The risk of infantile atopic dermatitis (AD) posed by maternal atopy and paternal atopy, respectively, were compared in the infants from a birth cohort in whom one of the parents had been designated atopic by skin prick testing. Nineteen with atopic mothers were compared with 20 with atopic fathers. AD, other atopic manifestations and potentially influential factors such as breast-feeding were documented prospectively during the first year in all infants. At 3, 6 and 12 month assessments skin prick sensitivity and total serum IgE concentration were determined. Nine of 19 infants with atopic mothers and two of 20 with atopic fathers had AD (P = 0.023) giving a relative risk of 4.7 (95% confidence interval 2.5 to 9.0). Seven of 19 with atopic mothers and none with atopic fathers had AD with onset before 6 months (P = 0.007). When all types of disease evidence (AD, recurrent wheeze and food reactions) were analysed together no significant difference was apparent between the groups. The two groups were found to be well matched with regard to breast-feeding, time of starting cow's milk, solids and egg, sex, month of birth, parental AD and smoking, race, household pets and neonatal IgE concentration. IgE concentrations at each age and the prevalence of skin prick positivity were similar between the groups. Maternal atopy poses a higher risk for infantile AD and paternal atopy. Whether this may be due to genetic or congenital factors or both is uncertain, but clearly the finding is of relevance in the prediction of allergy in childhood.

Screening for atopic disease using neonatal serum IgE has been advocated on the basis of the predictive value of elevated levels. However, this is only one measure of validity. The test was validated fully in 92 infants with a bi-parental history of atopy using 0.7 IU/ml as the cut-off. All infants were assessed prospectively for evidence of atopic disease (eczema, recurrent wheezing or food reactions) and skin-prick test positivity in the first year. Total serum IgE was measured by ultrasensitive ELISA on 61 cord blood samples and 92 samples taken at 7 days. All cord samples were re-analysed by PRIST and the first 33 by ultrasensitive RIA giving, respectively, 82% and 94% concordance (regarding undetectable, detectable and elevated levels) with ELISA. Maternal contamination was indicated in 7% of cord samples by high serum IgA. Ninety-five per cent of cord/7-day IgE pairs showed no change or minor rises at 7 days. Forty-nine per cent of the infants had evidence of atopic disease. Only 5% had elevated 7-day IgE. The positive and negative predictive values of the 7-day test were 60% and 52%, respectively, and specificity 96% but the sensitivity was only 7%. High levels did not distinguish the infants with the most unequivocal evidence of disease, i.e. eczema with a positive skin test. In conclusion IgE at 7 days is comparable to and more reliable than cord IgE. However, neonatal IgE screening is too insensitive to have clinical application.

Responses to the house dust mite during infancy may be important determinants of asthma in susceptible individuals. This study assessed early IgG subclass antibody responses to Dermatophagoides pteronyssinus in children of atopic parents. Sixteen atopic and 15 non-atopic children were selected from a birth cohort, and atopic status was established according to follow up over the first two years. IgG1 and IgG4 antibodies to D pteronyssinus were measured by enzyme linked immunosorbent assay at 7 days and 3, 6, 12, and 24 months. In all children D pteronyssinus IgG, fell at 3 months (indicating maternal antibody loss), rose progressively to 12 months, and waned at 24 months. D pteronyssinus IgG4 was only detectable at 7 days. Children who were atopic by 2 years and therefore at greater risk of asthma, tended to have higher D pteronyssinus IgG1 at 6 and 12 months.These data suggest greater exposure or responsiveness to dust mite during infancy than in the second year.

Serological responses to Epstein-Barr virus (EBV)-associated antigens were studied in nasopharyngeal carcinoma (NPC) patients in 2 countries non-endemic for the disease: the USSR (77 cases) and Cuba (55 cases). Two age- and sex-matched control groups were available, one consisting of patients with other head-and-neck tumours (OHNT) (171 from the USSR and 56 from Cuba), and the other of normal individuals (blood donors) (83 from the USSR and 80 from Cuba). Unlike the control groups, NPC patients from both countries had high levels of IgG and IgA antibodies, similar to those seen in patients from endemic areas. The only difference between NPC patients in the USSR and those in Cuba was lower (2-2.5 fold) anti-VCA IgG and IgA antibody titres. Using one-factor and multi-factor statistical methods the diagnostic value of different titres of EBV-specific IgG and IgA antibodies and their combinations for NPC patients (in the USSR) was evaluated. It was found that with simple mathematical analysis of EBV-specific antibody titres a differential diagnosis of NPC could be made to a significance level of 90%. The data obtained demonstrated the importance and reliability of EBV serology in the diagnosis of NPC in areas of low incidence of the disease.

ELISA is increasingly used to measure antibodies in new circumstances. Recently, it has been applied to the measurement of IgG subclass antibodies against common antigens in early childhood. These studies have raised concerns about the specificity of some of these assays. This paper details the results of experiments which have assessed the specificity of IgG1 binding to allergens of dust mite (Dermatophagoides pteronyssinus) and ryegrass (Lolium perenne) pollen by inhibition ELISA in the sera of 2-year-old children of atopic parents. Six sera which showed binding of IgG1 to D. pteronyssinus and six to L. perenne were used. All had IgG1 antibody against ovalbumin. In the children's sera, binding to D. pteronyssinus was substantially inhibited by preincubation with the homologous antigen, but not with ovalbumin, thereby confirming the specificity of the assay. However, suppression of IgG1 binding to L. perenne with the homologous antigen was comparatively small, and ovalbumin could cause an equivalent inhibition, indicating poor specificity. Furthermore, the level of IgG1 binding to L. perenne was closely correlated to the level of IgG1 binding to ovalbumin (r = 0.98; P < 0.001). When the assay was reversed, IgG1 binding to ovalbumin was only slightly inhibited by L. perenne, indicating that most antibody binding to ovalbumin was specific. Thus, binding IgG1 in both adult and child sera to D. pteronyssinus appeared to be specific, while child, but not adult, IgG1 binding to L. perenne showed poor specificity. This disparity may be due to differences in the affinities of the respective antibodies, and it illustrates the importance of determining assay specificity when making measurements in early childhood.