Subpopulations of T and B lymphocytes and levels of serum immunoglobulins G, A, M, E and subclasses G1, G2 and G3 were studied in 45 healthy school children aged 8-16 years during four seasons of the year. There were significant increases in CD4+ T helper cells, total T lymphocytes and CD4+/CD8+ (helper/cytotoxic) T-cell ratio during the spring season. While the levels of CD8+ T cells and total B lymphocytes remained statistically unchanged during all four seasons, the levels of natural (HNK-1) killer cells and macrophages increased significantly during the autumn and summer seasons respectively. The levels of immunoglobulins G, A, M and E remained statistically unchanged during all four seasons. Girls had higher levels of CD4+ T cells and a higher CD4+/CD8+ T-cell ratio than boys. Girls also had slightly higher levels of immunoglobulin G and M. These observations suggest that seasonal variations of some immunological parameters occur in healthy children. This may be an adaptive response to variable climatic and other environmental factors. These natural variations due to seasonal changes should be taken into account when immunological tests are used in clinical investigations.
The ingestion of food antigens usually results in the induction of oral tolerance, but the clinical and immunologic consequences of brief exposure to cow's milk proteins during the neonatal period are not well-documented. The aim of this work was to study immunoglobulin (Ig)E and IgG responses to cow's milk proteins and ovalbumin after exposure during the first three days of life in infants who were otherwise exclusively breast-fed. A group of 129 infants was randomly assigned at birth to one of three feeding regimens: human milk (HM), cow's milk formula (CMF), or a casein hydrolysate formula (CHF), during the first three days of life. They were then all exclusively breast-fed for a varying period of time and followed for two years. Serum IgG and IgE antibodies to cow's milk proteins and ovalbumin (OVA) were analyzed in blood samples obtained at birth, at 4 days and at 2, 4, 8, 12 and 24 months of age. The levels of IgG antibodies to beta-lactoglobulin (IgG-BLG) and bovine serum albumin (IgG-BSA) were higher in the CMF and the HM groups than in the CHF group for up to two years. This was particularly obvious for IgG-BLG in infants who started weaning before two months. The levels of IgG antibodies to casein (IgG-CAS) were higher in the CMF group, as compared with the CHF group at 8 and 12 months. The levels of IgG antibodies to OVA were similar in all three feeding groups. The levels of IgE antibodies to CAS or OVA were similar in the three feeding groups. Exposure to cow's milk during the first three days of life stimulated IgG antibody production to cow's milk proteins and this was still obvious at 2 years of age, while feeding with a casein hydrolysate during the first three days of life was associated with low levels of IgG antibodies to cow's milk proteins.
Ten researchers from the Nordic countries have reviewed the literature on early exposure in childhood, to pets and the risk of sensitisation/allergy. A search of the literature resulted in identification of about 1200 articles, of which 89 were selected for further examination. The group concluded that all exposure to pets involves a risk of sensitisation. Exposure in infancy involves an increased risk (normally RR = 1–1,5) of sensitisation and to a lesser degree of the development of symptoms. The group also concluded that pet allergens are present “everywhere”, as a result of people bringing allergens in their clothing, etc. The group concluded as a recommendation, that families with atopic individuals should wait until the child is at least two years old before getting a pet.
Low serum haptoglobin values are often found in children. Nine different parameters were studied in 125 healthy children aged 9-10 years to get indirect information on erythrocyte turnover and its possible relation to the low mean plasma haptoglobin level in childhood. The mean LD activity was higher than in adults. The mean carboxyhaemoglobin per cent saturation (COHb %) and the mean serum haptoglobin concentrations were lower than in adults. No significant correlation was found between serum haptoglobin and serum iron, serum bilirubin and COHb %. Significant correlation at low r-values was found between serum iron, serum bilirubin and COHb %. The low serum haptoglobin levels often seen in children seemed not to be caused by an increase in erythrocyte turnover.
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