OLB appears to be safe, has the best diagnostic yield, and leads to change in management more often than CTB or BAL in pediatric oncology patients with persistent pulmonary infiltrates.

Recent guidelines in British Columbia, Canada have suggested that the use of a maximum of 3 monthly doses of palivizumab 15 mg/kg intramuscularly for RSV immunoprophylaxis of high risk infants born prior to the RSV season is adequate to provide protection against severe RSV disease for a 5-month RSV season. Efficacy was established, however, with 2 large, randomized controlled clinical studies using 5 monthly doses of immunoprophylaxis. To evaluate the differences in expected palivizumab exposures between the 2 dosing regimens (3 vs 5 monthly doses across a 5-month period), we used a population pharmacokinetic (PK) model that was developed using palivizumab PK data collected from 22 clinical studies with a total of 1800 subjects. This model adequately described observed palivizumab concentrations from the different pediatric studies and was subsequently used to simulate expected palivizumab serum concentrations for 3 monthly doses compared with 5 monthly doses in children younger than 24 months with chronic lung disease of prematurity and infants younger than 6 months postnatal age who were born at ≤ 35 weeks gestational age. Results from the population PK model indicated lower serum concentrations of palivizumab during the fourth and fifth months, after an abbreviated 3-monthly-dose regimen when compared with the mean trough concentrations seen with the 5-monthly-dose regimen studied in the pivotal clinical trials in premature infants. Specifically, during the fourth and fifth months, 52% and 85%, respectively, would have levels below the lowest concentration (fifth percentile) in those receiving the 5-monthly-dose regimen. Simulations using this model did not support a 3-monthly-dose regimen to protect against severe RSV disease during the typical 5-month season.

Background Respiratory syncytial virus (RSV) is a leading cause of infant hospitalization in the United States. Preterm infants and those with select comorbidities are at highest risk of RSV-related complications. However, morbidity due to RSV infection is not confined to high-risk infants. We estimated the burden of medically attended (MA) RSV-associated lower respiratory tract infection (LRTI) among infants in the United States. Methods We analyzed commercial (MarketScan Commercial [MSC], Optum Clinformatics [OC]), and Medicaid (MarketScan Medicaid [MSM]) insurance claims data for infants born between April 2016 and February 2020. Using both specific and sensitive definitions of MA RSV LRTI, we estimated the burden of MA RSV LRTI during infants’ first RSV season, stratified by gestational age, comorbidity status, and highest level of medical care associated with the MA RSV LRTI diagnosis. Results According to the specific definition 75.0% (MSC), 78.6% (MSM), and 79.6% (OC) of MA RSV LRTI events during infants’ first RSV season occurred among term infants without known comorbidities. Conclusions Term infants without known comorbidities account for up to 80% of the MA RSV LRTI burden in the United States during infants’ first RSV season. Future prevention efforts should consider all infants.

We wished to determine whether Resonant Raman Spectroscopy (RRS) could be used to measure Amphotericin B (AmB) at therapeutic and subtherapeutic concentrations in a model system mimicking the anterior chamber of the eye. The goal was to develop a technique for non-invasive measurement of AmB levels in the aqueous humor (AH) of the eye. A krypton-ion laser source (406.7 nm) was used for excitation and Resonant Raman Spectra were captured with a confocal system in an anterior chamber (AC) model. These spectra were used to develop a correlation curve for prediction of AmB levels. Subsequently, one rabbit was evaluated with this system after 5 days of intravenous AmB administration (1 mg/kg/day) and AmB concentrations measured by RRS were compared to those measured by high-performance liquid chromatography (HPLC). AmB exhibited a unique spectral peak at 1557 cm(-1). Integrated area of this peak linearly correlated with AmB concentration in our model AC. When integrated peak area from multiple in vivo measurements in one animal at steady-state was plotted on this correlation curve, we were able to predict AmB levels. These closely approximated those measured by HPLC. These measurements were not significantly affected by photobleaching or depth profile at acquisition. RRS at 406.7 nm is a method that may be useful for non-invasive monitoring of intraocular AmB levels. This instrument can help physicians decide when repeat, invasive delivery of this drug is warranted based on measurement of actual drug levels in the AH. Also, there is the potential to measure the ocular concentrations of other pharmaceutical agents with similar instruments.