Unexpected long‐lasting anti‐HEV IgM positivity: Is HEV antigen a better serological marker for hepatitis E infection diagnosis?

Hepatitis E virus (HEV) is the leading cause of acute hepatitis worldwide. The minimum criterion for diagnosis of acute infection is detection of anti‐HEV antibodies, although there are scant data on IgM duration. Our aim was to assess the persistence of HEV markers after acute self‐limited hepatitis E. HEV serological tests (IgM by Mikrogen and Wantai and HEV‐Ag) and HEV RNA were carried out in two cohorts: (a) patients with prior acute hepatitis E (ALT >10 x ULN plus positive IgM ± HEV RNA) currently self‐limited and (b) 50 blood donors with positive HEV RNA. Among 25 cases of prior acute hepatitis E, after a median follow‐up of 34 months, all presented undetectable HEV RNA. However, anti‐HEV IgM remained detectable in 14 (56%) by Mikrogen, 6 (24%) by Wantai and none for HEV‐Ag. Anti‐HEV IgM tested positive in 80%‐100% within the second year and 17%‐42% over 3 years later, by Wantai and Mikrogen, respectively. Among HEV RNA‐positive donors, 12 (25%) tested positive for either IgM by Mikrogen or Wantai, 9 (18%) for both and 18 (36%) for HEV‐Ag. HEV‐Ag positivity was more likely as HEV RNA was higher (14% if <2.2 log IU/mL; 64% if RNA ≥ 3.7). Overall, HEV‐Ag performed best, with a positive predictive value of 100% and diagnostic accuracy of 57%. Anti‐HEV IgM exhibited unexpectedly long persistence after a self‐limited acute hepatitis E. HEV‐Ag had the best performance and could be especially useful in settings where HEV RNA is not available.     

Icteric acute hepatitis E with no response of immunoglobulin M class anti‐hepatitis E virus antibody

A 68‐year‐old Japanese man developed icteric acute hepatitis during periodic care after undergoing gastrectomy due to early gastric cancer. The routine serological markers for hepatitis A, B and C viruses were all negative. Although the liver enzymes spontaneously recovered without any specific therapy, cholestasis was relatively prolonged and successfully treated with prednisolone. Determination of serum hepatitis E virus (HEV) RNA revealed the transient infection of HEV, and both immunoglobulin (Ig)A and IgG class anti‐HEV antibodies were detected after the disease onset, whereas those were negative when measured 3 weeks prior to the onset. In addition, the titer of serum IgA class antibody was associated with the clinical signs of hepatitis. In contrast, no IgM class antibody was detected throughout the course. This case suggests that screening only with IgM class antibody is not sufficient to detect acute HEV infection.     

Consecutive evaluation of immunoglobulin M and G antibodies against hepatitis E virus

Hepatitis E virus (HEV) infection is sporadic in the Guangzhou city southern China. However, the evaluation of antibodies to HEV during consecutive time periods after infection has not been reported. We utilized enzyme immunosorbent assay (ELISA) to detect IgM and IgG anti-HEV in consecutive serum specimens from patients with acute hepatitis E and compared that data with detection rates of IgM and IgG anti-HAV in patients with acute hepatitis A. IgM anti-HEV can be detected as early as 4 days after onset of disease symptoms in some patients. The detection rate of IgM anti-HEV is significantly higher in specimens collected within 4 weeks (95%) of onset than in those specimens collected 4 to 18 weeks after onset (67.6%) (P<0.005). IgM anti-HEV had a similar pattern to IgM anti-HAV and can be used as a marker of acute HEV infection. In contrast with IgG anti-HAV, 56.8% of the specimens did not contain detectable levels of IgG anti-HEV (P<0.005). One should be cautioned against making a diagnosis of HEV infection solely by the currently available assays for IgG anti-HEV. In conclusion, IgM anti-HEV can be used as a reliable and sensitive marker for recent HEV infection, but serum specimens should be collected within 4 weeks after onset of symptoms to avoid false-negative results. In contrast, we should be aware of the failure to develop IgG anti-HEV in some patients. These patients carry the risk of reinfection.     

