Search Results (928)

Background/Objectives: Tuberculosis remains one of the preventable causes of mortality among liver transplant recipients. The prevalence of tuberculosis in solid organ transplant recipients is higher than in the general population. The aim of this study was to evaluate the incidence of latent tuberculosis infection (LTBI) and active tuberculosis after liver transplantation. Methods: This is a retrospective, single-center, case–control study. Adult liver transplant candidates who were evaluated between 1 January 2016 and 31 December 2022 were retrospectively assessed. Patients with pre-transplant tuberculin skin test (TST) and/or interferon-gamma release assay (IGRA) results who underwent transplantation were included in this study. Results: A total of 111 liver transplant recipients with available IGRA and/or TST results were included; 70 were men (63.1%) and 41 were women (36.9%), with a mean age of 53.5 ± 11.3 years. Demographic, clinical, and laboratory characteristics were evaluated. The most common indication for liver transplantation was viral hepatitis (33.3%), followed by cryptogenic cirrhosis (19.8%) and hepatocellular carcinoma (10.8%). All patients had a Bacillus Calmette–Guérin (BCG) vaccination scar. Ten patients received grafts from deceased donors, while 101 underwent living-donor liver transplantation. No patient received LTBI treatment before transplantation, whereas LTBI treatment was initiated in four patients after transplantation. None of the patients had a diagnosis of active tuberculosis prior to transplantation. Thoracic computed tomography revealed findings compatible with tuberculosis sequelae in 11 patients (9.9%). During a median follow-up period of 49 [27–64] months after transplantation, no cases of active tuberculosis were observed among patients with positive TST and/or IGRA results. Patients were divided into two groups according to their TST and IGRA results. Group 1 consisted of patients with IGRA positivity and/or a TST ≥ 5 mm, while Group 2 included patients with a TST < 5 mm and negative IGRA results. The only statistically significant difference between the groups was the administration of LTBI treatment (p = 0.027); four patients in Group 1 received LTBI therapy. None of these patients were able to continue prophylaxis due to treatment-related adverse effects. Conclusions: Prophylaxis with hepatotoxic agents poses a substantial risk in liver transplant candidates. Since the hepatotoxicity may cause early cessation of LTBI treatment, the risk–benefit ratio of post-transplant LTBI therapy should be carefully assessed. In situations where LTBI treatment is deferred, close clinical monitoring is strongly recommended. Full article

Background: Patients with latent tuberculosis infection are mainly asymptomatic, but they still carry a notable risk of developing active TB, particularly when the host becomes immunosuppressed. Hence, appropriate diagnosis and management for LTBI are essential. Tuberculin skin test (TST) and interferon-gamma release assays (IGRAs) are among the most commonly utilized methods for detecting LTBI. Until now, no agreement has been established regarding the most effective diagnostic test, either TST or IGRA, so our study aims to evaluate the diagnostic utility of TST versus IGRA in detecting LTBI. Methods: An extensive literature search was executed in several databases from inception till June 2024. We included all the available studies that compared TST versus IGRA concurrently applied to the same study participants, utilizing one of the following proxy reference standards: previous contact with a tuberculosis patient, tuberculosis history, chest x-ray suggestive of tuberculosis, or a combination of them. The sensitivity (SN) and specificity (SP) were imputed with their 95% confidence interval (CI). A bivariate random-effects model within the OpenMeta-Analyst software was utilized for data analysis. Results: We included 39 studies, and our primary analysis regarding LTBI revealed that TST has an SN of 0.320 (95% CI [0.254–0.393]) and an SP of 0.808 (95% CI [0.752–0.854]). Nevertheless, the IGRA exhibited a higher SN estimated at 0.362 (95% CI [0.295–0.434]) and a lower SP estimated at 0.758 (95% CI [0.700–0.808]). Regarding the adult population, TST consistently showed a lower SN and a higher SP relative to IGRA. However, within the pediatric population, TST showed higher SN and lower SP when compared to IGRA. Furthermore, TST also showed a lower SN and a higher SP within hemodialysis and organ transplant patients than IGRA. Conclusions: Our diagnostic test meta-analysis revealed that TST was associated with a lower SN and a higher SP than IGRA. Clinicians should interpret these findings with caution, considering the substantial heterogeneity observed across the included studies, the reliance on proxy reference standards, the potential influence of BCG vaccination status, and the considerable overlap in confidence intervals between TST and IGRA estimates across most analyses. Full article

