Wheeze Recognition Algorithm for Remote Medical Care Device in Children: Validation Study.

BACKGROUND: Since 2020, peoples' lifestyles have been largely changed due to the COVID-19 pandemic worldwide. In the medical field, although many patients prefer remote medical care, this prevents the physician from examining the patient directly; thus, it is important for patients to accurately convey their condition to the physician. Accordingly, remote medical care should be implemented and adaptable home medical devices are required. However, only a few highly accurate home medical devices are available for automatic wheeze detection as an exacerbation sign. OBJECTIVE: We developed a new handy home medical device with an automatic wheeze recognition algorithm, which is available for clinical use in noisy environments such as a pediatric consultation room or at home. Moreover, the examination time is only 30 seconds, since young children cannot endure a long examination time without crying or moving. The aim of this study was to validate the developed automatic wheeze recognition algorithm as a clinical medical device in children at different institutions. METHODS: A total of 374 children aged 4-107 months in pediatric consultation rooms of 10 institutions were enrolled in this study. All participants aged ≥6 years were diagnosed with bronchial asthma and patients ≤5 years had reported at least three episodes of wheezes. Wheezes were detected by auscultation with a stethoscope and recorded for 30 seconds using the wheeze recognition algorithm device (HWZ-1000T) developed based on wheeze characteristics following the Computerized Respiratory Sound Analysis guideline, where the dominant frequency and duration of a wheeze were >100 Hz and >100 ms, respectively. Files containing recorded lung sounds were assessed by each specialist physician and divided into two groups: 177 designated as "wheeze" files and 197 as "no-wheeze" files. Wheeze recognitions were compared between specialist physicians who recorded lung sounds and those recorded using the wheeze recognition algorithm. We calculated the sensitivity, specificity, positive predictive value, and negative predictive value for all recorded sound files, and evaluated the influence of age and sex on the wheeze detection sensitivity. RESULTS: Detection of wheezes was not influenced by age and sex. In all files, wheezes were differentiated from noise using the wheeze recognition algorithm. The sensitivity, specificity, positive predictive value, and negative predictive value of the wheeze recognition algorithm were 96.6%, 98.5%, 98.3%, and 97.0%, respectively. Wheezes were automatically detected, and heartbeat sounds, voices, and crying were automatically identified as no-wheeze sounds by the wheeze recognition algorithm. CONCLUSIONS: The wheeze recognition algorithm was verified to identify wheezing with high accuracy; therefore, it might be useful in the practical implementation of asthma management at home. Only a few home medical devices are available for automatic wheeze detection. The wheeze recognition algorithm was verified to identify wheezing with high accuracy and will be useful for wheezing management at home and in remote medical care.

Evaluation of oral immunotherapy efficacy and safety by maintenance dose dependency: A multicenter randomized study.

