Acute sporadic non-A, non-B, non-C, non-D, non-D, non-E hepatitis

Identifying the Aetiology of Acute Liver Failure Is Crucial to Impact Positively on Outcome

Management of children with acute liver failure is challenging. In this retrospective study, paediatric patients diagnosed with ALF at our centre, in the last 26 years, were divided into two groups (G1 = diagnosed from 1997 to 2009; G2 = from 2010 to 2022) and compared to see whether they differed with regard to aetiologies, need for liver transplantation (LT), and outcome. A total of 90 children (median age 4.6 years, range 1.2-10.4; M/F = 43/47) were diagnosed with ALF, by autoimmune hepatitis (AIH) in 16 (18%), paracetamol overdose in 10 (11%), Wilson disease in 8 (9%), and other causes in 19 (21%); 37 (41%) had indeterminate ALF (ID-ALF). Comparing the two periods, the clinical features, aetiologies, and median peak values of INR [3.8 (2.9-4.8) in G1 vs. 3.2 (2.4-4.8) in G2] were similar (p > 0.05). The percentage of ID-ALF tended to be higher in G1 compared to G2 (50% vs. 32% in G2, p = 0.09). The overall percentage of patients diagnosed with Wilson disease, inborn errors of metabolism, neonatal hemochromatosis or viral infection was higher in G2 (34% vs. 13% in G1, p = 0.02). A total of 21/90 patients (23%; 5 with indeterminate ALF) were treated with steroids; 12 (14%) required extracorporeal liver support treatment. The need for LT was significantly higher in G1 compared to G2 (56% vs. 34%; p = 0.032). Among 37 children with ID-ALF, 6 (16%) developed aplastic anaemia (all in G2, p < 0.001). The survival rate at last follow up was of 94%. On a KM curve, the transplant-free survival was lower in G1 compared to G2. In conclusion, we report a lower need for LT in children diagnosed with PALF during the most recent period compared to the first era. This suggests improvements over time in the diagnosis and management of children with PALF.

Role of Autoimmunity in Patients Transplanted for Acute Liver Failure of Unknown Origin: A Clinical and Graft Biopsy Analysis

The etiology and prognosis of acute liver failure (ALF) remains unknown in a significant proportion of cases. Signs of autoimmunity may be present, but no consistent pattern has been observed. We aimed to analyze if pretransplant immunological findings, human leukocyte antigen (HLA) haplotypes, and clinical features among patients with an unknown etiology differ from those of autoimmune or other known etiologies. We also analyzed whether such signs impact posttransplant biopsy findings or complications. All adult ALF patients undergoing liver transplantation (LT) in Finland during 1987-2015 were followed to 2016. Data were collected from the LT registry, pathology database, and patient records. A total of 124 patients were included in the analysis. Study subgroups were acute autoimmune hepatitis (AIH; n = 25), known non-AIH etiology (n = 54), and unknown etiology (n = 45). The unknown etiology group differed from the known non-AIH group with regard to the following pretransplant autoimmunity-associated features: positive perinuclear anti-neutrophil cytoplasmic antibodies (36% versus 8%; P = 0.02) and higher mean immunoglobulin A (IgA; 3.2 ± 1.7 versus 2.1 ± 1.4, P = 0.006) and immunoglobulin G (IgG; 12.7 ± 4.3 versus 8.5 ± 3.6, P = 0.001). AIH-associated HLA haplotypes B8, DR3, and B8DR3 were more common in the AIH group (40%, 44%, and 36%, respectively) and in the unknown group (29%, 33%, and 29%, respectively) than in the known non-AIH group (11%, 17%, and 11%, respectively) or in the Finnish general population (17%, 18%, and 8%, respectively). However, these findings had no association with protocol biopsies, extrahepatic autoimmune diseases, or survival. Patients with ≥ 1 rejection episode had higher pretransplant IgA (3.7 ± 2.3 versus 2.6 ± 1.2; P = 0.02) and IgG (16.4 ± 10.2 versus 12.4 ± 6.8; P = 0.03) than those without rejections. Autoimmunity-associated pretransplant laboratory findings and HLA haplotypes were common in ALF of unknown etiology, but they showed minimal predictive value for posttransplant biopsy findings, clinical complications, or survival.

