Diagnosis of extra pulmonary tuberculosis: An update on novel diagnostic approaches.

Tuberculosis (TB) remains a major global public health problem worldwide. Though Pulmonary TB (PTB) is mostly discussed, one in five cases of TB present are extrapulmonary TB (EPTB) that manifests conspicuous diagnostic and management challenges with respect to the site of infection. The diagnosis of EPTB is often delayed or even missed due to insidious clinical presentation, pauci-bacillary nature of the disease, and lack of laboratory facilities in the resource limited settings. Culture, the classical gold standard for the diagnosis of tuberculosis, suffers from increased technical and logistical constraints in EPTB cases. Other than culture, several other tests are available but their feasibility and effciacy for the detection of EPTB is still the matter of interest. We need more specific and precise test/s for the various forms of EPTB diagnosis which can easily be applied in the routine TB control program is required. A test that can contribute remarkably towards improving EPTB case detection reducing the morbidity and mortality is the utmost requirement. In this review we described the scenario of molecular and other noval methods available for laboratory diagnosis of EPTB, and also discussed the challenges linked with each diagnostic method. This review will make the readers aware of new emerging diagnostic techniques in the field of EPTB diagnosis. They can make an informed decision to choose the appropriate one according to the test availability, their clinical settings and financial considerations.

Stress resilience in patients with drug-resistant TB.

BACKGROUND: The worldwide increase in drug-resistant pulmonary TB (DR-PTB) has a significant impact on patient´s physical and mental health. The objective of this study is to assess the stress resilience of DR-PTB patients along with the factors associated with it.METHODS: A total of 385 adult DR-PTB patients with multidrug-resistant (MDR) and pre-extensive drug-resistant (pre-XDR) TB admitted to the National Institute of Diseases of the Chest Hospital (Dhaka, Bangladesh) between January 2020 and March 2021 were conveniently recruited. Resilience data were collected using a validated Stress Resilience Scale (RS 25) questionnaire.RESULTS: The mean resilience scores were significantly higher for patients with MDR-PTB than those with pre-XDR-PTB (P = 0.02). A majority of the MDR-PTB (77.0%) and pre-XDR-PTB (65.1%) patients belonged to the ≤45 years age group. Multiple linear regression revealed that sex (P < 0.001), level of education (P < 0.001), employment status (P = 0.003) and presence of asthma (P = 0.010) were significantly associated with stress resilience.CONCLUSION: We observed that stress resilience significantly differed between patients with MDR-PTB and those with pre-XDR-PTB based on sociodemographic characteristics.

Clinical Profile, Treatment, and Outcome of Patients with Secondary Hemophagocytic Lymphohistiocytosis in Critically Ill Patients: A Prospective Observational Study.

Introduction: The objective of the study was to evaluate the clinical profile and outcome of patients with secondary hemophagocytic lymphohistiocytosis (HLH) in critically ill patients. Materials and methods: A prospective observational study was conducted where critically ill adult patients presenting with fever and bicytopenia were evaluated according to the HLH-2004 diagnostic criteria for the presence of secondary HLH. The underlying trigger, clinical profile, treatment, and outcome of patients with HLH were analyzed. Results: Of the 76 critically ill patients with fever and bicytopenia, 33 (43%) patients were diagnosed with HLH. The following triggers for HLH were identified: bacterial infections (23%), fungal infections (10%), viral infections (10%), parasitic infections (10%), autoimmune diseases (13%), and malignancy (8%). A total of 78% of the HLH cases received steroids, but the use of steroids was not associated with improvement in mortality. Conclusion: There is a high prevalence of HLH in patients presenting with fever and bicytopenia in critically ill adult patients. Infections were identified as the most common trigger of HLH. How to cite this article: Fazal F, Gupta N, Soneja M, Mitra DK, Satpathy G, Panda SK, et al. Clinical Profile, Treatment, and Outcome of Patients with Secondary Hemophagocytic Lymphohistiocytosis in Critically Ill Patients: A Prospective Observational Study. Indian J Crit Care Med 2022;26(5):564-567.

Intracellular cytokine expression in invasive fungal sinusitis and its impact on patient outcome.

BACKGROUND: Cell-mediated immunity plays an important role in host defence against fungal pathogens, regulated by differentiation of lymphocytes towards T-helper 1 or 2 cells. This study reports intracellular cytokine variation in terms of invasive fungal sinusitis type and outcome. METHODS: The mononuclear leukocytes of 15 patients with invasive fungal sinusitis (mucormycosis in 8, aspergillus in 7) were stained with antibodies against intracellular cytokines, after fungal antigen stimulation and culture, and immunophenotyped. Patients were followed up for six months, with clinical course categorised as improvement, worsening or death. RESULTS: The mean percentages of mononuclear cells producing interleukins 4, 5, 10 and 12, and interferon-γ, in the mucormycosis group were 0.575, 0.284, 8.661, 4.460 and 1.134, respectively, while percentages in the aspergillosis group were 0.233, 0.492, 4.196, 4.466 and 1.533. Cells producing interleukin 4 and 10 were higher in the mucormycosis group, while those producing interleukin-12 and interferon-γ were lower. Cells producing interleukins 4 and 12 were higher in patients with a poor outcome (p-values of 0.0662 and 0.0373, respectively), while those producing interferon-γ were lower (p = 0.0864). CONCLUSION: Adaptive cell-mediated immunity is expressed differently in two categories of invasive fungal sinusitis, and the cytokine expression pattern is related to prognosis.

