Quabodepistat in combination with delamanid and bedaquiline in participants with drug-susceptible pulmonary tuberculosis: protocol for a multicenter, phase 2b/c, open-label, randomized, dose-finding trial to evaluate safety and efficacy.

BACKGROUND: Delamanid and bedaquiline are two of the most recently developed antituberculosis (TB) drugs that have been extensively studied in patients with multidrug-resistant TB. There is currently a need for more potent, less-toxic drugs with novel mechanisms of action that can be used in combination with these newer agents to shorten the duration of treatment as well as prevent the development of drug resistance. Quabodepistat (QBS) is a newly discovered inhibitor of decaprenylphosphoryl-ß-D-ribose-2'-oxidase, an essential enzyme for Mycobacterium tuberculosis to synthesize key components of its cell wall. The objective of this study is to evaluate the safety, efficacy, and appropriate dosing of a 4-month regimen of QBS in combination with delamanid and bedaquiline in participants with drug-susceptible pulmonary TB in comparison with the 6-month standard treatment (i.e., rifampicin, isoniazid, ethambutol, and pyrazinamide). METHODS: This phase 2b/c, open-label, randomized, parallel group, dose-finding trial will enroll approximately 120 participants (including no more than 15% with human immunodeficiency virus [HIV] coinfection) aged ≥ 18 to ≤ 65 years at screening with newly diagnosed pulmonary drug-sensitive TB from ~8 sites in South Africa. Following a screening period of up to 14 days, eligible participants will be randomized in a ratio of 1:2:2:1 to one of four arms. Randomization will be stratified by HIV status and the presence of bilateral cavitation on a screening chest x-ray. After the end of the treatment period, participants will be followed until 12 months post randomization. The primary efficacy endpoint is the proportion of participants achieving sputum culture conversion in Mycobacteria Growth Indicator Tube by the end of the treatment period. The safety endpoints consist of adverse events, clinical laboratory tests, vital signs, physical examination findings, and electrocardiographic changes. DISCUSSION: QBS's potent bactericidal activity and distinct mechanism of action (compared with other TB drugs currently available for human use) may make it an ideal candidate for inclusion in a novel treatment regimen to improve efficacy and potentially prevent resistance to concomitant TB drugs. This trial will assess the effectiveness, safety, and dosing of a new, shorter, QBS-based, combination anti-TB treatment regimen. TRIAL STATUS: ClinicalTrials.gov NCT05221502. Registered on February 3, 2022.

Ultrasensitive detection of CA125 based on a triple signal amplification strategy with a huge number of loaded probes via exonuclease cyclic cleavage, rolling cyclic amplification and strand self-growth.

A novel electrochemiluminescence (ECL) aptamer biosensor with high sensitivity and selectivity for the detection of tumor biomarker carbohydrate antigen 125 (CA125) was constructed, and a strategy of triple amplification of signals was proposed using an exonuclease cyclic cleavage aptamer, combined with rolling ring amplification technologies, generating multi-branched dendritic double-stranded DNA to load a large number of probes through "strand self-growth". The double-stranded DNA, which is abbreviated as CP/CA dsDNA, formed by hybridizing the single strand of capture DNA (CP DNA) with the single strand DNA of the CA125 aptamer (CA Apt) was modified on Fe3O4@Au. When CA125 was added, CP/CA dsDNA was unwound, and CA125 specifically combined with CA Apt to form a protein-aptamer complex, leaving only CP DNA on the surface of Fe3O4@Au. RecJf exonuclease cleaved the aptamer in the protein-aptamer complex and released CA125, which recombined with other CA125 aptamers, to form a cycle that produces more CP DNA on Fe3O4@Au. Three ssDNA (H1, H2, and H3) were introduced and hybridized with CP DNA to form a dsDNA with a "+" configuration structure. Then phi29 DNA polymerase, T4 DNA ligase, deoxy-ribonucleoside triphosphate (dNTP) and padlock probes were added to form a large number of complementary strands of padlock probes (CS padlock probes) by rolling cyclic amplification. CS padlock probes were linked to the "+" type dsDNA; then ssDNA H4 was added and hybridized with the CS padlock probe to form multi-branched dendritic dsDNA. A large number of tris(2,2'-bipyridyl)ruthenium(II) probes were embedded in the double strands, resulting in an extremely strong ECL signal in the presence of the co-reactant tri-n-propylamine (TPA). There is a linear relationship between the ECL signals and CA125 concentrations in the range of 1.0 × 10-15-1.0 × 10-8 mg mL-1, and the detection limit was 2.38 × 10-16 mg mL-1. It has been used for the determination of CA125 in serum samples.

