Inter-hemispheric somatosensory coherence and parental stress in hypersensitivity at 8 months old: An electroencephalography study.

OBJECTIVE: Infant hypersensitivity affects daily challenges and parental stress. Although the crucial role of tactile sensation in infants' brain function has been highlighted, hypersensitive infants and their families lack support. Electroencephalography may be useful for understanding hypersensitivity traits. We investigated the relationship between infant perceptual hypersensitivity and parental stress, somatosensory-evoked potential (SEP), and magnitude-squared coherence (MSC) in the general population. METHODS: Infants aged 8 months (n = 63) were evaluated for hypersensitivity and parental stress using a questionnaire and for cortical activity using electroencephalography. Vibration stimuli were applied to the infant's left foot. SEP components that peaked around 150 ms (N2) and at 200 ms (P2) after stimulus onset were evaluated by amplitude and latency at the midline electrode (Cz) and MSC between the midline electrodes (C3-C4). RESULTS: Parental stress was associated with infant hypersensitivity. The latency of Cz was delayed, and C3-C4 delta MSC was high in infants with hypersensitivity. CONCLUSIONS: Increasing inter-hemispheric MSC synchrony in the stimulated condition in infants with hypersensitivity suggested atypical somatosensory cortical function. SIGNIFICANCE: These findings contribute to identifying, understanding the mechanisms of, and developing effective coping strategies for early-stage hypersensitivity.

Nematode ascarosides attenuate mammalian type 2 inflammatory responses.

Mounting evidence suggests that nematode infection can protect against disorders of immune dysregulation. Administration of live parasites or their excretory/secretory (ES) products has shown therapeutic effects across a wide range of animal models for immune disorders, including asthma. Human clinical trials of live parasite ingestion for the treatment of immune disorders have produced promising results, yet concerns persist regarding the ingestion of pathogenic organisms and the immunogenicity of protein components. Despite extensive efforts to define the active components of ES products, no small molecules with immune regulatory activity have been identified from nematodes. Here we show that an evolutionarily conserved family of nematode pheromones called ascarosides strongly modulates the pulmonary immune response and reduces asthma severity in mice. Screening the inhibitory effects of ascarosides produced by animal-parasitic nematodes on the development of asthma in an ovalbumin (OVA) murine model, we found that administration of nanogram quantities of ascr#7 prevented the development of lung eosinophilia, goblet cell metaplasia, and airway hyperreactivity. Ascr#7 suppressed the production of IL-33 from lung epithelial cells and reduced the number of memory-type pathogenic Th2 cells and ILC2s in the lung, both key drivers of the pathology of asthma. Our findings suggest that the mammalian immune system recognizes ascarosides as an evolutionarily conserved molecular signature of parasitic nematodes. The identification of a nematode-produced small molecule underlying the well-documented immunomodulatory effects of ES products may enable the development of treatment strategies for allergic diseases.

Allergen disrupts amygdala-respiration coupling.

Allergic asthma affects both the respiratory function and central nervous system. Communication between the amygdala and respiratory control system is critical for regulating breathing function. To date, no study provides the effect of allergic inflammation on amygdala-respiration coupling. Here, we simultaneously recorded respiration and local field potentials of the amygdala during awake immobility in a rat model of allergic asthma. A decreased synchrony was found between amygdala and respiration in asthmatic rats. Allergen also reduced the modulatory effect of the respiration phase on amygdala power at delta, theta and gamma2 (80-120 Hz) frequencies. Moreover, in the animal model of allergic asthma, delta and theta oscillations strongly coordinate local gamma2 activity in the amygdala. These findings suggest that allergen can induce brain alterations and therefore shed light on future works to address how disruption of amygdala-respiration coupling contributes to respiratory dysfunction in allergic asthma.

Mimics of Allergy and Angioedema: Scombroid, Mast Cell Activation Disorders, and Hereditary Alpha Tryptasemia.