Evaluating for Human Herpesvirus 6 in the Liver Explants of Children With Liver Failure of Unknown Etiology

BACKGROUND

Liver failure of unknown etiology (LFUE) has a transplant-free survival rate <25%. Human herpesvirus 6 (HHV-6) may be associated with LFUE, but studies are limited by small sample size.

METHODS

We identified all children who underwent liver transplant for LFUE at a single quaternary children's hospital; 51/65 cases could be age matched with controls (children who underwent liver transplant for metabolic liver disease). Quantitative polymerase chain reaction for HHV-6 was performed on DNA from formalin-fixed paraffin-embedded liver explant tissue.

RESULTS

HHV-6 was detected in 34/51 cases (66.7%) and 19/51 controls (37.3%) (P = .005). Average HHV-6 viral load was 213207 copies/106 cells in positive cases (range: 7293-1102030) and 38115 copies/106 cells in positive controls (range: 1382-122375) (P = .0008). HHV-6 was present significantly more often in cases compared to controls in patients younger than 6 years. In particular, in patients younger than 3 years, HHV-6 was present in 13/27 cases (48.1%) and 2/27 controls (7.4%) (P = .0009).

CONCLUSIONS

HHV-6 was detected in liver explants significantly more often and in higher quantities in children transplanted for LFUE compared to controls, suggesting HHV-6 should be evaluated in young children who present with LFUE.

Transplant-free Survival in Chronic Liver Disease Presenting as Acute Liver Failure in Childhood

BACKGROUND

In adults, the absence of a preexisting chronic liver disease (CLD) is required to diagnose acute liver failure (ALF). The pediatric classification does not consider this aspect, thus previous studies pooled together children with ALF and children with unknown CLD presenting with acute hepatic decompensation (ALF-CLD). We aimed to compare prevalence, features, and outcome of children with ALF-CLD to those with a proper ALF.

METHODS

Patients admitted between 1996 and 2017 because of ALF defined by Pediatric Acute Liver Failure criteria (raised transaminases, International Normal Ratio ≥2.0, no history of liver disease) were classified as ALF-CLD if diagnosed with autoimmune hepatitis, Wilson disease, Budd-Chiari syndrome, hepatitis B virus reactivation, inborn errors of metabolism. The others were classified as ALF.

RESULTS

Seventy-four children (median age, 4 years; 1.0-8.8; male/female, 36/38] with ALF were found; 18 of <1 year of age were excluded. Fifty-six (median age, 6.6 years; 2.7-11.7; male/female, 23/33], 22 with ALF-CLD (autoimmune hepatitis, n = 14; Wilson disease, n = 6; inborn errors of metabolism, n = 2) and 34 with ALF (paracetamol overdose, n = 6; viral infections, n = 3; mushroom poisoning, n = 5; indeterminate, n = 20) were compared. In ALF-CLD, the median age at onset was higher, alanine aminotransferase, albumin, and International Normal Ratio levels were lower, splenomegaly, ascites, and cirrhosis were more common (all P < 0.01). On multivariate analysis, the diagnosis of ALF-CLD was an independent predictor of transplant-free survival (P = 0.006).

CONCLUSIONS

In children, ALF-CLD is common, has peculiar features, and is associated with a favorable outcome. This study suggests the need to distinguish this entity from other forms of ALF in children.

Successful management of acute liver failure in Italian children: A 16-year experience at a referral centre for paediatric liver transplantation

BACKGROUND

Identifying the causes of acute liver failure (ALF) and predictors of death or liver transplantation (LTX) is crucial to decide its management. We aimed to describe features and outcome of ALF in Italian children.