Phase I Single Ascending Dose and Food Effect Study in Healthy Adults and Phase I/IIa Multiple Ascending Dose Study in Patients with Pulmonary Tuberculosis to Assess Pharmacokinetics, Bactericidal Activity, Tolerability, and Safety of OPC-167832.

OPC-167832, an inhibitor of decaprenylphosphoryl-ß-d-ribose 2'-oxidase, demonstrated potent antituberculosis activity and a favorable safety profile in preclinical studies. This report describes the first two clinical studies of OPC-167832: (i) a phase I single ascending dose (SAD) and food effects study in healthy participants; and (ii) a 14-day phase I/IIa multiple ascending dose (MAD; 3/10/30/90 mg QD) and early bactericidal activity (EBA) trial in participants with drug-susceptible pulmonary tuberculosis (TB). OPC-167832 was well tolerated at single ascending doses (10 to 480 mg) in healthy participants and multiple ascending doses (3 to 90 mg) in participants with TB. In both populations, nearly all treatment-related adverse events were mild and self-limiting, with headache and pruritus being the most common events. Abnormal electrocardiograms results were rare and clinically insignificant. In the MAD study, OPC-167832 plasma exposure increased in a less than dose-proportional manner, with mean accumulation ratios ranging from 1.26 to 1.56 for Cmax and 1.55 to 2.01 for area under the concentration-time curve from 0 to 24 h (AUC0-24h). Mean terminal half-lives ranged from 15.1 to 23.6 h. Pharmacokinetics (PK) characteristics were comparable to healthy participants. In the food effects study, PK exposure increased by less than ~2-fold under fed conditions compared to the fasted state; minimal differences were observed between standard and high-fat meals. Once-daily OPC-167832 showed 14-day bactericidal activity from 3 mg (log10 CFU mean ± standard deviation change from baseline; -1.69 ± 1.15) to 90 mg (-2.08 ± 0.75), while the EBA of Rifafour e-275 was -2.79 ± 0.96. OPC-167832 demonstrated favorable pharmacokinetic and safety profiles, as well as potent EBA in participants with drug-susceptible pulmonary TB.

Determining the Delamanid Pharmacokinetics/Pharmacodynamics Susceptibility Breakpoint Using Monte Carlo Experiments.

Antimicrobial susceptibility testing, based on clinical breakpoints that incorporate pharmacokinetics/pharmacodynamics (PK/PD) and clinical outcomes, is becoming a new standard in guiding individual patient therapy as well as for drug resistance surveillance. However, for most antituberculosis drugs, breakpoints are instead defined by the epidemiological cutoff values of the MIC of phenotypically wild-type strains irrespective of PK/PD or dose. In this study, we determined the PK/PD breakpoint for delamanid by estimating the probability of target attainment for the approved dose administered at 100 mg twice daily using Monte Carlo experiments. We used the PK/PD targets (0- to 24-h area under the concentration-time curve to MIC) identified in a murine chronic tuberculosis model, hollow fiber system model of tuberculosis, early bactericidal activity studies of patients with drug-susceptible tuberculosis, and population pharmacokinetics in patients with tuberculosis. At the MIC of 0.016 mg/L, determined using Middlebrook 7H11 agar, the probability of target attainment was 100% in the 10,000 simulated subjects. The probability of target attainment fell to 25%, 40%, and 68% for PK/PD targets derived from the mouse model, the hollow fiber system model of tuberculosis, and patients, respectively, at the MIC of 0.031 mg/L. This indicates that an MIC of 0.016 mg/L is the delamanid PK/PD breakpoint for delamanid at 100 mg twice daily. Our study demonstrated that it is feasible to use PK/PD approaches to define a breakpoint for an antituberculosis drug.

Sputum lipoarabinomannan (LAM) as a biomarker to determine sputum mycobacterial load: exploratory and model-based analyses of integrated data from four cohorts.

