CD64 (Fcgamma receptor I) cell surface expression on maturing neutrophils from preterm and term newborn infants.

BACKGROUND: The expression of CD64 (FcgammaRI) is increased from an almost negligible to a marked level on neutrophils in patients with bacterial infections. CD64 expression on neutrophils might therefore be a potential candidate for the diagnosis of bacterial infections in infants. AIM: This study was performed to monitor changes of neutrophil expression of CD64 during the postpartum period to further evaluate the usefulness of this analysis. The possible influence on the expression of this receptor by other factors was also investigated, including respiratory distress syndrome (RDS) and preterm rupture of the membranes (PROM). METHODS: Cell surface expression of CD64 on neutrophils from preterm and term newborn infants and healthy adults was analysed by flow cytometry. The expression of the other Fcgamma receptors, CD32 and CD16, and the complement receptors CD11b/CD18 and CD35 was also analysed for comparison. RESULTS: Neutrophils from preterm newborn infants showed a moderately increased level of CD64 expression that, during their first month of life, was reduced to the level observed on neutrophils from term newborn infants and adults. In contrast, the level of neutrophil expression of CD32 and CD16 was significantly lower in preterm than term newborn infants and adults. Neutrophils from all groups indicated similar levels of CD11b expression, but the expression on neutrophils from newborn infants increased after birth. CONCLUSION: Our results showed that neutrophil expression of CD64 is moderately increased in preterm newborn infants at birth. It seems not to be influenced by RDS, PROM or other factors related to preterm birth but by bacterial infection.

Is there any role for protein hydrolysates to premature newborns?

UNLABELLED: The use of hydrolysed cow's milk formula seems to increase beyond what is recommended based on evidence regarding allergy-preventive effect. Infants born preterm are sometimes given such formulas without proven effect. CONCLUSION: If the use of hydrolysed cow's milk formula is based on allergy-preventive aspects, evidence-based recommendations should be followed.

Exhaled nitric oxide in a population-based study of asthma and allergy in schoolchildren.

Exhaled nitric oxide (NO) reflects inflammation in the lower airways and is well adapted for use in children. The aims of this study were to investigate the distribution of the fraction of expired NO (FENO) in school children and to compare FENO and spirometry in relation to the International Study of Asthma and Allergies in Childhood questionnaire. The study was performed in 959 randomly selected 13-14-year-old school children in Uppsala, Sweden. Exhaled NO was measured at an inhalation rate of 0.1 l/s (FENO0.1) and a spirometric test was performed and data from these measurements were related to questionnaire data. Exhaled NO was measured according to American Thoracic Society recommendations, except the use of a mouth wash and an exhalation flow rate of 0.1 l/s. The distribution of the mean FENO0.1 values was skewed, with a preponderance of very low levels and a widespread tail of values ranging up to 102 parts per billion (ppb). Boys exhibited significantly higher mean FENO0.1 values than girls, 5.2 (4.7-5.7) vs 4.4 (4.0-4.8) ppb (geometric mean and 95% CI), P <0.01). Children who reported wheezing in the last year had higher FENO0.1 values than children that had not, 8.5 (7.1-10.2) vs 4.3 (4.0-4.6) ppb, P <0.001). The same association was found to most symptoms indicating hay fever and eczema. In contrast to this, only weak or inconsistent associations were found between asthma and spirometric indices. Exhaled NO levels were found to be independently related to male gender, wheeze and rhinoconjuctivitis but not to current eczema. In conclusion, exhaled NO was closely associated with reported asthma and allergy symptoms whereas spirometric indices such as percent predicted forced expiratory volume in 1 s were not. As most asthma cases in a population are mild, the findings suggest that exhaled NO is a sensitive marker of asthma and allergy.

Monitoring of IgE-mediated food allergy in childhood.

UNLABELLED: Testing for IgE-mediated allergy is performed to reach or refute a suspected allergy. But a positive test does only indicate sensitization and not necessarily clinical allergy. A diagnostic challenge procedure is therefore necessary. Also, in the phase of tolerance development a challenge is needed as clinical tolerance is reached before allergen-specific IgE antibodies have disappeared. During recent years, an increasing interest has been given to the possibility of using the concentration of specific IgE and the size of the skin prick test wheal to tell the optimal time to do a challenge without exposing the child to a risk of a severe reaction. CONCLUSION: Algorithms on when to do and when not to do a food challenge may be useful but should be used with great caution. Reasonable consideration should be paid to the severity of previous reactions and the kind of allergen involved.

