1
|
Jamshidi S, Bokharaei-Salim F, Esghaei M, Bastani MN, Garshasbi S, Chavoshpour S, Dehghani-Dehej F, Fakhim S, Khanaliha K. Occult HCV and occult HBV coinfection in Iranian human immunodeficiency virus-infected individuals. J Med Virol 2020; 92:3354-3364. [PMID: 32232978 DOI: 10.1002/jmv.25808] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Revised: 03/01/2020] [Accepted: 03/17/2020] [Indexed: 12/12/2022]
Abstract
The presence of hepatitis C virus (HCV) genome in liver biopsy or peripheral blood mononuclear cell (PBMC) specimens in the absence of detectable HCV-RNA in plasma of the people with or without anti-HCV antibodies has defined as occult HCV infection (OCI), whereas occult hepatitis B virus infection (OBI) is detection of hepatitis B virus (HBV) genome in the absence of traceable hepatitis B surface antigen in the plasma samples of patients. The purpose of this study is to determine the presence of OBI and OCI in human immunodeficiency virus (HIV)-infected individuals. In this cross-sectional research, 190 Iranian HIV-infected individuals were enrolled from September 2015 to February 2019. All participants were tested regarding various serological markers for HCV and HBV infections. Viral RNA and DNA were extracted from plasma and PBMC specimens, and the presence of HCV-RNA in plasma and PBMC samples was tested using reverse transcriptase-nested polymerase chain reaction (PCR), HBV viral load was determined in plasma samples using COBAS TaqMan 48 Kit, and also the presence of the HBV-DNA in PBMC samples was tested by real-time PCR. In this study, the prevalence of OBI and OCI in HIV-infected individuals was 3.1% and 11.4%, respectively. The genotypes of HCV in the patients with OCI were as follows: 57.1% were infected with subtype 3a, 35.7% were infected with subtype 1a, and 7.1% was infected with subtype 1b. It is noteworthy that in this study, two patients (1.1%) had OCI/OBI coinfections. The present study revealed that 1.1% of Iranian HIV-infected individuals had OBI and OCI at the same time. Therefore, it seems that designing prospective surveys to determine the presence of this coinfection in HIV-infected individuals is informative.
Collapse
Affiliation(s)
- Sogol Jamshidi
- Department of Virology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Farah Bokharaei-Salim
- Department of Virology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Maryam Esghaei
- Department of Virology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Mohammad-Navid Bastani
- Department of Virology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Saba Garshasbi
- Vice Chancellor for Health, Iran University of Medical Sciences (IUMS), Tehran, Iran
| | - Sara Chavoshpour
- Department of Virology, School of Public Health, Tehran University of Medical Sciences (TUMS), Tehran, Iran
| | | | - Shahin Fakhim
- Department of Civil Engineering, Faculty of Engineering, Payame Noor University, Karaj, Iran
| | - Khadijeh Khanaliha
- Research Center of Pediatric Infectious Diseases, Institute of Immunology and Infectious Diseases, Iran University of Medical Sciences, Tehran, Iran
| |
Collapse
|
2
|
Daniel K, Palavecino EL, Nunez M. Low Yield of Hepatitis B Virus DNA Testing in the Absence of Surface Antigen. Am J Med Qual 2020; 36:68. [PMID: 32126795 DOI: 10.1177/1062860620908059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Krupa Daniel
- Wake Forest School of Medicine, Winston Salem, NC
| | | | | |
Collapse
|
3
|
Isolated Hepatitis B Core Antibody is Associated With Advanced Hepatic Fibrosis in HIV/HCV Infection But Not in HIV Infection Alone. J Acquir Immune Defic Syndr 2016; 72:e14-7. [PMID: 26829660 DOI: 10.1097/qai.0000000000000941] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
|
4
|
Mohraz M, Jafari R, Poortahmasebi V, Sadeghi A, Hajabdolbaghi M, Rasoolinejad M, Forooghi M, Norouzi M, Poorebrahim M, Khamseh A, Karkhaneh M, Alavian SM, Ebrahimian A, Jazayeri SM. Molecular analysis of occult hepatitis B infection among Iranian HIV-positive patients. Future Virol 2016. [DOI: 10.2217/fvl-2016-0032] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Aim: The aims of this study were to find out the prevalence of occult hepatitis B infection (OBI) in HIV-1 patients, as well as to analyze the mutational patterns of OBI-positive individuals. Materials & methods: 172 HBsAg-negative, HIV-1-positive patients were selected according to data extracted from questionnaires. HBV serologic and molecular assays were performed. An extensive mutational analysis was applied using direct sequencing on HBsAg. Results: Thirty-one samples (18%) were OBI positive. Among 24 available OBI-positive samples, 17 (71%) contained at least one mutation only within ‘a’ determinant region of HBsAg. A stretch of mutations was found between amino acid positions 121 and 136. The physicochemical properties of individual amino acid substitutions and their potential impacts on 3D structure of ‘a’ determinant mutants were also determined. Conclusion: HBV serologic assays are not reliable markers to exclude occult HBV infection in HIV-positive patients.