BACKGROUND: Generally, oral immunotherapy (OIT) aims for daily administration. Recently, the efficacy of treatment with OIT at a low dose has been reported. However, the optimal dose and the evaluation of dose-dependent OIT outcome have not been described. METHODS: A multicenter, parallel, open-labeled, prospective, non-placebo controlled, randomized study enrolled 101 Japanese patients for treatment with OIT. We hypothesized that target dose OIT would induce short-term unresponsiveness (StU) earlier than reduced dose OIT. StU was defined as no response to 6200 mg whole egg, 3400 mg milk, and 2600 mg wheat protein, as evaluated by oral food challenge after 2-week ingestion cessation. To compare the two doses of OIT efficacy, the maximum ingestion doses during the maintenance phase of OIT were divided into 100%-dose or 25%-dose groups against their target StU dose, respectively. A total of 51 patients were assigned to the 100%-dose group [hen's egg (HE) = 26, cow's milk (CM) = 13, wheat = 12] and 50 to the 25%-dose group (HE = 25, CM = 13, wheat = 12). Primary outcome was established by comparing StU at 1 year. Secondary outcome was StU at 2 years and established by comparing allergic symptoms and immunological changes. RESULTS: The year 1 StU rates (%) for the 100%- and 25%-dose groups were 26.9 vs. 20.0 (HE), 7.7 vs. 15.4 (CM), and 50.0 vs. 16.7 (wheat), respectively. The year 2 StU rates were 30.8 vs. 36.0 (HE), 7.7 vs. 23.1 (CM), and 58.3 vs. 58.3 (wheat), respectively. There were no statistically significant differences in StU between years 1 and 2. The total allergic symptom rate in the 25%-dose group was lower than that in the 100%-dose group for egg, milk, and wheat. Antigen-specific IgE levels for egg-white, milk, and wheat decreased at 12 months. CONCLUSIONS: Reduced maintenance dose of egg OIT showed similar therapeutic efficacy to the target dose. However, we were not able to clearly demonstrate the efficacy, particularly for milk and wheat. Reducing the maintenance dose for eggs, milk, and wheat may effectively lower the symptoms associated with their consumption compared to the target OIT dose. Furthermore, aggressive reduction of the maintenance dose might be important for milk and wheat, compared to the 25%-dose OIT. TRIAL REGISTRATION: UMIN000009373, Multicenter Oral Immunotherapy for Hen's Egg, Cow's Milk, and Wheat-Allergic Children at Outpatient Clinic.

Long-term safety, efficacy, pharmacokinetics and pharmacodynamics of omalizumab in children with severe uncontrolled asthma.

BACKGROUND: Omalizumab is effective and well-tolerated in children with moderate to severe allergic asthma. However, the effects of long-term treatment with omalizumab in this population haven't been well investigated. The objective of this study is to evaluate the long-term safety, efficacy, pharmacokinetics and pharmacodynamics of omalizumab in children with uncontrolled severe asthma. METHODS: Thirty-eight Japanese children (aged 7-16 years) who completed the 24-week treatment core study were included in an uncontrolled extension study, in which treatment with omalizumab continued until the pediatric indication was approved in Japan (ClinicalTrials.gov number: NCT01328886). RESULTS: Thirty-five patients (92.1%) completed the extension study. The median exposure throughout the core and extension studies was 116.6 weeks (range, 46.9-151.1 weeks). The most common adverse events were nasopharyngitis, influenza, upper respiratory tract infection, and asthma. Serious adverse events developed in 10 patients (26.3%), but resolved completely with additional treatments. Incidence of adverse events didn't increase with extended exposure with omalizumab. Twenty-nine patients (76.3%) achieved completely- or well-controlled asthma compared with 9 patients (23.7%) at the start of the extension study. QOL scores, the rates (per year) of hospitalizations and ER visits were significantly improved compared with the baseline of the core study [39.0 vs 48.0 (median), p < 0.001 for QOL, 1.33 vs 0.16, p < 0.001 for hospitalization, 0.68 vs 0.15, p = 0.002 for ER visits]. Remarkably, the mean total IgE level showed a decreasing trend while exposure to omalizumab remained at steady-state. CONCLUSIONS: Long-term treatment with omalizumab is well-tolerated and effective in children with uncontrolled severe allergic asthma. No new safety findings were identified.

MIP-1α level in nasopharyngeal aspirates at the first wheezing episode predicts recurrent wheezing.