Asthma and allergies at school--a Swedish national position paper.

The marked rise in allergies during the past decade has been increasingly perceptible for school personnel. A quarter of Swedish parents of children with allergies are unsatisfied with the school environment and how the schools are organized around their children. The Association of School Physicians has, together with six other medical, teaching and patient organizations, developed written guidelines for the management of asthma and allergies in Swedish schools. The aim was to regulate the responsibility of the school and its personnel for students with asthma and allergies, and to strengthen safety arrangements within schools. A secondary aim was to describe how the curriculum, teaching equipment, excursions, and other school activities, could be arranged appropriately and safely for students with asthma and allergies. Five-hundred copies of the document were circulated to all of Sweden's municipalities, county councils and pediatric departments. There was general agreement regarding the schools' responsibility that no child should risk becoming ill or having exacerbation of symptoms due to conditions at school. Recommendations regarding smoking on school premises and the use of perfumes were criticised. The strength of this document is that all organizations actively involved with schools have agreed upon these recommendations. This document serves to suggest a minimum level of activities thus ensuring that even students with asthma and allergies will receive appropriate schooling.

[Can asthma deaths in young people be predicted and prevented?]. / Kan astmadöd hos unga förutses och förebyggas?

UNLABELLED: In spite of increased asthma prevalence, the mortality in the disease has decreased during the last two decades in Sweden and in some other countries. However, in the age group 15-24 years an increased death rate was noted at the end of the 1980s. Therefore we started a prospective study from 1994 with the aim of trying to analyse the precipitating factors of all deaths in the ages 1-34 years in which the death certificate alleged asthma or anaphylaxis as the main or contributing cause of death. We conducted a confidential telephone enquiry of the next of kin of the deceased using a modified questionnaire developed by the British Thoracic Association. When available, patient records and post mortem protocols were obtained. RESULTS: The mortality in asthma in the ages 1-34 years has decreased from around 5 per million/year to 0.5/million/year over the period 1987-1998. The main preventable factors found in this analysis are undertreatment, non-compliance, psychosocial factors including alcohol/drug abuse, food allergy and inhalation allergy. Lacking awareness of the risks and underestimation of the severity of the asthma both by the physician and the patient seem to be dominating factors.

Is prevention of allergy and asthma possible?

UNLABELLED: Allergy and asthma are common diseases today. Ways to stop the ongoing increase in incidence of these diseases are highly desired. In this review the scientific basis for allergy and asthma prevention is discussed. RESULTS: Although secondary preventive measures are generally regarded as important, the views regarding the possibility of primary prevention vary. There is today only weak evidence that breastfeeding may reduce the risk of developing allergy, and if it does the effect is limited in degree and duration. There is some evidence that prolonged breastfeeding reduces the risk of developing asthma, at least in allergy-risk infants. There is also some evidence indicating that withholding solid foods in children at risk may have a beneficial effect. A dose-dependent risk of becoming sensitized to house dust mite and pet animal allergens has clearly been shown, but to what extent this sensitization is combined with asthma or clinical allergy is less well elucidated. Passive smoking increases the risk of wheezing problems and the indoor environment in damp houses seems to act synergistically with passive smoke. CONCLUSION: Primary prevention is rarely possible, but the risk of developing asthma and allergy may to some extent be reduced by taking certain measures, such as avoidance of tobacco smoke and damp houses. Breastfeeding seems to reduce the risk of wheezing, but as allergy-preventive measures, breastfeeding and avoiding pet animals have only marginal effects.

Development of allergies and asthma in infants and young children with atopic dermatitis--a prospective follow-up to 7 years of age.