METHODS

Retrospective review of cases presenting between 1996-2012. ALF was defined by high transaminases, INR ≥2.0 regardless of hepatic encephalopathy (HE), no evidence of underlying chronic liver disease.

RESULTS

55 children (median age 2.6 years, range 0.1-15.1; M/F=31/24) had ALF due to autoimmune hepatitis (AIH) in 10 (18%), metabolic disorders in 9 (17%), paracetamol overdose in 6 (11%), mushroom poisoning in 3 (5%), viral infection in 1 (2%), indeterminate in 26 (47%); 25/55 recovered with supportive management (45%); 28/55 underwent LTX and 2 died on the waiting list (55%). On multivariate analysis severity of HE grade 3-4 and bilirubin ≥12mg/dl were independent predictors of death or LTX (p<0.05). After a median follow up of 4 years (range 2-15.0 years) the overall survival rate was 93%.

CONCLUSION

Children with ALF can be managed successfully with combined medical treatment and transplantation, warranting a survival rate similar to children transplanted because of chronic conditions. In our cohort of patients severe HE and high bilirubin on admission were independent predictors of the need of LTX.

Fulminant hepatic failure of autoimmune aetiology in children

OBJECTIVE

Autoimmune hepatitis (AIH) is considered an underdiagnosed cause of fulminant hepatic failure (FHF). Autoimmune FHF (AI-FHF) is believed to lead invariably to liver transplantation (LTX) or death. We aimed to describe the autoimmune features of children diagnosed as having AI-FHF and indeterminate FHF (ID-FHF), and describe the outcome of patients with AI-FHF treated with immunosuppressive drugs.

METHODS

In this case-control study, the files of patients with AI-FHF and ID-FHF were reviewed and compared. AIH was diagnosed based on positive autoantibodies, raised immunoglobulin G, and histology when available. FHF was defined by raised transaminases, international normalised ratio ≥ 2.0, presence of encephalopathy, and no previously recognised liver disease.

RESULTS

A total of 46 children with FHF were managed in the last 15 years: 10/46 (22%) had AI-FHF, 20/46 (43%) ID-FHF, and 16 had other diagnosis. The mean follow-up time was 4.6 years. AI-FHF and ID-FHF differed for the presence of autoantibodies (10/10, 6/10 liver/kidney microsome [LKM]-type, vs 3/20, none LKM, P < 0.0001), immunoglobulin G level (1845 vs 880 mg/dL, P < 0.001), median age at diagnosis (6.4 vs 1.8 years, P = 0.017), and alanine aminotransferase level (1020 vs 2386 IU/L, P = 0.029). Liver histology did not allow to differentiate the 2 conditions. Among the patients with AI-FHF, 4/9 who received steroids recovered; 5/9 required LTX and 1 died awaiting treatment.

CONCLUSIONS

AIH is a much more common cause of FHF than previously suggested, and a complete autoantibody testing including LKM-type is essential in this setting. Autoantibodies are uncommon in ID-FHF, and histology cannot distinguish it from AI-FHF. A cautious steroid trial may avoid LTX in some of the patients with AI-FHF.

Hybrid DNA virus in Chinese patients with seronegative hepatitis discovered by deep sequencing