CD4+ CD25+ FOXP3+ T cell frequency in the peripheral blood is a biomarker that distinguishes intestinal tuberculosis from Crohn's disease.

BACKGROUND: Distinguishing between Crohn's Disease (CD) and Intestinal Tuberculosis (ITB) has been a challenging task for clinicians due to their similar presentation. CD4+FOXP3+ T regulatory cells (Tregs) have been reported to be increased in patients with pulmonary tuberculosis. However, there is no such data available in ITB. The aim of this study was to investigate the differential expression of FOXP3+ T cells in patients with ITB and CD and its utility as a biomarker. METHODS: The study prospectively recruited 124 patients with CD, ITB and controls: ulcerative colitis (UC) and patients with only haemorrhoidal bleed. Frequency of CD4+CD25+FOXP3+ Tregs in peripheral blood (flow cytometry), FOXP3 mRNA expression in blood and colonic mucosa (qPCR) and FOXP3+ T cells in colonic mucosa (immunohistochemistry) were compared between controls, CD and ITB patients. RESULTS: Frequency of CD4+CD25+FOXP3+ Treg cells in peripheral blood was significantly increased in ITB as compared to CD. Similarly, significant increase in FOXP3+ T cells and FOXP3 mRNA expression was observed in colonic mucosa of ITB as compared to CD. ROC curve showed that a value of >32.5% for FOXP3+ cells in peripheral blood could differentiate between CD and ITB with a sensitivity of 75% and a specificity of 90.6%. CONCLUSION: Phenotypic enumeration of peripheral CD4+CD25+FOXP3+ Treg cells can be used as a non-invasive biomarker in clinics with a high diagnostic accuracy to differentiate between ITB and CD in regions where TB is endemic.

T cell suppression in the bone marrow of visceral leishmaniasis patients: impact of parasite load.

Visceral leishmaniasis (VL) is a disseminated and lethal disease of reticulo-endothelial system caused by protozoan parasites Leishmania donovani and L. infantum, which are known to induce host T cell suppression. To understand the impact of parasite load on T cell function, the present was focused on parasite load with T cell function in bone marrow of 26 VL patients. We observed significant enrichment of forkhead box protein 3 (FoxP3)+ (P = 0·0003) and interleukin (IL)-10+ FoxP3+ regulatory T cells (Treg ) (P = 0·004) in the bone marrow (BM) of patients with high parasite load (HPL) compared with low parasite load (LPL). Concordantly, T effector cells producing interferon (IFN)-γ (P = 0·005) and IL-17A (P = 0·002) were reduced in the BM of HPL. Blocking of Treg -cell derived suppressive cytokines [(IL-10 and transforming growth factor (TGF)-ß] rescued the effector T cells and their functions. However, it was observed that TGF-ß levels were dominant, favouring Treg cell differentiation. Furthermore, the low ratio of IL-6/TGF-ß favours the suppressive milieu in HPL patients. Here we show the change in levels of various cytokines with the parasitic load during active VL, which could be helpful in devising newer immunotherapeutic strategies against this disease.

Exonal switch down-regulates the expression of CD5 on blasts of acute T cell leukaemia.

To date, CD5 expression and its role in acute T cell lymphoblastic leukaemia (T-ALL) have not been studied closely. We observed a significant reduction in surface expression of CD5 (sCD5) on leukaemic T cells compared to autologous non-leukaemic T cells. In this study, we have shown the molecular mechanism regulating the expression and function of CD5 on leukaemic T cells. A total of 250 patients suffering from leukaemia and lymphoma were immunophenotyped. Final diagnosis was based on their clinical presentation, morphological data and flow cytometry-based immunophenotyping. Thirty-nine patients were found to be of ALL-T origin. Amplification of early region of E1A and E1B transcripts of CD5 was correlated with the levels of surface and intracellular expression of CD5 protein. Functional studies were performed to show the effect of CD5 blocking on interleukin IL-2 production and survival of leukaemic and non-leukaemic cells. Lack of expression of sCD5 on T-ALL blasts was correlated closely with predominant transcription of exon E1B and significant loss of exon E1A of the CD5 gene, which is associated with surface expression of CD5 on lymphocytes. High expression of E1B also correlates with increased expression of cytoplasmic CD5 (cCD5) among leukaemic T cells. Interestingly, we observed a significant increase in the production of IL-2 by non-leukaemic T cells upon CD5 blocking, leading possibly to their increased survival at 48 h. Our study provides understanding of the regulation of CD5 expression on leukaemic T cells, and may help in understanding the molecular mechanism of CD5 down-regulation.

Programmed death-1+ T cells inhibit effector T cells at the pathological site of miliary tuberculosis.

