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X-linked recessive deficiency of TLR7, a MyD88- and IRAK-4-dependent endosomal ssRNA sensor, impairs SARS-CoV-2 recognition and type I IFN production in plasmacytoid dendritic cells (pDCs), thereby underlying hypoxemic COVID-19 pneumonia with high penetrance. We report 22 unvaccinated patients with autosomal recessive MyD88 or IRAK-4 deficiency infected with SARS-CoV-2 (mean age: 10.9 yr; 2 mo to 24 yr), originating from 17 kindreds from eight countries on three continents. 16 patients were hospitalized: six with moderate, four with severe, and six with critical pneumonia, one of whom died. The risk of hypoxemic pneumonia increased with age. The risk of invasive mechanical ventilation was also much greater than in age-matched controls from the general population (OR: 74.7, 95% CI: 26.8-207.8, P < 0.001). The patients susceptibility to SARS-CoV-2 can be attributed to impaired TLR7-dependent type I IFN production by pDCs, which do not sense SARS-CoV-2 correctly. Patients with inherited MyD88 or IRAK-4 deficiency were long thought to be selectively vulnerable to pyogenic bacteria, but also have a high risk of hypoxemic COVID-19 pneumonia.

Background: Phosphoglucomutase‐3 (PGM3) deficiency is a congenital disorder of glycosylation (CDG) with hyperimmunoglobulin IgE, atopy, and a variable immunological phenotype; most reported patients display dysmorphic features. The aim of the study was to characterize the genotype and phenotype of individuals with newly identified compound heterozygous variants in the phosphate‐binding domain of PGM3 in order to better understand phenotypic differences between these patients and published cases. Methods: We analyzed PGM3 protein expression, PGM3 enzymatic activity, the presence of other gene variants within the N‐glycosylation pathway, and the clinical and immunological manifestations of two affected siblings. Results: Patients belonged to a non‐consanguineous family, presenting with atopic dermatitis, elevated levels of IgE, and CD4+ lymphopenia (a more severe phenotype was observed in Patient 2), but lacked dysmorphic features or neurocognitive impairment. Compound heterozygous PGM3 variants were identified, located in the phosphate‐binding domain of the enzyme. PGM3 expression was comparable to healthy donors, but L‐PHA binding in naïve‐CD4+ cells was decreased. Examination of exome sequence identified the presence of one additional candidate variant of unknown significance (VUS) in the N‐glycosylation pathway in Patient 2: a variant predicted to have moderate‐to‐high impact in ALG12. Conclusions: Our analysis revealed that L‐PHA binding is reduced in naïve‐CD4+ cells, which is consistent with decreased residual PGM3 enzymatic activity. Other gene variants in the N‐glycosylation pathway may modify patient phenotypes in PGM3 deficiency. This study expands the clinical criteria for when PGM3 deficiency should be considered among individuals with hyper‐IgE. [ABSTRACT FROM AUTHOR]

Background: Renal disease is a leading cause of morbidity in HIV-infected adults in the highly active antiretroviral therapy (HAART) era. Cystatin C has been proposed as a more sensitive marker of renal function, but it may be affected by ongoing inflammation. We aimed to study the cystatin C levels in a cohort of HIV-infected pediatric patients at 3 Spanish centers., Methods: This is a multicenter cross-sectional observational study. Renal function was assessed by means of first morning urine protein/creatinine and albumin/creatinine ratios and creatinine-estimated glomerular filtration rates (GFRs), together with the following inflammation markers: cystatin C, reactive C protein, β-2-microglobulin and 25(OH)-vitamin D levels. A control group of healthy children and adolescents was used., Results: Eighty-three patients (51 females, median age: 13.3 years; 32 males, median age: 13.6 years) and 44 controls (24 females, median age: 12.2 years; 20 males, median age: 10.9 years) were included. Among the former, mean CD4 cell count was 860/mm, 29(35%) patients had a previous AIDS diagnosis, 73(88%) were on HAART and HIV viremia was undetectable in 61(73%). No differences in cystatin C levels were observed between the 2 groups. In HIV-infected patients, cystatin C levels correlated with GFR (r = -0.27; P = 0.01), age at first HAART (r = -0.21; P = 0.05), and β-2-microglobulin (r = 0.569; P < 0.01). In multivariate analysis, lower GFR (P = 0.014) and higher β-2-microglobulin levels (P = 0.001) remained as independent risk factors for higher cystatin C values., Conclusions: Cystatin C values were associated with GFR and β-2-microglobulin. Cystatin C may be useful as a marker of renal function in HIV-infected pediatric patients, independently of ongoing inflammation or viremia.

Introduction: Atypical febrile seizures (AFS) have been related with a higher incidence of severe pathologies of the central nervous system (CNS). Recent studies show a reduction in the prevalence of some of these diseases, a fact that could affect their management. AIMS. To determine the prevalence of severe pathologies of the CNS in patients treated for AFS in A and E departments and to detect any differences between these and patients suffering from AFS that is not associated to any severe pathology., Patients and Methods: A retrospective study was conducted by reviewing the medical records of patients diagnosed with AFS between November 2008 and November 2011., Results: Altogether, the sample consisted of 231 episodes of AFS (223 patients), with an average age of 1.7 years (p25-75=1.2-2.3 years), 133 (57.6%) of whom were males. Twelve patients (5.2%; 95% CI=2.7-8.9) were diagnosed with a severe pathology of the CNS. In patients with a severe pathology of the CNS, AFS is on most occasions the first episode (91.7% versus 63%; p=0.036) and more than one diagnostic criterion is present (50% versus 15.1%; p=0.007). Moreover, focal seizures (50% versus 12.8%; p=0.003) or epileptic status (25% versus 5.9%; p=0.041) are more common, and patients present altered levels of awareness that persist after the episode (66.7% versus 31.5%; p=0.002)., Conclusions: Given the fact that the prevalence of severe pathology of the CNS in patients with AFS is low, carrying out complementary tests or admission to hospital on a routine basis are not recommended. Certain characteristics of the episode increase the likelihood of AFS being the manifestation of a severe pathology of the CNS (being a first episode, presenting more than one diagnostic criterion for AFS and being a focal seizure or epileptic status), and should therefore be taken into account in the management of the patient.