Seronegative hepatitis--non-A, non-B, non-C, non-D, non-E hepatitis--is poorly characterized but strongly associated with serious complications. We collected 92 sera specimens from patients with non-A-E hepatitis in Chongqing, China between 1999 and 2007. Ten sera pools were screened by Solexa deep sequencing. We discovered a 3,780-bp contig present in all 10 pools that yielded BLASTx E scores of 7e-05-0.008 against parvoviruses. The complete sequence of the in silico-assembled 3,780-bp contig was confirmed by gene amplification of overlapping regions over almost the entire genome, and the virus was provisionally designated NIH-CQV. Further analysis revealed that the contig was composed of two major ORFs. By protein BLAST, ORF1 and ORF2 were most homologous to the replication-associated protein of bat circovirus and the capsid protein of porcine parvovirus, respectively. Phylogenetic analysis indicated that NIH-CQV is located at the interface of Parvoviridae and Circoviridae. Prevalence of NIH-CQV in patients was determined by quantitative PCR. Sixty-three of 90 patient samples (70%) were positive, but all those from 45 healthy controls were negative. Average virus titer in the patient specimens was 1.05 e4 copies/µL. Specific antibodies against NIH-CQV were sought by immunoblotting. Eighty-four percent of patients were positive for IgG, and 31% were positive for IgM; in contrast, 78% of healthy controls were positive for IgG, but all were negative for IgM. Although more work is needed to determine the etiologic role of NIH-CQV in human disease, our data indicate that a parvovirus-like virus is highly prevalent in a cohort of patients with non-A-E hepatitis.

Epidemiological characteristics and clinical manifestations of acute non-A-E hepatitis

Background/Aim. Acute non-A, non-B, non-C, non-D, non-E hepatitis (non-A-E AH) is an acute disease of the liver of unknown etiology for which one or more new, so far undetected, hepatotropic viruses may be responsible. The frequency of non-A-E AH ranges from 3.8% to 33.9%, and therefore it has a significant place within current infectology and hepatology. The aim of our study was to establish the frequency, clinical and biochemical characteristics, natural course and outcome of non-A-E AH and compare them with control groups affected by acute viral hepatitis A, B and C. Methods. This descriptive-analytic prospective study included 31 patients with non-A-E AH treated at the Institute of Infectious and Tropical Diseases, Clinical Center of Serbia, Belgrade, from 2003 to 2008. They were followed up during the period not less than 6 months. The controls involved randomly selected patients, treated at the same time with a definite diagnosis of acute viral hepatitis A, B and C. Statistical data analysis used Mann-Whitney Utest, Student's t-test and variance analysis. The value of p < 0.05 was considered statistically significant. Results. The frequency of non-A-E AH was 7.6%. Almost no difference was found between sexes (male/female ratio was 1 : 1.07); it was developed in all age groups, with the highest incidence in the middle age (mean age was 38.32 ? 15.3 years). It appeared equally throughout the whole year. Out of risk factors, inoculation risk was predominant (before all, dental interventions), mostly involving urban population living in comfortable conditions. The duration of incubation varied much ranging from 20 to 180 days (median 60 days). By clinical course, moderate and icteric forms were most common, mostly corresponding to acute hepatitis A and C. On the other hand, by duration of the disease (mean duration was 67.1 ? 27.1) and chronic transformation, non-A-E AH resembled to acute hepatitis B. Progression to chronicity was recorded in 9.68% of the patients. There was no fulminant neither cholestatic form of the disease. Conclusion. Based on the results obtained in this study, it is probable that there are some so far undetected primary hepatotropic viruses in our environment.

Diagnostic value and utility of the simplified International Autoimmune Hepatitis Group (IAIHG) criteria in acute and chronic liver disease

Diagnostic criteria for autoimmune hepatitis (AIH) have been created and revised by the International Autoimmune Hepatitis Group (IAIHG). Simplified criteria have been created, but remain independently unvalidated. We report on the diagnostic accuracy of the simplified criteria in patients across a range of diagnoses, including a subset of patients presenting with fulminant liver failure who required liver transplant. Patients with AIH and non-AIH etiologies of liver disease were identified from dedicated patient databases. Parameters relevant to the simplified and 1999 IAIHG criteria were recorded, and sensitivity, specificity, and positive and negative predictive values for scores of >or=6 (probable AIH) and >or=7 (definite AIH) were calculated. A total of 549 patients with chronic liver disease were evaluated, (221 with AIH, 26 with variant syndromes, and 302 with non-AIH). For scores >or=6, sensitivity was 90%, and specificity was 98% with positive and negative predictive values of 97% and 92%, respectively. For scores >or=7; sensitivity was 70%, and specificity was 100% with positive and negative predictive values of 100% and 74%, respectively. Seven false positive diagnoses of AIH occurred, all with simplified scores of 6. Concordance with 1999 criteria was 90% for probable and 61% for definite AIH. The frequency of an overall diagnosis of AIH (probable or definite AIH) among the 70 patients with fulminant liver failure was 24% for simplified criteria and 40% for 1999 criteria, respectively.