Coexistence of IgM antihepatitis A virus and IgM antihepatitis E virus in acute viral hepatitis: a prospective, multicentre study in Korea

This study investigated the clinical, serological and molecular characteristics of coexistence of both immunoglobulin M (IgM) antihepatitis A virus (HAV) and IgM antihepatitis E virus (HEV) in acute viral hepatitis using a prospective, multicentre design. Among a total of 771 symptomatic cases with acute viral hepatitis enrolled in a Korean city from September 2006 to August 2008, coexistence of IgM anti-HAV and IgM anti-HEV was found in 43 patients (A+E group; 6%), while the existence of IgM anti-HAV alone was found in 595 patients (A group; 77%) and that of IgM anti-HEV alone in 14 patients (E group; 2%). Clinical data analysis and measurement of IgM and IgG anti-HEV were performed using two different commercial kits, and HAV RNA and HEV RNA were detected in available serum or stool samples. The clinical features of the A+E group were similar to those of the A group. HAV RNA detection rates in the A+E and A group were similar, while HEV RNA was detected only in the stool samples of the E group, not in the A+E group. Comparative testing of anti-HEV using two different ELISA kits showed markedly discordant results for IgM anti-HEV positivity and consistently low positivity for IgG anti-HEV in the A+E group. Coexistence of IgM anti-HEV measured by the Genelabs ELISA kit in the setting of hepatitis A appears to yield false-positive results in nonendemic areas of HEV infection. Diagnosis of hepatitis E using IgM anti-HEV should be made with caution.     

RNA testing for the diagnosis of acute hepatitis A during the 2017 outbreak in France

Diagnostic of acute hepatitis A virus (HAV) infection is based on the detection of anti‐HAV IgM without testing for the pathogen itself. We evaluated the usefulness of HAV RNA testing for confirmation of acute hepatitis A and to provide indications about the level of HAV replication in HIV‐positive and HIV‐negative subjects during an unprecedented outbreak of HAV observed in France in 2017. HAV RNA was detected in 38 out of 41 (92.6%) subjects with a clinical diagnosis of acute hepatitis A, whereas nine cases tested positive for anti‐HAV IgM in whom the diagnosis of acute hepatitis A was not retained were found negative for HAV RNA. All subjects in the control group were also tested negative for HAV RNA. HAV viremia was correlated to ALT peak (r = .64; P < .0001). HIV‐infected patients have similar HAV RNA levels but were less likely to have prolonged international normalized ratio of prothrombin time when compared to the HIV‐uninfected group (P = .016), suggesting a less severe course of acute hepatitis. HAV RNA was detected in the serum of most of the patients with acute hepatitis A, indicating that the direct detection of HAV can be used to confirm hepatitis A in patients tested positive for anti‐HAV IgM antibodies. Nucleic acid tests should serve more broadly during the diagnosis workup of acute hepatitis A to improve the predictive values of HAV in vitro diagnostic tests and to confirm acute hepatitis A in patients tested positive with IgM with moderate or low S/CO values.     

抗戊型肝炎病毒E2 IgM诊断急性戊型肝炎的敏感性和特异性

目的评价抗戊型肝炎病毒（HEV）衣壳蛋白重组抗原E2 IgM（抗-E2 IgM）诊断急性散发性戊型肝炎的敏感性和特异性。方法用酶联免疫吸附法检测176份急性散发性戊型肝炎和191份急性散发性非甲～非戊型肝炎患者血清中抗-E2 IgM，与国产传统试剂和新加坡Genelabs试剂检测的IgM（GL—IgM）作比较；对抗-E2 IgM阳性血清检测血清中HEV RNA，采用logistic回归分析检测抗-E2 IgM和HEV RNA的相关因素。结果在176份急性戊型肝炎患者血清中，抗-E2 IgM的检出率为68．75％，国产传统试剂抗-HEV IgM检出率为56．25％，x^2IgM=6．49，P〈0．05。在191份急性非甲～非戊型肝炎血清中有37例（19．37％）抗-E2 IgM阳性，其中11例GL—IgM同时阳性；在158份抗-E2 IgM阳性血清中，有81例HEV RNA阳性（51．27％），其中急性戊型肝炎的阳性率为57．02％，急性非甲～非戊型肝炎的阳性率为32．43％，23例抗-E2 IgM阴性的急性戊型肝炎患者的血清，无一例检测到HEV RNA。Logistic多因素回归分析发现，抗-E2 IgM的检出率与发病至人院时间、年龄、血清胆红素、血清氨基转移酶水平无关，血清丙氨酸氨基转移酶水平与HEV RNA水平呈正相关（P=0．024）。结论抗-E2 IgM是HEV急性期感染敏感性和特异性强的血清学指标；HEV感染仍是部分临床诊断为急性非甲～非戊型肝炎的病因；持续HEV病毒血症可能是影响急性戊型肝炎病情的重要因素。     