Stem cells, also known as progenitor cells, can differentiate into specialized cells for specific tissues. Genetic mutations and epigenetic changes may cause normal stem cells to become cancer-initiating cells. Research indicates that cells acquiring a mutation for myeloproliferative neoplasm (MPN) are likely to be long-term hematopoietic stem cells (LT-HSCs) at the top of the hematopoietic hierarchy. Natural killer (NK) cells play a crucial role in combating cancer by targeting and eliminating cancer stem cells (CSCs) while promoting their maturation. NK cells do this through direct lysis of CSCs or by releasing cytokines like interferon-gamma (IFN-γ) and tumor necrosis factor-alpha (TNF-α), which inhibit tumor growth and metastasis by driving differentiation of CSCs. Interleukin-2 (IL-2) enhances the activity of CD4+ and CD8+ T cells and boosts NK cell cytotoxicity. This study highlights a case of MPN with a more clinically aggressive Type 1 calreticulin (CALR) mutation, where a combination of low-dose IL-2 immunotherapy and targeted therapy with oral tretinoin (all-trans retinoic acid, ATRA, a vitamin A derivative) improved immune cells, particularly NK-cell-mediated destruction of malignant cells, reduced CALR mutation levels to undetectable, and alleviated disease symptoms. The aim is to offer a new, low-toxicity personalized treatment strategy that eradicates cancer-initiating stem cells, reduces side effects, and provides an option for patients with limited conventional therapy alternatives. Full article

Myocarditis has been described following SARS-CoV-2 infection. The mechanisms underlying COVID-19-associated myocarditis remain incompletely understood. Peripheral blood mononuclear cells (PBMCs), IgG fractions, and myocardial biopsy tissue were obtained from a patient with COVID-19 myocarditis. Cellular responses to SARS-CoV-2 spike protein and myocardial tissue extract were assessed in vitro. PBMCs and purified IgG were passively transferred into Rag2/IL2RG-/- mice. Interferon-gamma (IFN-γ) production and cardiac IFN-γ transcript levels were measured. PBMCs from the myocarditis patient proliferated in response to spike protein and myocardial tissue extract, whereas PBMCs from a healthy control did not. PBMCs from the patient secreted higher concentrations of IFN-γ compared with the healthy control. Introduction of patient PBMCs or IgG into Rag2/IL2RG-/- mice resulted in higher cardiac IFN-γ transcript levels compared with control PBMCs or IgG. These findings demonstrate cellular reactivity to SARS-CoV-2 spike protein and myocardial tissue, increased IFN-γ production, and induction of cardiac IFN-γ expression following passive transfer of immune components. Full article

Approximately 25% of the global population is estimated to have latent tuberculosis infection (LTBI), with a 5–10% lifetime risk of progression to active disease. Although interferon-gamma release assays (IGRAs) are widely used for LTBI diagnosis, their high cost and operational complexity limit large-scale implementation in resource-limited settings. This study evaluated the diagnostic performance of a low-complexity, rapid, fluorescence-based point-of-care assay, ichroma IGRA-TB, for LTBI detection. A total of 300 participants enrolled at TB Screening and Treatment Centers and the Dhaka Hospital of icddr,b were categorized as healthy controls (n = 130), household contacts of TB patients (n = 70), GeneXpert MTB/RIF Ultra-positive active TB patients (n = 80), or individuals with a previous history of TB (n = 20). ichroma IGRA-TB was compared with QuantiFERON-TB Gold Plus (QFT-Plus) across all groups. Overall agreement between ichroma IGRA-TB and QFT-Plus was 91.9%, with a Cohen’s kappa of 0.83, indicating almost perfect concordance. Using culture as a surrogate reference standard, QFT-Plus demonstrated higher sensitivity (74.6%) than ichroma IGRA-TB (69.0%). Overall, ichroma IGRA-TB demonstrates high agreement with QFT-Plus and acceptable sensitivity, supporting its potential as a near-point-of-care tool for LTBI screening in resource-constrained settings. Full article