Collapse
Affiliation(s)
- Minoo Mohraz
- Iranian Research Center for HIV AIDS, High Risk Reduction Institute, Tehran, Iran
| | - Rezvaneh Jafari
- Hepatitis B Molecular Laboratory, Department of Virology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - Vahdat Poortahmasebi
- Hepatitis B Molecular Laboratory, Department of Virology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - Ahmadreza Sadeghi
- Hepatitis B Molecular Laboratory, Department of Virology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | | | - Mehrnaz Rasoolinejad
- Iranian Research Center for HIV AIDS, High Risk Reduction Institute, Tehran, Iran
| | - Maryam Forooghi
- Iranian Research Center for HIV AIDS, High Risk Reduction Institute, Tehran, Iran
| | - Mehdi Norouzi
- Hepatitis B Molecular Laboratory, Department of Virology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - Mansour Poorebrahim
- Department of Medical Biotechnology, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Azam Khamseh
- Hepatitis B Molecular Laboratory, Department of Virology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - Masoud Karkhaneh
- Hepatitis B Molecular Laboratory, Department of Virology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - Seyed Moayed Alavian
- Middle East Liver Disease (MELD) Center, No 178, Sepahboud Gharanee St. Tehran 1598976516, Iran
| | - Arefeh Ebrahimian
- Hepatitis B Molecular Laboratory, Department of Virology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | | |
Collapse
|
5
|
Chenari M, Norouzi M, Ghalichi L, Rezaee A, Yari A, Alavian SM, Jazayeri SM. Characterization of overt and occult hepatitis B virus infection among HTLV-1 positive healthy carriers in the Northeast of Iran; AN HTLV-I endemic area. J Med Virol 2014; 86:1861-7. [PMID: 25132488 DOI: 10.1002/jmv.24046] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/15/2014] [Indexed: 12/23/2022]
Abstract
To date, no studies have provided data on hepatitis B virus (HBV) prevalence among asymptomatic, healthy human T-lymphotropic virus (HTLV-I) positive carriers. This sero- and molecular epidemiology study was performed on patients in the Northeast of Iran, which is an endemic area for HTLV-I infection. A total of 109 sera were collected from HTLV-I positive healthy carriers who were admitted to Ghaem Hospital, Mashhad City. All were tested for HBV serology and subsequently, real time PCR was carried out on the samples, regardless of the results of the serology. Standard PCR and direct sequencing were applied on positive samples. All cases were negative for HBsAg, Anti-HBc, and anti-HBs were positive in 34 (31.1%), and 35 (32%) individuals, respectively. There were 19 (17.4%) cases that were positive only for anti-HBs, and they had already received HBV vaccine. 16 (15%) were positive for both anti-HBs and anti-HBc, indicating a past-resolved HBV infection. 18 (16.5%) were isolated as anti-HBc, and 56 (51.3%) were negative for all HBV serological markers. Only one subject (0.9%) had detectable HBV DNA (2153 copy/ml), and assigned as being an occult HBV infection. The low prevalence of HBsAg, despite the high percentage of anti-HBc positive cases, might be related to the suppression effect of HTLV-I on surface protein expression. The low prevalence of HBV infection among HTLV-I positive healthy carriers from an endemic region, indicates that the epidemiology of HTLV-I and HBV coinfection is related to the endemicity of HBV in that region, rather than HTLV-I endemicity.
Collapse
Affiliation(s)
- Maryam Chenari
- Hepatitis B Molecular Laboratory, Department of Virology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | | | | | | | | | | | | |
Collapse
|
6
|
Sagnelli E, Pisaturo M, Martini S, Filippini P, Sagnelli C, Coppola N. Clinical impact of occult hepatitis B virus infection in immunosuppressed patients. World J Hepatol 2014. [PMID: 25018849 DOI: 10.4254/wjh.v6i6.384] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Occult hepatitis B infection (OBI), is characterized by low level hepatitis B virus (HBV) DNA in circulating blood and/or liver tissue. In clinical practice the presence of antibody to hepatitis B core antigen in hepatitis B surface antigen (HBsAg)-/anti-HBs-negative subjects is considered indicative of OBI. OBI is mostly observed in the window period of acute HBV infection in blood donors and in recipients of blood and blood products, in hepatitis C virus chronic carriers, in patients under pharmacological immunosuppression, and in those with immunodepression due to HIV infection or cancer. Reactivation of OBI mostly occurs in anti-HIV-positive subjects, in patients treated with immunosuppressive therapy in onco-hematological settings, in patients who undergo hematopoietic stem cell transplantation, in those treated with anti-CD20 or anti-CD52 monoclonal antibody, or anti-tumor necrosis factors antibody for rheumatological diseases, or chemotherapy for solid tumors. Under these conditions the mortality rate for hepatic failure or progression of the underlying disease due to discontinuation of specific treatment can reach 20%. For patients with OBI, prophylaxis with nucleot(s)ide analogues should be based on the HBV serological markers, the underlying diseases and the type of immunosuppressive treatment. Lamivudine prophylaxis is indicated in hemopoietic stem cell transplantation and in onco-hematological diseases when high dose corticosteroids and rituximab are used; monitoring may be indicated when rituximab-sparing schedules are used, but early treatment should be applied as soon as HBsAg becomes detectable. This review article presents an up-to-date evaluation of the current knowledge on OBI.