Detection of hepatitis E virus RNA and genotype in Bangladesh

Background/Aims:  Hepatitis E virus (HEV) in Bangladesh has not been adequately documented. We report HEV RNA and genotype detection in Bangladesh.
Methods:  In total, 82 samples were used; 36 sporadic acute hepatitis (AH), 12 fulminant hepatitis (FH), 14 chronic liver disease (CLD) and 20 from an apparently healthy population (HP) positive for both immunoglobulin (Ig) M and IgG specific anti-HEV antibodies (anti-HEV). The male/female ratio was 61/21, ages 12–67 (mean 30.4) years. RNA was extracted, transcribed to cDNA and amplified in nt 6345–6490 (ORF2) of HEV. Nucleic and amino acid sequences were determined. Homology comparison between Bangladesh clones and other representative HEV clones and phylogenetic tree analyses were done. Relations between HEV RNA-positivity and clinical factors were analyzed.
Results:  HEV RNA was positive in 9/36 (25.0%) of AH cases, 4/12 (33.3%) FH, 3/14 (21.4%) CLD and 0/20 (0%) HP samples; total 16/82 (19.5%). Four factors correlated significantly with HEV RNA-positivity (Mann-Whitney U test); alanine aminotransferase (ALT) ( P  = 0.0229), aspartate aminotransferase (AST) ( P  = 0.0448), and titers of IgG ( P  = 0.0208) and IgM ( P  = 0.0095) specific anti-HEV. The 16 HEV clones were divided mainly into two groups, A and B, including six different cDNA sub-groups.
Conclusion:  HEV RNA was found in sporadic AH and FH and sub-clinical CLD cases, but not in HP. HEV RNA-positivity was significantly related to values of ALT and AST and titers of IgG and IgM specific anti-HEV, with IgM specific anti-HEV showing the most significant relationship. All clones were genotype I, which is prevalent in South Asia.     

急性戊型肝炎血清抗-HEV IgM、IgG和HEV RNA动态变化及其诊断价值

目的 分析急性戊型肝炎(AHE)患者血清抗-HEV IgM、抗HEV-IgG和HEV RNA变化规律。方法 2016年1月～2018年3月北京佑安医院就诊的AHE患者217例,动态检测血清抗-HEV IgM、抗HEV-IgG和HEV RNA变化。结果 首次检测血清抗-HEV IgM、IgG和HEV RNA均阳性31例(14.3%),抗-HEV IgM和IgG阳性99例(45.5%),抗-HEV IgM阳性8例(3.7%),抗-HEV IgG阳性72例(33.2%),抗-HEV IgM和HEV RNA均阳性3例(1.5%),抗-HEV IgG和HEV RNA均阳性2例(0.9%),抗-HEV IgM、IgG、HEV RNA均阴性2例(0.9%);在75例患者二次检测中,显示血清抗-HEV IgG阳性增多;在138例有准确的发病日期患者,在第1、2、3、4病周和第4病周后,血清HEV RNA阳性检出率分别为49.0%(25/51)、10.2%(6/59)、3.1%(1/32)、4.0%(1/25)和0.0%(0/0);血清抗-HEV IgM阳性检出率分别为70.6%(36/51)、69.5%(41/59)、65.6%(21/32)、48%(12/25)和56.5%(13/23);血清抗-HEV IgG阳性检出率分别为90.2%(46/51)、88.1%(52/59)、96.9%(31/32)、100%(25/25)和100.0%(23/23)。结论 AHE患者血清抗-HEV IgM、IgG和HEV RNA存在一定的变化规律,血清抗-HEV IgG阳性,结合典型的急性肝炎过程和排除其他病因后,可以诊断为AHE。     

Relationships among viral diagnostic markers and markers of liver function in acute hepatitis E

