Intestinal microbiota composition of children with infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and multisystem inflammatory syndrome (MIS-C).

Microbiota composition may play a role in the development, prognosis, or post-infection of COVID-19. There are studies evaluating the microbiota composition at the time of diagnosis and during the course of COVID-19, especially in adults, while studies in children are limited and no study available in children with multisystem inflammatory syndrome in children (MIS-C). This study was planned to compare intestinal microbiota composition in children diagnosed with MIS-C and acute COVID-19 infection with healthy children. In this prospective multicenter study, 25 children diagnosed with MIS-C, 20 with COVID-19 infection, and 19 healthy children were included. Intestinal microbiota composition was evaluated by 16 s rRNA gene sequencing. We observed changes of diversity, richness, and composition of intestinal microbiota in MIS-C cases compared to COVID-19 cases and in the healthy controls. The Shannon index was higher in the MIS-C group than the healthy controls (p < 0.01). At phylum level, in the MIS-C group, a significantly higher relative abundance of Bacteroidetes and lower abundance of Firmicutes was found compared to the control group. Intestinal microbiota composition changed in MIS-C cases compared to COVID-19 and healthy controls, and Faecalibacterium prausnitzii decreased; Bacteroides uniformis, Bacteroides plebeius, Clostridium ramosum, Eubacterium dolichum, Eggerthella lenta, Bacillus thermoamylovorans, Prevotella tannerae, and Bacteroides coprophilus were dominant in children with MIS-C. At species level, we observed decreased Faecalibacterium prausnitzii, and increased Eubacterium dolichum, Eggerthella lenta, and Bacillus thermoamylovorans in children with MIS-C and increased Bifidobacterium adolescentis and Dorea formicigenerasus in the COVID-19 group. Our study is the first to evaluate the microbiota composition in MIS-C cases. There is a substantial change in the composition of the gut microbiota: (1) reduction of F. prausnitzii in children with MIS-C and COVID-19; (2) an increase of Eggerthella lenta which is related with autoimmunity; and (3) the predominance of E. dolichum is associated with metabolic dysfunctions and obesity in children with MIS-C. CONCLUSIONS:  Alterations of the intestinal microbiota might be part of pathogenesis of predisposing factor for MIS-C. It would be beneficial to conduct more extensive studies on the cause-effect relationship of these changes in microbiota composition and their effects on long-term prognosis. WHAT IS KNOWN: • Microbiota composition may play a role in the development, prognosis, or post-infection of COVID-19.  • However, the number of studies on children is limited, and no study on multisystem inflammatory syndrome in children is currently available (MIS-C). WHAT IS NEW: • In individuals with MIS-C, the composition of the gut microbiota changed dramatically. • Decreased Faecalibacterium prausnitzii have been observed, increased Eggerthella lenta, which was previously linked to autoimmunity, and predominance of Eubacterium dolichum which was linked to metabolic dysfunction and obesity.

Investigation of the relationship of CO-RADS and CT patterns with laboratory parameters in COVID-19 patients and a new perspective on the total CT scoring system.

BACKGROUND: It is important to determine the correlation of the CO-RADS classification and computed tomography (CT) patterns of the lung with laboratory data. To investigate the relationship of CO-RADS categories and CT patterns with laboratory data in patients with a positive RT-PCR test. We also developed a structured total CT scoring system and investigated its correlation with the total CT scoring system. METHOD: The CT examinations of the patients were evaluated in terms of the CO-RADS classification, pattern groups and total CT score. Structured total CT score values were obtained by including the total CT score values and pattern values in a regression analysis. The CT data were compared according to the laboratory data. RESULTS: A total of 198 patients were evaluated. There were significant differences between the CO-RADS groups in terms of age, ICU transfer, oxygen saturation, creatinine, LDH, D-dimer, high-sensitivity cardiac troponin-T (hs-TnT), CRP, structured total CT score values, and total CT score values. A significant difference was also observed between the CT pattern groups and oxygen saturation, creatinine and CRP values. When the structured total CT score values and total CT score values were compared they were observed to be correlated. CONCLUSIONS: Creatinine can be considered as an important marker for the CO-RADS and pattern classifications in lung involvement. LDH can be considered as an important marker of parenchymal involvement, especially bilateral and diffuse involvement. The structured total CT scoring system is a new system that can be used as an alternative.

Correlation of Indeterminate Lesions of COVID-19 Pneumonia Detected on Computed Tomography with RT-PCR Results.

BACKGROUND: The typical findings of COVID-19 pneumonia include multilobar groundglass opacities and consolidation areas observed predominantly in the basal and peripheral parts of both lungs in computed tomography. OBJECTIVE: The current study aimed to correlate indeterminate lesions of COVID-19 pneumonia detected on computed tomography with the results of the reverse transcription-polymerase chain reaction (RT-PCR) test. METHODS: Patients with high-resolution computed tomography images that were reported to contain indeterminate lesions in terms of COVID-19 pneumonia were included retrospectively in the study. The lesions were categorized and the patterns were classified. The RT-PCR-positive and the RTPCR- negative patients were compared. P<0.05 was accepted as the statistical significance limit. RESULTS: The RT-PCR-positive patients exhibited a higher rate of peripheral lesions. Limited consolidation areas were not detected in the RT-PCR-positive patients. In the RT-PCR-negative patients, the rates of acinar nodules and the tree-in-bud pattern were significantly higher. The RTPCR- negative patients had higher nodular contour features and lesion coalescence. In the subgroup consisting of lesions with ground-glass opacities and/or ground-glass opacity around the nodule, the rate of nodular contour positivity was significantly higher in the RT-PCR- positive patients. CONCLUSION: COVID-19 pneumonia should be suspected when peripheral indeterminate lesions are detected. When indeterminate lesions, such as tree-in-bud pattern, acinar nodules and limited consolidation area are detected, alternative diagnoses should be considered first, even if there are ground glass opacities accompanying these lesions.