Screening of Rh-antibodies in Rh-negative female infants with Rh-positive mothers

Exposure to non-inherited maternal antigens by breastfeeding affects antibody responsiveness

The observation, by Ray Owen and colleagues in 1954, that D-negative women were less likely to form anti-D antibodies against their D-positive fetus if their mother possessed the D-antigen, was not found in all later studies. We hypothesized that breastfeeding, received by the mother, may affect her immunity against non-inherited maternal red blood cell antigens. We studied a cohort of 125 grandmother-mother-child combinations, from a follow-up study of mothers after intrauterine transfusion of the fetus for alloimmune hemolytic disease. For mismatched red blood cell antigens the mother was exposed to, whether or not antibodies were formed, we determined whether her mother, the grandmother, carried these antigens. The duration for which the mothers were breastfed was estimated by way of a questionnaire. Using multivariate logistic regression analyses, the interaction term (non-inherited maternal antigen exposure by categorized breastfeeding period) showed that a longer breastfeeding period was associated with decreased alloimmunization against non-inherited maternal antigens (adjusted odds ratio 0.66; 95% confidence interval 0.48–0.93). Sensitivity analysis with dichotomized (shorter versus longer) breastfeeding periods showed that this lower risk was reached after two months (aOR 0.22; 95% CI 0.07–0.71) and longer duration of breastfeeding did not seem to provide additional protection. These data suggest that oral neonatal exposure to non-inherited maternal red blood cell antigens through breastfeeding for at least two months diminishes the risk of alloimmunization against these antigens when encountered later in life.

Chimerism in transfusion medicine: the grandmother effect revisited

Transfusion therapy is complicated by the production of alloantibodies to antigens present in the donor and lacking in the recipient through the poorly-understood but likely multi-factorial process of alloimmunization. The low prevalence of alloimmunization in transfused patients (6.1%) (1) suggests that processes central to immunologic tolerance may be operating in the vast majority of transfused patients who do not produce alloantibodies. Using RhD as a prototype, evidence is reviewed that the ability to make antibodies to red blood cell (RBC) antigens may result in part from immunologic tolerance acquired in utero. These ideas are extended to other examples of maternal microchimerism (MMc) of other non-inherited maternal antigens (NIMA). An evolutionary argument is offered that multi-generational immunity supports the hypothesis that MMc may partly explain the "non-responder" phenotype in RBC alloimmunization.

Season of birth as predictor of atopic manifestations

The relation between month of birth, sensitisation, and manifestations of atopy was assessed in 209 children who were followed from birth to 12-15 years. Children born during the tree pollen season were less likely to develop allergic rhinoconjunctivitis, IgE antibodies to pollen, or a positive screening test for IgE antibodies (odds ratio 0.28, 0.41, 0.35, respectively) than children born during the rest of the year. The prevalence of IgE antibodies to food and animal dander at 9 months and to atopic disease was higher in children born in the autumn and winter, that is, September to February, compared to the spring and summer (egg 20% v 6%; milk 10% v 2%). Thus sensitisation to pollen and allergic rhinoconjunctivitis is least common in children born in the spring, while birth in September to February is associated with an increased incidence of sensitisation to food and of atopic disease.

Appearance of atopic disease in relation to serum IgE antibodies in children followed up from birth for 4 to 15 years

BACKGROUND

Few studies have addressed the relationship between sensitization and the development of atopic disease over many years.

OBJECTIVE

To study the temporal relationship between the appearance of IgE antibodies in serum and atopic disease, we studied 324 children from three different groups, who were followed up prospectively from birth for 4, 12, and 15 years, respectively.

METHODS

Serum samples were obtained at various ages and analyzed for IgE antibodies against egg white, cow's milk, wheat, animal dander, house dust mite, birch and timothy with Phadebas RAST (Kabi Pharmacia Diagnostics AB, Uppsala, Sweden) or Pharmacia CAP system. In addition, a screening test for atopy, the Phadiatop Paediatric test (Kabi Pharmacia Diagnostics AB) was performed. Presence of atopic disease was assessed by means of clinical examination, interviews, and questionnaires.

RESULTS

In 135 children IgE antibodies were detected at least once to at least one allergen. Antibodies to egg white appeared in 46 children before or at 2 years of age: in 57% of them IgE antibodies to inhalants developed within the next 2 years, and in 19 of 25 (76%) IgE antibodies to inhalants developed before or at 12 to 15 years. Antibodies to inhalant allergens appeared in 55 children during the first 4 years of life and in 64 before 12 to 15 years. Among the former 48% and among the latter 32% had previously detectable egg white antibodies. Atopic disease appeared before or at age 4 years in 80% of the 40 children with IgE antibodies against egg white up to 9 months of age and in 69% of the 58 children who had a positive Phadiatop Paediatric test result in infancy.

CONCLUSIONS

IgE antibodies in children are usually associated with current or later topic disease. Sensitization to foods in infants is usually associated with appearance of IgE antibodies to inhalants later in life.

Clinical symptoms and IgE responses to common food proteins in atopic and healthy children

The appearance of symptoms suggestive of allergy through the first 4 years of life was studied prospectively in eighty-six healthy newborn babies. Blood samples were obtained at birth, at 3, 8, 25 and 48 months of age and analyzed for levels of total serum IgE and for IgE antibodies to some common foods. The occurrence of IgE antibodies was related to atopic manifestations and to a detailed history of infant feeding and family history of allergy. All infants with elevated cord blood IgE (more than 1.3 kU/l) developed manifestations of atopy. Specific IgE antibodies against egg, cow's milk and soy were demonstrated at 3, 8, 25 and 48 months in nine, twenty-three, six and two children respectively. Egg was a more potent sensitizing agent than cow's milk, IgE antibodies to egg being present in thirty-one samples, to cow's milk in eleven and to soy in five samples. Nine infants developed IgE antibodies to eggs or cow's milk before the introduction of these nutrients into the food. The IgE antibody levels were generally low in healthy non-atopic children and did, with one exception, not reach RAST class 1. In contrast, the levels of IgE antibodies to egg or cow's milk were higher in eleven blood samples from atopic children. We conclude that transient low IgE antibody responses to food proteins appear relatively often even in healthy infants. High concentrations of IgE antibodies however are almost exclusively seen in infants with atopic disease. Sensitization may appear early in infancy sometimes even before the offending food has been introduced into the diet.