Scombroid poisoning, systemic mastocytosis, and hereditary alpha tryptasemia all present with episodes that resemble allergic reactions. Knowledge regarding systemic mastocytosis and hereditary alpha tryptasemia is quickly evolving. Epidemiology, pathophysiology, and strategies to identify and diagnose are discussed. Evidence-based management in the emergency setting and beyond is also explored and summarized. Key differences are described between these events and allergic reactions.

Overview of Allergy and Anaphylaxis.

Allergic reactions and anaphylaxis occur on a severity continuum from mild and self-limited to potentially life-threatening or fatal reactions. Anaphylaxis is typically a multiorgan phenomenon involving a broad range of effector cells and mediators. Emergency department visits for anaphylaxis are increasing, especially among children. There is a broad differential diagnosis for anaphylaxis, and the diagnosis of anaphylaxis can be aided by the use of the National Institutes of Allergy and Infectious Disease/Food Allergy and Anaphylaxis Network clinical diagnostic criteria. Risk factors for severe anaphylaxis include older age, delayed epinephrine administration, and cardiopulmonary comorbidities.

Hypersensitivity may be involved in severe COVID-19.

BACKGROUND: Deaths attributed to Coronavirus Disease 2019 (COVID-19) are mainly due to severe hypoxemic respiratory failure. Although the inflammatory storm has been considered the main pathogenesis of severe COVID-19, hypersensitivity may be another important mechanism involved in severe cases, which have a perfect response to corticosteroids (CS). METHOD: We detected the serum level of anti-SARS-CoV-2-spike S1 protein-specific IgE (SP-IgE) and anti-SARS-CoV-2 nucleocapsid protein-specific IgE (NP-IgE) in COVID-19. Correlation of levels of specific IgE and clinical severity were analysed. Pulmonary function test and bronchial provocation test were conducted in early convalescence of COVID-19. We also obtained histological samples via endoscopy to detect the evidence of mast cell activation. RESULT: The levels of serum SP-IgE and NP-IgE were significantly higher in severe cases, and were correlated with the total lung severity scores (TLSS) and the PaO2 /FiO2 ratio. Nucleocapsid protein could be detected in both airway and intestinal tissues, which was stained positive together with activated mast cells, binded with IgE. Airway hyperresponsiveness (AHR) exists in the early convalescence of COVID-19. After the application of CS in severe COVID-19, SP-IgE and NP-IgE decreased, but maintained at a high level. CONCLUSION: Hypersensitivity may be involved in severe COVID-19.

Allergic Aspects of IgG4-Related Disease: Implications for Pathogenesis and Therapy.

IgG4-related disease (IgG4-RD) is a rare systemic fibroinflammatory disease frequently associated with allergy. The pathogenesis of IgG4-RD is poorly understood, and effective therapies are limited. However, IgG4-RD appears to involve some of the same pathogenic mechanisms observed in allergic disease, such as T helper 2 (Th2) and regulatory T cell (Treg) activation, IgG4 and IgE hypersecretion, and blood/tissue eosinophilia. In addition, IgG4-RD tissue fibrosis appears to involve activation of basophils and mast cells and their release of alarmins and cytokines. In this article, we review allergy-like features of IgG4-RD and highlight targeted therapies for allergy that have potential in treating patients with IgG4-RD.

Sneezing reflex is mediated by a peptidergic pathway from nose to brainstem.

Sneezing is a vital respiratory reflex frequently associated with allergic rhinitis and viral respiratory infections. However, its neural circuit remains largely unknown. A sneeze-evoking region was discovered in both cat and human brainstems, corresponding anatomically to the central recipient zone of nasal sensory neurons. Therefore, we hypothesized that a neuronal population postsynaptic to nasal sensory neurons mediates sneezing in this region. By screening major presynaptic neurotransmitters/neuropeptides released by nasal sensory neurons, we found that neuromedin B (NMB) peptide is essential for signaling sneezing. Ablation of NMB-sensitive postsynaptic neurons in the sneeze-evoking region or deficiency in NMB receptor abolished the sneezing reflex. Remarkably, NMB-sensitive neurons further project to the caudal ventral respiratory group (cVRG). Chemical activation of NMB-sensitive neurons elicits action potentials in cVRG neurons and leads to sneezing behavior. Our study delineates a peptidergic pathway mediating sneezing, providing molecular insights into the sneezing reflex arc.

