James A. Underhill

Long-Term Outcome of Hepatitis C Infection after Liver Transplantation

BACKGROUND End-stage cirrhosis related to hepatitic C virus (HCV) is a common reason for liver transplantation, although viremia ia known to persist in most cases. We investigated the impact of persistent HCV infection after liver transplantation on patient and graft survival and the effects of the HCV genotype and the degree of HLA matching between donor and recipient on the severity of recurrent hepatitis. METHODS A group of 149 patients with HCV infection who received liver transplants between January 1982 and April 1994 were followed for a median of 36 months; 623 patients without HCV infection who underwent liver transplantation for end-stage chronic liver disease were used as a control group. A total of 528 liver-biopsy specimens from the HCV-infected recipients were reviewed, including 82 obtained one year after transplantation as scheduled and 39 obtained at five years as scheduled. In addition, biopsy specimens were obtained from 91 of the HCV-negative patients five years after transplantation. RESULTS Cumulative survival rates for the 149 patients with HCV infection were 79 percent after one year, 74 percent after three years, and 70 percent after five years, as compared with rates of 75 percent, 71 percent, and 69 percent, respectively, in the HCV-negative transplant recipients (P=0.12). Of the 130 patients with hepatitis C infection who survived more than 6 months after transplantation, 15 (12 percent) had no evidence of chronic hepatitis on their most recent liver biopsy (median followup, 20 months), 70 (54 percent) had mild chronic hepatitis (median, 35 months), 35 (27 percent) had moderate chronic hepatitis (median, 35 months), and 10 (8 percent) had cirrhosis (median, 51 months). Graft loss occurred after a median of 303 days in 27 of the 149 patients, including 5 with HCV-related cirrhosis and 3 with HCV-related cholestatic hepatitis. Infection with HCV genotype 1b was associated with more severe graft injury, whereas the primary immunosuppressive regimen used and the extent of HLA mismatching between donors and recipients had no significant effect on this variable. CONCLUSIONS After liver transplantation for HCV-related cirrhosis, persistent HCV infection can cause severe graft damage, and such damage is more frequent in patients infected with HCV genotype 1b than with other genotypes. After five years, the rates of graft and overall survival are similar between patients with and those without HCV infection.

Association between HLA class II genotype and spontaneous clearance of hepatitis C viraemia

BACKGROUND/AIMS Hepatitis C virus (HCV) infection becomes chronic in most cases, with only 10-20% of those infected not developing persistent viraemia. The immune response to HCV may be an important determinant of disease resolution and can be influenced by a number of host factors. The aim of this study was to assess the role of host HLA class II type in influencing viral clearance or susceptibility to chronic HCV infection. METHODS We have compared the distribution of HLA DRB1, DQA1 and DQB1 alleles in 49 patients with spontaneous clearance of HCV infection (HCV antibody positive but persistently HCV RNA negative), with 55 chronically infected patients and 134 racially matched controls. RESULTS Three alleles were found significantly more frequently in patients with spontaneous viral clearance compared to those with chronic infection-DRB1*04 (pc=0.0022, odds ratio OR=4.52), DQA1*03 (pc=0.0012, OR=4.69) and DQB1*0301 (pc=0.0078, OR=5.09). DQB1*0302 was found at reduced frequency in all HCV-antibody-positive patients compared to controls (pc=0.0063). CONCLUSIONS DRB1*04, DQA1*03 and DQB1*0301 are associated with spontaneous clearance of HCV viraemia, with the primary association likely to be with DQB1*0301 and the associations with DRB1*04 and DQA1*03 being due to linkage. In addition, DQB1*0302 is associated with protection from HCV infection. These findings suggest that host HLA class II genotype is an important factor in determining the outcome of infection with hepatitis C virus.

Cytokine polymorphisms associated with clinical features and treatment outcome in type 1 autoimmune hepatitis.

