Comparison of some different methods for analysis of thyroid autoantibodies: importance of thyroglobulin autoantibodies.

Blood samples from 141 children and adolescents were used to evaluate differences between commercial kits and radioimmunoassay (RIA) methods for detecting thyroid autoantibodies. Thyroglobulin autoantibodies (Tg-Ab) were analyzed with a hemagglutination kit and a RIA; thyroid peroxidase autoantibodies (TPO-Ab) were measured with a gelagglutination assay and a RIA. The results of the antibody tests were compared with thyroid function tests (triiodothyronine [T3], thyroxine [T4], thyrotropin [TSH]) and with the results of ultrasound of the thyroid in antibody-positive patients. The correlation of antibody levels between the two methods was higher for TPO-Ab than for Tg-Ab. Moderate to high levels of TPO-Ab correlated to elevated TSH levels. Autoimmune thyroiditis (AIT) was found in 6 of the 141 children. The RIA-based thyroglobulin assay was the only test that identified autoantibodies in all 6 cases. In contrast, the hemagglutination kit thyroglobulin assay failed to identify 4 of the 6 AIT cases.

The coexistence of thyroid autoimmunity in children and adolescents with various allergic diseases.

The aim of our study was to investigate the coexistence of thyroid autoimmunity and allergic diseases. The prevalence of thyroid autoantibodies was studied in sera from 140 children with different kinds of allergic diseases, 370 11-13-y-old schoolchildren without allergic diseases serving as controls. The prevalence of thyroid peroxidase autoantibodies was found to be higher among the patients than in the control group, 11.4% vs 5.4% (p < 0.05). Ultrasound investigation identified autoimmune thyroiditis in 4.3% (6/140) of the series, which was later confirmed with fine needle aspiration in all six cases, four of which were unknown prior to the study. Our findings may be useful to alert clinicians that thyroid diseases may be superimposed on allergic children.

A comparison of terbutaline inhaled by Turbuhaler and by a chlorofluorocarbon (CFC) inhaler in children with exercise-induced asthma.

The present study compared the bronchodilating effect of inhalation from the Turbuhaler (0.5 mg terbutaline x 2) with the effect of inhalation from the chlorofluorocarbon (CFC) inhaler (0.25 mg terbutaline x 4) in children aged 9-17 years with reproducible, exercise-induced asthma (EIA). The treatments were given on two occasions, 5 min apart (terbutaline 0.5 mg + 0.5 mg). The study was performed as a double-blind, double-dummy, and placebo-controlled trial in 12 asthmatic children. The study was conducted on three separate days. The bronchoconstriction was induced by steady running on a treadmill. Forced expiratory volume in 1 s (FEV1.0), vital capacity (VC), and volume of trapped gas (VTG) were measured before and after the exercise test and after treatment. The study showed that the same amount of terbutaline inhaled from the Turbuhaler or from a CFC inhaler is equally effective for reversing EIA, and that the Turbuhaler is possibly more effective for treating spasm in small airways.

Passive smoking and childhood asthma. Urinary cotinine levels in children with asthma and in referents.

Passive exposure to tobacco smoke was assessed in children with asthma (age 3-15) and in referents. There was statistically significantly (P less than 0.0005) higher excretion of the nicotine metabolite, cotinine, in the urine of 49 children with asthma (geometric mean 10 ng/ml) compared with 77 referents (4.8 ng/ml). Maternal smoking was statistically significantly more prevalent among the asthmatics than among the referents (relative risk = RR = 2.6, 95% C1 = 1.2-5.3). In conclusion, the exposure to environmental tobacco smoke in asthmatic children was higher than among healthy children, indicating that passive smoking may be a predisposing and/or aggravating factor for childhood asthma.

Heterozygous alpha 1-antichymotrypsin and PiZ alpha 1-antitrypsin deficiency. Prevalence and clinical spectrum in asthmatic children.

