J.E. Banatvala

COXSACKIE-B-VIRUS-SPECIFIC IgM RESPONSES IN CHILDREN WITH INSULIN-DEPENDENT (JUVENILE-ONSET; TYPE I) DIABETES MELLITUS

Coxsackie B1-6 virus IgM responses were detected by an enzyme-linked immunosorbent assay (ELISA) in 11 of 28 (39%) children aged 3-14 years in whom insulin-dependent (juvenile onset; type I) diabetes mellitus (IDDM) developed in 1982. 5 patients had a homotypic response to Coxsackie B4 and 1 had a homotypic response to B5. A serum sample had been obtained from each patient 2 to 16 weeks after onset of IDDM symptoms. Islet-cell cytoplasmic antibodies (IgG) and complement fixing islet cell antibodies were detected in 15 of 18 sera tested, but only 6 of these sera were positive for Coxsackie-B-virus-specific IgM which suggests that Coxsackie-B-virus and islet-cell antibodies are not cross-reactive. Coxsackie-B-virus-specific IgM responses were present in only 16 of 290 (5.5%) age-matched non-diabetic London children whose sera were also collected during 1982. Sera from children with virologically confirmed Coxsackie-B-virus infections showed that development of homotypic or heterotypic Coxsackie B1-6 responses was age-related. 29 of 36 (81%) children aged 6 months to 4 years had a homotypic response, whereas 44 of 57 (77%) persons aged 15 years had heterotypic responses. Mothers of 2 children with Coxsackie-B-virus-induced neonatal myocarditis had Coxsackie-B-virus-specific IgM responses directed against serotypes 3 and 4, whereas their infants had a response to Coxsackie B2 virus alone.

COXSACKIE B, MUMPS, RUBELLA, AND CYTOMEGALOVIRUS SPECIFIC IgM RESPONSES IN PATIENTS WITH JUVENILE-ONSET INSULIN-DEPENDENT DIABETES MELLITUS IN BRITAIN, AUSTRIA, AND AUSTRALIA

Patients from England, Austria, and Australia with recently diagnosed juvenile-onset insulin-dependent diabetes (type 1) mellitus (IDDM) and matched controls were tested for specific IgM responses to Coxsackie B1-5 viruses. 37 of 122 (30%) patients aged less than 15, but only 15 of 204 (6%) controls, were positive (p less than 0.005). Differences in Coxsackie B virus specific IgM responses between patients and controls were statistically significant for patients in England and Austria (p less than 0.005). Coxsackie B virus specific IgM responses were detected in only 3 of 31 patients aged greater than 16. Virus-specific IgM responses were directed against a single serotype, usually Coxsackie B4 or 5, in 23 of 37 (62.5%) children aged less than 15; 10 of 13 (77%) of children aged less than 7 had monotypic responses. Among families of Austrian patients with IDDM, 8 of 79 (10%) siblings had Coxsackie B virus specific IgM responses, 1 of whom subsequently had IDDM, but none of the 80 parents was positive. In contrast, there was no evidence of recent infection by mumps, rubella, or cytomegalovirus (CMV), since mumps-virus specific IgM was present in only 2 of 100 children with IDDM and 5 of 139 controls; no rubella or CMV specific IgM responses were detected in 60 sera from patients with IDDM.

Fetal infection after maternal reinfection with rubella: criteria for defining reinfection.

Five cases of asymptomatic maternal reinfection with rubella are described that occurred in England and Wales during 1985-8 and resulted in intrauterine infection. The criteria for diagnosing reinfection are described. In four cases the rubella contact was with the womans own children. Two women had therapeutic abortions, rubella virus being recovered from the products of conception, and three were delivered of infants with congenitally acquired disease. Though the risks associated with maternal reinfection with rubella are very small and being measured in a prospective study, it is hoped that the recently introduced augmented programme of rubella vaccination will reduce rubella in the community and therefore this small risk still further.

Coxsackie B Virus-Specific IgM Responses in Patients with Cardiac and Other Diseases

An enzyme-linked immunosorbent assay (ELISA) test using polyvalent antigens and antisera was developed to detect Coxsackie-B-virus-specific IgM responses. The sera of 24 of 64 (37.5%) patients with acute pericarditis and 14 of 38 (36%) with acute myocarditis were positive for Coxsackie-B-virus-specific IgM. 4 of 30 (13.3%) patients with acute ischaemic heart disease and 2 of 28 (7.1%) patients with congestive cardiomyopathy were also positive. Coxsackie-B-virus-specific IgM was detected in the sera of 21 of 57 (36.8%) patients with Bornholm disease and 2 of 4 patients with acute-onset juvenile diabetes. Coxsackie-B-virus-specific IgM responses persisted for 6-8 weeks. Sera from patients with chronic valvular heart disease, Mycoplasma pneumoniae infections, and virus infections caused by viruses other than Coxsackie-B viruses were all negative. False-positive results did not occur when sera containing high titres of rheumatoid factor were tested.

