Antibodies against SARS-CoV-2 in unvaccinated children hospitalized with COVID-19: An observational cohort study of pre-Omicron and Omicron variants era.

PURPOSE: This study aimed to investigate the antibodies against SARS-CoV-2 in children hospitalized due to COVID-19 during the era of pre-Omicron and Omicron variants. METHODS: This was a retrospective observational study conducted at a tertiary academic medical center in Thailand between June 2021 and August 2022. We collected the data of children aged under 18-year who were hospitalized from SARS-CoV-2 infection. After hospital discharge, we scheduled clinical follow-up 60 to 90 days post-infection clinical follow-up. We measured antibodies against SARS-CoV-2 anti-spike protein receptor-binding domain in the serum during a follow-up visit and compared the mean difference of antibody levels between children infected with COVID-19 during the pre-Omicron and Omicron eras. RESULTS: A total of 119 children enrolled into the study. There were 58 and 61 children hospitalized due to COVID-19 during pre-Omicron and Omicron era, respectively. The median (interquartile range, IQR) of SARS-CoV-2 antibodies in all cases was 206.1 (87.9-424.1) U/mL at follow-up. Children infected during pre-Omicron had SARS-CoV-2 antibody levels at follow-up higher than children infected during Omicron era [mean difference 292.57 U/mL, 95% CI 53.85-531.28, p = 0.017). There was no difference in SARS-CoV-2 antibody levels between the children based on gender, age, co-morbidities, chest radiograph classification, or diagnosis. CONCLUSIONS: The antibodies response to SARS-CoV-2 infection was weaker during the Omicron era than previous variant of concern. Immunization strategies and policies should be implemented in children even if they had been previously infected.

Case Report: Melioidosis-Related Severe Cutaneous Features of Erythema Nodosum in a Thai Child.

Erythema nodosum (EN) is characterized by rapidly developing, painful, erythematous subcutaneous nodules, most of which are located in the pretibial areas. This cutaneous finding can be caused by a variety of conditions, however Burkholderia pseudomallei is rarely the cause. This particular patient presented with a high-grade fever with characteristic EN on both pretibial areas. All of the typical EN causes were investigated, but the findings were all negative. The lesions progressed to severe hemorrhagic bleb features, and because the patient resided in Northeast Thailand, a melioidosis-endemic region, testing for B. pseudomallei was performed. Because a high level of melioidosis serology of more than 1:10,240 was detected, melioidosis therapy was started. At the 12-week follow-up after melioidosis therapy, the titer had declined to 1:1,280, indicating that melioidosis-related severe, cutaneous EN symptoms were the most likely diagnosis in this patient. We discovered a case of EN with severe hemorrhagic bleb features as a unique clinical manifestation of melioidosis. When a patient resides in an endemic area, B. pseudomallei should always be considered as a possible causative organism.

Clinical manifestations and pathological correlation of immunoglobulin A nephropathy in children.

BACKGROUND: IgA nephropathy in children has various clinical manifestations. Kidney biopsy is a gold standard for diagnosis by using Oxford classification 2016 with few studies about the correlation between clinical and pathology manifestations. This study aims to find these correlations at the time of diagnosis and during short-term follow-up. METHOD: In this retrospective cohort study, 47 pediatric patients who underwent renal biopsy from 2010 to 2021 in Thailand, were included. Oxford classification 2016 has been used to score patients' pathology. Univariate and multivariate associations have been used for correlation between clinical and pathologic parameters. RESULTS: The most common clinical manifestations were microscopic hematuria and proteinuria. There were 68% of children with mesangial hypercellularity (M1), 42% with segmental glomerulosclerosis (S1), 25% with moderate to severe crescent (C1/C2), 23% with endocapillary hypercellularity (E1), and 14% with moderate to a severe tubular atrophy/interstitial fibrosis (T1/T2). Microscopic hematuria was strongly associated with mesangial hypercellularity (M1) OR 7.14 (95%CI 1.83 - 27.88, p-value 0.005) and hypertension was strongly associated with segmental glomerulosclerosis (S1) adjusted OR 7.87 (95%CI 1.65 - 37.59, p-value 0.01). Intensive treatment was used more in the patients with tubular atrophy/interstitial fibrosis lesion on renal biopsy than other lesions from MEST-C scores OR 4.98 (95%CI 1.17-21.24, p-value 0.03). Furthermore, pulse methylprednisolone and cyclophosphamide were used in patients with crescentic lesions significantly than other lesions with OR 15.5 (95%CI 3.16- 75.93, p-value 0.001) and OR 5.75 (95%CI 1.31-25.29, p-value 0.021), respectively. CONCLUSION: Tubular atrophy/interstitial fibrosis and crescent lesions were correlated to intensive treatment in short-term outcomes.