William L. Irving

Influenza virus infection in the second and third trimesters of pregnancy: a clinical and seroepidemiological study

Objective To determine whether maternal influenza virus infection in the second and third trimesters of pregnancy results in transplacental transmission of infection, maternal auto‐antibody production or an increase in complications of pregnancy.

Impact of direct acting antiviral therapy in patients with chronic hepatitis C and decompensated cirrhosis

BACKGROUND & AIMS All oral direct acting antivirals (DAAs) effectively treat chronic hepatitis C virus (HCV) infection, but the benefits in advanced liver disease are unclear. We compared outcomes in treated and untreated patients with decompensated cirrhosis. METHODS Patients with HCV and decompensated cirrhosis or at risk of irreversible disease were treated in an expanded access programme (EAP) in 2014. Treatment, by clinician choice, was with sofosbuvir, ledipasvir or daclatasvir, with or without ribavirin. For functional outcome comparison, untreated patients with HCV and decompensated cirrhosis who were registered on a database 6months before treatment was available were retrospectively studied. Primary endpoint was sustained virological response 12weeks post antiviral treatment (treated cohort) and the secondary endpoint (both cohorts) was adverse outcomes (worsening in MELD score or serious adverse event) within 6months. RESULTS 467 patients received treatment (409 decompensated cirrhosis). Viral clearance was achieved in 381 patients (81.6%) - 209 from 231 (90.5%) with genotype 1 and 132 from 192 (68.8%) with genotype 3. MELD scores improved in treated patients (mean change -0.85) but worsened in untreated patients (mean+0.75) (p<0.0001). Patients with initial serum albumin <35g/L, aged >65 or with low (<135mmol/L) baseline serum sodium concentrations were least likely to benefit from therapy. CONCLUSIONS All oral DAAs effectively cured HCV in patients with advanced liver disease. Viral clearance was associated with improvement in liver function within 6months compared to untreated patients. The longer term impact of HCV treatment in patients with decompensated cirrhosis remains to be determined.

IL28B, HLA-C, and KIR variants additively predict response to therapy in chronic hepatitis C virus infection in a European Cohort: a cross-sectional study.

Vijayaprakash Suppiah and colleagues show that genotyping hepatitis C patients for the IL28B, HLA-C, and KIR genes improves the ability to predict whether or not patients will respond to antiviral treatment.

Clinical relapses and disease activity on magnetic resonance imaging associated with viral upper respiratory tract infections in multiple sclerosis

BACKGROUND Although the risk of clinical attacks of multiple sclerosis seems to be significantly increased with viral upper respiratory tract infections (URTI), serological evidence for the reported association remains controversial. In addition, although MRI is six to 10 times more sensitive than clinical exacerbations in indexing disease activity, any possible association between URTI and MRI activity has yet to be investigated. OBJECTIVES To examine the relation between URTI and disease activity, in multiple sclerosis patients participating in a placebo controlled trial of interferon β-1a, as indexed both by clinical exacerbation rate and by the number and volume of gadolinium - diethylenetriaminepenta acetic acid (Gd-DTPA) enhancing lesions on MRI. “At risk” periods were defined around symptomatic URTI, with or without serological confirmation. RESULTS The relative risk of clinical relapse for serologically unconfirmed symptomatic URTI was 2.1 (p=0.004). Raised antiviral antibody titres conferred a relative risk of multiple sclerosis exacerbations that was 3.4 times higher than the “not at risk” periods (annual attack rates of 5.7 v 1.6, respectively, p=0.006). There was no definite relation between the number or the volume of active lesions on MRI and either symptomatic or serologically defined at risk periods. CONCLUSIONS These results confirm the previously reported association between viral infections and multiple sclerosis exacerbations and indicate that the relative risk may be even higher when viral infection is serologically confirmed. However, the results, perhaps because of the confounding effects of interferon β-1a, do not provide convincing evidence of increased blood-brain barrier breakdown or inflammation during periods of virally induced immune stimulation.

