Evidence map›Paper›PMID 41468475›Full record

ArticlePloS one2025

Individuals with latent tuberculosis in a high TB endemic country show mild COVID-19.

Uzair Abbas, Kiran Iqbal Masood, Tulaib Iqbal, Bushra Jamil, Shama Qaiser, Maliha Yameen, Martin Rottenberg, Rabia Hussain, Zahra Hasan

Abstract read
In one paragraph

Article in PloS one, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 2 papers.

0numbers the graph read from it
0cells of the map it votes in
2citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

2 citing papers in PubMed.

  1. Article
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4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

9 authors.

Uzair AbbasDepartment of Pathology and Laboratory Medicine, Aga Khan University, Karachi, Pakistan.ORCID https://orcid.org/0000-0003-0517-247X
Kiran Iqbal MasoodDepartment of Pathology and Laboratory Medicine, Aga Khan University, Karachi, Pakistan.
Tulaib IqbalDepartment of Pathology and Laboratory Medicine, Aga Khan University, Karachi, Pakistan.
Bushra JamilDepartment of Infectious Diseases, Aga Khan University, Karachi, Pakistan.
Shama QaiserDepartment of Pathology and Laboratory Medicine, Aga Khan University, Karachi, Pakistan.
Maliha YameenDepartment of Pathology and Laboratory Medicine, Aga Khan University, Karachi, Pakistan.
Martin RottenbergDepartment of Microbiology, Tumor and Cell biology, Karolinska Institute, Stockholm, Sweden.
Rabia HussainDepartment of Pathology and Laboratory Medicine, Aga Khan University, Karachi, Pakistan.
Zahra HasanDepartment of Pathology and Laboratory Medicine, Aga Khan University, Karachi, Pakistan.ORCID https://orcid.org/0000-0001-7580-372X

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

introductionInfection with Mycobacterium tuberculosis (MTB) may result in active tuberculosis (TB), bacterial clearance, or asymptomatic latent infection (LTBi). During the COVID-19 pandemic, interactions between MTB and SARS-CoV-2 infections were coincident in high TB burden countries such as Pakistan. The impact of LTBi on COVID-19 is not well understood. Here we investigated the association of LTBi with COVID-19 and its severity by determining cellular activation to MTB, IgG antibody responses and expression of genes associated with host immunity.

methodsAge and sex matched Healthy Controls (HC, n = 147) and COVID-19 patients (n = 128) were recruited in this cross-sectional study. COVID-19 was categorized as ambulatory (n = 103) or hospitalized (n = 25) disease. LTBi was determined using the X.DOT-TB ELISpot assay. RT-PCR based mRNA levels of IFN-γ, IFN-α, IL-6, IL-10, OAS1, MAVS, SOCS1 and SOCS3 were determined in PBMCs. IgG to SARS-CoV-2 and rubella virus were measured.

resultsWe found that 18% of COVID-19 patients and 32% of HC were LTBi positive (p < 0.0001). All COVID-19 LTBi positive cases had ambulatory disease. Logistic regression analysis revealed individuals with LTBi to have a 54% lower risk of COVID-19. The frequency of MTB-specific IFN-γ producing T cells was lower in COVID-19 patients than in HC LTBi positive individuals (p = 0.0095). The presence of a BCG scar was not associated with the occurrence of COVID-19. Levels of IgG antibodies to SARS-CoV-2 were raised in COVID-19 cases but did not differ by LTBi status in HC or COVID-19 groups. IgG levels to rubella virus were similar regardless of LTBi status in control and patient groups. COVID-19 cases displayed higher expression of mRNA levels of MAVS, OAS-1, and SOCS3 (p < 0.05). Further, OAS-1 expression was raised in LTBi positive COVID-19 group as compared to the LTBi positive HC group (p = 0.019).

conclusionsWe observed that T cell reactivity to MTB was associated with milder COVID-19. Reduced severity of COVID-19 and higher OAS-1 gene expression in COVID-19 LTBi positive individuals suggest a protective effect in these individuals. Further studies are required to investigate the combined impact of MTB and SARS-CoV-2 infections in the host.

Indexed as

COVID-19Latent TuberculosisAdultCase-Control StudiesCross-Sectional StudiesFemaleHumansImmunoglobulin GMaleMiddle AgedMycobacterium tuberculosisPakistanSARS-CoV-2Immunoglobulin G

Identifiers

PMID41468475
PMCPMC12753056

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.