BACKGROUND: Respiratory virus-induced wheezing, such as that induced by respiratory syncytial virus (RSV) and human rhinovirus, is an important risk factor for recurrent wheezing and childhood asthma. However, no biomarkers for predicting recurrent wheezing have been identified. OBJECTIVE: We searched for predictors of recurrent wheezing using nasopharyngeal aspirates obtained from patients during the first wheezing episode who were hospitalized with an acute lower respiratory tract illness. METHODS: We enrolled 82 infants during the first wheezing episode (median age, 5.0 months) who were hospitalized for acute lower respiratory tract illness between August 2009 and June 2012 and followed these patients for 2.5 years. Nasopharyngeal aspirates and blood samples were obtained on the first day of hospitalization. Viral genomes were identified by using RT-PCR and sequencing. Levels of 33 cytokines, tryptase, IgE, anti-RSV IgE, and anti-RSV IgG were measured by using ELISAs or the Bio-Plex multiplex assay. Predictors of recurrent wheezing were examined by using a stepwise logistic regression model with backward elimination. RESULTS: Sixty percent of the patients experienced recurrent wheezing episodes. One or more viruses were detected in the nasopharynxes of 93% of the patients during the first wheezing episode. IFN-γ, IL-2, IL-9, MIP-1α, and MIP-1ß levels were significantly higher among patients with recurrent wheezing than among those without recurrent wheezing (P < .05 or .01). The stepwise model demonstrated that the MIP-1α level (odds ratio, 7.72; 95% CI, 1.50-39.77; P = .015) was the strongest independent predictor of the occurrence of recurrent wheezing. CONCLUSION: An increased MIP-1α level in nasopharyngeal aspirates from patients with acute respiratory symptoms during the first wheezing episode caused by viral infections might predict recurrent wheezing.

Omalizumab in Japanese children with severe allergic asthma uncontrolled with standard therapy.

BACKGROUND: Omalizumab has demonstrated clinical benefits in children with moderate to severe allergic asthma. However, no studies have been performed in Japanese asthmatic children. The aim of this study was to evaluate the efficacy including free IgE suppression and safety of omalizumab in Japanese children with severe allergic asthma. The primary objective was to examine whether omalizumab decreases serum free IgE levels to less than 25 ng/ml (target level of suppression). METHODS: Thirty-eight Japanese children (6-15 years) with uncontrolled severe allergic asthma despite inhaled corticosteroids (>200 µg/day fluticasone propionate or equivalent) and two or more controller therapies received add-on treatment with omalizumab in a 24-week, multicenter, uncontrolled, open-label study. RESULTS: The geometric mean serum free IgE level at 24 weeks was 15.6 ng/mL. Compared with baseline, total asthma symptom scores, daily activity scores and nocturnal sleep scores at 24 weeks were significantly improved. The rates of asthma exacerbation and hospitalization due to asthma were reduced by 69.2% and 78.2%, respectively (p < 0.001), versus baseline. Quality-of-life scores were also significantly improved (p < 0.001). In addition, 11 (28.9%) patients reduced the dose of any asthma controller medications. Thirty-six (94.7%) patients experienced at least one adverse event during the treatment period. All adverse events were mild or moderate in severity and no new safety concerns were detected. No patients discontinued the study. CONCLUSIONS: In Japanese children with severe allergic asthma, omalizumab decreased free IgE levels to less than 25 ng/mL. Omalizumab improved asthma control and was well-tolerated, as well.

Molecular evolution of the VP1, VP2, and VP3 genes in human rhinovirus species C.

Human rhinovirus species C (HRV-C) was recently discovered, and this virus has been associated with various acute respiratory illnesses (ARI). However, the molecular evolution of the major antigens of this virus, including VP1, VP2, and VP3, is unknown. Thus, we performed complete VP1, VP2, and VP3 gene analyses of 139 clinical HRV-C strains using RT-PCR with newly designed primer sets and next-generation sequencing. We assessed the time-scale evolution and evolutionary rate of these genes using the Bayesian Markov chain Monte Carlo method. In addition, we calculated the pairwise distance and confirmed the positive/negative selection sites in these genes. The phylogenetic trees showed that the HRV-C strains analyzed using these genes could be dated back approximately 400 to 900 years, and these strains exhibited high evolutionary rates (1.35 to 3.74 × 10(-3) substitutions/site/year). Many genotypes (>40) were confirmed in the phylogenetic trees. Furthermore, no positively selected site was found in the VP1, VP2, and VP3 protein. Molecular modeling analysis combined with variation analysis suggested that the exterior surfaces of the VP1, VP2 and VP3 proteins are rich in loops and are highly variable. These results suggested that HRV-C may have an old history and unique antigenicity as an agent of various ARI.