Background  Diagnosis of acute hepatitis E has been based in many clinics predominantly on detection of anti-HEV (hepatitis E virus) antibody. Now, new assays have been developed to detect other HEV markers. Our aim was to investigate the relationships among HEV diagnostic markers and liver function markers in acute hepatitis E. Methods  Seventy serum samples were collected from non-A, non-B, non-C acute hepatitis patients and tested for HEV markers (HEV antigen and RNA and anti-HEV IgM) and markers of liver function [alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), total iron binding capacity (TBA), γ-glutamyl transferase (GGT), total bilirubin (TBIL), and direct bilirubin (DBIL)]. Partial open reading frame (ORF) 2 sequences from HEV RNA-positive samples were cloned and analyzed. Results  The concordances between HEV antigen and HEV RNA and between HEV antigen and anti-HEV IgM were 77.1% and 72.9%, respectively, with significant correlations, while that between HEV RNA and anti-HEV IgM was 61.4% with no significant correlation. Eleven of 25 samples negative for anti-HEV IgM were positive for HEV antigen. The ALT, AST, ALP, TBA, GGT, TBIL, and DBIL levels did not differ significantly between the anti-HEV IgM-positive and -negative groups. However, the ALT, AST, ALP, TBA, and GGT levels were significantly higher in the HEV antigen-positive group than in the HEV antigennegative group. All of the HEV isolates cloned belonged to genotype 4. Conclusions  HEV antigen was highly correlated with HEV RNA and elevated ALT, AST, ALP, TBA, and GGT levels. Testing for HEV antigen in combination with anti-HEV IgM is useful for the diagnosis of HEV infection.     

Significance of serum IgA in patients with acute hepatitis E virus infection

AIM: To study the significance of serum anti-hepatitis E virus (HEV) IgA in patients with hepatitis E. METHODS: A new method was established to assay anti-HEV IgA, which could be detected in the middle phase of the infection. We compared anti-HEV IgA assay with anti-HEV IgM and anti-HEV IgG assay in sera from 60 patients with positive HEV-RNA. RESULTS: The 60 patients with positive HEV-RNA had both anti-HEV IgA and anti-HEV IgM and 410 patients with negative HEV-RNA were used as control. Periodic serum samples obtained from 60 patients with hepatitis E were tested for HEV RNA, anti-HEV IgM, anti-HEV IgA and anti-HEV IgG. Their HEV-RNA was detectable in the serum until 20±11 d. We used anti-HEV IgM and anti-HEV IgA assay to detect HEV infection and positive results were found in 90±15 d and 120±23 d respectively, the positive rate of anti-HEV IgA was higher than that of anti-HEV IgM and HEV-RNA (P <0.05). CONCLUSION: The duration of anti-HEV IgA in serum is longer than that of anti-HEV IgM, and anti-HEV IgA assay is a good method to detect HEV infection.     

Lack of evidence of hepatitis E virus infection among renal transplant recipients in a disease‐endemic area

Persistent hepatitis E virus (HEV) infection has been reported among solid‐organ transplant recipients in nonendemic areas. Such chronic infections have all been related to genotype 3 HEV, which is prevalent in these areas. Whether persistent infection occurs with genotype 1 HEV, prevalent in areas where the infection is hyperendemic, is unclear. We therefore tested sera from renal transplant recipients receiving immunosuppressive agents in India, where genotype 1 HEV infection is endemic, for alanine aminotransferase levels, and presence of IgM and IgG anti‐HEV antibodies and HEV RNA. Of the 205 subjects studied [aged 16–65 (median, 38) years, 182 male], 46 (22.4%) had abnormal ALT levels (>40 IU/mL). IgG anti‐HEV was detected in 52 (20.5%) and IgM anti‐HEV was detected in 14 (6.8%) subjects, including four who had IgG anti‐HEV; antibody positivity had no relation with serum ALT or serum creatinine. All the sera tested were negative for HEV RNA. These findings suggest that chronic infection with genotype 1 HEV is infrequent.     

