Detection of human cytomegalovirus- specific IgA antibodies in colostrum by enzyme-linked immunosorbent assay (ELISA)

Detection of cytomegalovirus antigen and antibodies in the urine of small infants and children

The diagnostic efficacy of an enzyme immune assay to detect cytomegalovirus (CMV) antigen in the urine of infected infants and children was determined, and the effect that CMV-specific antibodies present in the urine have on the sensitivity of the test was ascertained. The antigen was detected in 84.4% of the CMV-culture-positive samples, while CMV-specific IgA was detected in 24% of CMV-culture-positive specimens. The absence of CMV-specific IgA correlated with detection of CMV antigen in the CMV-culture-positive urine specimens (p less than 0.05).

Enzyme-linked immunosorbent determination of autoantibodies to zona pellucida as a possible cause of infertility in women

An enzyme-linked immunosorbent assay (ELISA) for determination of antibodies against the zona pellucida was developed and compared with the already available indirect immunofluorescence (IIF) technique. Sera from 100 women with explained and unexplained infertility were screened for the presence of autoantibodies to the zona pellucida by ELISA and IIF techniques. Porcine/goat zonae immobilized on activated microtitre plates or solubilized zona pellucida antigens adsorbed on poly-L-lysine-coated microtitre plates were used as a solid phase in an ELISA. Assay of anti-zona pellucida antibodies in xenogeneic and allogeneic sera was performed by incubation of test samples with the solid phase against human serum supplied by WHO as a reference positive control, followed by incubation with staphylococcal protein A conjugated to horseradish peroxidase. The ELISA was effectively used to screen the production of monoclonal antibodies from mouse myeloma X mouse splenocyte hybridomas. The sensitivity of the ELISA was more than 2500-fold greater than that of the IIF technique. Significantly high titres of autoantibodies to zona pellucida were found in patients with unexplained infertility as compared with patients with a known cause of infertility, and their normal counterparts.

Antimicrobial properties and microbial contaminants of breast milk--an update

A review of recent studies of antibacterial, antiviral and antiprotozoan factors in human breast milk is presented. Also reviewed are the microbial contaminants that have been detected in human milk with a particular focus on cytomegalovirus and rubella virus, both of which have recently been shown to infect infants via breast milk.

The diagnostic significance of specific serum IgA detection in cytomegalovirus infections

The prevalence of virus-specific serum antibodies of IgA class against cytomegalovirus (CMV) was determined in 228 healthy blood donors and in 112 patients suspected of CMV infection. All patients had a titer of 40 or higher in the complement fixation test. Specific CMV-IgA was found in 81 per cent of CMV-IgM positive patient sera and in 20 per cent of sera from patients strongly suspected of CMV infection, but with negative CMV-IgM. Less than 2 per cent of healthy blood donors had CMV specific serum IgA.

Specific immunoglobulin A antibodies to a peptide subunit sequence of bacterial cell wall peptidoglycan

Immunoglobulin A (IgA) antibodies in human sera with binding specificity for the C-terminal R-D-Ala-D-Ala sequence of the precursor peptide from bacterial cell wall peptidoglycan were detected by an enzyme-linked immunosorbent assay (ELISA). Specificity of the test system was proved by comparing the high binding of specific IgA to albumin-(D-Ala3) as an antigen with the failure to bind to albumin-(L-Ala3), by binding inhibition studies with L-Ala3, D-Ala3, or peptides with structural analogy to peptidoglycan peptide subunit peptides as inhibitors, and by excluding binding of peroxidase-labeled anti-human IgA to immunoglobulin classes others than IgA. Interference of rheumatoid factors of IgA class was excluded by an ELISA for assaying IgA-rheumatoid factor and by the fact that an IgA fraction essentially free of IgG and IgM was isolated from a serum reacting strongly positive in the ELISA for measuring specific IgA to the peptide subunit of peptidoglycan. This isolated IgA again exhibited binding specificity in the ELISA, thus corroborating the existence of specific IgA in human serum to the C-terminal R-D-Ala-D-Ala sequence of peptidoglycan precursor peptide. The existence of IgA antibodies with specificity for bacterial peptidoglycan was further proved by preadsorption of serum to peptidoglycans and subsequent measurement of specific IgA in the ELISA. Screening of human sera for IgA antibodies with specificity for R-D-Ala-D-Ala peptides revealed that specific antibodies directed against this sequence of bacterial cell wall peptidoglycan may be detected in several human sera.

Enzyme-linked immunosorbent assay for IgG antibodies to Epstein-Barr virus-associated early antigens and viral capsid antigen

An enzyme-linked immunosorbent assay has been developed for the detection of IgG antibodies to Epstein-Barr virus-associated early antigens and late antigens including the viral capsid antigen. The antibody titers of human sera determined in this way correlate well with those by indirect immunofluorescence. ELISA was more sensitive than the IF method. The assays described may be used for rapid and sensitive diagnosis of EBV-related diseases. In addition, the ELISA will be useful for the determination of antibody titers to isolated EBV-associated antigens, e.g., purified components of the EA complex.

Prevalence of antibodies to human cytomegalovirus in urban, kibbutz, and Bedouin children in southern Israel

Prevalence of antibody to human cytomegalovirus (CMV) was determined in a sample of 860 healthy children aged 1-13 years in Beer Sheva, in the Negev region of Israel. Three groups of children were tested: (1) urban Jewish children of low, middle, and high socioeconomic levels; (2) 8 rural communes (kibbutz) in which children live in close contact with each other from the 6th week of life under good hygienic conditions and a high standard of living; (3) Bedouin, seminomadic Arabs living in relatively poor hygienic conditions in the desert. Kibbutz children showed a significantly higher rate of CMV seropositivity by the second year of life than urban Jewish and Bedouin children (76% versus 44% and 54% respectively) with a gradual increase to 94% in the 10-13-year age group. Among children living in urban populations a significantly higher prevalence of CMV seropositivity was associated with crowding, but not with other socioeconomic indicators (place of residence, country of origin, or education level of parents). A marked rise of CMV seropositivity with age was found in urban Jewish children in the 2-5-year age group during which time they attend nurseries (44% to 67%) and in the Bedouin children in the 6-9-year age group (59% to 86%) when they first attend school. The data suggest that close contact is of major importance in CMV infection in childhood. The clinical implications of early acquisition and high prevalence of CMV antibodies in the kibbutz setting are discussed.