Malnutrition and tuberculosis are both problems of considerable magnitude in most of the underdeveloped regions of the world. These two problems tend to interact with each other. Tuberculosis mortality rates in different economic groups in a community tend to vary inversely with their economic levels. Similarly, nutritional status is significantly lower in patients with active tuberculosis compared with healthy controls. Malnutrition can lead to secondary immunodeficiency that increases the host's susceptibility to infection. In patients with tuberculosis, it leads to reduction in appetite, nutrient malabsorption, micronutrient malabsorption, and altered metabolism leading to wasting. Both, protein-energy malnutrition and micronutrients deficiencies increase the risk of tuberculosis. It has been found that malnourished tuberculosis patients have delayed recovery and higher mortality rates than well-nourished patients. Nutritional status of patients improves during tuberculosis chemotherapy. High prevalence of human immunodeficiency (HIV) infection in the underdeveloped countries further aggravates the problem of malnutrition and tuberculosis. Effect of malnutrition on childhood tuberculosis and tuberculin skin test are other important considerations. Nutritional supplementation may represent a novel approach for fast recovery in tuberculosis patients. In addition, raising nutritional status of population may prove to be an effective measure to control tuberculosis in underdeveloped areas of world.

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Extracellular vesicles (EVs), the small circulating vesicles released from urine samples of tuberculosis (TB) patients, contain a pool of biomarkers. We recently detected Mycobacterium tuberculosis lipoarabinomannan (LAM) and CFP-10 (Rv3874) biomarkers from the urinary EVs of pulmonary TB (PTB) and extrapulmonary TB (EPTB) patients by immuno-polymerase chain reaction (I-PCR) assay and the results were compared with the analogous enzyme-linked immunosorbent assay (ELISA). The detection limits of both purified LAM and CFP-10 were determined to be 1 fg/mL with I-PCR, which was 106 times lower than ELISA. Detection of LAM and CFP-10 biomarkers in urinary EVs of TB patients by I-PCR showed superiority over ELISA. Notably, LAM I-PCR revealed sensitivities of 74.3 and 67.9% in PTB (n = 74) and EPTB (n = 53) patients, respectively, with specificities of 91.5–92.8% (n = 116). Moreover, the sensitivities attained with LAM I-PCR were significantly higher (P < 0.01) than with CFP-10 I-PCR. After further improving the sensitivity and specificity of the assay, our I-PCR based on LAM detection in urinary EVs may be used as an adjunct test for rapid diagnosis of TB.

Aim: To improve the diagnostic accuracy of immuno-PCR (I-PCR) in tuberculosis (TB) patients by using functionalized gold nanoparticles (AuNPs) coupled with detection antibodies and oligonucleotides, and magnetic beads (MBs) conjugated with capture antibodies in the liquid phase. Materials & methods: MB-coupled AuNP-based I-PCR (MB-AuNP-I-PCR) assay was designed to detect a cocktail of Mycobacterium tuberculosis MPT64 and CFP-10 proteins in bodily fluids of TB patients. Results: The sensitivities of 89.3 (n = 94) and 78.1% (n = 73) were observed in pulmonary TB and extrapulmonary TB patients, respectively, with specificities of 97.9–98.3%. Notably, the sensitivities attained by MB-AuNP-I-PCR in smear-negative pulmonary TB and extrapulmonary TB patients were significantly higher (p < 0.05–0.001) than Magneto-ELISA and GeneXpert assay. Conclusion: The improved technology, as well as enhanced diagnostic accuracy of MB-AuNP-I-PCR, may lead to development of an attractive diagnostic kit.

PurposeDiagnosis of extrapulmonary tuberculosis (EPTB) poses serious challenges. A careful selection of appropriate gene targets is essential for designing a multiplex-polymerase chain reaction (M-PCR) assay.Materials and MethodsWe compared several gene targets of Mycobacterium tuberculosis, including IS6110, devR, and genes encoding MPB-64 (mpb64), 38kDa (pstS1), 65kDa (hsp65), 30kDa (fbpB), ESAT-6 (esat6), and CFP-10 (cfp10) proteins, using PCR assays on 105 EPTB specimens. From these data, we chose the two best gene targets to design an M-PCR.ResultsAmong all gene targets tested, mpb64 showed the highest sensitivity (84% in confirmed cases and 77.5% in clinically suspected cases), followed by IS6110, hsp65, 38kDa, 30kDa, esat6, cfp10, and devR. We used mpb64+IS6110 for designing an M-PCR assay. Our M-PCR assay demonstrated a high sensitivity of 96% in confirmed EPTB cases and 88.75% in clinically suspected EPTB cases with a high specificity of 100%, taking clinical diagnosis as the gold standard.ConclusionThese M-PCR results along with the clinical findings may facilitate an early diagnosis of EPTB patients and clinical management of disease.