Sporadic acute hepatitis E occurred constantly during the last decade in northeast Japan

Background  Recent studies have shown that indigenous hepatitis E virus (HEV) strains cause hepatitis E in industrialized countries. We aimed to clarify the characteristics of HEV infection in sporadic hepatitis patients during the last decade in Miyagi, northeast Japan. Methods  We analyzed 94 serum samples obtained from acute or fulminant hepatitis patients of non-A, non-B, and non-C etiology between 1999 and 2008. Antibody to HEV (anti-HEV) was assayed, and patients who were positive for IgM- and/or IgA-class anti-HEV were diagnosed with hepatitis E. HEV RNA was tested in these patients, and phylogenetic analysis was performed. The occurrence of hepatitis E was compared with that of hepatitis A. Results  Eight acute hepatitis patients (8.5%) were diagnosed with hepatitis E, and HEV RNA was detectable in seven patients. Five isolates of HEV were segregated into genotype 3 and the remaining two isolates into genotype 4. The year of the occurrence of hepatitis E was distributed almost equally from 1999 to 2008, whereas the cases of acute hepatitis A (n = 16) have decreased markedly in the last several years. In 2004–2008, the occurrence of hepatitis E was greater than that of hepatitis A (five cases vs. one case). As for seasonality, hepatitis E occurred more frequently from September to December than hepatitis A (five cases vs. four cases), although less frequently from January to April (one case vs. seven cases). Conclusion  The occurrence of hepatitis E has not decreased during the last decade in northeast Japan, in contrast to hepatitis A. The nucleotide sequence data reported in this study have been assigned GenBank/EMBL/DDBJ accession numbers AB206467 and AB453332–AB453337.     

HEV核酸、抗原、抗体对HEV感染的诊断价值

目的探讨HEV核酸(HEV RNA)、HEV抗原(HEV Ag)、HEV抗体(HEV IgM抗体和HEV IgG抗体)在临床诊断HEV感染中的作用。方法收集在北京大学人民医院进行HEV IgM抗体和HEV IgG抗体检测的13992例标本,其中1924例HEV IgM抗体或HEV IgG抗体阳性。分别采用荧光PCR法进行HEV RNA和基因型检测,酶联免疫吸附试验方法进行HEV Ag、HEV IgM抗体和HEV IgG抗体检测,并检测ALT、AST、TBil和DBil水平。计量资料两组间比较采用Mann-Whitney U检验。结果1924例标本中HEV IgM抗体阳性152例(7.9%),HEV IgG抗体阳性1897例(98.6%),HEV RNA阳性62例(3.2%),HEV Ag阳性55例(2.9%)。HEV IgM抗体阳性组中HEV RNA阳性率为40.8%(62/152),HEV Ag阳性率为36.2%(55/152)。HEV RNA阳性组中HEV Ag阳性率为88.7%(55/62)。HEV RNA阳性组(n=62)ALT、AST、TBil、DBil水平高于HEV RNA阴性组(n=90)(Z值分别为-7.609、-6.942、-5.815、-6.130,P值均<0.001),HEV Ag阳性组(n=55)ALT、AST、TBil、DBil水平明显高于HEV Ag阴性组(n=97)(Z值分别为-6.413、-5.786、-5.199、-5.545,P值均<0.001)。巢式PCR扩增测序结果显示58例HEV RNA阳性,4例阴性。HEV IgG抗体阳性高水平明显降低HEV Ag检测的S/CO值,甚至出现阴性结果。结论与HEV抗体相比,HEV Ag可以提高戊型肝炎的诊断水平,具有一定的临床意义;高水平的转氨酶或胆红素可以辅助诊断HEV感染;高水平的HEV IgG抗体会降低HEV Ag检测值,检测时应注意HEV Ag阴性时HEV IgG抗体值。     

Hepatitis E infection in HIV‐infected liver and kidney transplant candidates

Hepatitis E virus (HEV) has been reported to cause acute and chronic hepatitis in those with HIV infection and among solid organ transplant recipients in Europe. Limited data indicate that HEV is endemic in the United States, but the prevalence and significance of HEV infection among those with HIV and awaiting solid organ transplantation is unknown. We evaluated anti‐HEV IgM and IgG antibodies and HEV RNA in 166 HIV‐infected solid organ transplant candidates enrolled in the NIH HIV‐Transplant Cohort. Overall prevalence of anti‐HEV IgG approached 20% in both liver and renal transplant candidates. Evidence of recent infection was present in approximately 2% of liver transplant candidates and none of the kidney transplant candidates. HEV RNA was not detected in any patient. We conclude that markers of HEV infection are frequent among candidates for transplantation, but active, ongoing viremia is not seen. Evidence of recent infection (acute on chronic) liver disease was present in liver but not kidney recipients.     