Background/Objectives: Epidemiological studies have proven that coxsackievirus B3 (CVB3) is the major virus that causes acute and chronic myocarditis and pancreatitis. Currently, there are no antiviral therapeutic drugs or vaccines that are available for use as clinical therapeutics or vaccines. Subunit polypeptides-based vaccines, especially when combined with adjuvants, represent safe and effective vaccine platforms because they are considered to be better immunogens. The viral capsid protein VP1 of CVB3 is the most immunogenic viral polypeptide, providing opportunities for its use in designing subunit polypeptide vaccines. In the present study, we designed and produced a CVB3 vaccine candidate based on the recombinant expression of the major immunogenic viral protein VP1 of a wild-type CVB3 strain. Methods: We assessed its induced humoral and cellular immune responses and then evaluated its protective immunity against pathogenic CVB3 strain challenges in a Balb/c mouse model. Neutralizing specific antibodies and cytokine interferon gamma (INF-γ) production were determined in the sera of both prime- and prime-boost-immunized mice with the vaccine candidate. Results: Our results demonstrate that the recombinant rVP1 expressed in a eukaryotic insect cell baculovirus vector system elicited cellular and humoral immune responses, protecting Balb/c mice from lethal challenges. Conclusions: Hence, the vaccine produced based on the recombinant expression of VP1 is a promising and potential candidate against natural CVB3 infections. Full article

Severe fever with thrombocytopenia syndrome (SFTS) is a newly discovered tick-borne disease caused by SFTS virus (SFTSV) infection. Patients present with high fever, thrombocytopenia, and multiple organ dysfunction, with a high mortality rate and a lack of specific treatment, all of which indicate that research on the deterioration mechanism and treatment of this disease is urgent. Currently, multiple studies have indicated that cytokine storm is one of the core factors contributing to the deterioration of the disease. SFTSV inhibits the host’s type I interferon response through its non-structural protein NSs, thereby promoting immune evasion and viral replication. Extensive viral stimulation leads to dysfunction and abnormal polarization of immune cells (including monocytes, macrophages, dendritic cells, T cells, and B cells), triggering the massive release of pro-inflammatory factors(such as interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), and interleukin-1 beta (IL-1β)), anti-inflammatory factors (such as interleukin-10 (IL-10)), and chemokines(such as interferon-gamma inducible protein 10 (IP-10), monocyte chemoattractant protein-1 (MCP-1), and interleukin-8 (IL-8)). This cytokine storm exacerbates the imbalance between pro-inflammatory and anti-inflammatory factors, as well as immune paralysis, leading to vascular endothelial damage, microthrombosis, and ultimately, multi-organ failure, which determines the clinical outcome. Simultaneously, specific cytokines and immune cell phenotypes can serve as biomarkers for disease severity and prognosis. In terms of treatment, this article further summarizes the intervention strategies targeting the aforementioned immune links, including intravenous immunoglobulin (IVIG), tocilizumab (targeting the IL-6 receptor), inhibitors of Janus kinase (JAK) and nuclear factor-kappa B (NF-κB) signaling pathways, interferon, neutralizing antibodies, and other immunotherapy methods. By analyzing the dynamic changes and mechanisms of cytokine storm in the course of SFTS, and summarizing current potential immunotherapy methods, this article aims to provide a theoretical framework for the future treatment of SFTS. Full article

Cyanobacteria of the genus Phormidesmis are recognized as a promising source of biologically active secondary metabolites with anticancer and immunomodulatory properties. In the present study, we investigated both the cytotoxic and immunological effects of an extract obtained from Phormidesmis molle PACC (Plovdiv Algal Culture Collection) 8140 as well as its chemical composition. The extract was profiled by LC-ESI-MS/MS (Liquid chromatography—electrospray ionization—tandem mass spectrometry), and selected compounds were evaluated with in silico ADMET (Absorption, distribution, metabolism, excretion and toxicity) modeling. The cytotoxic potential of the extract was evaluated in vitro using the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) assay on human colorectal adenocarcinoma cell lines (Caco-2, HT-29, and LS-180). The immunological impact of the extract was assessed on human peripheral blood mononuclear cells (PBMCs) isolated from healthy donors. PBMCs were treated with 100 µg/mL extract for 48 h, followed by flow cytometric immunophenotyping and ELISA (Enzyme-linked immunosorbent assay)-based cytokine quantification. The extract induced a concentration- and time-dependent decrease in cancer cell viability after 24, 48, and 72 h of exposure. At 72 h, treatment with the highest concentration (200 µg/mL) reduced cell viability to 74% in Caco-2 cells, 69–70% in HT-29 cells, and 59–61% in LS-180 cells. Morphological changes observed after treatment with Phormidesmis extract showed pronounced cytotoxic and apoptosis-related effects in the colorectal cancer cell lines tested. Immunophenotyping revealed a pronounced expansion of natural killer (NK) cells (CD56⁺ and/or CD16⁺). CD3⁻CD56⁻CD16⁺ NK population was markedly increased (from 67.7 ± 0.95% in non-treated PBMCs to 94.66 ± 0.90% in extract-treated PBMCs, p < 0.001). In contrast, the proportions of CD8⁺ T cells, CD19⁺ B cells, and CD11b⁺ monocytes were significantly reduced (from 21.5 ± 4.50% to 7.22 ± 0.41%, from 11.9 ± 1.70% to 6.06 ± 0.42%, and from 66.4 ± 0.60% to 34.4 ± 0.87%, respectively). Cytokine analysis demonstrated strong suppression of Th1-associated cytokines, with significantly reduced interferon gamma (IFN-γ, 461 ng/mL in controls vs. 84 ng/mL in extract-treated cultures) and tumor necrosis factor alpha (TNF-α) levels (169 ng/mL in controls vs. 32 ng/mL in extract-treated cultures), whereas nterleukin-6 (IL-6) was moderately elevated (from 158 ng/mL in controls to 234 ng/mL in extract-treated cultures) and IL-10 remained low. These findings demonstrate that P. molle extract combines cytotoxic activity against cancer cells with potent immunomodulatory effects, highlighting its potential as a source of bioactive compounds for immune-based therapeutic strategies. Full article

