Use of Metagenomic Next-Generation Sequencing in the Identification of Pneumocystis Jiroveci Pneumonia in a Previously Healthy Infant Diagnosed With X-Linked Hyper-IgM Syndrome.

This case describes a four-month-old male who was admitted to the pediatric intensive care unit for acute respiratory failure in the setting of a co-infection requiring increased ventilatory support. Immunodeficiency workup demonstrated poor vaccination response and low immunoglobulin titers. mNGS via Karius® test was positive for Pneumocystis jiroveci (PJP), Parvovirus, and Bocavirus. The patient was successfully treated with trimethoprim-sulfamethoxazole and prednisone. Genetic workup via Invitae panel confirmed that the patient had X-linked Hyper-IgM Syndrome. Use of mNGS can help with early identification of pathogens that conventional testing does not detect, even in patients not already identified as immunocompromised.

Monocyte anisocytosis increases during multisystem inflammatory syndrome in children with cardiovascular complications.

BACKGROUND: Multisystem inflammatory syndrome in children (MIS-C) is a life-threatening complication that can develop weeks to months after an initial SARS-CoV-2 infection. A complex, time-consuming laboratory evaluation is currently required to distinguish MIS-C from other illnesses. New assays are urgently needed early in the evaluation process to expedite MIS-C workup and initiate treatment when appropriate. This study aimed to measure the performance of a monocyte anisocytosis index, obtained on routine complete blood count (CBC), to rapidly identify subjects with MIS-C at risk for cardiac complications. METHODS: We measured monocyte anisocytosis, quantified by monocyte distribution width (MDW), in blood samples collected from children who sought medical care in a single medical center from April 2020 to October 2020 (discovery cohort). After identifying an effective MDW threshold associated with MIS-C, we tested the utility of MDW as a tier 1 assay for MIS-C at multiple institutions from October 2020 to October 2021 (validation cohort). The main outcome was the early screening of MIS-C, with a focus on children with MIS-C who displayed cardiac complications. The screening accuracy of MDW was compared to tier 1 routine laboratory tests recommended for evaluating a child for MIS-C. RESULTS: We enrolled 765 children and collected 846 blood samples for analysis. In the discovery cohort, monocyte anisocytosis, quantified as an MDW threshold of 24.0, had 100% sensitivity (95% CI 78-100%) and 80% specificity (95% CI 69-88%) for identifying MIS-C. In the validation cohort, an initial MDW greater than 24.0 maintained a 100% sensitivity (95% CI 80-100%) and monocyte anisocytosis displayed a diagnostic accuracy greater that other clinically available hematologic parameters. Monocyte anisocytosis decreased with disease resolution to values equivalent to those of healthy controls. CONCLUSIONS: Monocyte anisocytosis detected by CBC early in the clinical workup improves the identification of children with MIS-C with cardiac complications, thereby creating opportunities for improving current practice guidelines.

Effects of Tocilizumab in COVID-19 patients: a cohort study.

BACKGROUND: Due to the lack of proven therapies, we evaluated the effects of early administration of tocilizumab for COVID-19. By inhibition of the IL-6 receptor, tocilizumab may help to mitigate the hyperinflammatory response associated with progressive respiratory failure from SARS-CoV-2. METHODS: A retrospective, observational study was conducted on hospitalized adults who received intravenous tocilizumab for COVID-19 between March 23, 2020 and April 10, 2020. RESULTS: Most patients were male (66.7%), Hispanic (63.3%) or Black (23.3%), with a median age of 54 years. Tocilizumab was administered at a median of 8 days (range 1-21) after initial symptoms and 2 days (range 0-12) after hospital admission. Within 30 days from receiving tocilizumab, 36 patients (60.0%) demonstrated clinical improvement, 9 (15.0%) died, 33 (55.0%) were discharged alive, and 18 (30.0%) remained hospitalized. Successful extubation occurred in 13 out of 29 patients (44.8%). Infectious complications occurred in 16 patients (26.7%) at a median of 10.5 days. After tocilizumab was administered, there was a slight increase in PaO2/FiO2 and an initial reduction in CRP, but this effect was not sustained beyond day 10. CONCLUSIONS: Majority of patients demonstrated clinical improvement and were successfully discharged alive from the hospital after receiving tocilizumab. We observed a rebound effect with CRP, which may suggest the need for higher or subsequent doses to adequately manage cytokine storm. Based on our findings, we believe that tocilizumab may have a role in the early treatment of COVID-19, however larger randomized controlled studies are needed to confirm this.