Collapse
Affiliation(s)
- Evangelista Sagnelli
- Evangelista Sagnelli, Mariantonietta Pisaturo, Salvatore Martini, Pietro Filippini, Nicola Coppola, Department of Mental Health and Public Medicine, Section of Infectious Diseases, Second University of Naples, 80131 Naples, Italy
| | - Mariantonietta Pisaturo
- Evangelista Sagnelli, Mariantonietta Pisaturo, Salvatore Martini, Pietro Filippini, Nicola Coppola, Department of Mental Health and Public Medicine, Section of Infectious Diseases, Second University of Naples, 80131 Naples, Italy
| | - Salvatore Martini
- Evangelista Sagnelli, Mariantonietta Pisaturo, Salvatore Martini, Pietro Filippini, Nicola Coppola, Department of Mental Health and Public Medicine, Section of Infectious Diseases, Second University of Naples, 80131 Naples, Italy
| | - Pietro Filippini
- Evangelista Sagnelli, Mariantonietta Pisaturo, Salvatore Martini, Pietro Filippini, Nicola Coppola, Department of Mental Health and Public Medicine, Section of Infectious Diseases, Second University of Naples, 80131 Naples, Italy
| | - Caterina Sagnelli
- Evangelista Sagnelli, Mariantonietta Pisaturo, Salvatore Martini, Pietro Filippini, Nicola Coppola, Department of Mental Health and Public Medicine, Section of Infectious Diseases, Second University of Naples, 80131 Naples, Italy
| | - Nicola Coppola
- Evangelista Sagnelli, Mariantonietta Pisaturo, Salvatore Martini, Pietro Filippini, Nicola Coppola, Department of Mental Health and Public Medicine, Section of Infectious Diseases, Second University of Naples, 80131 Naples, Italy
| |
Collapse
|
7
|
Prevalence of occult hepatitis B virus infection in a cohort of HIV-positive patients resident in Sicily, Italy. BIOMED RESEARCH INTERNATIONAL 2013; 2013:859583. [PMID: 24063015 PMCID: PMC3770005 DOI: 10.1155/2013/859583] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 04/30/2013] [Revised: 07/12/2013] [Accepted: 07/25/2013] [Indexed: 12/18/2022]
Abstract
Occult hepatitis B virus (OBI) in HIV-infected groups is still debated, as well as the associated risk-factors and clinical significance.
In this paper, we examined a total of 405 HBsAg-negative/HIV-infected patients enrolled from January 2007 to December 2009. Overall, the prevalence of OBI was 5.9% (95% confidence interval (CI95%): 3.8–8.7%); it was more frequently associated with “anti-HBc alone” serological marker (11.3%; adjusted odds ratio = 3.7, CI95%: 1.4–9.8), although it was also detected in the absence of any HBV serological marker (4.9%; CI95%: 2.3–9.1%). A low prevalence of anti-HCV-positive patients with OBI was found (3.1%; CI95%: 0.6–8.7%). HIV RNA plasma levels or other immunological/clinical characteristics were not significantly associated with OBI. All but one occult HBV infections were sustained by genotype D viral strains. OBI is relatively frequent in HIV-infected patients, although it does not seem to exert a relevant clinical impact. Viral genotypes in occult HBV infections reflect those circulating in the Mediterranean area.
Collapse
|
8
|
Martin CM, Welge JA, Rouster SD, Shata MT, Sherman KE, Blackard JT. Mutations associated with occult hepatitis B virus infection result in decreased surface antigen expression in vitro. J Viral Hepat 2012; 19:716-23. [PMID: 22967103 PMCID: PMC3442934 DOI: 10.1111/j.1365-2893.2012.01595.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Occult hepatitis B virus (HBV) infection is characterized by the absence of detectable hepatitis B surface antigen (HBsAg) in the serum, despite detectable HBV DNA. Investigations of the mechanisms underlying the development of occult HBV infection are lacking in the current literature, although viral mutations in the surface region, resulting in decreased HBsAg expression or secretion, represent one potential mechanism. Wild-type HBsAg expression vectors were constructed from genotype-matched chronic HBV sequences. Site-directed mutagenesis was then utilized to introduce three genotype A mutations - M103I, K122R and G145A - associated with occult HBV infection in vivo, alone and in combination, into the wild-type HBsAg vectors. Transfection of Huh7 and HepG2 cell lines was performed, and cell culture supernatants and cell lysates were collected over 7 days to assess the effects of these mutations on extracellular and intracellular HBsAg levels. The G145A mutation resulted in significantly decreased extracellular and intracellular HBsAg expression in vitro. The most pronounced reduction in HBsAg expression was observed when all three mutations were present. The mutations evaluated in vitro in the current study resulted in decreased HBsAg expression and potentially increased hepatic retention and/or decreased hepatic secretion of synthesized HBsAg, which could explain the lack of HBsAg detection that is characteristic of occult HBV infection in vivo.