BACKGROUND & AIMS Polymorphisms that control cytokine production can affect immunoregulation. The frequency and consequences of these polymorphisms in type 1 autoimmune hepatitis were determined. METHODS DNA samples from 155 patients and 102 ethnically similar normal individuals were assessed by polymerase chain reaction for polymorphisms of 4 different cytokine-producing genes. RESULTS Only genotypes associated with the guanine to adenine substitution at position -308 of the tumor necrosis factor gene occurred more commonly in patients than in normal subjects (56% vs. 26%; P < 0.001). Patients with this polymorphism had the HLA DRB1*0301 allele (81% vs. 10%; P < 0.000001) and A1-B8-DRB1*0301 (66% vs. 0%; P < 0.000001) phenotype more frequently and HLA DRB1*04 alleles less often (24% vs. 67%; P < 0.000001). They also entered remission less commonly (56% vs. 78%; P = 0.01), had treatment failure more often (20% vs. 7%; P = 0.03), and developed cirrhosis more frequently (40% vs. 19%; P = 0.05). These latter differences, however, were not statistically significant by adjusted P value. CONCLUSIONS A polymorphism of the tumor necrosis factor gene occurs more commonly in patients with type 1 autoimmune hepatitis than in normal subjects; it is associated with a poorer response to corticosteroids. The polymorphism may be inherited as part of the extended A1-B8-DRB1*0301 haplotype and may affect both disease expression and behavior.

Thiopurine methyltransferase phenotype and genotype in relation to azathioprine therapy in autoimmune hepatitis

BACKGROUND/AIMS Toxicity and efficacy of azathioprine is governed partly by the activity of thiopurine methyltransferase (TPMT). Azathioprine has been used for many years, with corticosteroids or alone, for the treatment of autoimmune hepatitis (AIH) but no studies of TPMT phenotype and genotype in relation to response to the drug in AIH have been published. METHODS Erythrocyte TPMT activities were measured by a radioincorporation assay in 72 consecutive outpatients with AIH, 53 of whom were genotyped for the commonest defective alleles in Europeans (TPMT*3A, *3B and *3C) by restriction fragment length polymorphism analysis. RESULTS TPMT activities were significantly lower in patients intolerant of azathioprine (group I, n=15) than in those who sustained remission on azathioprine alone (group II, n=28; P=0.003) and those who tolerated azathioprine but continued to require corticosteroids (group III, n=29; P<0.0001), and were higher in group III than in group II (P=0.034). Ten patients with defective alleles (all heterozygotes) had significantly lower TPMT activities (P=0.002). However, in 25% there was discordance between phenotype and/or genotype and response to azathioprine. CONCLUSIONS TPMT phenotyping or genotyping may be advisable before institution of azathioprine therapy in AIH but neither approach invariably predicts response to the drug.

Association of tumor necrosis factor polymorphism with primary sclerosing cholangitis.

BACKGROUND/AIMS Primary sclerosing cholangitis is associated with the HLA haplotypes A1-B8-DRB3*0101-DRB1*0301-DQA1*0501-DQB1*0201 and DRB3*0101-DRB1*1301-DQA1*0103-DQB1* 0603. However, the interpretation of these genetic associations is controversial. One explanation may be that HLA-encoded susceptibility is due to other genes carried on these haplotypes such as the HLA class III tumor necrosis factor genes. The aim of the study was to investigate tumor necrosis factor genetics in a large series of well-defined patients. METHODS One hundred and ten HLA genotyped patients and 126 control subjects were studied by polymerase chain reaction genotyping for 3 different tumor necrosis factor gene polymorphisms: -308, -238 and an Ncol restriction fragment length polymorphism in the lymphotoxin alpha gene. RESULTS Overall, 58% of patients had the TNF2 allele, compared with 29% of controls, p(c) = 0.0001. No association was found with either of the other tumor necrosis factor polymorphisms examined. TNF2 was significantly increased in the presence of B8 and DRB3*0101 only, and was independent of DRB1*0301 (p(c)<0.04). The associations with B8 and TNF2 were stronger than the associations with any of the HLA class II alleles examined. CONCLUSION HLA-encoded genetic susceptibility to primary sclerosing cholangitis may be determined by polymorphism within the HLA class III region, in particular with the TNF2 allele.

