Mannose-binding lectin (MBL) mediates protection against infections by using the complement system, but certain microorganisms may increase infectivity by exploiting this host defense system. Thus, it has been speculated whether genetically determined low MBL levels may confer partial protection against certain intracellular microorganisms, such as Mycobacterium tuberculosis. We investigated MBL alleles in 109 culture-positive human immunodeficiency virus-uninfected patients with tuberculosis living in Denmark and 250 white control subjects. Patients and control subjects were divided into 3 different groups defined by undetectable, low, and high serum MBL concentrations, which correlates to deficient, low, and high expressing MBL genotypes. A significantly decreased frequency of patients with the low-expressing MBL genotype was observed in white patients compared to control subjects. The same tendency also was observed in patients of other ethnic origin. It may be hypothesized that heterozygosity for MBL variant alleles, which encodes low serum MBL levels, is associated with protection against clinical tuberculosis.

Vitamin D is essential to immune function, but little is known about the vitamin D status in equatorial populations. A cross-sectional study was conducted among pulmonary tuberculosis (PTB) patients in Mwanza, Tanzania to identify the predictors of their vitamin D status. Data on sociodemography, season, and intake of food, alcohol, tobacco, and soil were collected, anthropometric measurements taken, and serum alpha(1)-antichymotrypsin (ACT), ferritin and soluble transferrin receptor (sTfR), and serum 25-hydroxy-(ergocalciferol+cholecalciferol) [25(OH)D] determined. Of the 655 patients studied, 79.7% (508/637) were culture-positive (PTB+) and 47.2% HIV infected. Mean serum ACT, an acute phase reactant, was 0.73 +/- 0.25 g/L with 69.2% >0.6 g/L. Mean serum 25(OH)D was 86.6 +/- 32.9 nmol/L, with 41.2% <75 nmol/L. Serum 25(OH)D was highest during the harvest season, May to July, compared with the remaining year. Single subjects had lower [10.4 (95% CI 4.0; 16.9) nmol/L] serum 25(OH)D concentrations than married subjects and PTB+ patients had concentrations lower [8.2 (95% CI 1.5; 14.9) nmol/L] than PTB- patients. Serum 25(OH)D increased with consumption of a large freshwater fish but not of small dried fish or other foods. BMI and serum TfR were positive predictors of serum 25(OH)D, whereas neither elevated serum ACT nor HIV were predictors. In conclusion, serum 25(OH)D is a valid measure of vitamin D status during the acute phase response. The lower concentrations in PTB+ patients may reflect lower sun exposure or increased utilization. The health consequences of hypovitaminosis D in low-income equatorial populations, at risk for both infectious and chronic diseases, should be studied.

Background There is limited data on outcomes of moderate to severe Coronavirus disease 2019 (COVID-19) among patients treated with remdesivir and dexamethasone in a real-world setting. Objective To compare the effectiveness of standard of care (SOC) alone vs SOC plus remdesivir and dexamethasone. Methods Two population-based nationwide cohorts of individuals hospitalized with COVID-19 during February through December 2020. Death within 30 days and need of mechanical ventilation (MV) were compared by inverse probability of treatment weighted (ITPW) logistic regression analysis and shown as odds ratio (OR) with 95% confidence interval (CI). Results The 30-d mortality rate of 1694 individuals treated with remdesivir and dexamethasone in addition to SOC was 12.6% compared to 19.7% for 1053 individuals receiving SOC alone. This corresponded to a weighted OR of 30-day mortality of 0.47 (95% CI, 0.38-0.57) for patients treated with remdesivir and dexamethasone compared to patients receiving SOC alone. Similarly, progression to MV was reduced (OR 0.36 (95% CI, 0.29-0.46)). Conclusions and relevance Treatment of moderate to severe COVID-19 during June through December that included remdesivir and dexamethasone was associated with reduced 30-day mortality and need of MV compared to treatment in February through May.

Our study confirms the presence of ESAT-6 and CFP-10 antibodies in patients with TB, and we demonstrate that significant antibody responses are not restricted to active TB disease but can reflect latent infection, particularly in areas with high levels of exposure to M. tuberculosis. This finding is important for the understanding of the poor discriminatory power of current serodiagnostic tests in regions of endemicity, and it may have major implications on the future development of serologic tests.