Outcomes after successful direct acting antiviral therapy for patients with chronic hepatitis C and decompensated cirrhosis

BACKGROUND & AIMS Direct-acting antivirals have become widely used for patients with chronic hepatitis C virus infection with decompensated cirrhosis. Virological responses are excellent and early improvements in liver function, at least in a proportion of patients, have been observed but the longer term impact of viral clearance on end-stage liver disease complications is unclear. METHODS Prospective study of patients with decompensated cirrhosis who received 12weeks of all-oral direct-acting antivirals through the English Expanded Access Programme. Endpoints were deaths, liver transplantation, hepatocellular carcinoma, serious decompensation events, sepsis or hospitalisations, and MELD scores between start of therapy to 15months post-treatment start. An untreated cohort of patients was retrospectively studied over 6months for comparison. RESULTS Amongst 317/406 patients who achieved sustained virological response at 24weeks post-treatment, there were 9 deaths (3%), 17 new liver cancers (5%), 39 transplantations (12%) and 52 with serious decompensations (16%), over 15months. When compared to the first six months from treatment start and to untreated patients, there was a reduction in incidence of decompensations [30/406 (7%) in months 6-15 and 72/406 (18%) in months 0-6 for treated patients vs. 73/261 (28%) in untreated patients]. There was no significant difference in liver cancer incidence (10/406 (2.5%) in months 6-15 and 17/406 (4%) in months 0-6 for treated patients vs. 11/261 (4%) in untreated patients). CONCLUSIONS This study suggests that antiviral therapy in patients with decompensated cirrhosis led to prolonged improvement in liver function, with no evidence of paradoxical adverse impact nor increase in liver malignancy. LAY SUMMARY This is a report of a large group of patients in England who have hepatitis C virus (HCV) infection with advanced liver disease. They have been treated with new anti-HCV drugs, which cured the infection in the majority. This study looks at their outcomes a year following treatment, in terms of deaths, cancers and other complications of advanced liver disease. We conclude that in most patients anti-HCV treatment is beneficial even in advanced liver disease.

Association between MHC Class II Alleles and Clearance of Circulating Hepatitis C Virus

The frequencies of HLA class I antigens and class II haplotypes were compared in subjects with previous (polymerase chain reaction [PCR]-negative) or with persistent (PCR-positive) hepatitis C virus (HCV) infection and in HCV patients with mild versus severe histologic activity scores on liver biopsy. The DRB1*11 allele group was found in 11 (31.4%) of 35 subjects with previous infection and in 11 (8.2%) of 135 subjects with persistent infection (P < .001). The DQB1*0301 allele was found in 18 (51.4%) of 35 subjects with previous infection and in 33 (24.4%) of 135 patients with persistent infection (P < .002). Both observations remained significant after correction for multiple testing. No significant association was shown between severity of disease and any HLA class I or II type. Thus, the HLA class II alleles DRB1*11 and DQB1*0301 are associated with clearance of circulating HCV.

Direct ex vivo comparison of the breadth and specificity of the T cells in the liver and peripheral blood of patients with chronic HCV infection

The role of intrahepatic lymphocytes in the control of hepatitis C virus (HCV) infection and the pathology associated with it is not understood; most studies of the immunology of this infection use peripheral blood lymphocyte populations. To address this further, we examined in detail the IHL from HCV‐infected patients and controls, focusing on the antigen‐specific CD8+ T lymphocyte component. Individual T cells from needle liver biopsies and peripheral blood were isolated from patients with chronic HCV infection and examined directly ex vivo. We used RT‐PCR spectratyping to compare the breadth of the T cell receptor usage in the liver in comparison with the peripheral blood, and applied MHC class I tetramer technology to investigate the numbers of HCV‐specific CD8+ cells in the two compartments. T cell receptor usage in the liver of HCV‐infected patients was broad, comparable with that in the peripheral blood of the same patients. A much higher proportion of liver CD8+ cells expressed receptors specific for HCV antigens compared with paired peripheral blood CD8+ cells. A greater proportion of the liver tetramer‐positive cells expressed the activation marker CD69, compared with those in the periphery or other CD8+ cells in the liver. In the course of chronic HCV infection, HCV‐specific CD8 cells, which have been recently activated, appear to accumulate specifically in the livers of infected patients but are present in much lower numbers in the peripheral circulation. Further studies are needed to determine the function of these cells and their role in protection and immunopathology.

