BACKGROUND. Initial reports from the severe acute respiratory coronavirus 2 (SARS-CoV-2) pandemic described children as being less susceptible to coronavirus disease 2019 (COVID-19) than adults. Subsequently, a severe and novel pediatric disorder termed multisystem inflammatory syndrome in children (MIS-C) emerged. We report on unique hematologic and immunologic parameters that distinguish between COVID-19 and MIS-C and provide insight into pathophysiology. METHODS. We prospectively enrolled hospitalized patients with evidence of SARS-CoV-2 infection and classified them as having MIS-C or COVID-19. Patients with COVID-19 were classified as having either minimal or severe disease. Cytokine profiles, viral cycle thresholds (Cts), blood smears, and soluble C5b-9 values were analyzed with clinical data. RESULTS. Twenty patients were enrolled (9 severe COVID-19, 5 minimal COVID-19, and 6 MIS-C). Five cytokines (IFN-γ, IL-10, IL-6, IL-8, and TNF-α) contributed to the analysis. TNF-α and IL-10 discriminated between patients with MIS-C and severe COVID-19. The presence of burr cells on blood smears, as well as Cts, differentiated between patients with severe COVID-19 and those with MIS-C. CONCLUSION. Pediatric patients with SARS-CoV-2 are at risk for critical illness with severe COVID-19 and MIS-C. Cytokine profiling and examination of peripheral blood smears may distinguish between patients with MIS-C and those with severe COVID-19.

Evaluation of 1000 patients at the UCSD Nasal Dysfunction Clinic in San Diego revealed differential olfactory impairment and differential symptom complaints based on diagnostic category, age, and gender.

Background Understanding the prevalence and clinical presentation of coronavirus disease 2019 in pediatric patients can help healthcare providers and systems prepare and respond to this emerging pandemic. Methods This was a retrospective case series of patients tested for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) across a pediatric healthcare network, including clinical features and outcomes of those with positive test results. Results Of 7256 unique children tested for SARS-CoV-2, 424 (5.8%) tested positive. Patients aged 18–21 years had the highest test positive rate (11.2%), while those aged 1–5 years had the lowest (3.9%). By race, 10.6% (226/2132) of black children tested positive vs 3.3% (117/3592) of white children. By indication for testing, 21.1% (371/1756) of patients with reported exposures or clinical symptoms tested positive vs 3.8% (53/1410) of those undergoing preprocedural or preadmission testing. Of 424 patients who tested positive for SARS-CoV-2, 182 (42.9%) had no comorbidities, 87 (20.5%) had asthma, and 55 (13.0%) were obese. Overall, 52.1% had cough, 51.2% fever, and 14.6% shortness of breath. Seventy-seven (18.2%) SARS-CoV-2–positive patients were hospitalized, of whom 24 (31.2%) required respiratory support. SARS-CoV-2-targeted antiviral therapy was given to 9 patients, and immunomodulatory therapy to 18 patients. Twelve (2.8%) SARS-CoV-2-positive patients required mechanical ventilation, and 2 patients required extracorporeal membrane oxygenation. Two patients died. Conclusions In this large cohort of pediatric patients tested for SARS-CoV-2, the rate of infection was low but varied by testing indication. The majority of cases were mild and few children had critical illness.

DAX1 (dosage-sensitive sex reversal, adrenal hypoplasia critical region, on chromosome X, gene 1; also known as NROB1, nuclear receptor subfamily 0, group B, member 1) encodes a nuclear receptor that is expressed in embryonic stem (ES) cells, steroidogenic tissues (gonads, adrenals), the ventromedial hypothalamus (VMH), and pituitary gonadotropes. Humans with DAX1 mutations develop an X-linked syndrome referred to as adrenal hypoplasia congenita (AHC). These boys typically present in infancy with adrenal failure but later fail to undergo puberty because of hypogonadotropic hypogonadism (HHG). The adrenal failure reflects a developmental abnormality in the transition of the fetal to adult zone, resulting in glucocorticoid and mineralocorticoid deficiency. The etiology of HHG involves a combined and variable deficiency of hypothalamic GnRH secretion and/or pituitary responsiveness to GnRH resulting in low LH, FSH and testosterone. Treatment with exogenous gonadotropins generally does not induce spermatogenesis. Animal models indicate that DAX1 also plays a critical role in testis development and function. As a nuclear receptor, DAX1 has been shown to function as a transcriptional repressor, particularly of pathways regulated by other nuclear receptors, such as steroidogenic factor 1 (SF1). In addition to reproductive tissues, DAX1 is also expressed at high levels in ES cells and plays a role in the maintenance of pluripotentiality. Here we review the clinical manifestations associated with DAX1 mutations as well as the evolving information about its function based on animal models and in vitro studies.

SARS-CoV-2 infection is diagnosed through detection of specific viral nucleic acid or antigens from respiratory samples. These techniques are relatively expensive, slow, and susceptible to false-negative results. A rapid noninvasive method to detect infection would be highly advantageous. Compelling evidence from canine biosensors and studies of adults with COVID-19 suggests that infection reproducibly alters human volatile organic compound (VOC) profiles. To determine whether pediatric infection is associated with VOC changes, we enrolled SARS-CoV-2 infected and uninfected children admitted to a major pediatric academic medical center. Breath samples were collected from children and analyzed through state-of-the-art GCxGC-ToFMS. Isolated features included 84 targeted VOCs. Candidate biomarkers that were correlated with infection status were subsequently validated in a second, independent cohort of children. We thus find that six volatile organic compounds are significantly and reproducibly increased in the breath of SARS-CoV-2 infected children. Three aldehydes (octanal, nonanal, and heptanal) drew special attention, as aldehydes are also elevated in the breath of adults with COVID-19. Together, these biomarkers demonstrate high accuracy for distinguishing pediatric SARS-CoV-2 infection and support the ongoing development of novel breath-based diagnostics.