Optimal T cell activation is vital for the successful resolution of microbial infections. Programmed death-1 (PD-1) is a key immune check-point receptor expressed by activated T cells. Aberrant/excessive inhibition mediated by PD-1 may impair host immunity to Mycobacterium tuberculosis infection, leading to disseminated disease such as miliary tuberculosis (MTB). PD-1 mediated inhibition of T cells in pulmonary tuberculosis and TB pleurisy is reported. However, their role in MTB, particularly at the pathological site, remains to be addressed. The objective of this study was to investigate the role of PD-1-PD-ligand 1 (PD-L1) in T cell responses at the pathological site from patients of TB pleurisy and MTB as clinical models of contained and disseminated forms of tuberculosis, respectively. We examined the expression and function of PD-1 and its ligands (PD-L1-PD-L2) on host immune cells among tuberculosis patients. Bronchoalveolar lavage-derived CD3 T cells in MTB expressed PD-1 (54·2 ± 27·4%, P ≥ 0·0009) with significantly higher PD-1 ligand-positive T cells (PD-L1: 19·8 ± 11·8%; P ≥ 0·019, PD-L2: 12·6 ± 6·2%; P ≥ 0·023), CD19+ B cells (PD-L1: 14·4 ± 10·4%; P ≥ 0·042, PD-L2: 2·6 ± 1·43%; not significant) and CD14+ monocytes (PD-L1: 40·2 ± 20·1%; P ≥ 0·047, PD-L2: 22·4 ± 15·6%; P ≥ 0·032) compared with peripheral blood (PB) of MTB and healthy controls. The expression of PD-1 was associated with a diminished number of cells producing effector cytokines interferon (IFN)-γ, tumour necrosis factor (TNF)-α, interleukin (IL)-2 and elevated apoptosis. Locally accumulated T cells were predominantly PD-1+ -PD-L1+ , and blocking this pathway restores the protective T cell response. We conclude that M. tuberculosis exploits the PD-1 pathway to evade the host immune response by altering the T helper type 1 (Th1) and Th2 balance at the pathological site of MTB, thereby favouring disease dissemination.

The development and evaluation of a community-based clinical diagnosis tool and treatment regimen for postpartum sepsis in Bangladesh and Pakistan.

BACKGROUND: Postpartum sepsis accounts for most maternal deaths between three and seven days postpartum, when most mothers, even those who deliver in facilities, are at home. Case fatality rates for untreated women are very high. Newborns of ill women have substantially higher infection risk. METHODS/DESIGN: The objectives of this study are to: (1) create, field-test and validate a tool for community health workers to improve diagnostic accuracy of suspected puerperal sepsis; (2) measure incidence and identify associated risk factors and; (3) describe etiologic agents responsible and antibacterial susceptibility patterns. This prospective cohort study builds on the Aetiology of Neonatal Infection in South Asia study in three sites: Sylhet, Bangladesh and Karachi and Matiari, Pakistan. Formative research determined local knowledge of symptoms and signs of postpartum sepsis, and a systematic literature review was conducted to design a diagnostic tool for community health workers to use during ten postpartum home visits. Suspected postpartum sepsis cases were referred to study physicians for independent assessment, which permitted validation of the tool. Clinical specimens, including urine, blood, and endometrial material, were collected for etiologic assessment and antibiotic sensitivity. All women with puerperal sepsis were given appropriate antibiotics. DISCUSSION: This is the first large population-based study to expand community-based surveillance for diagnoses, referral and treatment of newborn sepsis to include maternal postpartum sepsis. Study activities will lead to development and validation of a diagnostic tool for use by community health workers in resource-poor countries. Understanding the epidemiology and microbiology of postpartum sepsis will inform prevention and treatment strategies and improve understanding of linkages between maternal and neonatal infections.

Study of CC chemokine receptor 5 in renal allograft rejection.

Allospecific recruitment of T cells is primary to the pathogenesis of renal transplant rejection. Chemokines and their receptors inducing a Th1 cytokine response play a central role in this recruitment. Renal allograft biopsies of 28 patients with acute cellular rejection and 10 protocol biopsies (controls) were examined in accordance with Banff grading 2007 schema. Immunohistochemistry for CD3 and CC chemokine receptor 5 (CCR5) in sequential sections was performed and quantitatively assessed in the glomeruli, tubules, and interstitium. Histopathologic and clinical correlations were carried out. CD3- and CCR5-positive cells were observed in significantly higher numbers in rejection cases than in controls (P = 0.010). A larger proportion of CCR5-positive cells were noted in the foci of tubulitis compared to the interstitial infiltrates and glomeruli in all cases, and it correlated with the grade of cellular rejection (P = 0.010). A greater number of CCR5-positive cells were seen in early rejection (<6 months posttransplant) compared to late rejection. No clinical correlation with serum creatinine levels was found. CCR5-positive cells represent the alloaggressive subset of T cells in ACR, and their numbers correlate with rejection severity. CCR5 may be used as a marker of early acute rejection and may be an important target for future antirejection therapies.