CONCLUSION

The simplified criteria retain high specificity but exhibit lower sensitivity for scores of >or=7. The explanations for this are unclear but may relate to loss of such discriminating information as response to corticosteroids. Prospective evaluation of these criteria is required to corroborate these observations.

Long-term follow-up of patients with acute liver failure of indeterminate aetiology

OBJECTIVE

To determine the clinical characteristics of patients with acute liver failure of indeterminate cause and their long-term outcome in comparison with patients with acute liver failure of obvious aetiology (acetaminophen and mushroom poisoning, Budd-Chiari syndrome, acute viral hepatitis) and other controls (idiosyncratic drug reactions, autoimmune hepatitis and Wilson's disease).

MATERIAL AND METHODS

All patients with acute liver failure and listed for liver transplantation in Sweden between 1984 and 2006 were included in a retrospective analysis.

RESULTS

A total of 71 patients with acute liver failure were identified, 33 with indeterminate cause (IDC group), 23 with obvious aetiology (OE group) and 15 other controls (OC group). Before admission to the transplant centre, IDC patients were hospitalized in the referring hospital for 9 days (4-15) versus 1.5 days (1-3) in the OE group (p<0.001) and 7 days (2-14) in the OC group (NS). Serum bilirubin was higher (p<0.001), whereas peak creatinine was lower (p=0.001) in the IDC group compared with the OE group but was not significantly different from the OC group. There were no significant differences in 1-, 3-, 5- and 10-year patient and graft survival rates between the IDC group and the OE or the OC group.

CONCLUSIONS

Patients with acute liver failure of indeterminate cause seem to differ from those with obvious aetiology in clinical and biochemical presentation but are similar to other controls. The overall long-term outcome seems to be similar in patients with an unknown aetiology as in those with a specific aetiology.

Treatment of hepatitis-associated aplastic anemia with high-dose cyclophosphamide

OBJECTIVE

Demonstrate that high-dose cyclophosphamide (CY) is effective therapy for hepatitis-associated aplastic anemia (HAA).

BACKGROUND

HAA is a sequence of seronegative hepatitis followed by aplastic anemia. Optimal treatment is matched-sibling allogeneic bone marrow transplantation (BMT). The combination of antithymocyte globulin (ATG) and cyclosporine (CSA) has also been studied, but there are scarce data regarding treatment of HAA.

PROCEDURE

Five patients (median age 14 years; range 6-17 years) with HAA and without an HLA-matched sibling were treated with high-dose CY (50 mg/kg/day IV x 4 days) followed by granulocyte-colony stimulation factor (G-CSF).

RESULTS

After at least 1 year of follow-up, four of five patients are in remission without further immune suppression beyond high-dose CY. Of the 4 responders, median time to absolute neutrophil count (ANC) >500 microl(-1) was 51 days (range 44-369). Median time to transfusion independence for erythrocytes and platelets was 109 (range 57-679) and 160 (range 48-679) days, respectively. The fifth patient did not respond and proceeded to an unrelated donor transplant. One patient met criteria for autoimmune hepatitis (AIH) in addition to HAA. In this case, high-dose CY successfully induced remission of both diseases.

CONCLUSIONS

High-dose CY induces durable remissions in HAA and may be an effective treatment for AIH.