Blockade of NF-κB Translocation and of RANKL/RANK Interaction Decreases the Frequency of Th2 and Th17 Cells Capable of IL-4 and IL-17 Production, Respectively, in a Mouse Model of Allergic Asthma.

The main purpose of this study was to investigate whether the blockade of the interaction between the receptor activator of nuclear factor-κB (NF-ĸB) ligand (RANKL) and its receptor RANK as well as the blockade of NF-κB inhibitor kinase (IKK) and of NF-κB translocation have the potential to suppress the pathogenesis of allergic asthma by inhibition and/or enhancement of the production by CD4+ and CD8+ T cells of important cytokines promoting (i.e., IL-4 and IL-17) and/or inhibiting (i.e., IL-10 and TGF-ß), respectively, the development of allergic asthma. Studies using ovalbumin(OVA)-immunized mice have demonstrated that all the tested therapeutic strategies prevented the OVA-induced increase in the absolute number of IL-4- and IL-17-producing CD4+ T cells (i.e., Th2 and Th17 cells, respectively) indirectly, i.e., through the inhibition of the clonal expansion of these cells in the mediastinal lymph nodes. Additionally, the blockade of NF-κB translocation and RANKL/RANK interaction, but not IKK, prevented the OVA-induced increase in the percentage of IL-4-, IL-10- and IL-17-producing CD4+ T cells. These latter results strongly suggest that both therapeutic strategies can directly decrease IL-4 and IL-17 production by Th2 and Th17 cells, respectively. This action may constitute an important mechanism underlying the anti-asthmatic effect induced by the blockade of NF-κB translocation and of RANKL/RANK interaction. Thus, in this context, both these therapeutic strategies seem to have an advantage over the blockade of IKK. None of the tested therapeutic strategies increased both the absolute number and frequency of IL-10- and TGF-ß-producing Treg cells, and hence they lacked the potential to inhibit the development of the disease via this mechanism.

Metal-induced delayed type hypersensitivity responses potentiate particle induced osteolysis in a sex and age dependent manner.

It is widely recognized that innate macrophage immune reactions to implant debris are central to the inflammatory responses that drive biologic implant failure over the long term. Less common, adaptive lymphocyte immune reactions to implant debris, such as delayed type hypersensitivity (DTH), can also affect implant performance. It is unknown which key patient factors, if any, mediate these adaptive immune responses that potentiate particle/macrophage mediated osteolysis. The objective of this investigation was to determine to what degree known adaptive immune responses to metal implant debris can affect particle-induced osteolysis (PIO); and if this pathomechanism is dependent on: 1) innate immune danger signaling, i.e., NLRP3 inflammasome activity, 2) sex, and/or 3) age. We used an established murine calvaria model of PIO using male and female wild-type C57BL/6 vs. Caspase-1 deficient mice as well as young (12-16 weeks old) vs. aged (18-24 months old) female and male C57BL/6 mice. After induction of metal-DTH, and Cobalt-alloy particle (ASTM F-75, 0.4um median diameter) calvaria challenge, bone resorption was assessed using quantitative micro-computed tomography (micro-CT) analysis and immune responses were assessed by measuring paw inflammation, lymphocyte transformation test (LTT) reactivity and adaptive immune cytokines IFN-gamma and IL-17 (ELISA). Younger aged C57BL/6 female mice exhibited the highest rate and severity of metal sensitivity lymphocyte responses that also translated into higher PIO compared to any other experimental group. The absence of inflammasome/caspase-1 activity significantly suppressed DTH metal-reactivity and osteolysis in both male and female Caspase-1 deficient mice. These murine model results indicate that young female mice are more predisposed to metal-DTH augmented inflammatory responses to wear debris, which is highly influenced by active NLRP3 inflammasome/caspase-1 danger signaling. If these results are clinically meaningful for orthopedic patients, then younger female individuals should be appropriately assessed and followed for DTH derived peri-implant complications.