BACKGROUND: Despite the high global disease burden of tuberculosis (TB), the disease caused by Mycobacterium tuberculosis (Mtb) infection, novel treatments remain an urgent medical need. Development efforts continue to be hampered by the reliance on culture-based methods, which often take weeks to obtain due to the slow growth rate of Mtb. The availability of a "real-time" measure of treatment efficacy could accelerate TB drug development. Sputum lipoarabinomannan (LAM; an Mtb cell wall glycolipid) has promise as a pharmacodynamic biomarker of mycobacterial sputum load. METHODS: The present analysis evaluates LAM as a surrogate for Mtb burden in the sputum samples from 4 cohorts of a total of 776 participants. These include those from 2 cohorts of 558 non-TB and TB participants prior to the initiation of treatment (558 sputum samples), 1 cohort of 178 TB patients under a 14-day bactericidal activity trial with various mono- or multi-TB drug therapies, and 1 cohort of 40 TB patients with data from the first 56-day treatment of a standard 4-drug regimen. RESULTS: Regression analysis demonstrated that LAM was a predictor of colony-forming unit (CFU)/mL values obtained from the 14-day treatment cohort, with well-estimated model parameters (relative standard error ≤ 22.2%). Moreover, no changes in the relationship between LAM and CFU/mL were observed across the different treatments, suggesting that sputum LAM can be used to reasonably estimate the CFU/mL in the presence of treatment. The integrated analysis showed that sputum LAM also appears to be as good a predictor of time to Mycobacteria Growth Incubator Tube (MGIT) positivity as CFU/mL. As a binary readout, sputum LAM positivity is a strong predictor of solid media or MGIT culture positivity with an area-under-the-curve value of 0.979 and 0.976, respectively, from receiver-operator curve analysis. CONCLUSIONS: Our results indicate that sputum LAM performs as a pharmacodynamic biomarker for rapid measurement of Mtb burden in sputum, and thereby may enable more efficient early phase clinical trial designs (e.g., adaptive designs) to compare candidate anti-TB regimens and streamline dose selection for use in pivotal trials. Trial registration NexGen EBA study (NCT02371681).

Cumulative Fraction of Response for Once- and Twice-Daily Delamanid in Patients with Pulmonary Multidrug-Resistant Tuberculosis.

Pharmacokinetic (PK) and pharmacodynamic (PD) analyses were conducted to determine the cumulative fraction of response (CFR) for 100 mg twice-daily (BID) and 200 mg once-daily (QD) delamanid in patients with multidrug-resistant tuberculosis (MDR-TB), using a pharmacodynamic target (PDT) that achieves 80% of maximum efficacy. First, in the mouse model of chronic TB, the PK/PD index for delamanid efficacy was determined to be area under the drug concentration-time curve over 24 h divided by MIC (AUC0-24/MIC), with a PDT of 252. Second, in the hollow-fiber system model of tuberculosis, plasma-equivalent PDTs were identified as an AUC0-24/MIC of 195 in log-phase bacteria and 201 in pH 5.8 cultures. Third, delamanid plasma AUC0-24/MIC and sputum bacterial decline data from two early bactericidal activity trials identified a clinical PDT of AUC0-24/MIC of 171. Finally, the CFRs for the currently approved 100-mg BID dose were determined to be above 95% in two MDR-TB clinical trials. The CFR for the 200-mg QD dose, evaluated in a trial in which delamanid was administered as 100 mg BID for 8 weeks plus 200 mg QD for 18 weeks, was 89.3% based on the mouse PDT and >90% on the other PDTs. QTcF (QTc interval corrected for heart rate by Fridericia's formula) prolongation was approximately 50% lower for the 200 mg QD dose than the 100 mg BID dose. In conclusion, while CFRs of 100 mg BID and 200 mg QD delamanid were close to or above 90% in patients with MDR-TB, more-convenient once-daily dosing of delamanid is feasible and likely to have less effect on QTcF prolongation.

Factors related to disagreement between self-reported versus objective measurement of allergen sensitization at a tertiary pediatric center in Beijing, China.

BACKGROUND: The objectives of present study were to examine the level of disagreement between self-reported and objective measurement of sensitization to common inhalant allergens, and to explore the potential risk factors that might contribute to this discrepancy. METHODS: A total of 215 children were enrolled from pediatric clinics at a tertiary pediatric center in Beijing, China. A survey questionnaires regarding self-perceived sensitization was completed by participants' parents/caregiver, meanwhile, skin prick testing(SPT) was performed as objective assessment of sensitization. Extent of agreement between self-reported versus SPT-measured sensitization to individual allergen was calculated using Cohen's kappa (κ) coefficient. Multivariable regression analyses were used to determine the factors associated with discrepancy between self-reported and objective measurement of sensitization. RESULTS: 119(55.3%) patients have reported to be sensitized to at least one of inhalant allergen, whereas 167(77.7%) patients had a positive skin testing response. Agreement between self-perceived and actual aeroallergen sensitization was moderate for mites(κ = 0.518) and grass pollen mix(κ = 0.451), moreover, fair agreement was observed for mold(κ = 0.316) and cockroach(κ = 0.297), respectively. There was a least agreement between perceived and actual sensitization observed for pet dander, with a kappa coefficient of 0.005. Subjects' age, atopy history, ownership of pet may increase the risk of disagreement, moreover, background factors of informant, like: age, education level, and the relationship with enrolled subjects, were linked to the incidence of disagreement between self-reported sensitization in comparison with SPT results. CONCLUSION: Questionnaire-based self-assessment is easy way to collect clinical information on allergen sensitization; however, the accuracy of questionnaire-derived information is more likely to be influenced by respondent's background factors. The information from the questionnaire report is considered to be more reliable when in combination with objective assessment of sensitization, including blood IgE testing and SPT.

