Background Gut microbiota alterations have been implicated in the pathogenesis of coronavirus disease 2019 (COVID-19). This study aimed to explore gut microbiota changes in a prospective cohort of COVID-19 children and their asymptomatic caregivers infected with the severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) Omicron variant. Methods A total of 186 participants, including 59 COVID-19 children, 50 asymptomatic adult caregivers, 52 healthy children (HC), and 25 healthy adults (HA), were recruited between 15 April and 31 May 2022. The gut microbiota composition was determined by 16S rRNA gene sequencing in fecal samples collected from the participants. Gut microbiota functional profiling was performed by using Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt) software. Results The gut microbiota analysis of beta diversity revealed that the fecal microbial community of COVID-19 children remained far distantly related to HC. The relative abundances of the phyla Actinobacteria and Firmicutes were decreased, whereas Bacteroidetes , Proteobacteria , and Verrucomicrobiota were increased in COVID-19 children. Feces from COVID-19 children exhibited notably lower abundances of the genera Blautia , Bifidobacterium , Fusicatenibacter , Streptococcus , and Romboutsia and higher abundances of the genera Prevotella , Lachnoclostridium , Escherichia-Shigella , and Bacteroides than those from HC. The enterotype distributions of COVID-19 children were characterized by a high prevalence of enterotype Bacteroides . Similar changes in gut microbiota compositions were observed in asymptomatic caregivers. Furthermore, the microbial metabolic activities of KEGG (Kyoto Encyclopedia of Genes and Genomes) and COG (cluster of orthologous groups of proteins) pathways were perturbed in feces from subjects infected with the SARS-CoV-2 Omicron variant. Conclusion Our data reveal altered gut microbiota compositions in both COVID-19 children and their asymptomatic caregivers infected with the SARS-CoV-2 Omicron variant, which further implicates the critical role of gut microbiota in COVID-19 pathogenesis. Supplementary Information The online version contains supplementary material available at 10.1007/s12519-022-00659-6.

BackgroundThe management of LT patients during COVID-19 pandemic is important. Immunosuppressants (IS) are key therapy agents after liver transplant. Different ISs have different side effects. Calcineurin inhibitor (CNI) may lead to metabolic acidosis while mycophenolate mofetil (MMF) showed rare nephrotoxicity. We report a post-liver transplant girl who was infected with SARS-CoV-2, developing a severe mixed acidosis 3 months after the transplantation. Her acidosis was improved after withdrawing of MMF, leading the suspicion that acidosis maybe a rare side effect of MMF.Case presentationA girl was admitted to our hospital due to SARS-CoV-2 infection, 3 months before admission the patient received LT due to Niemann-Pick disease (NPD). During hospitalization, blood gas analysis showed severe mixed acidosis. To relieve mixed acidosis, the patient was given oral rehydration salt and liquid replacement therapy. Considering that immunosuppressants may cause metabolic acidosis, dose of CsA was decreased and MMF was discontinued.ResultsHowever, liquid replacement therapy and decreased CsA dose cannot improve the condition. As an attempt, MMF was discontinued, and 3 days later, the girl’s acidosis was relieved, the latest blood gas analysis was normal with the original dose of CsA and no use of MMF or other IS. In addition, we used Naranjo Scale to see if adverse drug reactions (ADRs) existed. The final score was 6 which means MMF contributes to acidosis probably.ConclusionThe girl’s mixed acidosis cannot be explained by Niemann-Pick disease and SARS-CoV-2 infection. CNIs could cause metabolic acidosis but declining the dose of CsA didn’t improve her acidosis while withdrawing MMF showed a good effect. Together with the Naranjo Scale result, we suspect that acidosis maybe a rare side effect of MMF.

Background: ANK1 mutations are usually related to hereditary spherocytosis. Few studies show direct relationships between ANK1 mutations and liver damage. Recent researches revealed that ANK1 mutations may downregulate the expression of hepcidin, a key hepatic hormone important to iron homeostasis. Hepcidin deficiency can induce iron overload that do harm to liver cells and cause ferroptosis.Case Presentation: In both cases, yellowing of skin and hepatomegaly were found. Lab results showed increased alanine aminotransferase (ALT) and aspartate aminotransferases (AST). Genetic tests confirmed de novo heterozygous mutations in ANK1 gene. Liver biopsy of one child indicated mild liver damage. Prussian blue staining revealed iron accumulation. Conclusions: Here we report 2 cases featuring ANK1 mutations with liver damage of unidentified causes. We suspect that ANK1 mutation is related to liver damage through decreasing hepcidin, which may cause iron overload and then ferroptosis.

Background Arthrogryposis-renal dysfunction-cholestasis (ARC) syndrome is a rare disease with a high mortality rate caused by VPS33B or VIPAS39 mutations. ARC syndrome typically presents with arthrogryposis, renal tubular leak and neonatal cholestatic jaundice, and most patients with this disease do not survive beyond one year. Case presentation Here, we report the case of a 13-year-old girl with ARC featuring an incomplete and mild phenotype with novel compound heterozygous mutations of VPS33B. The patient presented with arthrogryposis (claw-shaped limbs), ichthyosis, jaundice, and pruritus. Laboratory tests revealed highly evaluated levels of total bilirubin (TB), direct bilirubin (DB), and total bile acid (TBA) as well as normal levels of gamma-glutamyltransferase (GGT). However, signs of renal dysfunction, as well as other manifestations of ARC syndrome, including nervous system abnormalities, deafness, and failure to thrive, were not observed. The patient’s clinical symptoms of jaundice and pruritus were significantly alleviated by administration of ursodeoxycholic acid. Whole-exome sequencing (WES) revealed novel compound heterozygous mutations of VPS33B, c.1081 C > T (p.Q361X,257)/c.244 T > C (p.C82R). Both variants were predicted to be pathogenic in silico and have never been reported previously. To date, the patients’ cholestatic jaundice has been well controlled with continuous treatment of ursodeoxycholic acid. Conclusions We report the case of a Chinese female with ARC including novel compound heterozygous mutations of VPS33B and an incomplete and mild phenotype. Early diagnosis and suitable symptomatic therapies are critical for the management of ARC patients with mild manifestations and prolonged lifespan.