SERUM IgM AND IgG RESPONSES IN POSTNATALLY ACQUIRED RUBELLA

Abstract Sucrose-density-gradient studies on sera from patients recently convalescent from rubella showed that specific IgM could be detected by haemagglutination-inhibition tests for up to 20 days from the onset of illness. This was associated with a significant increase in the concentrations of total IgM but not IgG, the IgM response being maximal 5-14 days after the onset of illness. After a month, only IgG could be detected. Complement-fixation antibodies, even when appearing early, consisted of IgG alone. Serum-total-IgG concentrations showed little variation in healthy patients throughout pregnancy, while IgM concentrations were reduced during the second trimester of pregnancy. The presence of a rubella-infected conceptus did not produce an unusually prolonged IgM response. Reduction in antibody titre in sera after treatment with 2-mercaptoethanol provided a less reliable method for demonstrating recent infection, since reductions in titre were associated usually with significantly raised total-IgM levels.

Failure of acyclovir cream in treatment of recurrent herpes labialis.

A double blind, randomised, crossover placebo controlled trial of 5% acyclovir cream, applied topically five times a day for five days, was carried out in 45 patients with recurrent herpes labialis. These patients had a total of 72 episodes, 34 of which were treated with the 5% acyclovir cream and 38 with placebo cream. Treatment was begun by the patients as soon as possible after the onset of prodromal symptoms. There was no significant clinical benefit from treatment with acyclovir cream compared with placebo cream. The median healing times were nine days with acyclovir cream, 10 days with placebo cream, and 13 days when no treatment was given. The possibility that the 40% propylene glycol cream base alone has a therapeutic effect must therefore be considered.

The Effect of Trypsin on the Growth of Rotavirus

It has been found that 1000-fold more bovine rotavirus is obtained when trypsin is incorporated in the maintenance medium and allowed to remain throughout the growth cycle. This holds true for primary calf kidney (CK) cells and also for several continuous and semi-continuous cell lines. In the presence of trypsin it has been possible to pass the virus serially on continuous cell lines seven times. Concentrations of 1 to 10 microgram/ml of trypsin are found to be effective. Preliminary results suggest that the same technique will be effective for the in vitro propagation of human rotavirus.

RUBELLA VIRAEMIA AND ANTIBODY RESPONSES AFTER RUBELLA VACCINATION AND REIMMUNISATION

Eleven 4-13 year old schoolgirls, who were seronegative by haemagglutination inhibition (HI) and radioimmunoassay (RIA) tests despite having been given HPV77-DE5 vaccine 3-9 years previously, were revaccinated with RA27/3. They showed evidence of residual immunity since they had accelerated immune responses, little or no rubella-specific IgM, no viraemia, and no vaccine-induced reactions. In contrast, all but one of the five adult women who were primary vaccinees showed a more delayed immune response. Three of four women tested had viraemia and two had vaccine-induced reactions. Enhanced HI and enhanced RIA showed that many of the schoolgirls had antibody before challenge, as did a fifth adult, who also showed an accelerated immune response, yet became viraemic.

ROTAVIRUS INFECTIONS IN A MATERNITY UNIT

Between May and August 1975, rotaviruses were detected in the stools of 76 out of 174 (44%) newborn babies in the maternity unit at this hospital. Infection occurred less frequently in breast-fed than in bottle-fed babies (P less than 0.001). However, only 7 out of 76 (8%) babies who excreted rotaviruses had symptoms and these were mild. Complement fixation tests did not show any apparent difference in the antibody titres or serological responses between mothers of rotavirus positive or negative babies. When 68 faecal extracts known to contain rotaviruses by electron microscopy were inoculated by centrifugation on to monolayers of continuous pig kidney cell cultures (IB-RS-2), rotavirus antigen was detected by immunofluorescence in 65 (95.5%) specimens, 58 being positive after centrifugation at 3000 g and a further 7 after centrifugation at 10 000 g. Antigen was first detected 6 hours after inoculation of specimens, maximum levels being detected at 24 hours.

Rubella vaccination: persistence of antibodies for up to 16 years.

Sera from 123 volunteers vaccinated six to 16 years previously with one of four rubella vaccines (Cendehill, RA27/3, HPV77-DE5, and To-336) were tested for rubella antibodies by single radial haemolysis and radioimmunoassay. By radioimmunoassay 110 (89.4%) of the vaccinees had antibody concentrations greater than the minimum immune titre (that is, greater than 15,000 IU/1), 11 (8.9%) were seropositive but had concentrations less than or equal to 15,000 IU/1, and two (1.6%) were seronegative. Eight (6.5%) were seronegative by single radial haemolysis, of whom five had received Cendehill vaccine. Six to eight years after vaccination subjects who had received Cendehill vaccine had the lowest geometric mean titre of antibody by radioimmunoassay while the subjects who had received HPV77-DE5 vaccine had the highest. Although antibody concentrations less than or equal to 15,000 IU/1 were not detected among subjects given RA27/3 vaccine six to eight years previously, such low levels were detected in two (15.4%) vaccinated 11-16 years previously. These results emphasise the importance of long-term surveillance programmes so that vaccination policies may be reviewed.