Lipoarabinomannan in sputum to detect bacterial load and treatment response in patients with pulmonary tuberculosis: Analytic validation and evaluation in two cohorts.

BACKGROUND: Lipoarabinomannan (LAM) is a major antigen of Mycobacterium tuberculosis (MTB). In this report, we evaluated the ability of a novel immunoassay to measure concentrations of LAM in sputum as a biomarker of bacterial load prior to and during treatment in pulmonary tuberculosis (TB) patients. METHODS AND FINDINGS: Phage display technology was used to isolate monoclonal antibodies binding to epitopes unique in LAM from MTB and slow-growing nontuberculous mycobacteria (NTM). Using these antibodies, a sandwich enzyme-linked immunosorbent assay (LAM-ELISA) was developed to quantitate LAM concentration. The LAM-ELISA had a lower limit of quantification of 15 pg/mL LAM, corresponding to 121 colony-forming units (CFUs)/mL of MTB strain H37Rv. It detected slow-growing NTMs but without cross-reacting to common oral bacteria. Two clinical studies were performed between the years 2013 and 2016 in Manila, Philippines, in patients without known human immunodeficiency virus (HIV) coinfection. In a case-control cohort diagnostic study, sputum specimens were collected from 308 patients (aged 17-69 years; 62% male) diagnosed as having pulmonary TB diseases or non-TB diseases, but who could expectorate sputum, and were then evaluated by smear microscopy, BACTEC MGIT 960 Mycobacterial Detection System (MGIT) and Lowenstein-Jensen (LJ) culture, and LAM-ELISA. Some sputum specimens were also examined by Xpert MTB/RIF. The LAM-ELISA detected all smear- and MTB-culture-positive samples (n = 70) and 50% (n = 29) of smear-negative but culture-positive samples (n = 58) (versus 79.3%; 46 positive cases by the Xpert MTB/RIF), but none from non-TB patients (n = 56). Among both LAM and MGIT MTB-culture-positive samples, log10-transformed LAM concentration and MGIT time to detection (TTD) showed a good inverse relationship (r = -0.803, p < 0.0001). In a prospective longitudinal cohort study, 40 drug-susceptible pulmonary TB patients (aged 18-69 years; 60% male) were enrolled during the first 56 days of the standard 4-drug therapy. Declines in sputum LAM concentrations correlated with increases of MGIT TTD in individual patients. There was a 1.29 log10 decrease of sputum LAM concentration, corresponding to an increase of 221 hours for MGIT TTD during the first 14 days of treatment, a treatment duration often used in early bactericidal activity (EBA) trials. Major limitations of this study include a relatively small number of patients, treatment duration up to only 56 days, lack of quantitative sputum culture CFU count data, and no examination of the correlation of sputum LAM to clinical cure. CONCLUSIONS: These results indicate that the LAM-ELISA can determine LAM concentration in sputum, and sputum LAM measured by the assay may be used as a biomarker of bacterial load prior to and during TB treatment. Additional studies are needed to examine the predictive value of this novel biomarker on treatment outcomes.

Delamanid: From discovery to its use for pulmonary multidrug-resistant tuberculosis (MDR-TB).

