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M Whelton

Publications and source records attributed to M Whelton.

16 recordsLinked to original sources
PubMed2001

Strategy for the maximization of clinically relevant information from hepatitis C virus, RT-PCR quantification.

BACKGROUND: The increasing clinical application of viral load assays for monitoring viral infections has been an incentive for the development of standardized tests for the hepatitis C virus. OBJECTIVE: To develop a simple model for the prediction of baseline viral load in individuals infected with the hepatitis C virus. METHODOLOGY: Viral load quantification of each patient's first sample was assessed by RT-PCR-ELISA using the Roche MONITOR assay in triplicate. Genotype of the infecting virus was identified by reverse line probe hybridization, using amplicons resulting from the qualitative HCV Roche AMPLICOR assay. RESULTS: Retrospective evaluation of first quantitative values suggested that 82.4% (n=168/204) of individuals had a viral load between 4.3 and 6.7 log(10) viral copies per ml. A few patients (3.4%; n=7/204) have a serum viremia less than the lower limit of the linear range of the RT-PCR assay. Subsequent, prospective evaluation of hepatitis C viral load of all new patients using a model based on the dynamic range of viral load in the retrospective group correctly predicted the dynamic range in 75.9% (n=33/54). CONCLUSION: The dynamic range of hepatitis C viremia extends beyond the linear range of the Roche MONITOR assay. Accurate determination of serum viremia is substantially improved by dilution of specimens prior to quantification.

DNA, Viral↗
PubMed2001

HLA class II genes determine the natural variance of hepatitis C viral load.

The aim of this study was to investigate the relationship between human leukocyte antigen (HLA) class II genes and the natural fluctuations in hepatitis C viral load in a homogeneous patient population. The study group consisted of 57 viremic (hepatitis C virus [HCV] 1b) women for whom HLA class II DRB1 and DQB1 haplotyping, virologic, histologic, and biochemical markers of disease activity were available. All patients were infected with HCV 1b from the same source of hepatitis C-contaminated anti-D immunoglobulin during the period from May 1977 to November 1978. The mean slope of change of viral load was 0.34 (SD +/- 0.73) log(10) viral copies/mL/year, which is significantly different from zero, P < 10(-9). Analysis of the relationship between the slope of change of viral load and HLA class II haplotype indicated a significantly different slope of change of viral load between the alleles of (1) DRB1(*)15 and DRB1(*)0701, and (2) DQB1(*)0602 and DQB1(*)0201, P(c) =.036 and P(c) =.026 after Bonferroni correction for multiple comparisons, respectively. Significant differences for grade and stage of disease at liver biopsy were observed for DQB1(*)0501 and DQB1(*)0201 alleles; P =.019, r(s) =.64, and P =.047, r(s) =.57, respectively. In addition, significant differences in stage of disease were found to exist between DRB1(*)13 and DRB1(*)0701, P =.031, r(s) = -.71. Our results define an association between the slope of change of viral load and HLA class II haplotype in patients infected with genotype 1b of HCV. This suggests a role for host immunogenetic factors in HCV infection in this homogeneous group.

Adult↗
PubMed2001

Tissue viral load variability in chronic hepatitis C.

OBJECTIVE: Liver biopsy is regarded as the gold standard for assessing disease activity in chronic hepatitis C, but sampling error is a potential limitation. Whether sampling variability applies equally to viral load assessment as it does to histology is uncertain. To examine this, we compared viral load between right- and left-lobe biopsy specimens from patients infected with hepatitis C virus (HCV). METHODS: Bilobe biopsies were taken from 16 patients who were serum positive for HCV RNA by reverse transcription-polymerase chain reaction. Genotype was identified by reverse line probe hybridization. There was an absence of competing risk factors for infectious and other liver diseases in this patient group. Histology and hepatic viral load were assessed blindly. None of the patients had received antiviral therapy at the time of study. RESULTS: Detection of HCV in right and left lobes was concordant with serum positivity in all cases. The viral load between lobes was highly correlated (p = 0.0003, r = 0.79). In contrast, the histological activity indices of inflammation and fibrosis/cirrhosis were poorly correlated between lobes (p = 0.038, r = 0.60, and p = 0.098, r = 0.50, respectively). CONCLUSION: Hepatic viral load variability does not suffer from the same degree of heterogeneity of sampling variability as does histology.