In a case-control study we compared the prevalence of heterozygous deficiency of two closely related anti-neutrophil protease inhibitors, alpha 1-antitrypsin and alpha 1-antichymotrypsin, in 172 consecutive children with asthma. In a cohort study the clinical spectrum and severity were compared. On the basis of family studies 5/172 (2.9%) were classified as heterozygotes for alpha 1-antichymotrypsin deficiency, a high prevalence compared with that of an unselected adult population (prevalence ratio 4.5 (1.7-11.9), P less than 0.005). This finding suggests that the carrier state of this rare allele (prevalence 0.64%) may predispose to asthma in children. Among these heterozygous patients the prevalence of positive RAST tests for foodstuffs was significantly increased (prevalence ratio 4.8 (1.7-13.2), P less than 0.005) and 2/5 manifested food allergy with Quincke oedema. Either the PiMZ or SZ phenotype of alpha 1-antitrypsin deficiency was found in 12 (7.0%) of the 172 patients, a prevalence similar to that of a normal population (prevalence ratio 1.3 (0.67-2.6), P = 0.44). However, the asthma was more severe among the Z allele carriers, judged by the number of hospital admissions, compared with the non-Z asthmatic children (mean 2.92 vs. 1.72, P less than 0.05). The results indicate that heterozygous deficiency of protease inhibitors directed against neutrophil proteases may affect the severity and clinical spectrum of childhood asthma, and to some degree be predisposing.

A double-blind comparison between a new multidose powder inhaler (Turbuhaler) and metered dose inhaler in children with asthma.

Turbuhaler is a ready-loaded multiple dose inhaler which does not require co-ordination between release of dose and inhalation. 57 children with asthma participated in this clinical trial to compare the clinical effect and acceptance of terbutaline sulphate via Turbuhaler with that of metered dose inhaler (MDI). The trial consisted of two parts. In the first part of the study, which made use of a double-blind cross-over design, the clinical effect and number of treatment occasions with Turbuhaler were compared with those of MDI. In the second part, which was open, all patients were treated with Turbuhaler for 2 weeks. At the end of this period the patients were asked to make a subjective assessment of effect and to state their preference. There was no difference in clinical effect and number of treatment occasions between Turbuhaler and MDI. A majority of the patients thought Turbuhaler had the best effect and was easy to use.

Treatment of asthma in pre-school children with inhalation of terbutaline in Turbuhaler compared with Nebuhaler.

The aim of this study was to evaluate the efficacy, safety and preference of pre-school children with regard to two different devices for treatment of bronchial asthma with terbutaline. Turbuhaler, a powder inhaler preloaded with pure terbutaline for inhalation, was compared with a pressurized metered dose inhaler, attached to a Nebuhaler. The study had an open, cross-over randomized design. Each treatment period consisted of 2 weeks. Diary cards were filled in every morning and evening by the parents regarding PEF, asthma symptoms, extra inhalations of terbutaline, and side effects. Twenty-one children (mean age 3.9 years) were included in the study. A highly significant (P less than 0.001) increase in peak expiratory flow (PEF) was obtained after inhalation with both devices. The PEF values in the mornings after inhalation of terbutaline with Turbuhaler were significantly higher (P = 0.046) than those with Nebuhaler. Further, the PEF baseline values in the evenings before inhalation were also significantly higher (P = 0.03) with Turbuhaler. No difference was found in asthma symptoms and extra medication between the two devices. Side effects were mild and few with both devices. The parents found Turbuhaler easier to handle and 19 of 21 preferred this device for future use.

Prevention of exercise-induced asthma by drugs inhaled from metered aerosols.

The capacity of salbutamol 0.3 mg (SAL), disodium cromoglycate 3 mg (DSCG), a combination (SAL + DSCG), and ipratropium bromide 80 ug (IB), all given as metered aerosols to prevent exercise-induced (EIA), was compared with that of a placebo, a peroral lactose pill. Seven children participated, having reproducible EIA provoked by running on a treadmill at a heart rate of 170 sustained for 6 min. FEV1 and volume of trapped gas (VTG), defined as the air volume released during rebreathing oxygen with maximum breaths at the end of a multiple breath nitrogen wash out, were used as tests of spasm in large and small airways. SAL and SAL + DSCG offered complete protection in large and small airways. DSCG and IB prevented EIA in large airways (FEV1) to 95%, but only to about 50% in small airways (VTG). SAL or SAL + DSCG gave significantly better protection (FEV1 and VTG) than DSCG and IB (P less than 0.01). Differences between DSCG and IB were not statistically significant. DSCG or propellant caused significant irritation and spasm in small airways (VTG) before exercise. Most subjects seemed to obtain satisfactory protection against EIA by beta 2-agonists.

Decrease of exercise-induced asthma after physical training.