Tuberculosis (TB), caused by Mycobacterium tuberculosis (MTB), is the leading cause of death from an infectious disease globally. The widespread and ever-increasing resistance to TB drugs is reducing the effectiveness of treatment and jeopardizing TB control. New effective drugs with acceptable safety profiles are needed to turn the tide. Since the early 1990s, Otsuka Pharmaceutical Co., Ltd. has had a TB drug development program that resulted in the selection and development of delamanid (OPC-67683, Deltyba®), a first-in-class bicyclic nitroimidazole. Delamanid was initially approved by the European Medicines Agency (EMA) in 2014 for the treatment of adult pulmonary multi-drug resistant (MDR)-TB when an effective treatment regimen cannot otherwise be composed for reasons of resistance or tolerability. It has since been approved by several other countries/regions. In this review, we describe the history of delamanid's development, including the screening process, in vitro and in vivo characterization, as well as various clinical studies. Delamanid possesses potent activity against replicating, dormant, and intracellular MTB bacilli, and is bactericidal in mouse and guinea pig TB models. Delamanid resistance mechanisms have been attributed to genes in the F420-dependent deazaflavin nitroreductase bio-activation pathway, found in mycobacterium species but not in common bacterial or mammalian cells. Published susceptibility testing results from 744 clinical isolates from delamanid-naïve patients indicate that the natural resistance rate to delamanid is very low (1.3%). Delamanid is largely metabolized by albumin in serum, and to a much less extent by cytochrome P450 enzymes. Furthermore, it neither inhibits nor induces P450 enzymes. In terms of efficacy, delamanid demonstrated activity in an early bactericidal activity trial in drug susceptible pulmonary TB patients and increased 2-month sputum culture conversion rates when added to an optimized background regimen in MDR-TB patients in a phase 2b global clinical trial. In addition, recent results outside clinical studies show favourable responses in highly resistant TB patients including extensively drug resistant (XDR)-TB when treated with delamanid-containing regimens in routine programmatic settings. The primary safety concern with delamanid is QTcF interval prolongation, although this observation has thus far not been associated with any clinical cardiac events. Overall, delamanid appears to be a well-tolerated and safe anti-TB drug when compared to other drugs used to treat MDR-TB.

Mechanisms of resistance to delamanid, a drug for Mycobacterium tuberculosis.

Delamanid, a bicyclic nitroimidazooxazole, is effective against M. tuberculosis. Previous studies have shown that resistance to a bicyclic nitroimidazooxazine, PA-824, is caused by mutations in an F420-dependent bio-activation pathway. We investigated whether the same mechanisms are responsible for resistance to delamanid. Spontaneous resistance frequencies were determined using M. bovis BCG Tokyo (BCG) and M. tuberculosis H37Rv. F420 high-performance liquid chromatography (HPLC) elution patterns of homogenates of delamanid-resistant BCG colonies and two previously identified delamanid-resistant M. tuberculosis clinical isolates were examined, followed by sequencing of genes in the F420-dependent bio-activation pathway. Spontaneous resistance frequencies to delamanid were similar to those of isoniazid and PA-824. Four distinct F420 HPLC elution patterns were observed, corresponding to colonies with mutations on fgd1, fbiA, fbiB, and fbiC with no change in the ddn mutants from the wildtype. Complementation with the wildtype sequence of the mutated gene restored susceptibility. The two delamanid-resistant clinical isolates had ddn mutations and the wildtype F420 HPLC elution pattern. In conclusion, delamanid-resistant bacilli have mutations in one of the 5 genes in the F420-dependent bio-activation pathway with distinct F420 HPLC elution patterns. Both genetic and phenotypic changes may be considered in the development of a rapid susceptibility test for delamanid.

Clinical Course and Factors Associated with Asthma Control in Children under Control-based Asthma Management: A Prospective Study.

In the current study, we sought to track the clinical course of children under control-based asthma management and focused on respiratory pathogens monitoring. We prospectively explored influencing factors for asthma control. 121 children with uncontrolled asthma between 3-14 years of age were recruited. Common respiratory pathogens were detected with pharyngeal swabs and serum aeroallergen-specific IgE was measured. Numeric asthma control scores, airway resistance and fractional concentrations of exhaled nitric oxide (FENO) were evaluated. A proper control-based asthma management plan was established by the study physician. Regular reviews were performed, with the above measurements retested at set time intervals. The proportion of patients achieving asthma control at 1 month and 3 months were 59% and 76% ; respectively (p=0.013). These patients exhibited significant improvement in numeric scores and lung function parameters. The prevalence of common respiratory pathogens did not significantly differ between reviews. The number of sensitized aeroallergens significantly increased with age (r=0.235, p=0.010). Children with a high visual analogue scale (VAS) score for asthma at baseline were less likely to achieve asthma control after 1 month, while those sensitized to more aeroallergens were more likely to achieve asthma control after 1 month (p=0.016 and 0.012). In summary, children with asthma showed significant improvements in control rates and lung function during control-based asthma management, independent of respiratory pathogens testing reults. Patients with high VAS scores and fewer sensitizations to aeroallergens had difficulty achieving short-term asthma control.