Adult↗
PubMed2000

Natural fluctuations of hepatitis C viral load in a homogeneous patient population: a prospective study.

The aim of this study was to determine the variation in hepatitis C viral load over an extended period of patient follow up. Serum samples were collected from 49 female individuals who were identified as having been infected from the same source of hepatitis C-contaminated anti-D immunoglobulin during the period from 1977 (May) to 1978 (November). All patients attended the hepatitis C clinic at Cork University Hospital, Cork, Ireland. The study group was homogeneous with respect to gender, hepatitis C virus (HCV) genotype (1b), and duration of infection. None of the patients had received antiviral therapy at the time of completion of study. Viral load quantifications were assessed using the Roche Monitor (F. Hoffmann-La Roche, Ltd., Basel, Switzerland) assay. The mean age of the study group at time of infection was 30.3 years (SD +/- 6.1) with a range from 18.5 to 43 years. The mean time of follow-up was 4. 1 years (SD +/- 1.0) with a range from 1.2 to 5 years. The mean rate of change of viral load per year was 0.23 log(10) viral copies per mL serum for the study group (SD +/- 0.19) with a range of -0.18 to 0.78 that was significantly different from zero, P < 10(-10). The rate of change of viral load per year was negatively correlated with viral load at first determination, r = -.35, P =.01. Age at infection did not correlate with the slope of change of viral load, P =.10. In conclusion, most women infected with HCV 1b will have an increase in viral load over time but a few patients who acquire infection early in adult life will show a decrease in viral load.

Adolescent↗
PubMed2000

Viral clearance in hepatitis C (1b) infection: relationship with human leukocyte antigen class II in a homogeneous population.

The aim of this study was to investigate the possibility of a significant relationship between human leukocyte antigen (HLA) class II and the clearance of hepatitis C virus (HCV). The study group consisted of 156 Irish women who iatrogenically received HCV 1b-contaminated Anti-D immunoglobulin between May 1977 and November 1978. Thus, the study population was homogeneous in terms of gender, source of infection, and ethnicity. On Screening in 1994, all individuals were anti-HCV antibody positive by recombinant immunoblot assay, while 46% (n = 72) of the group were HCV-positive by reverse transcriptase-polymerase chain reaction (RT-PCR). HLA DRB1 and DQB1 status was molecularly defined by high resolution reverse line probe hybridization methodology. Clearance of HCV 1b was found to be associated with DRB1*01. However, this association was lost after Bonferroni correction for multiple comparisons. Extended haplotype analysis between specific DRB1 and DQB1 allelic combinations identified a significant reduction in the frequency of DQB1*0501 in the presence of DRB1*0701 in the persistently infected individuals in the study group (P <.05). No associations with either viral clearance or persistence were found at the DQB1 locus. Our results suggest that HLA DRB1*01 appears to contribute to the spontaneous resolution of a primary HCV infection in the Irish population. The presence of DRB1*0701 in the absence of DQB1*0501 possibly reflects an influence of this allele in persistence of HCV infection. Defined and homogeneous patient populations offer the best opportunity to illuminate previously disguised immunogenetic factors important in the clearance of HCV 1b.

Alleles↗
PubMed1999

Viral load and clinicopathological features of chronic hepatitis C (1b) in a homogeneous patient population.

Monitoring the progression of hepatitis C virus (HCV) includes clinical, biochemical, and histological parameters. Quantitation of viral load by reverse-transcription polymerase chain reaction (RT-PCR) may offer a more reliable marker of disease status. Conflicting reports on viral titers may reflect heterogeneity of patient population, mode of infection, and viral type/subtype. The aim of this study was to correlate quantitative serum viral load with alanine transaminase (ALT) and histological status in a homogenous population. The study population consisted of 77 Rhesus-negative women with chronic hepatitis C type 1b. Homogenous features of this study population included: same defined source of infection (contaminated anti-D immunoglobulin); same duration of disease (17 years at the time of study); same viral type/subtype; same ethnic origin; all healthy child-bearing females at the time of infection; and an absence of competing risk factors for infectious and other liver diseases. None of the patients had received antiviral treatment at the time of study. Liver biopsy was performed on all patients. All biopsies were scored by a single histopathologist who was blinded to the clinical and viral status of each patient. A weak, but statistically significant, correlation (rs =.26; P <.05) between serum viral load and the degree of inflammation (mean value: 3.87 +/- 2.17 [SD]) was found. There was no significant correlation between serum viral load and the degree of fibrosis (mean value: 0.84 +/- 0.8 [SD]; P =.06). There was no significant correlation between serum viral load and ALT, although there was a correlation between ALT and the degree of inflammation (rs =.241; P =.035).

