR, Engels EA, et al: Seroprevalence of human herpesvirus 8 among injection drug users in San Francisco. J Infect Dis 187:974-981, 2003 21. Challine D, Roudot-Thoraval F, Sarah T, et al: Seroprevalence of human herpesvirus 8 antibody in populations at high or low risk of transfusion, graft, or sexual transmission of viruses. Transfusion 41:1120-1125, 2001 22. Hirokawa K, Utsuyama M, Kasai M, Kurashima C: Aging and immunity. Acta Pathol Jpn 42:537-548, 1992 23. Descamps-Latscha B, Jungers P, Witko-Sarsat V: Immune system dysregulation in uremia: Role of oxidative stress. Blood Purif 20:481-484, 2002 24. Biggar RJ, Engels EA, Whitby D, Kedes DH, Goedert JJ: Antibody reactivity to latent and lytic antigens to human herpesvirus-8 in longitudinally followed homosexual men. J Infect Dis 187:12-18, 2003