Amoxicillin oral provocation challenge in a primary care clinic: a descriptive analysis.

BACKGROUND: Penicillin is the most frequently reported drug allergen; however, most of these allergies are not true allergies and do not justify the prescription of alternative, less effective and more expensive antibiotic drugs. We aimed to show that patients at low risk of amoxicillin allergy can safely and efficiently undergo oral provocation challenge (OPC) by their primary care physician. METHODS: In this descriptive analysis, we conducted a retrospective chart review of all primary care patients who had undergone OPC from November 2017 to October 2019 in the Amoxicillin Allergy Clinic at the North Perth Family Health Team, Listowel, Ontario. Eligibility for OPC among patients 18 months and older was determined through review of a self-reported patient intake form asking about symptoms, onset, duration, history and family history of allergic reactions, as well as the patient's electronic medical record. Patients were considered to be at low risk of true penicillin allergy if there was no history of anaphylaxis or severe cutaneous reactions. Those with low-risk allergic reactions returned for testing with an OPC to amoxicillin. We collected data on clinical characteristics, antibiotic exposure, parental drug allergy, response to OPC and wait time from referral. We used t tests to describe and compare these variables. Our primary outcome was reaction to OPC by severity as categorized by the World Allergy Organization grading system. Our secondary outcome was the time from referral to completed testing. RESULTS: In total, we included 99 patients (mean age 28.3, standard deviation [SD] 21.2 yr); 72 (73%) were female. Of those tested, 97% (n = 96) completed the OPC with no reaction, 3% (n = 3) had mild immediate reactions, and no serious immediate reactions developed. Mean wait time to testing was 59.0 (SD 69.8) days, with a median (interquartile range) of 39.5 (13.5-70.0) days. INTERPRETATION: Oral provocation challenge presents a safe and accessible opportunity for primary care providers to address erroneous allergy labels to penicillin and related drugs within the primary care office setting. There could be positive public health implications if OPC to penicillin drugs is implemented in primary care.

Hemodialysis Emergencies: Core Curriculum 2021.

Since maintenance hemodialysis (HD) first became available in the United States in 1962, there has been tremendous growth in the population of patients with kidney failure. HD has become a routine treatment carried out in outpatient clinics, hospitals, nursing facilities, and in patients' homes. Although it is a complex procedure, HD is quite safe. Serious complications are uncommon due to the use of modern HD machines and water treatment systems as well as the development of strict protocols to monitor various aspects of the HD treatment. The practicing nephrologist must be knowledgeable about life-threatening complications that can occur during HD and be able to recognize, manage, and prevent them. This installment in the AJKD Core Curriculum in Nephrology reviews the pathogenesis, management, and prevention of 9 HD emergencies. The HD emergencies covered include dialyzer reactions, dialysis disequilibrium syndrome, uremic/dialysis-associated pericarditis, air embolism, venous needle dislodgement, vascular access hemorrhage, hemolysis, dialysis water contamination, and arrhythmia episodes.

Whole-body vibration mediates mechanical hypersensitivity through Aß-fiber and C-fiber thermal sensation in a chronic pain model.