Exercise-induced asthma (EIA) is a multifactorial disease induced by cooling and drying of the airways. Mediator release or vagal stimulation, or both, may transmit the reaction to bronchial muscles. Premedication with beta 2-aerosol before exercise has the best preventive effect, although disodium cromoglycate (DSCG) or atropine prevent EIA in about 50% of the patients. EIA is provoked when the anaerobic threshold is passed. Training with high load interval exercise after premedication increased the anaerobic threshold in three groups of children, and a significant decrease in EIA was recorded, while a non-training control group showed no changes.

Improvement after training of children with exercise-induced asthma.

Fifty children with exercise-induced asthma (EIA) volunteered to take part in a study of the influence of training on EIA. 1) Ten children did not change physical activity. 2) Twelve children trained after premedication with salbutamol inhalations. 3) Thirteen children trained after premedication with disodium chromoglicate (DSCG) and used that drug for treatment. 4) Fifteen children trained in their own regimen, commonly after premedication with salbutamol. Their training programme (groups 2-3) consisted of high load exercise periods of two minutes interrupted by intervals of rest for two minutes during 30 minutes followed by interval swimming for another 30 minutes, twice a week for 3-4 months. Before the training period the degree of EIA was tested with a battery of lung function tests before and after running for 6 minutes on a treadmill at heart rate 170. EIA after training was measured applying the same procedure. Cardiocirculatory performance was evaluated before and after training with work on a cycle ergometer and expressed as W/kg body weight at heart rate 170. The children in groups 2, 3 and 4 improved their physical working capacity by 11% (p less than 0.01), 21% and 11%, respectively, but no improvement was found in group 1. Significant improvements in EIA after the training periods were found in all training groups, but basal asthma improved most in group 3, probably due to the basal treatment with DSCG.

Food hypersensitivity in patients with pollen allergy.

Six hundred patients with pollen allergy answered a questionnaire about food hypersensitivity. Hypersensitivity to various nuts, fruits and roots was reported more often by patients with birch pollen allergy (70%) than by patients without birch pollen allergy (19%). The stronger the skin test reaction to birch pollen, the higher was the incidence of food hypersensitivity. A negative correlation was found between grass pollen allergy and food hypersensitivity. In the diagnosis of springtime hayfever, the presence of hypersensitivity to nuts, fruits and roots supports a diagnosis of birch pollen allergy.

Lung function studies in children with allergic rhinitis.

Thirty carefully selected children with seasonal allergic rhinitis but without history or signs of lung involvement were examined clinically and by lung function tests during the pollen season as well as in the pollen-free season. During the pollen-free season the children had - if anything - slightly better lung function than a healthy control material. During the pollen season the only change was a slight increase in FRC and a decrease in lung clearance index, directly proportional to the change in FRC. Sixteen of the children performed an exercise test in the pollen-free season. A small increase in the volume of trapped gas (VTG) was noted, indicating a subclinical spasm in small airways. Salbutamol inhalation after exercise reduced VTG below base-line values, indicating disappearance of subclinical bronchospasm. Hay fever children thus have a tendency towards bronchospasm after, exercise in the pollen-free season, which, however, is of no clinical importance, as their VTG also after the exercise was less (better) than the predicted normal.

Lung function in cystic fibrosis: acute effect of salbutamol.

Pulmonary function tests including spirometry, N2 washout and volume of trapped gas (VTG) were obtained in 12 children with cystic fibrosis (CF), 6-18 years of age, before and after inhalation of 0.2 mg salbutamol. 11 children had pathologically increased VTG while the lung clearance index (LCI) was abnormal in 9, V'max 25/TLC (maximal flow at 25% of vital capacity/total lung capacity) in 8, residual volume in 6, but FEV1 in only 2 children. VTG/TLC% increased with age while V'max 25/TLC and FEV1 did not change. Neither was clinical score related to age in our subjects. No improvement in lung function occurred after salbutamol inhalation. VTG proved most sensitive for showing abnormality in children with CF.

The volume of trapped gas: a new and sensitive test for the detection of exercise-induced bronchospasm in children.

The volume of trapped gas (VTG) was measured at the end of a nitrogen multiple breath wash out procedure in 16 asthmatic and 10 healthy children before and after exercise. When compared to conventional spirometric variables VTG was the most sensitive test for detection of exercise-induced asthma (EIA). The VTG was significantly higher before exercise in the asthmatic children and increased significantly after exercise, while it did not change in the healthy controls. The significance of changes caused by EIA increased if VTG/TLC % or VTG/VC % wer used. Salbutamol inhalation normalized the VTG in all the asthmatic children.