Seasonal variation in circulating group 2 innate lymphoid cells in mugwort-allergic asthmatics during and outside pollen season.

BACKGROUND: Group 2 innate lymphoid cells (ILC2s) are a newly identified cell population with the potent capability to produce Th2-type cytokines in a non-antigen specific manner. Previous study demonstrated that enhanced circulating ILC2s in cat-allergic patient after experimental allergen challenge, whereas the effects of natural allergen exposure on peripheral ILC2s are still unclear. We therefore examined the variations in circulating ILC2s among asthmatic patients sensitized to different allergens in- and outside- pollen season. METHODS: 10 patients sensitized to mugwort, 10 patients sensitized to house dust mites (HDM) and 12 healthy controls were recruited into this study. Blood samples were collected from the patients in- and outside- pollens season, 2-3 months apart. ILC2s (Lin-CD127+ CRTH2+) were enumerated by flow cytometry, as well as intracellular IL-5 and IL-13 expression. The levels of IL-5 and IL-13 in supernatants of Lineage- and Lineage+ cells stimulated with IL-25 and/or IL-33 in the presence of IL-2 were measured using a Milliplex human cytokine array kit. RESULTS: An obvious seasonal increases in percentages of total and IL-13+ ILC2s were observed in patients with mugwort sensitization during natural pollen exposure, however, the percentages of peripheral ILC2s in HDM-allergic patients were not affected significantly. A positive correlation between FeNO and IL-13+ILC2s was found in patients sensitized to mugwort. A mixture of IL-33 and IL-25 induced a significant production of IL-13 and IL-5 from Lineage- cells of both mugwort-allergic and HDM-allergic asthmatics. Stimulation with IL-33 alone induced a significantly greater quantity of IL-13 by Lineage-cells from mugwort-allergic asthmatic compared with that from HDM-allergic asthmatics, whereas IL-25 induced a significantly greater amount of IL-5 by the Lineage-cells from mugwort-allergic asthmatic compared with that from HDM-allergic asthmatics. CONCLUSION: Within pollen season the frequencies and function profiles of circulating ILC2s among asthmatic children are altered dynamically, which may be closely related to the sensitized type of allergens.

Allergy march of Chinese children with infantile allergic symptoms: a prospective multi-center study.

BACKGROUND: Allergy march refers to progression of allergic diseases from infantile food allergy to the development of asthma and allergic rhinitis (AR). Evidence come mostly from studies in European countries. This study aimed to investigate allergy march in Chinese children with infantile food protein allergy (FPA) with a special focus on the effect of different formula interventions. METHODS: From 2008 to 2010, 153 infants diagnosed with FPA were recruited in five tertiary hospitals across China. They were randomly treated with amino-acid-based formula or soy-protein-based formula for a period of 3 months. Long-term follow-up was performed when they reached early school age, using questionnaires, physical examinations, and serum-specific immunoglobulin E. RESULTS: The overall follow-up rate was 73.20%. In patients who reached their early school years, the prevalence of physician-diagnosed AR and asthma were 43.75% and 23.21%, respectively. Only 40% of the subjects remained positive for food sensitizations upon follow-up. Twenty-six subjects receiving aeroallergen screening tests in infancy all proved negative, but upon follow-up, 65.57% were sensitized to aeroallergens (P=0.005). No significant difference between the effects of amino-acid-based formula and soy-protein-based formula on children's allergy march was observed. CONCLUSIONS: A high proportion (47.32%) of Chinese infants with early allergic symptoms developed respiratory allergies by their early school years. Most food-sensitized infants outgrew their condition several years later, but then aeroallergen sensitization often occurred. Amino-acid-based formula showed no advantages over soy protein-based formula with respect to arresting the allergy march.

MIC of Delamanid (OPC-67683) against Mycobacterium tuberculosis Clinical Isolates and a Proposed Critical Concentration.

