WHAT THE COVID-19 PANDEMIC TAUGHT US IN CHILDREN (preprint)

Objective: The COVID-19 pandemic is an important cause of morbidity and mortality, which has had a negative impact worldwide. We aimed to contribute to the medical literature by sharing the knowledge and experience of pediatric patients who were diagnosed as having COVID-19 in a one-year period. Method: Patients aged 1 month to 18 years who were diagnosed as having COVID-19 in our clinic, between March 2020 and April 2020, from when COVID-19 was declared as a pandemic, were included in the study. Results: Four hundred sixty-seven children were included in the study. There were 34 (7.3%) patients under one year of age, 111 (23.8%) between 1-5 years, 98 (30.4%) between 5-10 years, 142 (30.4%) between 11-15 years, and 82 (17.6%) age over 15 years. Fever (88.2%), vomiting (32.4%), and diarrhea (29.4%) in patients aged under 1 year, sore throat (36.6%) in patients aged 11-15 years, and dysgeusia (11%), anosmia (14.6%), headache (18.3%), malaise (40.8%), myalgia (28%), and dyspnea (17.1%) in those aged over 15 years of age were found significantly more common compared with the other age groups. Thirty-five (7.5%) patients were asymptomatic, 365 (78.1%) had mild disease, 35 (7.5%) were moderate, 27 (5.8%) were severe, and five (1.07%) were critical. Leukocyte count, erythrocyte sedimentation rate, ferritin, and C-reactive protein values were significantly higher in hospitalized patients. Four patients died during the study period (0.8%, 4/494). Conclusion: Although COVID-19 has an asymptomatic and mild course in children, it should be kept in mind that it may have a severe course.

Rare predicted loss-of-function variants of type I IFN immunity genes are associated with critical COVID-19 (preprint)

Background We previously reported inborn errors of TLR3- and TLR7-dependent type I interferon (IFN) immunity in 1-5% of unvaccinated patients with life-threatening COVID-19, and autoantibodies against type I IFN in another 15-20% of cases. Methods We report here a genome-wide rare variant burden association analysis in 3,269 unvaccinated patients with life-threatening COVID-19 (1,301 previously reported and 1,968 new patients), and 1,373 unvaccinated SARS-CoV-2-infected individuals without pneumonia. A quarter of the patients tested had antibodies against type I IFN (234 of 928) and were excluded from the analysis. Results No gene reached genome-wide significance. Under a recessive model, the most significant gene with at-risk variants was TLR7, with an OR of 27.68 (95%CI:1.5-528.7, P=1.1x10-4), in analyses restricted to biochemically loss-of-function (bLOF) variants. We replicated the enrichment in rare predicted LOF (pLOF) variants at 13 influenza susceptibility loci involved in TLR3-dependent type I IFN immunity (OR=3.70 [95%CI:1.3-8.2], P=2.1x10-4). Adding the recently reported TYK2 COVID-19 locus strengthened this enrichment, particularly under a recessive model (OR=19.65 [95%CI:2.1-2635.4]; P=3.4x10-3). When these 14 loci and TLR7 were considered, all individuals hemizygous (n=20) or homozygous (n=5) for pLOF or bLOF variants were patients (OR=39.19 [95%CI:5.2-5037.0], P=4.7x10-7), who also showed an enrichment in heterozygous variants (OR=2.36 [95%CI:1.0-5.9], P=0.02). Finally, the patients 13 with pLOF or bLOF variants at these 15 loci were significantly younger (mean age [SD]=43.3 [20.3] years) than the other patients (56.0 [17.3] years; P=1.68x10-5). Conclusions Rare variants of TLR3- and TLR7-dependent type I IFN immunity genes can underlie lifethreatening COVID-19, particularly with recessive inheritance, in patients under 60 years old.

REACTIVATION OF TUBERCULOSIS AND COVID-19 (preprint)

Coronavirus disease 2019 (COVID-19) is a viral disease caused by a novel coronavirus that can lead to severe acute respiratory failure. Recent studies have shown that aggravating factors in the etiology of COVID-19 disease include genetic defects and autoantibodies against type 1 interferon. Mycobacterium tuberculosis is an immobile aerobic bacillus that causes tuberculosis disease. SARS-CoV-2 infection and immunosuppressive drugs may temporarily inhibit immunologic system, then may lead to active tuberculosis by reactivation or infection of M. tuberculosis. We aimed to show that there is a relationship between covid-19 infection and an increase in the number of tuberculosis patients. Eight patients diagnosed with tuberculosis in the Pediatric Pulmonology and Pediatric Infectious Diseases Clinics of Necmettin Erbakan University, Meram Medical Faculty between March 2020 and May 2021 were enrolled in this study. The presence of COVID-19 infection was confirmed by COVID-19 antibody test and patient’s detailed medical history. The patient with negative antibody test was also included in the study if other family members confirmed for COVID-19 infection by RT-PCR. We evaluated demographic data, laboratory findings, imaging tests and pathology results of all patients. The remarkable increase in the number of tuberculosis activation in the recent year suggests the role of COVID-19 infection. The pathologic structure of the virus may be responsible of the increase, although the mechanism is not fully understood. Further research should be done on this topic.

OUTCOMES OF COVID-19 INFECTIONS IN CHILDREN: A SINGLE-CENTER RETROSPECTIVE STUDY (preprint)

Objective: The COVID-19 pandemic is an important cause of morbidity and mortality, which has had a negative impact worldwide. Our aim was to describe clinical findings and outcomes of SARS-CoV-2 viral infection and Covid-19 disease cared for at a large pediatric tertiary care hospital during the first year of the pandemic. Methods: Patients aged 1 month to 18 years who were diagnosed as having COVID-19 between March 2020 and April 2021 were included. The files of patients diagnosed with covid-19 were reviewed retrospectively. Results: 467 children were included in the study. There were 34 (7.3%) patients under one year of age, 111 (23.8%) between 1-5 years, 98 (30.4%) between 5-10 years, 142 (30.4%) between 11-15 years, and 82 (17.6%) age over 15 years. Fever (88.2%), vomiting (32.4%), and diarrhea (29.4%) in patients aged under 1 year, sore throat (36.6%) in patients aged 11-15 years, and dysgeusia (11%), anosmia (14.6%), headache (18.3%), malaise (40.8%), myalgia (28%), and dyspnea (17.1%) in those aged over 15 years of age were found significantly more common compared with the other age groups (p<0.05). Thirty-five (7.5%) patients were asymptomatic, 365 (78.1%) had mild disease, 35 (7.5%) were moderate, 27 (5.8%) were severe, and five (1.07%) were critical. Leukocyte count, erythrocyte sedimentation rate, ferritin, and C-reactive protein values were significantly higher in hospitalized patients. Four patients died during the study period (0.8%, 4/467). Conclusion: While SARS-CoV-2 infection may be asymptomatic and Covid-19 disease usually has a mild clinical course, some children have severe disease or mortality.