Collapse
Affiliation(s)
- Christina M. Martin
- Division of Digestive Diseases, University of Cincinnati College of Medicine, Cincinnati, OH 45267
| | - Jeffrey A. Welge
- Departments of Psychiatry and Environmental Health, University of Cincinnati College of Medicine, Cincinnati, OH 45267
| | - Susan D. Rouster
- Division of Digestive Diseases, University of Cincinnati College of Medicine, Cincinnati, OH 45267
| | - Mohamed Tarek Shata
- Division of Digestive Diseases, University of Cincinnati College of Medicine, Cincinnati, OH 45267
| | - Kenneth E. Sherman
- Division of Digestive Diseases, University of Cincinnati College of Medicine, Cincinnati, OH 45267
| | - Jason T. Blackard
- Division of Digestive Diseases, University of Cincinnati College of Medicine, Cincinnati, OH 45267, Address requests for reprints to: Jason Blackard, PhD Division of Digestive Diseases University of Cincinnati College of Medicine ML 0595, 231 Albert Sabin Way Cincinnati, OH 45267 Phone: (513) 558-4389 Fax: (513) 558-1744
| |
Collapse
|
9
|
Occult Hepatitis B (OBH) in Clinical Settings. HEPATITIS MONTHLY 2012. [DOI: 10.5812/hapatmon.6126] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/13/2023]
|
10
|
Alavian SM, Miri SM, Hollinger FB, Jazayeri SM. Occult Hepatitis B (OBH) in Clinical Settings. HEPATITIS MONTHLY 2012; 12:e6126. [PMID: 23087749 PMCID: PMC3475016 DOI: 10.5812/hepatmon.6126] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 05/20/2012] [Revised: 06/20/2012] [Accepted: 07/08/2012] [Indexed: 12/11/2022]
Abstract
CONTEXT Occult hepatitis B (OHB), or persistent HBV DNA in patients who are hepatitis B surface antigen (HBsAg) negative, is a recently recognized entity. In an attempt to summarize the issues, this review presents an overview of the current proposed hypothesis on the clinical relevance and also updates the knowledge on the classification of OHB in different clinical settings. EVIDENCE ACQUISITION OHB COULD BE FOUND IN DIFFERENT POPULATION AND CLINICAL BACKGROUNDS INCLUDING: viral co-infections (with either human immunodeficiency or hepatitis C viruses), HBV chronic carriers, dialysis patients, transplantation settings and certain clinical situations (named in here: special clinical settings) with no apparent distinguishable clinical parameters. RESULTS The exact magnitude, pathogenesis, and clinical relevance of OHB are unclear. Even the possible role exerted by this cryptic infection on liver disease outcome, and hepatocellular carcinoma development remains unknown. CONCLUSIONS Monitoring of Individuals with positive anti-HBc, mass immunization programs and improvement in diagnostic tools seem to be important to control the probability of transmission of HBV through cryptic HBV infection.
Collapse
Affiliation(s)
- Seyed Moayed Alavian
- Baqiyatallah Research Center for Gastroenterology and Liver Disease, Baqiyatallah University of Medical Sciences, Tehran, IR Iran
| | - Seyed Mohammad Miri
- Baqiyatallah Research Center for Gastroenterology and Liver Disease, Baqiyatallah University of Medical Sciences, Tehran, IR Iran
| | | | - Seyed Mohammad Jazayeri
- Department of Virology, School of Public Health, Tehran University of Medical Sciences, Tehran, IR Iran
- Corresponding author: Seyed Mohammad Jazayeri, Department of Virology, School of Public Health, Tehran University of Medical Sciences, P.O. Box: 15155-6446, Tehran, IR Iran.Tel.: +98-2188992660, Fax: +98-2188992660, E-mail:
| |
Collapse
|
11
|
Sen S, Panda SP, Shanmuganandan K, Gupta R, Praharaj A. Prevalence of occult hepatitis B amongst Indian human immunodeficiency virus type 1 infected individuals-a pilot study. Med J Armed Forces India 2012; 68:16-9. [PMID: 24669033 DOI: 10.1016/s0377-1237(11)60127-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2011] [Accepted: 08/24/2011] [Indexed: 02/05/2023] Open
Abstract
BACKGROUND The diagnosis of hepatitis B is routinely based on the detection of hepatitis B surface antigen (HBsAg) only. However, occult hepatitis B virus (HBV) infection (OBI), which is defined as infection with positive hepatitis B core antibody (anti-HBc) antibodies, positive DNA (deoxyribonucleic acid) PCR (polymerase chain reaction), and undetectable HBsAg, as well as anti-HBs antibodies in serum or plasma of HBV infected individuals, will remain undetected using this screening diagnostic approach of detecting HBsAg. The current study aims in studying the prevalence of the OBI amongst human immunodeficiency virus type 1 (HIV-1) infected individuals who have not been exposed to anti-retroviral therapy. METHOD Estimation of HBsAg, anti-HBs, and anti-HBc total antibody status amongst 100 HIV-1 infected study participants was carried out using enzyme-linked immunosorbent assay (ELISA) kits. Detection of HBV-DNA was carried out by in-house qualitative PCR. CD4 + T lymphocyte counts were analysed using Becton Dickinson's (BD) FACSCount™ system. RESULTS The median age of the HIV-1 infected study population was 35 years (range: 22-67), with the gender distribution being 53 males and 47 females. The mean CD4 T lymphocyte count of the study participants was 210/mm(3). Overall, serological evidence of HBV infection was observed in 28% of the HIV-1 infected study participants. There was 5% seropositivity for HBsAg, of which 2% were additionally positive for HBV-DNA-PCR. "Anti-HBc alone" status was seen in 18% of study participants, this being statistically higher in those with CD4 T lymphocyte counts < 200/mm(3). While there was a single specimen with co-positivity for anti-HBc total antibodies and HBV-DNA, 5% of the in the study population exhibited anti-HBs antibodies positivity, with one sample exhibiting dual positivity for HBsAg and anti-HBs antibodies. CONCLUSION Occult HBV infections may contribute to chronic liver damage, and associ-ated reactivation amongst immunocompromised individuals, HIV-1 in-fected being a subset of them. "Anti-HBc" testing followed by HBV-DNA detection by PCR can be utilised for such populations to detect OBIs. Early detection of hepatitis B viraemia will be important for deciding the antiviral therapeutic protocol so as to avoid evolution of antiviral resistance in the circulating HBV strains in HIV-1 infected individuals harbouring OBIs.