The significance of autoantibodies and immunoglobulins in acute liver failure: a cohort study

BACKGROUND/AIMS

The cause of cryptogenic ('seronegative') acute liver failure (ALF) is unknown; the presence of non-organ specific autoantibodies (NOSA) may indicate an autoimmune pathogenesis. We investigated the prevalence of autoimmune features including antibodies to soluble liver antigen (anti-SLA) determined by Radioligand assay (RLA) in ALF patients.

METHODS

The prevalence and relationship to the immunoglobulin (Ig) response of NOSA and anti-SLA were determined in 73 ALF patients of different causes. Patients were scored using the revised system for diagnosis of autoimmune hepatitis (AIH).

RESULTS

Autoantibodies were present in 23 (32%) patients; 16 had anti-SLA, 6 ANA, 4 ASM and 1 AMA. They were absent in paracetamol-related disease and present in 23 of 53 (43%) of non-paracetamol (NP) cases (p<0.0003). Two of 16 (13%) with NP drug-induced (NPDI), 9 of 21 (43%) viral and 5 of 16 (31%) cryptogenic cases had anti-SLA. NOSA and anti-SLA were not associated with liver injury severity or outcome. IgM was higher in those with viral disease (p<0.00001). AIH scores classified 50% of cryptogenic cases as 'probable autoimmune hepatitis'.

CONCLUSIONS

Autoantibodies are common in ALF; cryptogenic cases have features suggestive of an autoimmune pathogenesis. IgM is elevated in viral cases but infrequently in ALF of other causes.

Association of fulminant non-A non-B hepatitis with homozygosity for HLA A1-B8-DR3

BACKGROUND

For the majority of cases of acute liver failure in western Europe and North America an etiology cannot be defined. The condition is most often called fulminant non-A, non-B (NANB) hepatitis. Features such as female preponderance and presence of serum autoantibodies suggest a possible autoimmune basis. The aim of the present paper was to examine a possible human leukocyte antigen (HLA) association with fulminant NANB hepatitis.

METHODS

HLA A, B, and DR data of 55 adult Caucasian fulminant NANB patients were compared with those of 1449 local Caucasian controls.

RESULTS

In Caucasian patients, homozygosity (but not heterozygosity) for the alleles A1, B8, and DR3 were associated with fulminant NANB hepatitis (Pcorrected = 0.02, <0.00001 and 0.002, respectively). Greatest relative risk (RR) was associated with homozygosity for the A1-B8-DR3 haplotype (P < 0.00001; RR: 12.8; 95% confidence interval [CI]: 5.7-22.3). HLA DR8 was also associated with development of the syndrome (RR: 4.2; 95%CI: 1.6-9.2).

CONCLUSIONS

Homozygosity for the HLA haplotype A1-B8-DR3 confers susceptibility to the development of fulminant NANB hepatitis. This observation may imply a role for the immune response genes (which are flanked by HLA B and DR) in the pathogenesis of this syndrome.

Ethnic differences in the prevalence of cryptogenic cirrhosis

OBJECTIVES

Nonalcoholic steatohepatitis (NASH) associated with obesity and type 2 diabetes mellitus (DM) is postulated to be the cause of most cases of cryptogenic cirrhosis (CC). While ethnic differences in the prevalence of obesity and DM in the United States are well documented, there is little information regarding prevalence of CC or NASH among different U.S. ethnic groups. This study was performed to assess the demographic characteristics of patients with CC at a U.S. county hospital with a racially and ethnically diverse patient population.

METHODS

Medical records and pathology databases were reviewed to identify patients at Parkland Memorial Hospital, Dallas County, Texas from 1990 to 2001 with CC or cirrhosis attributed to NASH.

RESULTS

Forty-one patients (12 men, 29 women) were found to meet these criteria. Of these, 68% were obese (BMI > or = 30) and/or had type 2 DM and 74% of liver biopsies revealed one or more features of NASH. Of patients with CC 68% were Hispanic while only 7% were African American, despite the fact that Hispanics comprised < 26% and African Americans > 40% of adult medicine patients. Prevalence of CC among Hispanic and African American patients was 3.1-fold higher and 3.9-fold lower, respectively, than among European American patients despite similar prevalence of DM among Hispanics and African Americans.