BACKGROUND: The prognosis of atopic dermatitis is usually good, but the risk of developing asthma and allergic rhinitis is very high. The aim of this study was to follow children with atopic eczema up to school age to chart the course of sensitization and development of clinical allergy, as well as to study risk factors of sensitization. METHODS: Ninety-four children with atopic dermatitis were followed up to 7 years of age. The children were examined twice a year up to 3 years of age, and thereafter once yearly. At each visit, a clinical examination was performed, and a blood sample was taken. After 3 years of age, skin prick tests (SPTs) with inhalation allergens were performed at each visit. Information was obtained about atopy in the family, feeding patterns during infancy, symptoms of atopic disease, infections, and environmental factors. RESULTS: During the follow-up, the eczema improved in 82 of the 94 children, but 43% developed asthma and 45% allergic rhinitis. The risk of developing asthma was higher in children with a heredity of eczema. Presence of severe eczema at the time of inclusion in the study was associated with an increased tendency to produce food-specific IgE. An early onset of eczema was associated with an increased risk of sensitization to inhalant allergens, and development of urticaria. Early allergic reactions to food were associated with later reactions to food, allergic rhinitis, urticaria, and sensitization to both food and inhalant allergens. Early feeding patterns, time of weaning, and introduction of solid food did not influence the risk of development of allergic symptoms. A large number of periods or days with fever during the follow-up was associated with an increased risk of developing allergic rhinitis and urticaria. CONCLUSIONS: Our results confirm the good prognosis for the dermatitis and the increased risk of developing asthma and allergic rhinitis. Development of other allergic symptoms or sensitization was associated with the following factors: a family history of eczema, age at onset of eczema and its severity, early adverse reactions to foods, and proneness to infections.

Neutrophils from term and preterm newborn infants express the high affinity Fcgamma-receptor I (CD64) during bacterial infections.

The high affinity Fcgamma-receptor I (FcgammaRI, CD64) is normally expressed only to a very low extent by neutrophils. During bacterial infections, however, neutrophils from adult patients significantly increase their expression of FcgammaRI. Stimulation through FcgammaRI is a highly effective way to improve various aspects of neutrophil function, including phagocytosis. In our study the expression of FcgammaRI on neutrophils from preterm (n = 9) and term (n = 3) newborn infants, children (n = 14), and adults (n = 6) during the early phase of an acute bacterial infection was investigated. Our results showed that neutrophils from newborn infants with bacterial infection expressed FcgammaRI to a significantly higher extent than both noninfected preterm (p < 0.001) and term (p < 0.001) newborn infants and that neutrophils from preterm neonates expressed FcgammaRI to the same extent as neutrophils from term neonates and older infants, children, and adults. No difference in the neutrophil cell surface expression of FcgammaRI during bacterial infections was found among newborn infants, children, and adults. Expression of FcgammaRI probably represents an important mechanism to improve neutrophil phagocytosis as well as other aspects of neutrophil function during bacterial infections, especially in preterm infants. Our study indicates that measurement of cell surface expression of FcgammaRI on neutrophils could be a useful indicator of severe bacterial infections in preterm and term neonates, as well as in older children and adults.

A study on severe food reactions in Sweden--is soy protein an underestimated cause of food anaphylaxis?

BACKGROUND AND METHODS: Because of a fatal case of soy anaphylaxis occurring in Sweden in 1992, a study was started the following year in which all physicians were asked to report fatal and life-threatening reactions caused by food. The results of the first 3 years of the study are reported here, including results from another ongoing study on deaths from asthma during the same period. RESULTS: In 1993-6, 61 cases of severe reactions to food were reported, five of them fatal. Peanut, soy, and tree nuts seemed to have caused 45 of the 61 reactions, and four of them were fatal. If two cases occurring less than a year before our study started are included, we are aware of two deaths caused by peanuts and four deaths caused by soy. All four youngsters who died from soy anaphylaxis with asthma were severely allergic to peanuts but had no previously known allergy to soy. In most cases, there was a rather symptom-free period for 30-90 min between early mild symptoms and severe and rapidly deteriorating asthma. CONCLUSIONS: Soy has probably been underestimated as a cause of food anaphylaxis. Those at risk seem to be young people with asthma and peanut allergy so severe that they notice symptoms after indirect contact.

Prevalence of childhood asthma, rhinitis and eczema in Scandinavia and Eastern Europe.