The increasing global burden of multidrug-resistant tuberculosis (MDR-TB) requires reliable drug susceptibility testing that accurately characterizes susceptibility and resistance of pathogenic bacteria to effectively treat patients with this deadly disease. Delamanid is an anti-TB agent first approved in the European Union in 2014 for the treatment of pulmonary MDR-TB in adults. Using the agar proportion method, delamanid MIC was determined for 460 isolates: 316 from patients enrolled in a phase 2 global clinical trial, 76 from two phase 2 early bactericidal activity trials conducted in South Africa, and 68 isolates obtained outside clinical trials (45 from Japanese patients and 23 from South African patients). With the exception of two isolates, MICs ranged from 0.001 to 0.05 µg/ml, resulting in an MIC50 of 0.004 µg/ml and an MIC90 of 0.012 µg/ml. Various degrees of resistance to other anti-TB drugs did not affect the distribution of MICs, nor did origin of isolates from regions/countries other than South Africa. A critical concentration/breakpoint of 0.2 µg/ml can be used to define susceptible and resistant isolates based on the distribution of MICs and available pharmacokinetic data. Thus, clinical isolates from delamanid-naive patients with tuberculosis have a very low MIC for delamanid and baseline resistance is rare, demonstrating the potential potency of delamanid and supporting its use in an optimized background treatment regimen for MDR-TB.

[A comparision of the effects of subcutaneous and sublingual immunotherapy on immunological responses in children with asthma].

OBJECTIVE: To compare the difference in the effects of subcutaneous immunotherapy (SCIT) and sublingual immunotherapy (SLIT) on immunological responses in children with asthma. METHODS: A total of 86 children with asthma caused by dust mites were enrolled and divided into a SLIT group (n=29), a SCIT group (n=13), a group receiving complete SCIT course (complete SCIT group; n=14), and a group receiving conventional medication (control group, n=30). Peripheral blood mononuclear cells were isolated and stimulated with house dust mite extract for 48 hours in vitro, and the percentage of regulatory T cells (Treg%) in CD4+ T cells was measured by flow cytometry. Analysis of variance with repeated measures was applied to compare the changes in humoral immunological indices and therapeutic effects in the SCIT and SLIT groups before treatment and after 6 and 12 months of treatment. RESULTS: Before antigenic stimulation, Treg% in CD4(+) T cells in the SCIT group was significantly higher than that in the SLIT and control groups; after antigenic stimulation was given, Treg% in the four groups decreased significantly. After 6 and 12 months of immunotherapy, the SCIT group had significant changes in serum sIgE and sIgG4 levels, while the SLIT group only showed a significant change in serum sIgE level. CONCLUSIONS: Temporal difference exists in different immunotherapies to cause immunological responses in children with asthma, and immunological responses induced by SCIT may occur earlier.

[Related factors for asthmatic children's responses to long-term treatment].

OBJECTIVE: To study the changes in pulmonary function and fractional exhaled nitric oxide in exhaled breath (FeNO) in asthmatic children who have different responses to regular treatment. METHODS: A total of 52 asthmatic children who had a good compliance with regular stepped control treatment were selected as subjects. They were followed up every three months to evaluate the asthma control level, pulmonary ventilation function, and FeNO for 9 months. Besides, medications for asthma control were recorded. RESULTS: At three follow-up points (months 3, 6, and 9), the percentage of asthmatic children who used the first or the second level of control treatment in the stable group (with stable response to the treatment) was significantly higher than in the unstable group (with unstable response to the treatment) (P<0.05), while the percentage of asthmatic children who used the third level of control treatment in the stable group was significantly lower than in the unstable group (P<0.05). At the three follow-up points, the stable group had a significantly higher ratio of forced expiratory volume in 1 second to forced vital capacity (FEV1/FVC) than the unstable group (P<0.05); at the 3-month and 9-month follow-up points, the stable group had a significantly higher percentage of predicted maximum mid-expiratory flow (MMEF%) than the unstable group (P<0.05); at the initial evaluation and 3-month follow-up point, the stable group had a significantly higher FeNO than the unstable group (P<0.05). CONCLUSIONS: Continuously monitoring FEV1/FVC, MMEF% and FeNO is useful in the early evaluation of the responses to treatment in children with asthma.

[Quality control for maximal expiratory flow-volume curve as a pulmonary function test in school-age children].