Autoinflammatory diseases are characterized by inappropriate activation of innate immunity resulting in excessive or persistent inflammation in the absence of infection. γδ T cells possess innate-like properties, including rapid responsiveness to stress-induced self-molecules, phosphoantigens, and inflammasome-derived cytokines, while retaining adaptive effector functions. Neutrophils and macrophages are well-established drivers of autoinflammatory disease, but increasing evidence implicates γδ T cells as key intermediaries by linking innate immune activation to tissue-specific inflammatory pathology. Here, we review evidence that in both monogenic and multifactorial autoinflammatory diseases—including, for example, familial Mediterranean fever, hyper-immunoglobulin (Ig) D syndrome, gout, Behçet’s disease, Still’s disease, atherosclerosis, and neurodegenerative disorders—γδ T cells display altered frequencies, activation states, cytokine polarization, and tissue recruitment. In inflammasome-driven diseases, skewing of γδ T cells toward interleukin (IL)-17 production has been observed, often accompanied by reduced interferon (IFN)γ secretion, thereby amplifying neutrophilic inflammation and tissue damage. In other diseases, e.g., Behcet’s disease, IFNγ and tumor necrosis factor (TNF)α producton predominate. Transcriptomic and tissue-based analyses support the accumulation and functional specialization of γδ T cells at sites of sterile inflammation. Collectively, these findings position γδ T cells as central amplifiers and modulators of inappropriate innate immune activation in the context of autoinflammatory diseases. Improved understanding of γδ T cell subset-specific regulation may inform novel therapeutic strategies targeting autoinflammatory diseases. Full article

Congenital toxoplasmosis (CT) results from vertical transmission of Toxoplasma gondii during maternal infection in pregnancy. Early diagnosis in newborns is crucial to initiate timely therapy and prevent long-term sequelae. The IgM Immunosorbent Agglutination Assay (ISAGA) has historically been considered an important diagnostic tool for CT; however, its recent market withdrawal necessitates alternative approaches. We conducted a retrospective observational study at Fondazione IRCCS Policlinico San Matteo, Pavia, Italy, including 44 newborns born to mothers with confirmed toxoplasmosis between 2019 and 2022. Newborns were classified as CT (n = 19) or non-CT (n = 25) based on serological follow-up, comparative Western blot (CWB) and Interferon Gamma Release Assay (IGRA). Sensitivity and specificity of CWB, IgM Chemiluminescent Immunoassay (CLIA), and IgM ISAGA were assessed at birth and at one month. At birth, CWB demonstrated 88.9% sensitivity, significantly higher than IgM CLIA (52.6%) and IgM ISAGA (57.9%). Specificity was 100% at birth and 92% at one month. CWB retained high sensitivity at one month (81.8%). IGRA complemented CWB in confirming or excluding infection in cases with equivocal or false-negative serology. Comparative Western blot thus represents a robust diagnostic alternative for CT, ensuring early detection and timely treatment, particularly in the absence of IgM ISAGA. Full article

