Peripheral obstruction without airflow limitation is rare and not specific to asthma in children

Late-onset pulmonary complications following allogeneic hematopoietic cell transplantation in pediatric patients: a prospective multicenter study

The primary objective of our multicenter prospective study was to describe the incidence of late-onset non-infectious pulmonary complications (LONIPCs) in children undergoing hematopoietic cell transplantation (HCT) using sensitive criteria for pulmonary function test (PFT) abnormalities including the non-specific pattern of airflow obstruction. Secondary objectives were to assess the factors associated with LONIPC occurrence and the sensitivity of the 2014 NIH-Consensus Criteria of bronchiolitis obliterans syndrome (BOS). PFT and clinical assessment were performed prior to HCT and at 6, 12, 24, and 36 months post-HCT. LONIPC diagnosis was validated by an Adjudication Committee. The study comprised 292 children from 12 centers. Thirty-two individuals (11%, 95% CI: 8-15%) experienced 35 LONIPCs: 25 BOS, 4 interstitial lung diseases, 4 organizing pneumonia and 2 pulmonary veno-occlusive diseases. PFT abnormalities were obstructive defects (FEV1/FVC z-score < -1.645; n = 12), restrictive defects (TLC < 80% predicted, FEV1 and FVC z-scores < -1.645; n = 7) and non-specific pattern (FEV1 and FVC z-score< -1.645, FEV1/FVC z-score > -1.645, and TLC > 80% predicted; n = 8). HCT for malignant disease was the only factor associated with LONIPC (P = 0.04). The 2014 NIH-Consensus Criteria would only diagnose 8/25 participants (32%) as having BOS. In conclusion, 11% of children experienced a LONIPC in a prospective design. Clinical Trials.gov identifier (NCT number): NCT02032381.

Lung function tracking in children with perinatally acquired HIV following early antiretroviral therapy initiation

INTRODUCTION

Lung disease remains a frequent complication in children with perinatal HIV infection (CHIV) and exposure without infection (CHEU), resulting in diminished lung function. In CHIV, early antiretroviral therapy (ART) initiation improves survival and extrapulmonary outcomes. However, it is unknown if there is benefit to lung function.

METHODS

Cohorts of CHIV (ART initiated at median 4.0 months), CHEU and HIV-unexposed children (CHU) prospectively performed pulmonary function testing (PFT) consisting of spirometry, plethysmography and diffusing capacity from 2013 to 2020. We determined lung function trajectories for PFT outcomes comparing CHIV to CHU and CHEU to CHU, using linear mixed effects models with multiple imputation. Potential confounders included sex, age, height, weight, body mass index z-score, urine cotinine and Tanner stage.

RESULTS

328 participants (122 CHIV, 126 CHEU, 80 CHU) performed PFT (ages 6.6-15.6 years). Spirometry (forced expiratory volume in 1 s, FEV1, forced vital capacity (FVC), FEV1/FVC) outcomes were similar between groups. In plethysmography, the mean residual volume (RV) z-score was 17% greater in CHIV than CHU (95% CI 1% to 33%, p=0.042). There was no difference in total lung capacity (TLC) or RV/TLC z-scores between groups. Diffusing capacity for carbon monoxide was similar in all groups, while alveolar volume (VA) differed between HIV groups by sex.

CONCLUSION

Our study indicates that early ART initiation can mitigate the loss of lung function in CHIV with lasting benefit through childhood; however, there remains concern of small airway disease. CHEU does not appear to disrupt childhood lung function trajectory.

Clinical performance of spirometry and respiratory oscillometry for prediction of severe exacerbations in schoolchildren with asthma

OBJECTIVE

To determine the performance of spirometry and respiratory oscillometry (RO) in the prediction of severe asthma exacerbations (SAEs) in children.

METHODS

In a prospective study, 148 children (age 6-14 years) with asthma were assessed with RO, spirometry and a bronchodilator (BD) test. Based on the findings of spirometry and the BD test, they were classified into three phenotypes: air trapping (AT), airflow limitation (AFL) and normal. Twelve weeks later, they were re-evaluated in relation to the occurrence of SAEs. We analysed the performance of RO, spirometry and AT/AFL phenotypes for prediction of SAEs by means of positive and negative likelihood ratios, ROC curves with the corresponding areas under the curve (AUCs) and a multivariate analysis adjusted for potential confounders.

RESULTS

During the follow-up, 7.4% of patients had SAEs, and there were differences between phenotypes (normal, 2.4%; AFL, 17.9%; AT, 22.2%, P = .005). The best AUC corresponded to the forced expiratory flow between 25% and 75% of vital capacity (FEF_25-75): 0.787; 95% confidence interval, 0.600-0.973. Other significant AUCs were those for the reactance area (AX), forced expiratory volume in the first second (FEV₁), the post-BD change in forced vital capacity (FVC), and the FEV₁/FVC ratio. All of the variables had a low sensitivity for prediction of SAEs. The AT phenotype had the best specificity (93.8%; 95% CI, 87.9-97.0), but the positive and negative likelihood ratios were both significant only for the FEF_25-75. In the multivariate analysis, only some spirometry parameters were significative for prediction of SAEs (AT phenotype, FEF_25-75 and FEV₁/FVC).

CONCLUSIONS

Spirometry performed better than RO for prediction of SAEs in the medium term in schoolchildren with asthma.