Severity of respiratory signs and symptoms and virus profiles in Japanese children with acute respiratory illness.

Associations between the severity of respiratory signs and symptoms and the respiratory viruses identified in 214 Japanese children with acute respiratory illness (ARI) enrolled between January and December 2012 were studied. Respiratory rate, wheezing, cyanosis, and the use of accessory muscles were used as indices of respiratory severity and phylogenetic analysis of the viruses identified in these children was performed. Respiratory viruses such as respiratory syncytial virus (RSV), human rhinovirus (HRV), human parainfluenza virus (HPIV), and human metapneumovirus (HMPV) were prevalent, being detected in approximately 70% of the patients (151/214 patients). Co-detection of viruses occurred in about 9% of patients. RSV was identified more frequently in cases scored as moderate/severe than in those scored as mild (P < 0.05). Severity scores of patients with RSV were significantly higher than those of cases with HPIV. Moreover, severity scores in patients with mild disease and co-detections were higher than in those in whom only HPIV or adenovirus was detected. Phylogenetic analysis showed that many genotypes of HRV-A and -C with wide genetic divergence were associated with acute respiratory illness (ARI). On the other hand, only a limited number of genotypes of RSV were associated with ARI. HPIV and HMPV were associated with ARI at similar frequencies. These results suggest that different respiratory viruses with unique genetic characteristics can be found in patients with mild to severe ARI.

Genetic analysis of attachment glycoprotein (G) gene in new genotype ON1 of human respiratory syncytial virus detected in Japan.

We studied the evolution of the G gene in the new genotype ON1 of RSV detected from patients with acute respiratory infection in Japan. Phylogenetic analyses and the evolutionary timescale were obtained by the Bayesian MCMC method. We also analyzed p-distance and positive selection sites. A new genotype ON1 emerged around 2001. The evolution rate was rapid (3.57 × 10(-3) substitutions/site per year). The p-distance was short and no positive selection site was found in the present strains. These results suggested that a new genotype ON1 of RSV-A emerged approximately10 years ago and spread to some countries with a high evolution rate.

A molecular epidemiological study of respiratory viruses detected in Japanese children with acute wheezing illness.

BACKGROUND: Recent studies strongly suggest that some respiratory viruses are associated with the induction of acute wheezing and/or exacerbation of bronchial asthma. However, molecular epidemiology of these viruses is not exactly known. METHODS: Using PCR technology, we attempted to detect various respiratory viruses from 115 Japanese children. Furthermore, the detected viruses were subjected to homology, pairwise distance, and phylogenetic analysis. RESULTS: Viruses were detected from 99 (86.1%) patients. Respiratory syncytial virus (RSV) alone and human rhinovirus (HRV) alone were detected in 47 (40.9%) and 36 (31.3%) patients, respectively. Both RSV and HRV were detected in 14 (12.2%) patients. Human metapneumovirus (HMPV) alone and human parainfluenza virus (HPIV) alone were detected in 1 (0.9%) patient each, respectively. Homology and phylogenetic analyses showed that the RSV and HRV strains were classified into genetically diverse species or subgroups. In addition, RSV was the dominant virus detected in patients with no history of wheezing, whereas HRV was dominant in patients with a history of wheezing. CONCLUSIONS: The results suggested that these genetically diverse respiratory viruses, especially RSV and HRV, might be associated with wheezing in Japanese children.

Genotyping and phylogenetic analysis of the major genes in respiratory syncytial virus isolated from infants with bronchiolitis.