Adult↗
PubMed1998

Coeliac disease and epilepsy.

Whether there is an association between coeliac disease and epilepsy is uncertain. Recently, a syndrome of coeliac disease, occipital lobe epilepsy and cerebral calcification has been described, mostly in Italy. We measured the prevalence of coeliac disease in patients attending a seizure clinic, and investigated whether cerebral calcification occurred in patients with both coeliac disease and epilepsy. Screening for coeliac disease was by IgA endomysial antibody, measured by indirect immunofluorescence using sections of human umbilical cord. Of 177 patients screened, four patients were positive. All had small-bowel histology typical of coeliac disease. The overall frequency of coeliac disease in this mixed patient sample was 1 in 44. In a control group of 488 pregnant patients, two serum samples were positive (1 in 244). Sixteen patients with both coeliac disease and epilepsy, who had previously attended this hospital, were identified. No patient had cerebral calcification on CT scanning. Coeliac disease appears to occur with increased frequency in patients with epilepsy, and a high index of suspicion should be maintained. Cerebral calcification is not a feature of our patients with epilepsy and coeliac disease, and may be an ethnically-or geographically-restricted finding.

Adolescent↗
PubMed1997

Hepatitis C virus liver disease in women infected with contaminated anti-D immunoglobulin.

Screening for hepatitis C virus (HCV) infection is carried out by detection of antibodies to the virus (enzyme-linked immunosorbent assay (ELISA) and recombinant immunoblot assay (RIBA)) with confirmation by identification of HCV RNA genome in serum (polymerase chain reaction (PCR)). We describe the histological features on liver biopsy in 88 women with chronic HCV infection (serum positive on ELISA, RIBA and PCR) acquired from virus contaminated anti-D immunoglobulin. For the majority of these patients the time interval from virus infection to presentation was between 17 and 18 years. We separately assessed necroinflammatory disease activity and architectural features on liver biopsy and applied a scoring system which permitted semi-quantitative documentation of abnormal features. Only three women showed liver biopsies within normal limits (+/-focal steatosis). The remaining 85 cases showed a predominantly mild or moderate degree of disease activity with interface hepatitis (56.8% of cases), spotty necrosis, apoptosis and focal inflammation (88.6% of cases) and portal inflammation (90.9% of cases). Confluent necrosis was an uncommon finding (2.3% of cases). Assessment of architectural features showed normal appearance in 35.2% of biopsies. The predominant architectural abnormality noted was portal tract fibrosis. Ten per cent of cases, however, showed significant fibrous band and/or nodule formation.

Adult↗
PubMed1994

The Jarisch-Herxheimer reaction in leptospirosis.

Three patients with leptospirosis whose condition worsened after initiation of antibiotic therapy are reported. Their clinical deterioration appeared to be due to the development of the Jarisch-Herxheimer reaction rather than to progression of their underlying infection. Relevant aspects of the management of patients with leptospirosis are discussed.

Adolescent↗
PubMed1990

Neuropathy due to podophyllin intoxication.

A 22-year-old man developed a severe sensorimotor neuropathy following ingestion of podophyllin, which had been prescribed for genital condylomata. The initial toxic symptoms were vomiting and diarrhoea, followed by peripheral neuropathy. The neuropathy was still present 18 months later. Nerve conduction studies and sural nerve biopsy confirmed the presence of axonal degeneration.

Adult↗
PubMed1982

Epilepsy and coeliac disease.

A number of neurological disorders have been described in association with coeliac disease, including epilepsy. A review of 177 patients with coeliac disease failed to show an increased prevalence of epilepsy. This is contrary to the findings of other workers, and requires further investigation.

Adolescent↗