Background/Objectives: Latent tuberculosis infection (LTBI) represents a critical reservoir for subsequent development of active tuberculosis (ATB) and poses significant challenges for early diagnosis and disease prevention. Traditional immunological assays, such as interferon-gamma release assays (IGRAs), are limited in their ability to reliably distinguish LTBI from ATB. Recent advances in high-throughput omics technologies and machine learning (ML) approaches offer new opportunities for precise, biomarker-based differential diagnostics. Methods: Transcriptomic and proteomic profiling of host immune responses has revealed reproducible gene and protein signatures associated with LTBI and ATB. The integration of ML techniques—including feature selection, dimensionality reduction, multimodal learning, and explainable AI—facilitates the construction of robust diagnostic models. Single-modality signatures, derived from RNA-seq, microarrays, or proteomic assays, are complemented by multimodal approaches that incorporate soluble mediators, immunological readouts, and imaging-derived features. Deep learning frameworks, such as convolutional neural networks and transformer-based architectures, enhance the extraction of complex molecular and structural patterns from high-dimensional datasets. Results: ML-driven analyses of transcriptomic and proteomic data consistently outperform conventional immunological tests in terms of sensitivity, specificity, and clinical applicability. Multimodal integration further improves diagnostic accuracy and robustness. These advances support the translational development of concise, quantitative reverse transcription PCR (qRT-PCR)-based biomarker panels suitable for routine clinical application, enabling early and reliable differentiation between LTBI and ATB. Overall, the combination of high-throughput omics and AI-based analytical frameworks provides a promising pathway for enhancing global tuberculosis diagnostics. Conclusions: This review provides a structured and critical synthesis of transcriptomic and proteomic biomarker research for LTBI and ATB discrimination, with a particular emphasis on machine learning–based analytical frameworks. Unlike previous narrative reviews, we systematically compare data-generating platforms, modelling strategies, validation approaches, and sources of heterogeneity across studies. We further identify key translational barriers, including cohort homogeneity, platform dependency, and limited external validation, and propose directions for future research aimed at improving clinical applicability. Full article

Duck Tembusu virus (DTMUV), an emerging Flavivirus, is a major avian pathogen that imposes enormous economic losses on the global duck industry, necessitating urgent development of effective countermeasures. Although Interferon-gamma (IFNγ) is a crucial broad-spectrum antiviral cytokine, its role against DTMUV infection remains mechanistically undefined. In this study, we first demonstrated that DTMUV induced duck IFNγ (duIFNγ) production in immune and non-immune cells. Importantly, duIFNγ exhibited a dual anti-DTMUV function in vitro: it not only prevented viral replication but also displayed the capacity to clear existing virus from infected cells. Mechanistically, cycloheximide (CHX) experiments confirmed that duIFNγ exerts its antiviral effect by disrupting the viral RNA synthesis/translation phase. Furthermore, transcriptomic profiling (RNA-seq) precisely revealed that duIFNγ restricts DTMUV replication by activating multiple host defense pathways, notably Programmed Cell Death (e.g., Caspase signaling) and the RIG-I-like Receptor (RLR) signaling pathways. Collectively, these findings provide critical insights into the function and mechanism of duIFNγ in combating DTMUV in vitro, laying a robust theoretical foundation for exploring duIFNγ or its induced effectors as novel therapeutics for DTMUV infection. Full article

Neoadjuvant systemic therapy (NST) is standard for locally advanced breast cancer (BC), yet predictors of pathological complete response (pCR) remain elusive. While Natural Killer (NK) cells are vital for anti-tumor response, their specific receptor dynamics during NST are poorly defined. This study provides a high-dimensional characterization of the peripheral NK cell landscape and immune signatures associated with therapeutic success. This prospective cohort study included 34 BC patients and 35 healthy donors (HD). Clinical characteristics were collected, and peripheral blood NK cell subsets were evaluated. We utilized high-parameter flow cytometry and unsupervised clustering (UMAP) to longitudinally track NK cell phenotypes (NKG2D, DNAM-1, PD-1, TIGIT) pre- and post-NST. NK cell cytotoxicity was evaluated, and serum levels of related IL-17A (interleukin), IL-2, IL-4, IL-10, IL-6, TNF-α (tumor necrosis factor-alpha), Fas, sFasL, IFN-γ (interferon-gamma), and Granzyme A were analyzed. Patients exhibited distinct NK cell profiles according to the pathological response. Only 12 BC patients achieved pCR. These patients showed improved NK cell cytotoxicity and higher concentrations of IL-2, TNF-α, sFASL, and Granzyme B after treatment compared with Non-pCR patients. In contrast, in Non-pCR patients, the percentages of CD56^bright NK cells increased after neoadjuvant therapy, whereas the more cytotoxic CD56^dim NK cell population decreased. Additionally, NK cells from Non-pCR patients exhibited higher co-expression of inhibitory checkpoints (TIGIT and PD-1), indicating reduced NK cell function. Otherwise, pCR patients displayed a more favorable balance of activating receptors (NKG2D and DNAM-1), and a favorable shift in the TIGIT/DNAM-1 activating-to-inhibitory axis. This study highlights the potential role of NK cells in determining the response to neoadjuvant therapy in BC patients. Those who achieved pCR showed enhanced NK cell activity and higher expression of activating receptors. Moreover, NK cells from Non-pCR patients showed lower cytotoxicity and higher expression of inhibitory receptors. These results suggest that NK cell phenotype evaluation could serve as a biomarker of treatment response in patients with BC. They also showed that the TIGIT/DNAM-1 axis can be a critical determinant of pCR. Full article

