Background Vitamin D deficiency has been associated with an increased risk of respiratory infections. Objectives The study aimed to evaluate the serum 25-hydroxyvitamin D [25(OH)D] concentration in patients admitted to the intensive care unit (ICU) as a predictor of coronavirus disease 2019 (COVID-19) mortality. Methods A single-center retrospective observational study was conducted. Forty adult patients (50% men) with confirmed COVID-19 who were admitted to the ICU were enrolled. The primary endpoint was mortality at day 60. Serum 25(OH)D concentration was measured on the day of admission to the ICU. We used the Mann–Whitney test, Fisher's exact test, Kaplan–Meier analysis, and receiver operator characteristic (ROC) analysis to assess serum 25(OH)D concentration as a predictor of COVID-19 mortality. Results All 40 patients had a low median (IQR) serum 25(OH)D concentration at admission [12 (9–15) ng/mL]. The median (IQR) serum 25(OH)D concentration was greater in survivors [13.3 (10.0–17.1) ng/mL, n = 22] than in nonsurvivors [9.6 (7.9–14.2) ng/mL; n = 18], P = 0.044. The area under the ROC curve was 0.69 (95% CI: 0.52, 0.86; P = 0.044). The 60-d mortality rate of those with serum 25(OH)D concentrations ≤9.9 ng/mL (n = 14, 71%) tended to be greater than that of those with concentrations >9.9 ng/mL (n = 26, 31%) (P = 0.065), and they had a 5.6-fold higher risk of death (OR: 5.63; 95% CI: 1.35, 23.45; P = 0.018). Conclusions The ICU patients had a low serum 25(OH)D concentration. Serum 25(OH)D concentrations ≤9.9 ng/mL on admission can be used to predict in-hospital mortality in patients with COVID-19. This trial was registered at clinicaltrials.gov as NCT04450017.

Vitamin D as an immunomodulator has not been studied in patients with severe COVID-19. This study aimed to estimate the efficacy of vitamin D3 supplementation on cellular immunity and inflammatory markers in patients with COVID-19 admitted to the intensive care unit (ICU). A single-center, double-blind, randomized, placebo-controlled pilot trial was conducted (N = 110). Patients were randomly assigned to receive a weekly oral dose of 60,000 IU of vitamin D3 followed by daily maintenance doses of 5000 IU (n = 55) or placebo (n = 55). Primary outcomes were lymphocyte counts, natural killer (NK) and natural killer T (NKT) cell counts, neutrophil-to-lymphocyte ratio (NLR), and serum levels of inflammatory markers on 7th day of treatment. On day 7, patients in the vitamin D3 group displayed significantly higher NK and NKT cell counts and NLR than those in the placebo group did. The mortality rate (37% vs 50%, P = 0.16), need for mechanical ventilation (63% vs 69%, P = 0.58), incidence of nosocomial infection (60% vs 41%, P = 0.05) did not significantly differ between groups. Vitamin D3 supplementation, compared with placebo, significantly increased lymphocyte counts, but did not translate into reduced mortality in ICU.Trial Registration: ClinicalTrials.gov Identifier: NCT05092698.

The microbiota of the respiratory tract remains a relatively poorly studied subject. At the same time, like the intestinal microbiota, it is involved in modulating the immune response to infectious agents in the host organism. A causal relationship between the composition of the respiratory microbiota and the likelihood of development and the severity of COVID-19 may be hypothesized. We analyze biomaterial from nasopharyngeal smears from 336 patients with a confirmed diagnosis of COVID-19, selected during the first and second waves of the epidemic in Russia. Sequences from a similar study conducted in Spain were also included in the analysis. We investigated associations between disease severity and microbiota at the level of microbial community (community types) and individual microbes (differentially represented species). To search for associations, we performed multivariate analysis, taking into account comorbidities, type of community and lineage of the virus. We found that two out of six community types are associated with a more severe course of the disease, and one of the community types is characterized by high stability (very similar microbiota profiles in different patients) and low level of lung damage. Differential abundance analysis with respect to comorbidities and community type suggested association of Rothia and Streptococcus genera representatives with more severe lung damage, and Leptotrichia, unclassified Lachnospiraceae and Prevotella with milder forms of the disease.

Background. Providing an efficient care to the patients of the most severely affected category ICU patients has become one of the serious problems appearing in the COVID-19 pandemics. A typical patients clinical portrait in ICUs of COVID centers is very similar in different countries, however, the key to improve the treatment results for critically ill patients has not yet been found. Currently, 160 patients have been treated in the ICU of the FRCC of the FMBA of Russia. To May 16, 2020, the lethality in the ICU was 48.9% by the closed cases, the lethality among the patients on ventilation was 57.9%. The aim of the study is to identify predictors of the severe pneumonia caused by the SARS-CoV-2 virus, and to describe the clinical characteristics of patients admitted to an intensive care unit of the COVID-center of the Federal Research Clinical Center of FMBA of Russia. Methods. In this report, we describe the clinical, laboratory and instrumental data of 70 patients admitted to the ICU, and discuss the found predictors of the severe COVID-19 pneumonia course. Results. The following factors have been determined which contribute to the development of the severe course of the disease and to the risk of the unfavorable outcome: male gender, age older than 70.5 years, initial lymphocytopenia of lower than 0.98109/l, neutrophil to lymphocyte ratio of higher than 7.75, D-dimer level of higher than 0.85 g/ml, IL-6 of higher than 184.7 pg/ml, procalcitonin of higher than 0.22 ng/ml, hyperglycemia of higher than 9 mmol/l, signs of myocardial damage (high-sensitive troponin Т of higher than 22 pg/ml, echocardiography data), signs of the presence of a secondary bacterial infection and a severe vitamin D deficiency (lower than 9.9 ng/ml). The pathophysiological basics for the contribution of each factor to the severe course of the disease are provided. Conclusions. Clinical features of the patients change in course of pandemia. These influenced by changes in treatment approaches and new discoveries in disease pathophysiology. Above mentioned predictors of severe course of disease is partly modifiable and we are able to influence them and perhaps achieve better results in treatment of severe patients with COVID-19

The SARS-CoV-2 pandemic is a big challenge for humanity. The COVID-19 severity differs significantly from patient to patient, and it is important to study the factors protecting from severe forms of the disease. Respiratory microbiota may influence the patient's susceptibility to infection and disease severity due to its ability to modulate the immune system response of the host organism. This data article describes the microbiome dataset from the upper respiratory tract of SARS-CoV-2 positive patients from Russia. This dataset reports the microbial community profile of 335 human nasopharyngeal swabs collected between 2020-05 and 2021-03 during the first and the second epidemic waves. Samples were collected from both inpatients and outpatients in 4 cities of the Russian Federation (Moscow, Kazan, Irkutsk, Nizhny Novgorod) and sequenced using the 16S rRNA gene amplicon sequencing of V3-V4 region. Data contains information about the patient such as age, sex, hospitalization status, percent of damaged lung tissue, oxygen saturation (SpO2), respiratory rate, need for supplemental oxygen, chest computer tomography severity score, SARS-CoV-2 lineage, and also information about smoking and comorbidities. The amplicon sequencing data were deposited at NCBI SRA as BioProject PRJNA751478.