Collapse
Affiliation(s)
- Sourav Sen
- Commanding Officer, Military Hospital, Gaya
| | | | - K Shanmuganandan
- Senior Advisor (Medicine & Rheumatology), Army Hospital (R&R), Delhi Cantt
| | - Rm Gupta
- Senior Advisor (Pathology & Microbiology), Command Hospital (NC), Udhampur
| | - Ak Praharaj
- Professor & Head, Department of Microbiology, Pune - 40
| |
Collapse
|
12
|
Di Lello FA, Macías J, Cifuentes CC, Vargas J, Palomares JC, Pineda JA. Low prevalence of occult HBV infection among HIV-infected patients in Southern Spain. Enferm Infecc Microbiol Clin 2011; 30:312-4. [PMID: 22071227 DOI: 10.1016/j.eimc.2011.09.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2011] [Revised: 08/08/2011] [Accepted: 09/01/2011] [Indexed: 10/15/2022]
Abstract
INTRODUCTION The aim of this study was to assess the prevalence of occult HBV infection in HIV-positive patients in a centre in Southern Spain. METHODS The HBV serological markers were investigated in all the patients and the presence of HBV-DNA was tested by PCR in patients with isolated anti-HBc. RESULTS An isolated anti-HBc pattern was detected in 144/520 (27.7%) patients. HBV-DNA was detected in one of these patients (0.7%). CONCLUSIONS In Southern Spain, there is a low prevalence of occult HBV infection among HIV-infected patients, despite increasing immigration from endemic countries.
Collapse
|
13
|
Gutiérrez-García ML, Fernandez-Rodriguez CM, Lledo-Navarro JL, Buhigas-Garcia I. Prevalence of occult hepatitis B virus infection. World J Gastroenterol 2011; 17:1538-42. [PMID: 21472117 PMCID: PMC3070122 DOI: 10.3748/wjg.v17.i12.1538] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/06/2010] [Revised: 11/16/2010] [Accepted: 11/23/2010] [Indexed: 02/06/2023] Open
Abstract
Occult hepatitis B virus (HBV) infection (OBI) is characterized by the persistence of HBV DNA in the liver tissue in individuals negative for the HBV surface antigen. The prevalence of OBI is quite variable depending on the level of endemic disease in different parts of the world, the different assays utilized in the studies, and the different populations studied. Many studies have been carried out on OBI prevalence in different areas of the world and categories of individuals. The studies show that OBI prevalence seems to be higher among subjects at high risk for HBV infection and with liver disease than among individuals at low risk of infection and without liver disease.
Collapse
|
14
|
Reuter S, Oette M, Wilhelm FC, Beggel B, Kaiser R, Balduin M, Schweitzer F, Verheyen J, Adams O, Lengauer T, Fätkenheuer G, Pfister H, Häussinger D. Prevalence and characteristics of hepatitis B and C virus infections in treatment-naïve HIV-infected patients. Med Microbiol Immunol 2010; 200:39-49. [PMID: 20853118 DOI: 10.1007/s00430-010-0172-z] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2010] [Indexed: 02/07/2023]
Abstract
In HIV-infected treatment-naïve patients, we analyzed risk factors for either chronic hepatitis B (HBV) infection, occult HBV infection (OHBV) or a positive hepatitis C (HCV) serostatus. A total of 918 patients of the RESINA-cohort in Germany were included in this study. Before initiating antiretroviral therapy, clinical parameters were collected and blood samples were analyzed for antibodies against HIV, HBV and HCV, HBs antigen and viral nucleic acids for HIV and HBV. Present or past HBV infection (i.e. HBsAg and/or anti-HBc) was found in 43.4% of patients. HBsAg was detected in 4.5% (41/918) and HBV DNA in 6.1% (34/554), resulting in OHBV infection in 2.9% (16/554) of patients. OHBV infection could not be ruled out by the presence of anti-HBs (50.1%) or the absence of all HBV seromarkers (25%). A HCV-positive serostatus was associated with the IVDU transmission route, non-African ethnicity, elevated liver parameters (ASL or GGT) and low HIV viral load. Replicative HBV infection and HCV-positive serostatus both correlated with HIV resistance mutations (P = 0.001 and P = 0.028). HBV and HCV infection are frequent co-infections in HIV treatment-naive patients. These co-infections influence viral evolution, clinical parameters and serological markers. Consequently, HIV patients should routinely be tested for HBV and HCV infection before initiating HIV treatment. OHBV infection constituted almost half of all HBV infections with detectable HBV DNA. Due to a lack of risk factors indicating OHBV infection, HBV diagnosis should not only include serological markers but also the detection of HBV DNA.
Collapse
Affiliation(s)
- Stefan Reuter
- Clinic of Gastroenterology, Hepatology and Infectious Diseases, University Hospital, Moorenstr. 5, 40225 Duesseldorf, Germany.