CONCLUSION

These findings support the hypothesis that NASH associated with obesity and DM is responsible for the majority of cases of CC among Hispanics and European Americans. However, the current findings also indicate that this form of cirrhosis is unexpectedly rare among African Americans.

Sequencing and characterization of A-2 plaque virus: A new member of the Picornaviridae family

A-2 plaque virus (A2 virus) was originally isolated from the icteric-phase sera of US servicemen with viral hepatitis in the 1960s, but apart from a preliminary characterization little is known about the agent. We have now successfully cloned and sequenced the complete viral genome. A2 viral RNA consists of 7312 nucleotides, excluding the 62 nucleotide poly(A) tract at the 3' end, with one large open reading frame. Although clearly a member of the Picornaviridae, there is low homology to the available sequences, suggesting it is only loosely related to the classic rhino/enterovirus genus. In addition, there was no reactivity with group specific monoclonal antibody blends against polioviruses, enteroviruses 70 and 71, coxsackievirus B, and echoviruses. Two tamarins were inoculated with A2 virus to study viral pathogenesis. Both animals that received A2 virus became transiently viremic 1 week after the infection, as determined by RT-PCR, and they developed an antibody response to A2 virus. However, no physical signs or biochemical abnormalities, including elevated liver transaminases, were observed. In addition, no liver samples from patients with fulminant hepatitis (n = 7) or controls (n = 7) were positive for A2 viral RNA nor was anti-A2 neutralizing antibody detected in sera from hepatitis patients (n = 14), healthy laboratory donors (n = 14), or US blood donors (n = 33); however, most sera contained antibodies reactive with A2 virus proteins. These results suggest that A2 virus is a new member of the Picornaviridae but that its pathogenicity in nonhuman primates and association with human disease still need to be determined.

Hepatitis C, E, F, G, and non-A-G

Inflammation of the liver is known as hepatitis. Six or seven viruses, hepatitis viruses A through G, are responsible for most cases of viral hepatitis. In this second of a series of three articles, current knowledge regarding hepatitis C, E, F, G, and non-A-G is reviewed. Up to 80% of patients infected with hepatitis C progress to chronic liver disease. Hepatitis E is an enteric hepatitis that is endemic in Asia. Hepatitis F may be a mutant hepatitis C. Hepatitis G is a posttransfusion hepatitis. Non-A-G hepatitis consists of all of the hepatitis viruses awaiting identification. Up-to-date information regarding each of these types of hepatitis viruses is presented herein, because every phase of patient care improves when health care professionals are knowledgeable regarding the illnesses of their clients.

Transfusion-associated TT virus infection and its relationship to liver disease

TT virus (TTV) has been proposed as the causative agent of non-A to E hepatitis. We studied the association between TTV viremia and biochemical evidence of hepatitis in blood donors and prospectively-followed patients. TTV was found in 7.5% of 402 donors and in 11.0% of 347 patients before transfusion. The rate of new TTV infections was 4.7% in 127 nontransfused, and 26.4% in 182 transfused patients (P <.0001). The risk of infection increased with the number of units transfused (P <.0001). The rate of new TTV infections in 13 patients with non-A to E hepatitis (23.2%) was almost identical to the rate in 124 patients who were transfused, but did not develop hepatitis (21.8%). Of 45 patients with acute hepatitis C, 40.0% were simultaneously infected with TTV. TTV did not worsen the biochemical severity (mean ALT: 537 in TTV+; 550 in TTV-) or persistence of hepatitis C. In non-A to E cases, the mean ALT was 182 in those TTV-positive and 302 in TTV-negatives. No consistent relationship between alanine transaminase level and TTV DNA level was observed in 4 patients with long-term, sequential samples. Of 21 viremic subjects, 67% cleared TTV within 5 years (38% in 1 year); 33% were viremic throughout follow-up extending to 22 years. We conclude that TTV is a very common, often persistent infection that is transmitted by transfusion and by undefined nosocomial routes. We found no association between TTV and non-A to E hepatitis and no effect of TTV on the severity or duration of coexistent hepatitis C. TTV may not be a primary hepatitis virus.