Whole-body vibration (WBV), which is widely used as a type of exercise, involves the use of vibratory stimuli and it is used for rehabilitation and sports performance programmes. This study aimed to investigate the effect of WBV treatment in a chronic pain model after 10 WBV sessions. An animal model (chronic pain) was applied in 60 male Wistar rats (±180 g, 12 weeks old) and the animals were treated with low intensity exercise (treadmill), WBV (vibrating platform), and a combined treatment involving both. The controls on the platform were set to a frequency of 42 Hz with 2 mm peak-to-peak displacement, g ≈ 7, in a spiral mode. Before and after the vibration exposure, sensitivity was determined. Aß-fibers-mediated mechanical sensitivity thresholds (touch-pressure) were measured using a pressure meter. C-fibers-mediated thermal perception thresholds (hot pain) were measured with a hot plate. After each session, WBV influenced the discharge of skin touch-pressure receptors, reducing mechanical sensitivity in the WBV groups (P < 0.05). Comparing the conditions "before vs. after", thermal perception thresholds (hot pain) started to decrease significantly after the third WBV session (P < 0.05). WBV decreases mechanical hyperalgesia after all sessions and thermal sensitivity after the third session with the use of WBV.

The real-world "ControL'Asma" study: a nationwide taskforce on asthma control in children and adolescents.

BACKGROUND: Asthma control is the goal of asthma management. A nationwide study on this aspect was launched by the Italian Society of Paediatric Allergy and Immunology (ControL'Asma study). OBJECTIVE: To define variables associated with different asthma control grades in a nationwide population of asthmatic children and adolescents. METHODS: This cross-sectional real-world study included 480 asthmatic children and adolescents (333 males, median age 11.2 years) consecutively enrolled in 10 third level pediatric allergy clinics. According to the Global Initiative for Asthma (GINA) document, history, medication use, perception of asthma symptoms assessed by visual analog scale (VAS), clinical examination, lung function, childhood asthma control test (cACT)/asthma control test (ACT), and asthma control level were evaluated. RESULTS: Considering GINA criteria, asthma was well controlled in 55% of patients, partly controlled in 32.4%, and uncontrolled in 12.6%. Regarding cACT/ACT, asthma was uncontrolled in 23.2%. Patients with uncontrolled asthma had the lowest lung function parameters and VAS scores, more frequent bronchial obstruction and reversibility, and used more oral and inhaled corticosteroids (CS). CONCLUSIONS: The ControL'Asma study, performed in a real-world setting, showed that asthma in Italian children and adolescents was usually more frequent in males. Asthmatic patients had an early onset and allergic phenotype with very frequent rhinitis comorbidity. Uncontrolled and partly controlled asthma affected about half of the subjects, and the assessment of asthma symptom perception by VAS could be a reliable tool in asthma management.

No difference in omalizumab efficacy in patients with asthma by number of asthma-related and allergic comorbidities.

BACKGROUND: Comorbidities are common in asthma and may complicate treatment response. OBJECTIVE: To examine response to omalizumab in patients with moderate-to-severe allergic asthma by asthma-related and allergic comorbidities. METHODS: Patients aged 12 years or more from placebo-controlled 008/009 (n = 1071), EXTRA (n = 848), and INNOVATE (n = 419), and single-armed PROSPERO (n = 801) omalizumab studies were included. Poisson regression/analysis of covariance models were used to estimate adjusted exacerbation rates and forced expiratory volume in 1 second (FEV1) change from baseline after omalizumab initiation for subgroups by number of comorbidities (0, 1 [008/009]; 0, 1, ≥2 [EXTRA and INNOVATE]; 0, 1, 2, ≥3 [PROSPERO]). Self-reported comorbidities included allergic rhinoconjunctivitis, chronic rhinosinusitis, recurrent acute sinusitis, nasal polyps, atopic and contact dermatitis, urticaria, food allergy, anaphylaxis, other allergies, gastroesophageal reflux disease, eosinophilic esophagitis, and eosinophilic granulomatosis with polyangiitis. RESULTS: In the EXTRA and INNOVATE studies, no consistent pattern was observed for placebo-corrected relative rate reduction in normalized asthma exacerbations among omalizumab-treated comorbidity subgroups. In PROSPERO, on-study exacerbation rates in the comorbidity subgroups were similar (0, 0.68; 1, 0.70; 2, 0.77; ≥3, 0.80). FEV1 improvements were observed throughout the study for omalizumab vs placebo for all comorbidity subgroups. There were no consistent differences in FEV1 improvements among comorbidity subgroups in 008/009, EXTRA, or INNOVATE. Similarly, no among-group differences were observed for FEV1 change from baseline at month 12 in PROSPERO (0, 0.05 L; 1, 0.08 L; 2, 0.00 L; ≥3, 0.04 L). The 95% confidence intervals overlapped substantially in all instances. CONCLUSION: In these analyses of placebo-controlled/single-armed studies, on-study exacerbation rates and FEV1 improvements with omalizumab treatment were similar irrespective of comorbidity burden. TRIAL REGISTRATION: ClinicalTrials.gov identifiers are as follows: EXTRA, NCT00314574 (https://clinicaltrials.gov/ct2/show/NCT00314574); INNOVATE, NCT00046748 (https://clinicaltrials.gov/ct2/show/NCT00046748); and PROSPERO, NCT01922037 (https://clinicaltrials.gov/ct2/show/NCT01922037).