Autoimmune diseases result from a breakdown of immune tolerance influenced by genetic and environmental factors. Regulatory T cells (Tregs) maintain immune homeostasis, while interferon-γ (IFNγ) has context-dependent proinflammatory and regulatory roles. In B10.S mice, mercury-induced autoimmunity (HgIA) emerges within approximately 4 weeks of Hg exposure and is marked by antinucleolar antibody (ANoA) production, polyclonal B-cell activation, and deposition of immune complexes in the kidney. We investigated whether Tregs attenuate HgIA and evaluated IFNγ’s role in this regulation. Female WT and IFNγ^−/− B10.S mice received HgCl₂ or water for 4 weeks until all mice developed ANoA. CD4⁺CD25⁺Foxp3⁺ Tregs or CD4⁺CD25⁻Foxp3⁻ cells were transferred into HgCl₂-exposed WT recipients and monitored for 13 weeks. Compared with Hg-primed non-Tregs, Hg-primed WT Tregs were statistically associated with significantly reduced autoantibody levels, lower IgG1/IgG2a, and significantly decreased glomerular IgG/C3c deposition, suggesting that Hg exposure may modulate Treg function. Conversely, both water- and Hg-primed Tregs and non-Tregs from IFNγ^−/− donors elicited profoundly diminished autoantibody production and renal pathology in recipients. IFNγ^−/− mice lacked fibrillarin-specific responses, highlighting its requirement for HgIA initiation. While non-Treg transfer failed to suppress HgIA, Treg transfer reduced HgIA and highlighted relevance for immune-regulatory therapies, especially where environmental toxicants may drive autoimmune disease. Full article

Latent tuberculosis infection (LTBI) represents a major global health concern as it constitutes the principal reservoir for future tuberculosis (TB) disease. Its identification is particularly important in Bacille Calmette–Guérin (BCG)-vaccinated populations, where cross-reactivity of purified protein derivative limits the specificity of the tuberculin skin test and hampers targeted preventive therapy. Early Mycobacterium tuberculosis antigens encoded within the RD1 region, especially ESAT-6, CFP-10 and TB7.7, have enabled the development of antigen-specific interferon-gamma release assays (IGRAs) and recombinant skin tests with improved BCG-independent specificity. This narrative review integrates and critically appraises current evidence on the immunobiological properties of early and latency-associated antigens, the cellular mechanisms underlying T-cell-dependent immune reactivity, and the diagnostic performance of IGRAs and ESAT-6/CFP-10-based skin tests, rather than merely summarizing individual studies. Although these platforms rely on different assay principles (in vitro cytokine release versus in vivo delayed-type hypersensitivity), both measure antigen-specific T-cell memory and do not define the biological stage of infection or reliably distinguish latent from incipient or active TB. Across most adult populations, IGRAs demonstrate high specificity and acceptable sensitivity, whereas reduced sensitivity and higher rates of indeterminate results are observed in young children and immunocompromised individuals. ESAT-6/CFP-10-based skin tests show diagnostic accuracy comparable to IGRAs and may offer operational advantages in resource-limited settings. Latency-associated antigens and host biomarkers such as IP-10, together with multi-analyte immune signatures, represent promising avenues for improving diagnostic sensitivity and prognostic stratification but currently lack sufficient validation for routine clinical use. Overall, RD1-encoded antigens remain central to LTBI immunodiagnosis, while future research should focus on developing stage-resolving and prognostic biomarkers, optimized antigen panels, and standardized interpretive frameworks. Full article