Plasma Immune Biomarkers Predictive of Progression to Active Tuberculosis in Household Contacts of TB Patients.

BACKGROUND: The progression from Mycobacterium tuberculosis infection to active tuberculosis (TB) disease varies among individuals, and identifying biomarkers to predict progression is crucial for guiding interventions. In this study, we aimed to determine plasma immune biomarker profiles in healthy household contacts of index pulmonary TB (PTB) patients who either progressed to TB or remained as non-progressors. METHODS: A cohort of household contacts of adults with PTB was enrolled, consisting of 15 contacts who progressed to TB disease and 15 non-progressors. Plasma samples were collected at baseline, 4 months, and 12 months to identify predictive TB progression markers. RESULTS: Our findings revealed that individuals in the progressor group exhibited significantly decreased levels of IFNγ, IL-2, TNFα, IL1α, IL1ß, IL-17A, and IL-1Ra at baseline, months 4 and 12. In contrast, the progressor group displayed significantly elevated levels of IFNα, IFNß, IL-6, IL-12, GM-CSF, IL-10, IL-33, CCL2, CCL11, CXCL8, CXCL10, CX3CL1, VEGF, Granzyme-B and PDL-1 compared to the non-progressor group at baseline, months 4 and 12. ROC analysis identified IFNγ, GM-CSF, IL-1Ra, CCL2 and CXCL10 as the most promising predictive markers, with an AUC of ≥90. Furthermore, combinatorial analysis demonstrated that GM-CSF, CXCL10 and IL-1Ra, when used in combination, exhibited high accuracy in predicting progression to active TB disease. CONCLUSIONS: Our study suggests that a specific set of plasma biomarkers GM-CSF, CXCL10 and IL-1Ra, can effectively identify household contacts at significant risk of developing TB disease. These findings have important implications for early intervention and preventive strategies in TB-endemic regions.

Relative contribution of biomedical, demographic, and socioeconomic factors to COVID-19 vaccine receipt in rural India.

BACKGROUND: In the first year of roll-out, vaccination for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) prevented almost 20 million deaths from coronavirus disease 2019 (COVID-19). Yet, little is known about the factors influencing access to vaccination at the individual level within rural poor settings of low-income countries. The aim of this study was to examine determinants of vaccine receipt in rural India. METHODS: A census of a rural village in Tamil Nadu was undertaken from June 2021 to September 2022. We surveyed 775 participants from 262 households. Household-level data on socioeconomic status (SES), water, sanitation, and hygiene practices, and individual-level demographic information, travel history, and biomedical data, including anthropometry, vital signs, and comorbidities, were collected. Logistic regression models with 5-fold cross-validation were used to identify the biomedical, demographic, and socioeconomic determinants of vaccine receipt and the timing of receipt within the first 30 days of eligibility. Vaccine ineligible participants were excluded leaving 659 eligible participants. There were 650 eligible participants with complete biomedical, demographic, and socioeconomic data. RESULTS: There were 68.0% and 34.0% of individuals (N = 650) who had received one and two vaccine doses, respectively. Participants with household ownership of a permanent account number (PAN) or ration card were 2.15 (95% CI:1.32-3.52) or 3.02 (95% CI:1.72-5.29) times more likely to receive at least one vaccine dose compared to households with no ownership of such cards. Participants employed as housewives or self-employed non-agricultural workers were 65% (95% CI:0.19-0.67) or 59% (95% CI:0.22-0.76) less likely to receive at least one vaccine dose compared to salaried workers. Household PAN card ownership, occupation and age were linked to the timing of vaccine receipt. Participants aged ≤18 and 45-60 years were 17.74 (95% CI:5.07-62.03) and 5.51 (95% CI:2.74-11.10) times more likely to receive a vaccine within 30 days of eligibility compared to 19-44-year-olds. Biomedical factors including BMI, vital signs, comorbidities, and COVID-19 specific symptoms were not consistently associated with vaccine receipt or timing of receipt. No support was found that travel history, contact with COVID-19 cases, and hospital admissions influenced vaccine receipt or timing of receipt. CONCLUSION: Factors linked to SES were linked to vaccine receipt, more so than biomedical factors which were targeted by vaccine policies. Future research should explore if government interventions including vaccine mandates, barriers to vaccine access, or peer influence linked to workplace or targeted vaccine promotion campaigns underpin these findings.

Impact of Strongyloides stercoralis infection on complement activation in Type 2 diabetes mellitus: Insights from a clinical and anthelmintic intervention study.

BACKGROUND: Numerous studies indicate a potential protective role of helminths in diabetes mellitus (DM) progression. The complement system, vital for host defense, plays a crucial role in tissue homeostasis and immune surveillance. Dysregulated complement activation is implicated in diabetic complications. We aimed to investigate the influence of the helminth, Strongyloides stercoralis (Ss) on complement activation in individuals with type 2 DM (T2D). METHODOLOGY: We assessed circulating levels of complement proteins (C1q, C2, C3, C4, C4b, C5, C5a, and MBL (Lectin)) and their regulatory components (Factor B, Factor D, Factor H, and Factor I) in individuals with T2D with (n = 60) or without concomitant Ss infection (n = 58). Additionally, we evaluated the impact of anthelmintic therapy on these parameters after 6 months in Ss-infected individuals (n = 60). RESULTS: Ss+DM+ individuals demonstrated reduced levels of complement proteins (C1q, C4b, MBL (Lectin), C3, C5a, and C3b/iC3b) and complement regulatory proteins (Factor B and Factor D) compared to Ss-DM+ individuals. Following anthelmintic therapy, there was a partial reversal of these levels in Ss+DM+ individuals. CONCLUSION: Our findings indicate that Ss infection reduces complement activation, potentially mitigating inflammatory processes in individuals with T2D. The study underscores the complex interplay between helminth infections, complement regulation, and diabetes mellitus, offering insights into potential therapeutic avenues.

