Unusual Differences in the Pulmonary Histopathology of Mice after Intranasal Infection with Mycelial Propagules of Histoplasma capsulatum Strains Classified as LAm A2 and NAm 2 Phylogenetic Species.

The ascomycete Histoplasma capsulatum is the causative agent of systemic respiratory mycosis histoplasmosis, which sometimes develops acute disseminated or chronic clinical forms, with the latter usually associated with granuloma formation. The present report shows differential histopathological changes in the pulmonary inflammatory response of mice infected intranasally with the mycelial morphotype of H. capsulatum strains with distinct genotypes, EH-46 and G-217B, classified as LAm A2 and NAm 2 phylogenetic species, respectively. Infected male BALB/c mice were sacrificed at different postinfection times, and their serial lung sections were stained with periodic acid-Schiff and analyzed via microscopy. In mice infected with the LAm A2 strain, the results showed progressive changes in the inflammatory infiltrate of the lung parenchyma during the first hours and days postinfection as well as granulomas with macrophages containing intracellular yeast cells, which prevailed at 14 and 21 days postinfection. Bronchiolar-associated lymphoid tissue was induced in mice infected with both strains, primarily in mice infected with the NAm 2 strain. Several lung sections from mice infected with the LAm A2 strain showed PAS-positive yeast cells aggregated in a perinuclear crown-like arrangement in macrophages from 3 h to 21 days postinfection. These findings highlight differences in the host pulmonary inflammatory response associated with distinct H. capsulatum species.

Predictors of response to medications for asthma in pediatric patients: A systematic review of the literature.

OBJECTIVES: There has been no systematic review of studies aimed to predict differential responses to medication regimens for asthma controller therapies in pediatric patients. The aim of the present study was to summarize those identifying biomarkers for the different asthma controller therapies. METHODS: Studies published by June 2019 that report phenotypic or genotypic characteristics or biomarkers that could potentially serve as response predictors to asthma controller therapies in pediatric patients were included. The quality of studies was assessed using the Cochrane Risk of Bias tool and the Newcastle-Ottawa Scale tool. RESULTS: Of 385 trials identified, 30 studies were included. Children with asthma and a positive family history of asthma, with more severe disease, of the white race, with allergy biomarkers, nonobese, with lower lung function, high bronchial hyperresponsiveness to methacholine, or having variants in the FCER2 and CRHR1 gene respond better to inhaled corticosteroids (ICS). Younger age (<10 years), short disease duration (<4 years), high cotinine and urinary leukotriene E4 (LTE4) levels, and 5/5 ALOX5 were associated with a better response to leukotriene receptor antagonist (LTRA). For patients that remain symptomatic, white Hispanics were more likely to respond to LTRA, blacks to ICS, white non-Hispanics to LTRA or LABA, and children without a history of eczema, regardless of race or ethnicity to LABA set-up therapy. In severe persistent asthma, those with atopy and body mass index greater than or equal 25 were more likely to benefit from omalizumab. CONCLUSION: Several phenotypic characteristics, biomarkers, or pharmacogenomics markers could be useful for predicting the best drug for asthma treatment.