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Biomedical subjects

E H Boxall

Publications and source records attributed to E H Boxall.

At least 37 records · Page 2Linked to original sources

Enhanced luminescent assays for hepatitis markers: assessment of post vaccine responses.

A range of solid phase immunoassays have been developed using enhanced chemiluminescence to provide a signal which can be measured in a qualitative or quantitative manner. The "Amerlite" anti-HBs assay has been used routinely to test more than 3000 post-vaccine anti-HBs levels. The results show that 5% of vaccinees are non-responders, but that more than 30% produce antibody levels greater than 1000 mIU/ml.

Adolescent↗

Prevention of perinatal transmission of hepatitis B virus (HBV): a comparison of two prophylactic schedules.

Perinatal transmission of hepatitis B virus (HBV) from HBsAg carrier mothers who were HBeAg+, antiHBe+, or negative for both HBe markers, was interrupted using either 4 doses of vaccine, or one dose of hepatitis B immunoglobulin (HBIG) at birth, combined with 4 doses of vaccine. In those infants who received HBIG at birth, the antiHBs titre was significantly higher at 1 and 2 months old, but at 6, 9, and 18 months old, there was no significant difference. Among the infants of carrier mothers who did not display HBeAg (i.e., were antiHBe+, or negative for both HBe markers), a transient subclinical infection would have been expected in around 10% had there been no intervention. No evidence of such infection was detected, and no difference in outcome was found between the two treatment groups. Amongst infants born to HBeAg+ carrier mothers, infection occurred in 1 out of 8 who had received HBIG and vaccine, and in 3 of 8 who had received vaccine only. The difference in outcome was not statistically significant, but the numbers analysed were small. The infections which occurred in spite of prophylaxis may be attributable to in utero infection, poor response to vaccine by the infant, or to the mother having a particularly high HBV-DNA level. HBIG given at birth to infants of HBeAg+ carrier mothers may enhance the protection of infants who are destined to be poor responders to vaccine.

Carrier State↗

Hepatitis B vaccine in the prevention of perinatally transmitted hepatitis B virus infection: final report on a West Midlands pilot study.

A four-dose vaccination schedule was used to interrupt perinatal transmission of hepatitis B virus from carrier mothers to their babies. Of 49 babies immunised and successfully followed up, 43 (88%) became immune: 15 out of 21 (71%) of babies born to HBeAg + mothers became immune, the other 6 becoming the only carrier babies in the study. Without immunisation a carrier rate in excess of 70% would have been expected in this high-risk group. Vaccine alone, given in a rapid immunisation schedule, protected the majority of babies at risk. In those babies in whom the carrier state occurred in spite of immunisation, infection may have taken place in utero, or the infant may have failed to produce adequate antibody in response to the vaccine.

Carrier State↗

Hepatitis B virus infection: detection of circulating HBsAg/IgM antibody immune complexes.

Circulating hepatitis B surface antigen (HBsAg) IgM antibody complexes have been described in patients infected with hepatitis B virus (HBV). A radioimmunoassay to test for these complexes was developed and compared with a commercial kit. Complexes were demonstrated in both test systems. HBsAg/IgM antibody complexes were present initially in patients with acute HBV infection but disappeared within an average of 6 weeks after onset. In HBV carriers immune complexes persisted over a long time. This test is of value in providing additional information about the outcome of HBV infections and sequential testing for HBsAg/IgM is of prognostic value for clinicians.

Antigen-Antibody Complex↗

Chronic hepatitis B in male and female children of HBsAg carrier mothers.

We have studied a group of children born to HBsAg+ mothers, resident in the English West Midlands; none of the children had sought medical attention for hepatitis B-related problems. Forty-two out of 48 children born to HBeAg+ mothers were HBsAg+. Among these children, the mean age of the HBeAg+ girls was significantly lower than that of the HBeAg+ boys (P = 0.05), suggesting that girls eradicate HBeAg at a younger age than boys. Among all children born to HBsAg+ mothers, liver function tests were normal except in 2 HBsAg+ boys who had elevated serum aminotransferase activities. Excluding these boys, serum alanine aminotransferase activity, while within the normal range, was significantly higher in HBeAg+ and anti-HBe+ children than in their immune (anti-HBs+) and non-infected siblings (P less than 0.01 and P less than 0.05). Waning infectivity was observed in many HBsAg+ mothers, giving rise to a typical pattern of infection within a family: older children, born to the still HBeAg+ mother, being HBeAg+ carriers, while younger siblings, born when the mother had become anti-HBe+, had no markers of infection. These younger children are vulnerable to 'horizontal' transmission.