High genomic similarity between European type hepatitis E virus subgenotype 3e strains isolated from an acute hepatitis patient and a wild boar in Mie,Japan

A 67‐year‐old male living in Tsu city, Mie prefecture, Japan was referred to our hospital for further examination of acute liver injury and was diagnosed as having clinical hepatitis E virus (HEV) infection in January 2010. The HEV strain (HE‐JA11‐1701) isolated from the patient belonged to genotype 3 and European‐type subgenotype 3e. It was presumed that the patient had been infected from a wild boar (Sus scrofa leucomystax) because he consumed meat/viscera from a wild boar that he had captured himself as a hunter approximately 2 months before disease onset. A specimen of the boar meat/viscera that the patient had ingested was not available. However, the HE‐JA11‐1701 strain was 99.8% identical within the 412‐nucleotide sequence of the open reading frame 2 region to a HEV strain (JBOAR012‐Mie08) that had been recovered from a wild boar captured near the patient's hunting area in 2008. A phylogenetic analysis confirmed that the two HEV strains had a close genetic relationship and were segregated into subgenotype 3e, supported by a high bootstrap value of 99%. Of note, the HE‐JA11‐1701 and JBOAR012‐Mie08 strains were remotely related to the 3e strains reported in Japan and European countries, with a nucleotide difference of 7.9–13.9%, reinforcing the uniqueness of the 3e strains obtained in the present study. These results strongly support our speculation that the patient developed acute hepatitis E via consumption of HEV‐infected boar meat/viscera. Genetic analyses of HEV strains are useful for tracing infectious sources in sporadic cases of acute hepatitis E.     

DNA vaccination against hepatitis E virus infection in cynomolgus macaques

Background : The feasibility of DNA vaccination against hepatitis E in non‐human primates has not been evaluated. In the present study a full‐length hepatitis E virus (HEV) open reading frame (ORF)2 (Burmese strain) was assembled, cloned, and used for genetic immunization of cynomolgus macaques (cynos), which were subsequently challenged with a heterologous HEV strain (Mexico). Methods : Four cynos were vaccinated intramuscularly with the HEV ORF2 DNA cassette and one animal was vaccinated with a mock DNA construct. Results : Following vaccination anti‐HEV antibodies were detected in the four HEV‐DNA‐vaccinated cynos, but not in the control animal. When challenged, two of the four HEV‐DNA‐vaccinated cynos were protected against HEV infection and had no elevated alanine aminotransferase activity, viremia, or fecal shedding. The two other DNA‐vaccinated animals developed HEV infection and disease. Conclusion : These findings demonstrate the feasibility of DNA vaccination for the protection of HEV infection and warrant further studies to explore routes other than intramuscular for induction of a stronger and efficacious immune response. © 2002 Blackwell Publishing Asia Pty Ltd     

Hepatitis E virus prevalence in Flemish blood donors

Transmission of hepatitis E virus (HEV) through transfusion of blood components has already been reported in several European countries. Here, we assessed the HEV prevalence in Flemish blood donors. This study is of importance in order to assess the risk of HEV transmission through blood transfusion. We analysed 38 137 blood donation samples that were collected by the Red Cross Flanders during the period May‐June 2015. All samples were screened for the presence of HEV RNA and a selection for HEV‐specific IgM/IgG. After pooling per 6, 11 pools reacted positive during RNA screening. Reactive pools were deconstructed, and individual samples were retested. After deconstruction, seven samples were confirmed as HEV RNA positive. Serological screening of the confirmed RNA‐positive samples showed that six out of these seven samples were HEV IgM positive, of which three donors were also IgG positive. Serological screening was also performed on the samples that constituted the four initially HEV RNA reactive pools where RNA positivity was not confirmed on the individual level. In three pools, we found indirect evidence of recent HEV exposure. Within 356 randomly selected samples, 31 donations were HEV IgG positive. Here we show that at least 1:5448 of blood donations in Flanders may originate from donors that are actively infected with HEV. Upon transfusion, these donations may pose a major threat towards patients at risk. Finally, a serological analysis showed that the anti‐HEV IgG prevalence in Flemish blood donors is 8.71%.