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
15
|
Núñez M. Routine hepatitis B virus DNA testing in human immunodeficiency virus-infected patients with positive hepatitis B core antibody but negative hepatitis B surface antigen is not justified by current evidence. Hepatology 2010; 51:1087-8. [PMID: 19960553 DOI: 10.1002/hep.23395] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
|
16
|
Iorio A, Marchesini E, Awad T, Gluud LL. Antiviral treatment for chronic hepatitis C in patients with human immunodeficiency virus. Cochrane Database Syst Rev 2010:CD004888. [PMID: 20091566 DOI: 10.1002/14651858.cd004888.pub2] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
BACKGROUND Antiviral treatment for chronic hepatitis C may be less effective if patients are co-infected with human immunodeficiency virus (HIV). OBJECTIVES To assess the benefits and harms of antiviral treatment for chronic hepatitis C in patients with HIV. SEARCH STRATEGY Trials were identified through manual and electronic searches in The Cochrane Hepato-Biliary Group Controlled Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library, MEDLINE, EMBASE, and Science Citation Index Expanded. The last search was May 2009. SELECTION CRITERIA Randomised trials comparing at least 12 weeks of any anti-HCV treatment versus another treatment regimen or no treatment. Included patients had chronic hepatitis C and stable HIV irrespective of previous antiviral therapy. DATA COLLECTION AND ANALYSIS Data extraction and assessment of risk of bias were done in duplicate. Analysis was by intention-to-treat. MAIN RESULTS Fourteen trials were included. None of the included 2269 patients were previously treated for chronic hepatitis C. Peginterferon (either 2a, 180 microgram, or 2b, 1.5 microgram/kg, once weekly) plus ribavirin was more effective in achieving end of treatment and sustained virological response compared with interferon plus ribavirin (5 trials, 1340 patients) or peginterferon (2 trials, 714 patients). The benefit of peginterferon plus ribavirin was seen irrespective of HCV genotype although patients with genotype 1 or 4 had lower response rates (27%) than patients with genotype 2 or 3 (56%). The remaining trials compared different treatment regimens in patients who were treatment naive or had no virological response after three months of treatment, but overall they had not enough power to show any effect of increasing the dose of interferon or adding both amantadine or ribavirin. The overall mortality was 23/2111 patients with no significant differences between treatment regimens. Treatment increased the risk of adverse events including anaemia and flu-like symptoms, and several serious adverse events occurred including fatal lactic acidosis, liver failure, and suicide due to depression. AUTHORS' CONCLUSIONS Peginterferon plus ribavirin may be considered a treatment for patients with chronic hepatitis C and stable HIV who have not received treatment for hepatitis C as the intervention may clear the blood of HCV RNA. Supporting evidence comes mainly from the analysis of this non-validated surrogate outcome assessed in comparisons against other antiviral treatments. There is no evidence on treatment of patients who have relapsed or did not respond to previous therapy. Careful monitoring of adverse events is warranted.
Collapse
Affiliation(s)
- Alfonso Iorio
- Department of Internal Medicine, University of Perugia, Ospedale Santa Maria della Misericordia, Località Sant'Andrea delle Fratte, Perugia, Italy, 06126
| | | | | | | |
Collapse
|
17
|
Morsica G, Ancarani F, Bagaglio S, Maracci M, Cicconi P, Cozzi Lepri A, Antonucci G, Bruno R, Santantonio T, Tacconi L, Baldelli F, Piscopo R, Santoro D, Lazzarin A, D'Arminio Monforte A. Occult hepatitis B virus infection in a cohort of HIV-positive patients: correlation with hepatitis C virus coinfection, virological and immunological features. Infection 2009; 37:445-9. [PMID: 19669092 DOI: 10.1007/s15010-008-8194-9] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2008] [Accepted: 10/28/2008] [Indexed: 12/16/2022]
Abstract
BACKGROUND An evaluation of the prevalence of occult hepatitis B virus (HBV) infection in HIV-positive individuals is important as HBV infection may have an impact on the outcome of the liver disease in these patients. MATERIALS AND METHODS Of the 1,593 HIV-positive subjects enrolled in the Italian Cohort Naïve Antiretroviral (ICONA) program, 175 (10.9%) were selected for inclusion in the study on the basis of hepatitis B surface antigen (HBsAg) negativity and antibody to hepatitis B core antigen (anti- HBc) positivity; 101/175 (58%) were also anti-hepatitis C virus (HCV) positive. HBV-DNA was detected in plasma using a highly sensitive PCR assay (detection limit: 2.6 copies/ml). Two different genomic regions were assayed. Quantification was performed by real-time PCR. The HBV genotype was determined in 20 cases with occult HBV infection. Data on the antiretroviral therapy (ART) regimen was obtained in 169 individuals: 53 (31.4%) patients were ART-naive, 46 (27.2%) were under ART without lamivudine or tenofovir, and the remaining 70 (41.4%) were under ART including lamivudine or tenofovir. RESULTS 27/175 (15%) patients had detectable HBV-DNA in their plasma: 21/101 (21%) were anti-HCV positive and 6/74 (8%) were anti-HCV negative. Genotype D was invariably found in the 20 cases analyzed. Occult HBV infection was significantly higher in HCV-coinfected subjects: adjusted OR 5.02, 95% CI 1.31-19.26, p = 0.02. The value was not associated with immune status, HIV load, or ART regimen. CONCLUSIONS In relation to the high prevalence of occult HBV infection, particularly in HIV/HCV-coinfected individuals, it is necessary to clarify the clinical impact of this cryptic infection by monitoring HBV-DNA in plasma using the correct approach. Similarly to HBsAg-positive individuals of the Mediterranean area, HBV genotype D is invariably detected in this cohort of HIV-infected patients with occult HBV infection.
Collapse
Affiliation(s)
- G Morsica
- Dept. of Infectious Diseases, S. Raffaele Scientific Institute, Milan, Italy.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
18
|
Palacios R, Mata R, Hidalgo A, Muñoz L, Viciana I, Del Arco A, López-Cortés LF, Peña A, de la Torre J, Santos J. Very low prevalence and no clinical significance of occult hepatitis B in a cohort of HIV-infected patients with isolated anti-HBc seropositivity: the BHOI study. HIV CLINICAL TRIALS 2009; 9:337-40. [PMID: 18977722 DOI: 10.1310/hct0905-337] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
PURPOSE Data on occult HBV infection in HIV patients are conflicting. We aimed to analyse the prevalence and clinical significance of occult hepatitis B in HIV-infected subjects. METHOD An open-label, cross-sectional, multicentre study including all subjects with isolated anti-HBc seropositivity from a cohort of 3,030 HIV-infected patients was undertaken. HBsAg and HBsAb were both negative in all cases, and those patients with acute or convalescent hepatitis B were excluded. HBV DNA was quantified by PCR with a detection limit of 20 IU/mL. RESULTS We found 5 cases (2.5%) of occult hepatitis B among 202 HIV-patients with isolated anti-HBc. The mean HBV DNA was 66 (15-112) IU/mL, none had symptomatic hepatitis, and their features, including aminotransferase levels, were similar to those without occult HBV infection. CONCLUSIONS Occult hepatitis due to HBV is very unusual in HIV-positive patients with isolated anti-HBc. The use of standard regimens of HAART including drugs with activity against HBV might underestimate the prevalence of occult HBV infection. These patients had a very low viral load, no identifiable risk factors, and no greater risk of hypertransaminasaemia or the development of symptomatic hepatitis.