Tumor necrosis factor genomic polymorphism and outcome of acetaminophen (paracetamol)-induced acute liver failure

BACKGROUND/AIMS High levels of tumor necrosis factor-alpha are associated with an increased risk of severe encephalopathy in acute liver failure, and experimental studies suggest that tumor necrosis factor-alpha plays a role in the development of acetaminophen (paracetamol)-induced liver injury and associated multiple organ failure. Inter-individual variations in the production of tumor necrosis factor-alpha have been linked to genomic polymorphisms within the tumor necrosis factor-alpha locus. This study examined whether specific tumor necrosis factor polymorphisms are associated with variations in the severity of clinical features in acetaminophen-induced acute liver failure. METHODS Genotypes at the -308 tumor necrosis factor A and tumor necrosis factor B Nco1 polymorphic sites were determined in 97 patients with severe acetaminophen-induced hepatotoxicity and 109 controls, using polymerase chain reaction and restriction fragment length polymorphism. The relationship between liver injury, multiple organ failure and encephalopathy, determined retrospectively from clinical notes and genotype, was examined. RESULTS No significant association was found between either tumor necrosis factor A or B genotype and parameters for multiple organ failure or liver injury. The tumor necrosis factor B1B1 genotype was significantly under-represented in those patients developing severe encephalopathy (p=0.03) and a multivariate logistic regression analysis confirmed the influence of tumor necrosis factor B genotype (p<0.01). The association was independent of the HLA class II allele DRB1*03, which is closely linked to the TNFB locus. CONCLUSIONS The development of acute liver failure is unlikely to be primarily sepsis driven. However, the apparent protective effect of the tumor necrosis factor B1B1 genotype on the development of severe encephalopathy may be related to the effects of this genotype on tumor necrosis factor-alpha production in sepsis.

Polymorphism in the Human Complement C4 Genes and Genetic Susceptibility to Autoimmune Hepatitis

Susceptibility to autoimmune hepatitis is associated with the HLA-DR3 and DR4 haplotypes, but which genes are directly involved in the pathogenesis, has not been established. Low levels of complement component C4 and elevated frequencies of C4 null allotypes have been described in patients, suggesting that the C4 genes, which are closely linked with the HLA loci, may play a role. We therefore examined restriction fragment length polymorphisms in the C4 and 21-hydroxylase genes, and determined HLA-A and B phenotypes, and HLA-DR, DQ and DP genotypes in a large series of Caucasoid patients with autoimmune hepatitis and matched controls. A DNA deletion of the C4A gene and the 21-hydroxylase A pseudogene was found to be present in 50% of patients compared to 23% of controls (Pc < 0.005, relative risk = 3.3). This increase, however, appears to be due to linkage disequilibrium with HLA-DR52a which was most strongly associated with the disease. Complete C4A deficiency, determined by homozygosity for the deletion increased the risk to 18.1 (16% versus 1%, Pc < 0.005), suggesting an additional role for C4 in disease susceptibility. C4 deletions were associated with an increased mortality and tendency to relapse whilst on treatment but did not correlate with age of onset of disease. Our data suggest that MHC-encoded susceptibility to autoimmune hepatitis is polygenic, involving the HLA-DR genes plus other loci, and C4 deficiency may be a marker of disease susceptibility and/or severity.

Transmission disequilibrium analysis of HLA class II DRB1, DQA1, DQB1 and DPB1 polymorphisms in schizophrenia using family trios from a Han Chinese population

Our goal was to evaluate the role of HLA in the risk of developing schizophrenia, in a Han Chinese population. In several Japanese studies, there is evidence of association with DR1 and schizophrenia. A variety of other associations have been reported in other populations, including negative associations with DQbeta(*)0602 and positive associations with DR1(*)0101. Using sequence specific oligonucleotides, we genotyped four HLA markers (DRB1, DQA1, DQB1 and DPB1) in 165 family trios, consisting of Han Chinese schizophrenic subjects and their parents. Individual markers were analysed for transmission distortion in the trios using the transmission disequilibrium test. Multiple haplotype transmission was performed using the program TRANSMIT v2.5. The four markers were in strong linkage disequilibrium with each other (P value from 0.002 to 0). There was no evidence of overall transmission disequilibrium for each of the four loci. For DRB1, we did not find transmission distortion for the DRB1(*)04 and DRB1(*)08 alleles, as reported previously, but the DRB1(*)03 allele was preferentially not transmitted (P=0.009), and the DRB1(*)13 allele was preferentially transmitted from parents to schizophrenic offspring (P=0.041). Using haplotypes of pairs of markers, a significant global P value of 0.019 was achieved when using DRB1 and DQA1, mainly as a result of the excess transmission of DRB1(*)13-DQA1(*)01 (P=0.012) and a deficit in transmission of DRB1(*)03-DQA1(*)05 (P=0.002). In summary, we did not confirm any of the specific HLA allelic associations reported previously in Japanese or other populations. However, our results are compatible with the view that this region of HLA might contain a susceptibility gene which is in linkage disequilibrium with DRB1 and DQA1 genes.

