Tony Foucard

Neutrophils from Term and Preterm Newborn Infants Express the High Affinity Fcγ-Receptor I (CD64) During Bacterial Infections

The high affinity Fcγ-receptor I (FcγRI, 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 FcγRI. Stimulation through FcγRI is a highly effective way to improve various aspects of neutrophil function, including phagocytosis. In our study the expression of FcγRI 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 FcγRI 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 FcγRI to the same extent as neutrophils from term neonates and older infants, children, and adults. No difference in the neutrophil cell surface expression of FcγRI during bacterial infections was found among newborn infants, children, and adults. Expression of FcγRI 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 FcγRI on neutrophils could be a useful indicator of severe bacterial infections in preterm and term neonates, as well as in older children and adults.

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.

Human neutrophil lipocalin (HNL) as a diagnostic tool in children with acute infections: A study of the kinetics

AIM To study the changes in blood of human neutrophil lipocalin (HNL) and C-reactive protein (CRP) during the course of an acute infection in children. METHODS Children (n=92) hospitalized with symptoms and signs of acute infections were included and categorized into five groups, i.e. bacterial infection, suspected bacterial infection, viral infection, suspected viral infection and others. Blood was taken at admittance and the following 3-4 d for the measurement of CRP and HNL. RESULTS Both CRP and HNL were significantly raised at admittance in bacterial infection as compared to viral infection (p<0.001). After 25-48 h, 83% of the children with bacterial infections still had raised CRP levels in contrast to 11% having raised HNL levels. The levels of CRP, but not those of HNL, were significantly correlated to days of symptoms before admission. CONCLUSIONS HNL is a promising diagnostic tool in the distinction of acute infections caused by bacteria or virus. The differences in the kinetics of CRP and HNL make HNL a better marker for monitoring antibacterial treatment, since HNL is probably elevated only when an active bacterial infection is at hand.

A FOLLOW‐UP STUDY OF CHILDREN WITH ASTHMATOID BRONCHITIS I. Skin Test Reactions and IgE Antibodies to Common Allergens

Eighty‐one children, 2–66 months old, with asthmatoid bronchitis were followed for 15–40 months (mean 31 months). The children were physically examined 3–4 times a year. Blood samples were taken on these occasions. Skin prick tests were done at the beginning and at the end of the investigation period. Antibodies of the IgE class, as measured by RAST, were found against animal danders, pollens or house dust in 5 children at the first examination and during the follow‐up period in another 5 children. Strongly positive prick test reactions were accompanied by a positive RAST in 86%, smaller wheals less frequently. IgE antibodies to egg white or cows milk were found in 26 children, in many cases during the first year of life and occasionally as early as at the age of 3 months. As the children grew older the titres decreased and the antibodies seemed to be of clinical importance only in a few cases with high titres to the egg white extract. In contrast, IgE antibodies to animal danders were not detected until 11/2 years of age and those to pollen not until 3 years of age. These antibodies showed increasing titres with time and they seemed to be of clinical importance in all but a few cases with very low titres.

In vitro Estimation of Allergens by a Radioimmune Antiglobulin Technique Using Human IgE Antibodies

A radioimmune method based on detection of IgE antibodies (RAST) has been used for allergen quantitation, both as a direct test and as an inhibition test. Commercially available allergen extracts from

Asthma mortality among Swedish children and young adults, a 10-year study

BACKGROUND Previous reports indicate that morbidity and mortality from asthma have increased during the past decades. Here, the mortality rate associated with asthma and possible risk factors in children and young adults in Sweden during the period 1994-2003 were evaluated. METHODS The medical profession was asked to report suspected cases of death from asthma in individuals 1-34 years of age. All death certificates containing relevant ICD codes were reviewed. Medical records and autopsy reports were assessed and telephone interviews with next-of-kin performed. RESULTS During the 10-year period 37 deaths due to asthma were identified. The median age at the time of death was 27 years and 6 of the deceased were younger than 15. The overall incidence of death from asthma decreased from 1.54 deaths per million in 1994 to 0.53 per million in 2003. Common risk factors were under-treatment (23/37), poor adherence to prescribed treatment (17/37) and adverse psychosocial situation (19/37). An alarming finding was that 11 of the 37 deaths were probably caused by food allergy and for 8 subjects death was associated with exposure to pet dander. The death certificates were found to contain inaccuracies with 30% of those for whom asthma was reported as the underlying cause having died from other causes. CONCLUSION Asthma mortality in children and young adults in Sweden decreased between 1994 and 2003. Food allergy and inadequate treatment were the major risk factors for such a death. Recognition and special care of patients with asthma who have shown signs of non-compliance, denial or severe food allergy must be encouraged.

Serum-levels of lactoferrin, lysozyme and myeloperoxidase in normal, infection-prone and leukemic children

Serum levels of lactoferrin, lysozyme and myeloperoxidase have been established in 31 healthy children. On average, serum lactoferrin was 330 micrograms/1, serum lysozyme 1638 micrograms/1 and serum myeloperoxidase 174 micrograms/1. Serum myeloperoxidase was, on average, significantly higher in children than in adults (p = 0.01), whereas serum lactoferrin and serum lysozyme were equal to those of adults. In a group of infection-prone children (n = 31), both serum lactoferrin and serum myeloperoxidase, but not the serum lysozyme levels, were significantly lower (p less than 0.001 and p = 0.002, respectively) than those of the reference children in spite of normal intracellular contents and even somewhat higher peripheral blood polymorphonuclear counts. Based on the assumption that serum lactoferrin and serum myeloperoxidase reflect turnover and activity of neutrophil granulocytes, the findings could suggest reduction in these respects and could be one contributing factor to the high infection propensity of these children. Serum levels of the three proteins have also been measured in 10 children with suspected or various forms of manifest leukemia. It is suggested that the levels reflect turnover and stage of maturation of the myeloid and monocytic cells and could, therefore, aid in the understanding and diagnosis of these diseases.

A FOLLOW-UP STUDY OF CHILDREN WITH ASTHMATOID BRONCHITIS: II. Serum IgE and Eosinophil Counts in Relation to Clinical Course

After a follow‐up period for 15–40 months (mean 31 months) of 81 children, aged 2–66

Risk factors associated with allergic and non-allergic asthma in adolescents.

Introduction:  Risk factors for asthma have been investigated in a large number of studies in adults and children, with little progress in the primary and secondary prevention of asthma.

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

Background: The expression of CD64 (FcγRI) 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 Fcg 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 CD 16 was significantly lower in preterm than term newborn infants and adults. Neutrophils from all groups indicated similar levels of CD 11b expression, but the expression on neutrophils from newborn infants increased afterbirth.