Adolescent↗

Change in immune response to hepatitis B in boys with haemophilia.

Eleven of 27 haemophilic boys who received a common batch of Factor VIII concentrate subsequently developed acute hepatitis B; although 9 were considered not to have been previously exposed to the virus, 2 other boys had been considered immune to hepatitis B. The amount of concentrate received by each child, together with their HIV-antibody status and T-lymphocyte subset distribution prior to exposure, did not influence their response to the hepatitis B virus (HBV). The two previously immune children who became infected, however, had evidence of the HIV-associated persistent generalized lymphadenopathy syndrome. Detailed investigation of the suspect batch of concentrate revealed hepatitis B surface antibody to a titre of 112 miu/ml, but surface antigen was not detectable, even after dissociation of antigen and antibody. As a result of this outbreak, 5 of the 11 boys remain carriers of the virus and 2 other family members have contracted acute hepatitis B. The possibility that the response of the haemophiliacs to HBV may be altered due to acquired alteration of their immune function is discussed. Regular screening of haemophiliacs, including those immune to hepatitis B, is recommended, since even with regular donor screening, HBV remains a major infective risk to haemophiliacs receiving Factor VIII replacement therapy, and the risk to an individual may change with time.

Carrier State↗

Prognosis of children who are carriers of hepatitis B.

Fifteen children who had become positive for hepatitis B surface antigen (HBsAg) by perinatal transmission were traced and re-examined after a mean of 8.1 years; all had been born in England to mothers from ethnic minorities who were carriers of HBsAg. Fourteen of the children remained carriers of HBsAg; of these, more girls than boys developed antibody to hepatitis B e antigen (anti-HBe). Those children whose transaminase activities had been above normal within the first three years of life were more likely to have developed anti-HBe. The earlier production of anti-HBe suggests that girls have a more effective immune response. Increased transaminase activity early in the course of asymptomatic carriage of HBsAg may be a favourable prognostic sign.

Alanine Transaminase↗

Hepatitis B vaccine in the prevention of perinatally transmitted hepatitis B virus infections: initial report of a study in the West Midlands of England.

A study was carried out to evaluate the efficacy of hepatitis B vaccine in interrupting perinatal transmission of hepatitis B virus from carrier mothers to their babies. A four-dose schedule was used. Eight of nine babies of e antigen carrier mothers became actively immune when immunisations were started within 48 hr of birth. Effectiveness was reduced if immunisation was delayed. This report includes results from a total of 32 babies, the longest period of follow-up being 2 years. The success of this scheme is comparable to that of more intensive prophylaxis of immunoglobulin either alone or combined with vaccine and should be seriously considered for the babies of all hepatitis B carrier mothers.

Carrier State↗

Enzyme-linked immunosorbent assay (ELISA) for the detection of hepatitis Be antigen and antibody: report of a field trial.

A field trial of an enzyme-linked immunosorbent assay (ELISA) for the detection of the hepatitis Be markers is reported. It is simple to perform, is designed to be read by eye and does not require any expensive apparatus. When compared with a commercially available RIA kit for the detection of the same markers, ELISA was shown to be as sensitive as RIA for the detection of anti-HBe but slightly less sensitive for the detection of HBeAg. However if all specimens negative for both HBeAg and anti-HBe by ELISA are considered to be potentially infectious, the ELISA should prove to be as useful as RIA for determining the "e" status of HBsAg-positive patients and, therefore, provide a reliable indication of the risk of secondary spread of hepatitis B infection to contacts by needle stick accident, close personal contact or perinatal transmission.

Antibodies, Viral↗

Hepatitis viruses.

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Carrier State↗