Enhanced Liver Fibrosis (ELF) test accurately identifies liver fibrosis in patients with chronic hepatitis C

Summary.  Assessment of liver fibrosis is important in determining prognosis and evaluating interventions. Due to limitations of accuracy and patient hazard of liver biopsy, non‐invasive methods have been sought to provide information on liver fibrosis, including the European liver fibrosis (ELF) test, shown to have good diagnostic accuracy for the detection of moderate and severe fibrosis. Access to independent cohorts of patients has provided an opportunity to explore if this test could be simplified. This paper reports the simplification of the ELF test and its ability to identity severity of liver fibrosis in external validation studies in patients with chronic hepatitis C (CHC). Paired biopsy and serum samples from 347 naïve patients with CHC in three independent cohorts were analysed. Diagnostic performance characteristics were derived (AUROC, sensitivity and specificity, predictive values), and clinical utility modelling performed to determine the proportion of biopsies that could have been avoided if ELF test was used in this patient group. It was possible to simplify the original ELF test without loss of performance and the new algorithm is reported. The simplified ELF test was able to predict severe fibrosis [pooled AUROC of 0.85 (95% CI 0.81–0.89)] and using clinical utility modelling to predict severe fibrosis (Ishak stages 4–6; METAVIR stages 3 and 4) 81% of biopsies could have been avoided (65% correctly). Issues of spectrum effect in diagnostic test evaluations are discussed. In chronic hepatitis C a simplified ELF test can detect severe liver fibrosis with good accuracy.

Development of a strand-specific RT-PCR based assay to detect the replicative form of hepatitis C virus RNA

The recent development of tagged RT-PCR and rTth RT-PCR has greatly improved strand-specific detection of hepatitis C virus (HCV) RNA but these assays are still prone to some false detection of the incorrect strand of RNA. In this study we aimed to address additional factors which contribute towards false detection of HCV RNA. Firstly the benefits of both tagged primers and the thermostable reverse transcriptase rTth during cDNA synthesis were combined and it was found that strand specificity was greatly improved without compromising sensitivity. The reliability of the assay was then optimised by addressing the following issues: control synthetic transcripts should be free of contaminating plasmid DNA, residual RT activity should be minimised in the presence of PCR primers and cDNA should be free of unincorporated tagged RT primer prior to PCR amplification. The alterations made to the assay eliminated completely false detection of the incorrect strand of RNA in the control assay whilst the correct strand was consistently detected at a cDNA dilution of 10(-3)-10(-4). Negative strand was not detected in RNA isolated from serum but was detected, at a ten-fold lower level than positive strand, in RNA isolated from liver tissue.

TT virus sequence heterogeneity in vivo: evidence for co-infection with multiple genetic types

TT virus (TTV) is a newly described DNA virus of humans that exhibits an unusually high degree of genetic heterogeneity. We have performed extensive analysis of the TTV populations present in samples, taken over a period of 2 to 6 years, from three individuals with persistent TTV infection. TTV DNA titres estimated for sequential samples were found to be quite stable over the entire study period in two patients, but fluctuated considerably in the third. DNA sequence analysis revealed different genetic diversity among TTV populations from samples from the three patients. In one case, absolute sequence homogeneity was observed among samples over a 3 year period. In a second, a limited amount of heterogeneity was found, including one sequence exhibiting G-->A hypermutation. TTV DNA sequences from the third patient exhibited quite remarkable genetic heterogeneity: evidence was found of seven distinct infecting viruses, representing four of the six TTV genotypes that have been described. In addition, minor variants of three of these seven sequences were observed. The heterogeneity of the viral population in this individual declined steadily over a 6 year period. This patient infected with a genetically diverse TTV population had the highest viral DNA titre.