Role of HLA compatibility in pediatric liver transplantation

BACKGROUND The influence of HLA mismatching in liver transplantation remains controversial. To date, few studies have focused solely on the pediatric population, and none have investigated DR and DQ mismatches using molecular genotyping. We sought to investigate HLA-A, -B, -DR, and -DQ mismatches in a large series of primary pediatric liver transplant recipients. Living-related liver transplants were excluded. METHODS A total of 138 consecutive first liver transplants performed between January 1991 and July 1996 were studied. Minimum follow-up was 1 year, and both patient and graft survival rates were assessed. The incidence of the most common complications was analyzed. HLA-A and -B phenotyping was performed by complement-dependent microcytotoxicity or polymerase chain reaction (PCR)-sequence-specific primer protocols in 133 of 138 patients. HLA-DR and -DQ genotyping was performed by standard PCR-sequence-specific oligonucleotide and/or PCR-sequence-specific primer protocols in 135 patients. RESULTS Overall, there was no influence of HLA mismatching on either graft or patient survival rates. However, patients with two mismatches at the A locus showed a significantly lower incidence of acute rejection than those with one A mismatch (52% vs. 72%; P < 0.03) and patients with two B locus mismatches had a better graft survival rate at 5 years than those with one mismatch (76% vs. 62%), although this was of only borderline significance (P < 0.09). No differences were found in the severity of the episodes of rejection, incidence of chronic rejection, cytomegalovirus hepatitis, and other causes of graft loss. CONCLUSION This study indicates that HLA-A, -B, -DR, and -DQ mismatches are not detrimental in primary pediatric liver transplantation.

Lymphocyte subset abnormalities, autoantibodies and their relationship with HLA DR types in children with type 1 (insulin-dependent) diabetes and their first degree relatives

SummaryType 1 (insulin-dependent) diabetes mellitus is associated with abnormalities of circulating lymphocyte subsets and autoantibodies. To investigate the prevalence of these in non-diabetic siblings and nondiabetic parents of children with Type 1 diabetes, we analysed T-cell subsets of function and activation in 31 families with an index case of Type 1 diabetes and related these to autoantibodies and HLA DR type. Using two and three colour cytofluorimetry, we studied total and activated (HLA-DR + ) CD3 +, CD4 +, CD8 + lymphocytes and on CD4 + lymphocytes the CD45RA/RO “naive” and “memory” cell phenotypes. Diabetic children (mean duration of disease 3.1 years) had a reduced total lymphocyte count (p < 0.05), their non-diabetic siblings a reduced CD4+ T-helper cell count (p < 0.05), and their parents a reduced percentage and number of CD3 + T cells (p < 0.01 and p < 0.05) compared with age-matched control subjects. Diabetic children, their siblings and parents all had significantly increased levels of activated CD4 + T-helper cells (p < 0.01, p < 0.05 and p < 0.01). In diabetic children and their siblings there was a significant over-expression of the CD45RO “memory” cell marker and significant under-expression of the CD45RA “naive” cell marker, whilst these were normal in the parents. Islet cell antibody positive diabetic children had significantly higher levels of CD45RO-expressing CD4 + lymphocytes than those who were islet cell antibody negative (p < 0.05). Amongst the siblings and parents, possession of HLA-DR4 was associated with lower percentages of CD4 + and higher percentages of CD8 + T cells. These findings extend current knowledge about the role of immunoregulatory CD45RA/ RO cells in Type 1 diabetes. In addition, they demonstrate lymphocyte subset abnormalities in unaffected family members, some of which may be influenced by HLA DR alleles.