Disulfide disruption reverses mucus dysfunction in allergic airway disease.

Airway mucus is essential for lung defense, but excessive mucus in asthma obstructs airflow, leading to severe and potentially fatal outcomes. Current asthma treatments have minimal effects on mucus, and the lack of therapeutic options stems from a poor understanding of mucus function and dysfunction at a molecular level and in vivo. Biophysical properties of mucus are controlled by mucin glycoproteins that polymerize covalently via disulfide bonds. Once secreted, mucin glycopolymers can aggregate, form plugs, and block airflow. Here we show that reducing mucin disulfide bonds disrupts mucus in human asthmatics and reverses pathological effects of mucus hypersecretion in a mouse allergic asthma model. In mice, inhaled mucolytic treatment loosens mucus mesh, enhances mucociliary clearance, and abolishes airway hyperreactivity (AHR) to the bronchoprovocative agent methacholine. AHR reversal is directly related to reduced mucus plugging. These findings establish grounds for developing treatments to inhibit effects of mucus hypersecretion in asthma.

Unconjugated bilirubin is associated with protection from early-life wheeze and childhood asthma.

BACKGROUND: Wheeze and allergic sensitization are the strongest early-life predictors of childhood asthma development; the molecular origins of these early-life phenotypes are poorly understood. OBJECTIVES: We sought to identify metabolites associated with early-life wheeze, allergic sensitization, and childhood asthma. METHODS: We conducted a nested case-control study using Environmental influences on Child Health Outcomes Program cohorts for discovery and independent replication. Wheeze and allergic sensitization were defined by number of wheeze episodes and positive specific IgE at age 1 year, respectively. Asthma was defined as physician diagnosis of asthma at age 5 or 6 years. We used untargeted metabolomics, controlling for observed and latent confounding factors, to assess associations between the plasma metabolome and early-life wheeze, allergy, and childhood asthma. RESULTS: Eighteen plasma metabolites were associated with first-year wheeze in the discovery cohort (n = 338). Z,Z unconjugated bilirubin (UCB) and its related metabolites exhibited a dose-response relationship with wheeze frequency; UCB levels were 13% (ß = 0.87; 95% CI, 0.74-1.02) and 22% (ß = 0.78; 95% CI, 0.68-0.91) lower in children with 1 to 3 and 4+ wheeze episodes compared with those who never wheezed, respectively. UCB levels were also associated with childhood asthma (ß = 0.82; 95% CI, 0.68-0.98). Similar trends were observed in 2 independent cohorts. UCB was significantly negatively correlated with eicosanoid- and oxidative stress-related metabolites. There were no significant associations between metabolites and allergic sensitization. CONCLUSIONS: We identified a novel inverse, dose-dependent association between UCB and recurrent wheeze and childhood asthma. Inflammatory lipid mediators and oxidative stress byproducts inversely correlated with UCB, suggesting that UCB modulates pathways critical to the development of early-life recurrent wheeze and childhood asthma.