Collapse
Affiliation(s)
- R Palacios
- Infectious Diseases Unit, Hospital Virgen de la Victoria, Málaga, Spain
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
19
|
Piroth L, Lafon ME, Binquet C, Bertillon P, Gervais A, Lootvoet E, Lang JM, Jaureguiberry JPD, Chene G, Leport C, The Anrs Co8 Aproco-Copilote Study. Occult hepatitis B in HIV-HCV coinfected patients. ACTA ACUST UNITED AC 2009; 40:835-9. [DOI: 10.1080/00365540801918511] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Lionel Piroth
- From the Service des Maladies Infectieuses et Tropicales, CHU Dijon
| | | | - Christine Binquet
- Département de Biostatistiques et d'Informatique Médicale, CHU Dijon
| | | | - Anne Gervais
- Service des Maladies Infectieuses et Tropicales, CHU Bichat Claude Bernard, Paris
| | | | | | | | | | - Catherine Leport
- Service des Maladies Infectieuses et Tropicales, CHU Bichat Claude Bernard, Paris
| | | |
Collapse
|
20
|
Cohen Stuart JWT, Velema M, Schuurman R, Boucher CAB, Hoepelman AIM. Occult hepatitis B in persons infected with HIV is associated with low CD4 counts and resolves during antiretroviral therapy. J Med Virol 2009; 81:441-5. [PMID: 19152397 DOI: 10.1002/jmv.21422] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Occult hepatitis B virus (HBV) is defined by the presence of plasma HBV DNA in individuals with HBV core antibodies (anti-HBc), but without HBV surface antigen (HBsAg). The prevalence of occult HBV in HIV-infected patients remains controversial, and the risk factors, clinical significance and effect of highly active antiretroviral therapy (HAART) are unknown. The aim of this study was to determine prevalence, risk factors, and clinical significance of occult HBV in HIV-infected patients and to evaluate the effect of HAART. Plasma HBV DNA levels were determined in 191 HIV positive, antiretroviral naïve patients, who were anti-HBc positive and HBsAg negative. Quantitative HBV DNA was determined using a Taqman real-time nested PCR. Additionally, plasma HIV RNA levels, CD4 cell counts, anti-HBs-antibodies, anti-HCV-antibodies, ALT, AST, and gammaGT were determined. Occult HBV (a plasma HBV DNA level >50 copies/ml) was detected in 9/191 (4.7%) of the patients. Among 45 anti-HBs-negative patients (isolated anti-HBc positive), the prevalence was 11.1%. Patients with occult HBV had significantly lower CD4 count compared to anti-HBc-positive/HBsAg negative/HBV DNA-negative patients (105 +/- 157 (median +/- SD) vs. 323 +/- 299 cells/mm(3), P = 0.019). When HAART (including lamivudine) was initiated in the patients with occult HBV, HBV DNA was no longer detectable in any of the patients during 3 years of follow-up. In conclusion, occult HBV was associated with low CD4 counts and may be viewed as opportunistic reactivation of HBV that resolves as a consequence of HAART induced immune reconstitution and/or the effect of lamivudine.
Collapse
Affiliation(s)
- James W T Cohen Stuart
- Department of Virology, Eijkman Winkler Institute for Medical Microbiology, Infectious Diseases and Inflammation, University Medical Center Utrecht, Utrecht, The Netherlands.
| | | | | | | | | |
Collapse
|
21
|
Hoffmann CJ, Charalambous S, Martin DJ, Innes C, Churchyard GJ, Chaisson RE, Grant AD, Fielding KL, Thio CL. Hepatitis B virus infection and response to antiretroviral therapy (ART) in a South African ART program. Clin Infect Dis 2008; 47:1479-85. [PMID: 18937580 DOI: 10.1086/593104] [Citation(s) in RCA: 104] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
BACKGROUND Coinfection with hepatitis B virus (HBV) and human immunodeficiency virus (HIV) is common in Africa; however, the impact of HBV infection on the outcomes of antiretroviral therapy programs is unclear. We evaluated the impact of chronic hepatitis B on HIV virologic response, changes in CD4 cell count, hepatotoxicity, and mortality among Africans receiving highly active antiretroviral therapy (HAART). METHODS We conducted a retrospective cohort study involving a workplace HAART program in South Africa. Participants received HAART according to a protocol and were followed up for up to 72 weeks. On the basis of pre-HAART serum assays, patients were classified as being hepatitis B surface antigen (HBsAg) negative, HBsAg positive with a low HBV DNA level (</= 1 x 10(4) copies/mL), and HBsAg positive with a high HBV DNA level (> 1 x 10(4) copies/mL). The relationships between HBV status and HIV RNA suppression, change in CD4 cell count, mortality, and hepatotoxicity were assessed with use of regression techniques. RESULTS Five hundred thirty-seven individuals fulfilled the inclusion criteria; 431 (80.3%) of these patients were HBsAg negative, 60 (11.2%) were HBsAg positive with a low HBV DNA level, and 46 (8.6%) were HBsAg positive with a high HBV DNA level. All groups had similar rates of HIV RNA suppression (P = .61), CD4 cell count increases (P =.75), and mortality (17 total deaths; P=.11) for up to 72 weeks after the initiation of HAART. Baseline transaminase levels were highest in the group with high HBV DNA levels (P=.004). Hepatotoxicity was similar between the HBsAg-negative group and the group with low HBV DNA levels but was higher in the group with high HBV DNA levels (incidence rate ratio, 4.4). CONCLUSIONS We revealed that HBV status does not affect HIV RNA suppression, CD4 cell count response, or mortality during the first 72 weeks of HAART in an African setting. The risk of HBV-associated hepatotoxicity, however, is associated with the baseline HBV DNA level.