We performed the genotyping and phylogenetic analysis of respiratory syncytial virus (RSV) isolated from 17 infants with bronchiolitis in Kanagawa Prefecture, Japan in 2005 and 2006. The major genes in these samples (attachment [G] glycoprotein gene, fusion [F] protein gene, and nucleoprotein [N] gene) were sequenced and analyzed genetically. Phylogenetic analysis of these genes revealed that 7 and 10 strains could be classified into subgroups A and B, respectively. Phylogenetic analysis of the G gene revealed that the subgroup A and B strains were unique genotypes GA2 and BA, respectively. Moreover, the amino acid sequences for these genotypes suggested a relatively high frequency of amino acid substitutions in the G and F proteins in these strains, whereas the N protein was highly homologous. These results suggest that RSV genotypes GA2 and BA may be associated with bronchiolitis in the cases studied here.

Acute allergic reaction due to milk proteins contaminating lactose added to corticosteroid for injection.

We encountered two patients with severe cow's milk allergy who reacted strongly to an injection of methylprednisolone sodium succinate (Sol-Medrol 40 mg Pfizer, Japan). They came to our hospital because of an asthmatic attack or urticaria and were treated with Sol-Medrol 40 mg. After the injection, the allergic reaction was immediate. Skin prick tests demonstrated that the beta-lactoglobulin contaminating the lactose of the drug preparation caused the immediate allergic reaction.

Dermal testing of vaccines for children at high risk of allergies.

Vaccinations for children with allergic diseases often need to be postponed or terminated because of the presumed risk of an immediate-type allergic reaction such as anaphylaxis. A new skin test protocol for predicting allergic reactions using the vaccine itself and the following stepwise vaccination method were developed and tested. Intradermal tests using 1:10 and 1:100 diluted measles vaccine indicated that the former was superior to the latter because a positive reaction against 1:10 diluted vaccine was found in 28.6% of 49 patients with severe allergic diseases including bronchial asthma, atopic dermatitis, food allergies and allergies to two or more allergens with high levels of IgE, as compared with the reaction against 1:100 diluted vaccine in 10.2% of the patients. Patients negative for 1:10 skin tests were safe from the following full-dose vaccine shots. Three patients showed very strong local reactions against measles vaccine, and avoided receiving the following full-dose shot. Positive reactions to skin tests of 1:10 diluted vaccine were found in 11 patients, who were given stepwise vaccinations. Three patients had adverse reactions, and two of them had been negative for 1:100 skin tests. In the case of influenza vaccine, skin tests were again more sensitive to 1:10 than to 1:100 diluted vaccine, because 3 out of 14 patients with positive reactions showed immediate-type adverse reactions against the following stepwise vaccinations, and 1 of them was negative for the 1:100 skin test. Moreover, the results of the skin prick test (undiluted vaccine) and the intradermal skin test (1:10 diluted vaccine) indicated that the latter was more useful in both cases of measles (54 patients) and influenza vaccine (69 patients). Overall, the skin test using 1:10 diluted vaccine was the more suitable for predicting an immediate-type reaction to measles and influenza vaccinations. Patients having negative 1:10 skin tests can be expected to show no adverse reactions to the remaining injections and even the positive subjects will complete the course of vaccine doses by the stepwise method.

Neonatal periventricular leukomalacia due to severe, poorly controlled asthma in the mother.

BACKGROUND: We report a neonatal case of cystic periventricular leukomalacia (PVL) in which the hypoxia was considered to have been caused by severe asthma in the mother, who had not taken any medication during pregnancy because she was anxious about its possible effects on her unborn child. METHODS: After the mother had severe exacerbation of asthma for five days, the baby was born at 36 weeks in gestation, weighing 2100 g, and with moderate asphyxia. Although the baby had been aggressively treated in a neonatal intensive care unit, at birth, an ischemic area had been formed in the periventricular areas in the brain echogram. We suspected that she had severe brain damage due to prenatal hypoxia. RESULTS: The baby was found to have cystic PVL by ultrasonography at age 15 days, and diplegia at age 4 months. CONCLUSIONS: The poorly controlled, persistent and severe asthma of the mother may have caused prenatal hypoxia, resulting in the cystic PVL and lower limb palsy. Pregnant patients with poorly controlled asthma should be advised of the great risk of this condition to the fetus. Also, patients should be assured of the safety of modern asthma treatments.