Factors affecting TST level in patients undergoing dialysis: a multicenter study

Latent tuberculosis diagnostics: current scenario and review

This review presents a comprehensive examination of the contemporary landscape pertaining to latent tuberculosis infection (LTBI) diagnostics, with a particular emphasis on the global ramifications and the intricacies surrounding LTBI diagnosis and treatment. It accentuates the imperative of bolstering diagnostic, preventive, and treatment modalities for tuberculosis (TB) to fulfill the ambitious targets set forth by the World Health Organization aimed at reducing TB-related mortalities and the incidence of new TB cases. The document underscores the significance of addressing LTBI as a means of averting the progression to active TB, particularly in regions burdened with high TB prevalence, such as India. An in-depth analysis of the spectrum delineating latent and active TB disease is provided, elucidating the risk factors predisposing individuals with LTBI to progress towards active TB, including compromised immune functionality, concurrent HIV infection, and other immunosuppressive states. Furthermore, the challenges associated with LTBI diagnosis are elucidated, encompassing the absence of a definitive diagnostic assay, and the merits and demerits of tuberculin skin testing (TST) and interferon-γ release assays (IGRAs) are expounded upon. The document underscores the necessity of confronting these challenges and furnishes a meticulous examination of the advantages and limitations of TST and IGRAs, along with the intricacies involved in interpreting their outcomes across diverse demographics and settings. Additionally, attention is drawn towards the heritability of the interferon-γ response to mycobacterial antigens and the potential utility of antibodies in LTBI diagnosis.

Latent Tuberculosis: Challenges in Diagnosis and Treatment, Perspectives, and the Crucial Role of Biomarkers

Tuberculosis (TB) is the major cause of morbidity and mortality globally, which is caused by a single infectious agent Mycobacterium tuberculosis. For years, many TB control programmes are established for effective diagnosis and treatment of active TB cases, but these approaches alone are insufficient for TB eradication. This review aims to discourse on the crucial management of latent tuberculosis infection. This review will first summarize the current status, and methods for diagnosing latent tuberculosis then describes the challenges involved in the diagnosis and treatment of latent tuberculosis, and finally encounters the purpose of biomarkers as predicting tool in latent tuberculosis.

The Interferon-Gamma Release Assay versus the Tuberculin Skin Test in the Diagnosis of Mycobacterium tuberculosis Infection in BCG-Vaccinated Children and Adolescents Exposed or Not Exposed to Contagious TB

BACKGROUND

Children have an increased risk of developing active tuberculosis (TB) after exposure to Mycobacterium tuberculosis (M.tb), and they are more likely to develop the most severe forms of TB. Rapid diagnosis and treatment of latent M.tb infection (LTBI) is essential to lessen the devastating consequences of TB in children.

OBJECTIVE

The aim of the study was to evaluate TST (tuberculin skin test) and IGRA (interferon-gamma release assay) utility in identifying LTBI in a cohort of Bacille Calmette-Guérin (BCG)-vaccinated Polish children and adolescents exposed or not exposed to contagious TB. In addition, we asked whether quantitative assessment of IGRA results could be valuable in predicting active TB disease.

RESULTS

Of the 235 recruited volunteers, 89 (38%) were TST-positive (TST+), 74 (32%) were IGRA-positive (IGRA+), and 62 (26%) were both TST+ and IGRA+. The frequency of TST positivity was significantly higher in the group with (59%) than without TB contact (18%). The percentage of TST+ subjects increased with age from 36% in the youngest children (<2 years) to 47% in the oldest group (>10 years). All positive IGRA results were found solely in the group of children with TB contact. There was a significant increase in the rate of positive IGRA results with age, from 9% in the youngest to 48% in the oldest group. The 10 mm TST cutoff showed good sensitivity and specificity in both TB exposed and nonexposed children and was associated with excellent negative predictive value, especially among nonexposed volunteers. Mean IFN-γ concentrations in IGRA cultures were significantly higher in the group of LTBI compared to the children with active TB disease, both TST+ and TST-.

CONCLUSIONS

Both TST and IGRA can be used as screening tests for BCG-vaccinated children and adolescents exposed to contagious TB.

Screening and testing for latent tuberculosis infection among patients who are immunocompromised

ABSTRACT

It is critical to detect latent tuberculosis infection through screening and testing individuals at high risk of progression to active tuberculosis, including patients who are immunocompromised. NPs should be familiar with available testing for accurate diagnosis in order to expedite treatment.

Diagnosis for Latent Tuberculosis Infection: New Alternatives

Latent tuberculosis infection (LTBI) is a subclinical mycobacterial infection defined on the basis of cellular immune response to mycobacterial antigens. The tuberculin skin test (TST) and the interferon gamma release assay (IGRA) are currently used to establish the diagnosis of LTB. However, neither TST nor IGRA is useful to discriminate between active and latent tuberculosis. Moreover, these tests cannot be used to predict whether an individual with LTBI will develop active tuberculosis (TB) or whether therapy for LTBI could be effective to decrease the risk of developing active TB. Therefore, in this article, we review current approaches and some efforts to identify an immunological marker that could be useful in distinguishing LTBI from TB and in evaluating the effectiveness of treatment of LTB on the risk of progression to active TB.

The relationship between lymphocyte subsets, nutritional status and tuberculin reactivity in continuous ambulatory peritoneal dialysis and hemodialysis patients

Aim

Skin test anergy is common in patients with uremia and during maintenance hemodialysis treatment. However, up to date only one study concerning skin test in peritoneal dialysis patients has focused on the issue. Our cross-sectional controlled study was conducted to analyze the correlation of purified protein derivative (PPD) test response with demographical features, nutritional parameters and the distribution of peripheral blood lymphocyte subsets in peritoneal dialysis and hemodialysis patients

Patients and methods

Stable 30 hemodialysis (HD) patients (16 men, 14 women) and 30 continuous ambulatory peritoneal dialysis (PD) patients (17 men, 13 women) were included. Thirty healthy cases (15 men, 15 women) with a mean age of 32.4 ± 9.4 constituted the control group.

Results

In the HD group, 14 patients (46.6%) were PPD positive, and ın the PD group 16 patients (53.3%) were PPD positive. In the PPD-positive HD patients 64.2% (9/14), and in the PPD-positive PD patients 62.4% (10/16) had an induration of 10 mm or greater. In the control group, 21 of 30 patients (70%) were PPD positive. Comparison of both HD and PD groups with the control group showed significant differences in PPD reactivity (p < 0.01). Albumin levels were significantly high in the control groups (p < 0.01), and cholesterol levels were significantly high in the PD and the control groups (p < 0.05). Transferrin levels were significantly high in the PD (p < 0.01). The lymphocyte counts were significantly high in the control group compared to the HD patients (p < 0.05). The lymphocyte subset percentages CD19 were high in the control groups (p < 0.05), and CD16/56 was significantly high in the PD groups (p < 0.05). All the parameters were also similar between PPD-positive and -negative same groups.

Conclusion

The prevalence of PPD positivity was lower in the PD and HD groups. The PPD test responses were not related to the peripheral lymphocyte counts, subsets and malnutrition parameters.