Collapse
|
22
|
Piroth L, Carrat F, Larrat S, Goderel I, Martha B, Payan C, Lunel-Fabiani F, Bani-Sadr F, Perronne C, Cacoub P, Pol S, Morand P. Prevalence and impact of GBV-C, SEN-V and HBV occult infections in HIV-HCV co-infected patients on HCV therapy. J Hepatol 2008; 49:892-8. [PMID: 18752863 DOI: 10.1016/j.jhep.2008.06.024] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/29/2008] [Revised: 06/10/2008] [Accepted: 06/10/2008] [Indexed: 02/08/2023]
Abstract
BACKGROUND/AIMS It has been suggested that, in HIV-HCV co-infected patients, co-infections with other viruses may affect the response to HCV therapy. We aimed to assess the prevalence of GBV-C, SEN-V and occult HBV infections, their impact on HCV and HIV infections and on the response to HCV therapy in HIV-HCV co-infected patients. METHODS Three-hundred and sixty eight patients were tested before starting interferon-ribavirin for the presence of occult hepatitis B DNA, GBV-C RNA and SEN-V DNA by using real time PCR. Clinical, immunological, virological, histological characteristics and response to HCV therapy were compared according to the presence or not of each viral co-infection. RESULTS HBV DNA, GBV-C RNA and SEN-V DNA were found in 5 (1.4%, CI95%: 0.2-2.4%), 104 (29.9%, CI95%: 25.1-34.7%) and 209 patients (57.9%, CI95%: 52.8-63.0%), respectively. GBV-C positive patients had significantly higher CD4 count at baseline, during and after HCV therapy, even after stratification on antiretroviral treatment. No other significant difference was observed according to the presence or not of GBV-C or SEN-V co-infection, in particular regarding virological responses to HCV combination therapy. CONCLUSIONS There is no reason to withhold HCV therapy in HIV infected patients who have access to HAART, because of occult HBV, GBV-C or SEN-V co-infections.
Collapse
Affiliation(s)
- Lionel Piroth
- Service des Maladies Infectieuses, CHU Dijon, 10, Boulevard du Maréchal de Lattre de Tassigny, 21079 DIJON Cedex, France.
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
23
|
Care of HIV patients with chronic hepatitis B: updated recommendations from the HIV-Hepatitis B Virus International Panel. AIDS 2008; 22:1399-410. [PMID: 18614862 DOI: 10.1097/qad.0b013e3282f8b46f] [Citation(s) in RCA: 133] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Nearly 10% of the estimated 36 million people having HIV worldwide suffer from chronic hepatitis B virus (HBV) infection. The advent of new antiviral agents against HBV and the recent availability of improved molecular diagnostic tools have revolutioned the management of HIV/HBV coinfected patients. The present study represents an update of the current knowledge about HBV/HIV coinfection and an intent to provide practical advise about how to give the best care to HIV-infected persons with chronic hepatitis B.
Collapse
|
24
|
Abstract
Persons at high risk for human immunodeficiency virus (HIV) infection are also likely to be at risk for other infectious pathogens, including hepatitis B virus (HBV) or hepatitis C virus (HCV). These are bloodborne pathogens transmitted through similar routes; for example, via injection drug use (IDU), sexual contact, or from mother to child during pregnancy or birth. In some settings, the prevalence of coinfection with HBV and/or HCV is high. In the context of effective antiretroviral therapy (ART), liver disease has emerged as a major cause of morbidity and mortality in HIV-infected persons. Further, coinfection with viral hepatitis may complicate the delivery of ART by increasing the risk of drug-related hepatoxicity and impacting the selection of specific agents (e.g., those dually active against HIV and HBV). Expert guidelines developed in the United States and Europe recommend screening of all HIV-infected persons for infection with HCV and HBV and appropriate management of those found to be chronically infected. Treatment strategies for HBV infection include the use of nucleos(t)ide analogues with or without anti-HIV activity and/or peginterferon alfa (PegIFN) whereas HCV treatment is limited to the combination of PegIFN and ribavirin (RBV). Current approaches to management of HIV-infected persons coinfected with HBV or HCV are discussed in this review.
Collapse
Affiliation(s)
- Mark S Sulkowski
- Johns Hopkins University School of Medicine, 600 North Wolfe Street, 1830 Building, Room 448, Baltimore, MD 21287, USA.
| |
Collapse
|
25
|
Cacoub P, Piroth L. Prise en charge des malades coinfectés VIH-VHC et VIH-VHB. ACTA ACUST UNITED AC 2007; 31:887-94. [DOI: 10.1016/s0399-8320(07)73986-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
|