There is evidence that the prevalence of allergies and asthma differs between populations in western and eastern Europe. This study investigated the prevalence of wheezing, rhinitis and eczema among schoolchildren in urban and rural areas of Scandinavia and the formerly socialist countries of Eastern Europe. A total of 79,000 children from two age groups (13-14 yrs and 6-7 yrs) in 18 study centres responded to a questionnaire within the International Study of Asthma and Allergy in Children (ISAAC). The 12 month period prevalence of symptoms of asthma, allergic rhinoconjunctivitis and atopic eczema was calculated. The prevalence of wheezing among the 13-14 yr old children was 11.2-19.7% in Finland and Sweden, 7.6-8.5% in Estonia, Latvia and Poland and 2.6-5.9% in Albania, Romania, Russia, Georgia and Uzbekistan (except Samarkand). The prevalence of itching eyes and flexural dermatitis varied in a similar manner between the three regions. The regional differences were less pronounced among the 6-7 yr old children in the seven participating centres. The highest prevalence of rhinitis was recorded in April-July in Scandinavia and during the winter months in the other countries. The prevalence of atopy-related disorders was higher in Scandinavia than in Estonia, Latvia and Poland, which in turn had a higher prevalence than five other countries of eastern Europe with a culture less similar to western Europe. This supports the hypothesis that "Western life style" is associated with a high prevalence of childhood allergy.

Exercise tests in large groups of children are not a suitable screening procedure for undiagnosed asthma.

Schoolchildren (n = 473), 12-13 years of age, from five schools, and without known asthma, participated in a screening test for exercise-induced asthma (EIA). The children were tested in large groups of 10-15 pupils. Peak expiratory flow (PEF) was measured before, immediately after, and 6-8 min after 6 min of running exercises in a gymnasium. A fall in PEF of at least 10% on two separate test occasions was considered an abnormal result. Children with abnormal results were given an asthma questionnaire and then tested individually in hospital with a standardized exercise test measuring FEV1, PEF, and flow/volume curve. In the screening test, 23 (4.9%) of the 473 children had an abnormal result. When tested in hospital, five (1%) children had a decrease in PEF and/or FEV1 of at least 10% (10-14%) after exercise. Furthermore, three of these five children had a history indicating mild EIA. We conclude that the use of PEF measurement as a screening method for EIA in large groups of schoolchildren cannot be recommended because it yields many false-positive results.

[Fatal and severe food hypersensitivity. Peanut and soya underestimated allergens]. / Letala och svåra reaktioner av livsmedel. Jordnöt och soja underskattade allergen.

Severe allergic reactions caused by foodstuffs have been reported in Sweden since 1993, 60 cases, five of them fatal, occurring during the first 3-year period. More than 70 per cent of all reactions reported were caused by patients, soya beans, nuts or almonds. In only 13 per cent of reported cases were the patients over 17 years of age. Several severe reactions were caused by soy protein, and mainly in children and adolescents with extremely severe peanut allergy and asthma. In many cases, severe symptoms first appeared more than one hour after soy intake. The report suggests soy allergy to be associated with an underestimated risk of severe reactions.

Asthma mortality rate in Swedish children and young adults 1973-88.

To investigate the asthma mortality rate in Sweden for the period 1973-88, we reviewed all death certificates for suspected death from asthma coded as 493 of the International Classification of Diseases (ICD)-8 and ICD-9 for the age group 1-24 years. Age-related mortality rates were calculated and compared with the results from a previous Swedish study of 1952-72. To identify factors contributing to death, we assessed hospital records. The mortality rate was 3.46 for the period 1973-88 and 3.31 for the earlier period, a net increase of 5%. This small overall increase includes a minor decrease in deaths for the age group 1-14 years and a rather pronounced increase for 15-24-year-old asthmatic patients. More deaths among "mild" asthmatic patients were found in the higher age group for 1986-8 than 1973-81. In younger children, asthma was more severe, and no difference was found between the two periods of the study. Asthma mortality is increasing in Sweden in adolescents and young adults, and there is a tendency to increasing mortality from less severe asthma not treated with anti-inflammatory drugs.