Acute sporadic non-A, non-B hepatitis in Northeastern Brazil: etiology and natural history

In a 4-year follow-up study, patients with acute sporadic non-A, non-B (NANB) hepatitis were evaluated to determine the etiology and natural history of the disease. Acute hepatitis C virus (HCV) was detected in 13 of 43 (30%) of patients, anti-hepatitis E virus (HEV) IgG in 5 (12%), and 25 (58%) were considered non-A-E. The HCV RNA was detected in all HCV patients but none of the non-A-E cases. The initial clinical and biochemical presentation of the HCV and non-A-E cases was quite similar, although 2 of the non-A-E patients had severe disease. The 5 patients who were found to be anti-HEV IgG-reactive recovered within 6 months of follow-up. Of the 13 HCV cases, alanine transaminase (ALT) levels returned to normal in 7 (53. 8%), while 6 (46.2%) continued to show abnormal ALT after 6 months of follow-up. However, 9 (69.2%) of them remained HCV-RNA-positive, denoting virological/biochemical dissociation. Long-term follow-up showed a reappearance of HCV RNA in 2 of the 4 patients who were in virological remission performing 84% of chronicity rate. Acute non-A-E hepatitis patients were less likely to evolve toward chronicity, as compared with acute HCV cases (16% vs. 84%; P =.0001). Only 4 (16%) of the non-A-E patients were hepatitis G virus (HGV)-RNA-positive. Concerning risk factors for acquiring parenterally transmitted viruses, tattooing was the only one that could be associated with HCV transmission (P =.002). No risk factors could be identified for putative non-A-E virus transmission. Liver biopsies performed for chronic HCV patients showed a variable degree of inflammation, while the non-A-E patients presented less severe histological disease.

HGV/GBV-C infection in liver transplant recipients: antibodies to the viral E2 envelope glycoprotein protect from de novo infection

BACKGROUND/AIMS

Liver transplantation for endstage liver cirrhosis provides a useful model to investigate the pathogenetic role of hepatotropic viral agents. Recently, a new member of the Flaviviridae family, provisionally named HGV/GBV-C virus, has been associated with acute and chronic non A-E hepatitis. We studied 136 patients with cirrhosis consecutively transplanted at our institution for evidence of hepatitis G virus infection and correlation with the patients' clinical course.

METHODS

All patients survived for at least 6 months after transplantation (median follow-up 44 months) and underwent routine liver biopsies. Hepatitis G virus infection was studied using both direct viral RNA identification by RT-PCR and indirect detection of antibodies to the E2 glycoprotein.

RESULTS

There was a high frequency of the hepatitis G virus among patients undergoing liver transplantation, with HGV RNA and anti-E2 prevalence rates of 18.4% and 26.5%, respectively. HGV RNA prevalences significantly increased after transplantation (47.8%), with 47.3% rate of new infections in susceptible subjects. Anti-E2 antibodies were significantly more prevalent among patients transplanted for HCV-related cirrhosis and represented a strong protective factor against hepatitis G virus reinfection or recurrent infection. No correlation was found between HGV RNA or anti-E2 prevalences and survival after transplantation or rates of recurrent liver damage.

CONCLUSIONS

All available evidence suggests that, although liver transplant patients are heavily exposed to hepatitis G virus both before and after transplantation, hepatitis G virus does not induce liver disease in this setting. Most infections appear to be self-limited and induce a protective immunity which is marked by the presence of anti-E2 antibodies.