Exhaled TGF-ß1 levels before and after an exercise challenge in asthmatic and healthy children, and during exacerbation.

BACKGROUND: There is conflicting data regarding the role of transforming growth factor-ß1 (TGF-ß1) in the pathogenesis of airway hyper-reactivity and asthma exacerbation. OBJECTIVE: To investigate the role of exhaled-TGF-ß1 in exercise-induced bronchospasm (EIB) in asthmatic and nonasthmatic healthy children, and in asthma exacerbation and asthma control. METHODS: The exhaled-TGF-ß1 levels of 56 stable asthmatic children and 15 nonasthmatic healthy children were evaluated before and 30 min after an exercise challenge. The exhaled-TGF-ß1 levels of 20 additional children with asthma exacerbation were evaluated. RESULTS: While no significant difference in the exhaled-TGF-ß1 levels was found at the baseline, exhaled-TGF-ß1 levels after the exercise challenge were significantly higher in the non-EIB (n = 31) asthmatics when compared to the asthmatic children with EIB (n = 25) (p = 0.04). Although there was a statistically significant increase in the concentration of the exhaled-TGF-ß1 after the exercise challenge in the non-EIB asthmatics (p = 0.008), the concentration of the TGF-ß1 was not increased after the exercise challenge in EIB + asthmatics. The exhaled-TGF-ß1 was significantly correlated with the ACT score (p = 0.01, r = 0.49) and the baseline FEV1 level (p = 0.02, r = 0.35). The exhaled-TGF-ß1 levels were significantly higher in the stable asthmatic children when compared to the nonasthmatic children (p < 0.0001). There was no significant difference in exhaled-TGF-ß1 levels after the exercise challenge in the nonasthmatics. The exhaled-TGF-ß1 levels were significantly lower in those children with asthma exacerbation when compared to the stable asthmatic children (p = 0.0003). CONCLUSION: Our results suggest that TGF-ß1 may play a role in suppressing airway reactivity and its deficiency is associated with asthma exacerbation.

The sensitivity and specificity of the forced oscillation technique in the diagnosis of bronchoconstriction in children.

OBJECTIVE: The forced oscillation technique (FOT) is a useful diagnostic respiratory system for children. However, the final value of the FOT in the diagnosis of bronchoconstriction is still open. The aim of the study was to evaluate the sensitivity and specificity of the FOT vs. body plethysmography tests in the measure of bronchoconstriction in asthmatic children. MATERIALS AND METHODS: A total of 102 children aged 2 to 6 years diagnosed with early-onset asthma and 52 healthy controls were included in this prospective, randomized study. All asthmatic patients and healthy controls underwent a basic FOT as one measurement, according to the recommendation of the Resmon Pro FOT. Then, the reversibility test was performed 20 min after the administration of 200 mg salbutamol using the FOT and body plethysmography in all patients. RESULTS: The mean basic Rrs, Xrs and sRaw in asthmatic patients were, respectively, 11.13 ± 1.28 kPa sL-1, -4.6 ± 1.18 kPa sL-1 and 1.72 ± 0.58 kPa s. Similar parameters were significantly better in the control group (p < 0.05). A total of 73 (71.6%) asthmatic patients had a positive test using the FOT according to Calogero. In 4 (7.7%) patients in the control group, a positive test was obtained. In body plethysmography, similar results were reached, with a positive test in 76 (74.5%) study patients and 5 (9.6%) control patients. CONCLUSIONS: A bronchial reversibility test with the use of the FOT is useful for the diagnosis of bronchial asthma, especially with the use of an Rrs parameter, such as the body plethysmography test.