OBJECTIVE: To assess the quality control for the maximal expiratory flow-volume (MEFV) curve in school-age children. METHODS: Eight hundred and sixty-two children who had two or more MEFV manoeuvres were classified into ≥6-year-old (n=379), ≥8-year-old (n=210), ≥10-year-old (n=64), and 12-17-year-old groups (n=109). The parameters of quality control and concordance with quality control criteria for MEFV were compared between the two groups. In addition, patients who were diagnosed with asthma were classified into two groups, one with normal pulmonary function (n=155) and the other with abnormal pulmonary function (n=62), based on the results of spirometry. Differences in the parameters of quality control for spirometry were compared between the two groups. RESULTS: Eight hundred and sixty-two children underwent 2 367 MEFV manoeuvres, 97.8% of which met the start of test criterion for backward extrapolated volume (VBE) of less than 0.15 L, with the highest concordance in the ≥6-year-old group and the lowest concordance in the 12-17-year-old group. Three hundred and eighty-one children (44.2%) met the end of test criterion for forced expiratory time (FET) and the concordance in children over 10 years of age was lower than that in children under 10 years of age (P<0.05). Differences in two best forced expiratory volume in first second (FEV1) and forced vital capacity (FVC) manoeuvres were within 150 mL in 91.9% and 84.8%, respectively, of the children. The parameters of quality control for spirometry were better for asthmatic children with abnormal pulmonary function compared with asthmatic children with normal pulmonary function (P<0.05). CONCLUSIONS: Concordance with the start of test criteria and the manoeuvre repeatability criteria is high, whereas the concordance with the end of test criteria is low. It is suggested that the concordance with the FET criteria should be improved.

Two classes of anti-platelet drugs reduce anatomical infarct size in monkey hearts.

BACKGROUND: Recent studies in rabbits have demonstrated that platelet P2Y12 receptor antagonists are cardioprotective, and that the mechanism is surprisingly not related to blockade of platelet aggregation but rather to triggering of the same signal transduction pathway seen in pre- and postconditioning. We wanted to determine whether this same cardioprotection could be documented in a primate model and whether the protection was limited to P2Y12 receptor antagonists or was a class effect. METHODS: Thirty-one macaque monkeys underwent 90-min LAD occlusion/4-h reperfusion. RESULTS: The platelet P2Y12 receptor blocker cangrelor started just prior to reperfusion significantly decreased infarction by an amount equivalent to that seen with ischemic postconditioning (p < 0.001). For any size of risk zone, infarct size in treated hearts was significantly smaller than that in control hearts. OM2, an investigational murine antibody against the primate collagen receptor glycoprotein (GP) VI, produced similar protection (p < 0.01) suggesting a class effect. Both cangrelor and OM2 were quite effective at blocking platelet aggregation (94 % and 97 %, respectively). CONCLUSIONS: Thus in a primate model in which infarct size could be determined directly platelet anti-aggregatory agents are cardioprotective. The important implication of these investigations is that patients with acute myocardial infarction who are treated with platelet anti-aggregatory agents prior to revascularization may already be in a postconditioned state. This hypothesis may explain why in recent clinical trials postconditioning-mimetic interventions which were so protective in animal models had at best only a modest effect.

Platelet P2Y12 blockers confer direct postconditioning-like protection in reperfused rabbit hearts.

BACKGROUND: Blockade of platelet activation during primary percutaneous intervention for acute myocardial infarction is standard care to minimize stent thrombosis. To determine whether antiplatelet agents offer any direct cardioprotective effect, we tested whether they could modify infarction in a rabbit model of ischemia/reperfusion caused by reversible ligation of a coronary artery. METHODS AND RESULTS: The P2Y12 (adenosine diphosphate) receptor blocker cangrelor administered shortly before reperfusion in rabbits undergoing 30-minute regional ischemia/3-hour reperfusion reduced infarction from 38% of ischemic zone in control hearts to only 19%. Protection was dose dependent and correlated with the degree of inhibition of platelet aggregation. Protection was comparable to that seen with ischemic postconditioning (IPOC). Cangrelor protection, but not its inhibition of platelet aggregation, was abolished by the same signaling inhibitors that block protection from IPOC suggesting protection resulted from protective signaling rather than anticoagulation. As with IPOC, protection was lost when cangrelor administration was delayed until 10 minutes after reperfusion and no added protection was seen when cangrelor and IPOC were combined. These findings suggest both IPOC and cangrelor may protect by the same mechanism. No protection was seen when cangrelor was used in crystalloid-perfused isolated hearts indicating some component in whole blood is required for protection. Clopidogrel had a very slow onset of action requiring 2 days of treatment before platelets were inhibited, and only then the hearts were protected. Signaling inhibitors given just prior to reperfusion blocked clopidogrel's protection. Neither aspirin nor heparin was protective. CONCLUSIONS: Clopidogrel and cangrelor protected rabbit hearts against infarction. The mechanism appears to involve signal transduction during reperfusion rather than inhibition of intravascular coagulation. We hypothesize that both drugs protect by activating IPOC's protective signaling to prevent reperfusion injury. If true, patients receiving P2Y12 inhibitors before percutaneous intervention may already be postconditioned thus explaining failure of recent clinical trials of postconditioning drugs.