Hookworm infection induces glycometabolic modulation in South Indian individuals with type 2 diabetes.

Objectives: A number of epidemiological studies have demonstrated that there is an inverse relationship between helminth infections and diabetes mellitus, suggesting that helminth infection may have a positive effect on type 2 diabetes mellitus (T2DM). However, the association between hookworm infection and T2DM has barely been studied. Hence, we aimed to investigate and analyze the interaction and association between hookworm infection and T2DM. Methods: We examined the effect of hookworm infection on biochemical parameters, including plasma random blood glucose, glycated hemoglobin, and the plasma levels of pancreatic hormones, incretins, and adipokines in individuals with T2DM with (INF, n = 35) or without (UN, n = 35) hookworm infection. Moreover, we re-evaluated these analyte concentrations in a subset of INF individuals 6 months following anthelmintic therapy. Results: Compared to UN individuals, INF individuals had significantly lowered levels of random blood glucose and glycated hemoglobin. INF individuals also exhibited significantly diminished levels of adiponectin, adipsin, C-peptide, insulin, and glucagon compared to UN individuals. In contrast, INF individuals displayed substantially elevated levels of visfatin and incretins compared to UN individuals. Interestingly, this effect was not seen following anthelmintic treatment. Conclusion: Our study findings indicate that concomitant hookworm infection exerts a beneficial effect on glycometabolic parameters in T2DM.

Levels of Complement Components in Children With Acute COVID-19 or Multisystem Inflammatory Syndrome.

Importance: Multisystem inflammatory syndrome in children (MIS-C) is a severe and unrestrained inflammatory response with multiorgan involvement, which occurs within a few weeks following the resolution of acute SARS-CoV-2 infection. The complement system is a vital part of the innate immune system and plays a role in COVID-19 pathogenesis. Objective: To examine and compare the levels of complement components and regulators along with complement activation products in the different clinical spectrum of children with SARS-CoV-2 and a control group. Design, Setting, and Participants: This cross-sectional study analyzed children with MIS-C admitted to a single hospital in India from June through September 2020. Eligible participants were children who were hospitalized of either sex, aged 1 to 18 years. Data were analyzed August 2022. Measures: Levels of complement components and regulators along with complement activation products in all the groups of children. Mann-Whitney U test and Kruskal-Wallis analysis were used to compare the complement component levels, and Spearman rank correlation analysis was used to describe the association between complement components and laboratory and biochemical parameters. Results: A total 145 children were included (median age, 5 years [range, 1 month-17 years); 84 [58%] male): 44 children with MIS-C, 33 with acute COVID-19 (reverse transcriptase-polymerase chain reaction [RT-PCR] positive), 47 with convalescent COVID-19 (immunoglobulin G-positive non-MIS-C) and 21 children for a control group (both serology and RT-PCR negative). Children with MIS-C and COVID-19 had higher levels of C1q (geometric mean [SD]: MIS-C, 61.5 [18.5] ng/mL; acute COVID-19, 56.9 [18.6] ng/mL; controls, 24.1 [3.3] ng/mL), C2 (MIS-C, 605.8 [219.7] ng/mL; acute COVID-19, 606.4 [167.7] ng/mL; controls, 255.9 [73.3] ng/mL), C3 (MIS-C, 318.2 [70.7] ng/mL; acute COVID-19, 237.7 [61.8] ng/mL; controls, 123.4 [15.7] ng/mL), C4b (MIS-C, 712.4 ng/mL; acute COVID-19, 640.7 ng/mL; controls, 351.5 ng/mL), C5 (MIS-C, 1487 ng/mL; acute COVID-19, 1364 ng/mL; controls, 561.9 ng/mL), C5a, (MIS-C, 2614.0 [336.2] ng/mL; acute COVID-19, 1826.0 [541.0] ng/mL; controls, 462.5 [132.4] ng/mL), C3b/iC3b (MIS-C, 3971.0 [635.1] ng/mL; acute COVID-19, 3702.0 [653.9] ng/mL; controls, 2039.0 [344.5] ng/mL), and factor B (MIS-C, 47.6 [7.8] ng/mL; acute COVID-19, 44.6 [6.3] ng/mL; controls, 27.5 [5.0] ng/mL), factor D (MIS-C, 44.0 [17.2] ng/mL; acute COVID-19, 33.8 [18.4] ng/mL; controls, 21.3 [6.1] ng/mL), and factor H (MIS-C, 53.1 [4.0] ng/mL; acute COVID-19, 50.8 [5.7] ng/mL; controls, 43.6 [3.8] ng/mL) in comparison with convalescent and control children. In addition, children with MIS-C had significantly elevated levels of C3 (318.2 [70.7] ng/mL vs 237.7 [61.8] ng/mL), C5a (2614 [336.2] ng/mL vs 1826 [541.0] ng/mL), and mannose-binding lectin (79.4 [12.4] ng/mL vs 69.6 [14.7] ng/mL) in comparison to children with acute COVID-19. Levels of some of these analytes at admission (ie, pretreatment) were more elevated in children with MIS-C who needed pediatric intensive care unit (PICU) support as compared with those who did not require PICU support, and in children with COVID-19 who developed moderate to severe disease compared with those who developed mild disease. Overall, MIS-C and acute COVID-19 were associated with the hyperactivation of complement components and complement regulators. Conclusions and Relevance: In this cross-sectional study, the complement system was associated with the pathogenesis of MIS-C and COVID-19 in children; complement inhibition could be further explored as a potential treatment option.