Impact of socioeconomic status and living condition on latent tuberculosis diagnosis among the tribal population of Melghat: A cohort study.

AIMS: To study socioeconomic status (SES) and living conditions (LC) as risk factors for latent tuberculosis infection (LTBI) and their impact on QuantiFERON-TB gold (QFT-G) and tuberculin skin test (TST) outcome for determining a better diagnostic test for LTBI in the malnourished tribal population of Melghat. SETTINGS AND DESIGN: Six hundred sixty nine participants matching the inclusion criteria were recruited from 10 tribal villages of Melghat region, India. SUBJECTS AND METHODS: Complete information related to various risk factors and test outcome was obtained on 398 participants, which was analyzed as per predefined conceptual framework. Factors were classified based on their relevance either at individual or household level, and subsequently based on the possibility of intervention. Data were partitioned into concordant and discordant sets depending on test agreement. RESULTS: In concordant set, the two tests revealed that LTBI was significantly associated with smoking (adjusted odds ratio [aOR]: 2.64 [95% confidence interval [CI]: 1.03-6.79]), tobacco usage (aOR: 2.74 [95% CI: 1.50-4.99]), and malnourishment (aOR: 1.97 [95% CI: 1.12-3.48]) after basic adjustment. Inclusion of latent variable SES and LC in the model has mediating effect on the association of above factors with LTBI. Further, the association of SES and LC with LTBI in concordant set was unaltered in presence of other cofactors. From discordant set, results of QFT-G corroborated with that of concordant set. CONCLUSIONS: Poor SES and LC can be considered as strong risk factors linked with LTBI as compared to malnourishment, which is often targeted in such communities. Further, our study showed QFT-G test as a reliable tool in screening of LTBI in the tribal population of Melghat, India.

Synthetic Peptide-Based Antibody Detection for Diagnosis of Chikungunya Infection with and without Neurological Complications.

Synthetic peptide-based diagnosis of Chikungunya can be an efficient and more accessible approach in immunodiagnostics. Here, we describe the identification of Chikungunya-specific 40 kD protein for development of synthetic peptide-based enzyme-linked immunosorbent assay for the detection of Chikungunya virus-specific antibodies in the patient's sample. The total sodium dodecyl sulfate-polyacrylamide gel electrophoresis protein profile of the patient's sample can be done to identify specific protein bands. The identified proteins can be subjected to liquid chromatography-tandem mass spectrometry (LC-MS/MS) for characterization. After characterization, immunogenic peptides can be designed using softwares and subsequently synthesized chemically. The peptides can be used to develop more specific, sensitive, and simpler diagnostic assay.

Diagnosis of Herpes Simplex Encephalitis by ELISA Using Antipeptide Antibodies Against Type-Common Epitopes of Glycoprotein B of Herpes Simplex Viruses.

Herpes simplex encephalitis (HSE) represents one of the most severe infectious diseases of the central nervous system (CNS). As effective antiviral drugs are available, an early, rapid, and reliable diagnosis has become important. The objective of this article was to develop a sensitive ELISA protocol for herpes simplex viruses (HSV) antigen detection and quantitation by assessing the usefulness of antipeptide antibodies against potential peptides of HSV glycoprotein B (gB). A total of 180 cerebrospinal fluid (CSF) samples of HSE and non-HSE patients were analyzed using a panel of antipeptide antibodies against synthetic peptides of HSV glycoprotein gB. The cases of confirmed and suspected HSE showed 80% and 51% positivity for antipeptide against synthetic peptide QLHDLRF and 77% and 53% positivity for antipeptide against synthetic peptide MKALYPLTT, respectively for the detection of HSV antigen in CSF. The concentration of HSV antigen was found to be higher in confirmed HSE as compared to suspected HSE group and the viral load correlated well with antigen concentration obtained using the two antipeptides in CSF of confirmed HSE group. This is the first article describing the use of antibodies obtained against synthetic peptides derived from HSV in diagnostics of HSE using patients' CSF samples.

Comparative evaluation of risk factors, outcome and biomarker levels in young and old acute ischemic stroke patients.

BACKGROUND: Stroke is the third leading cause of death and disability worldwide accounting for 400-800 strokes per 100,000 individuals each year. PURPOSE: In the present study, we compared risk factors, clinical outcome, and prognostic biomarkers NSE, S-100 ßß and ITIH4 levels in young and old acute ischemic stroke (AIS) patients. METHODS: We compared the risk factors and clinical outcomes in young (n = 38) and old (n = 66) AIS patients admitted to tertiary health care centre in Central India. In addition, we also evaluated NSE, S100ßß & ITIH4 levels in admission and discharge samples of young and old AIS patients with different clinical outcome. RESULTS: Hypertension was a major risk factor in 45% of young and 80% of old AIS patients. Hospital outcome was less favorable in young AIS patients with higher dependent rates of 24% as compared to 12% in old AIS patients. Whereas long term outcome at 12 and 18 months after discharge was more favorable in young AIS patients with low dependency rates of 16% and 11% as compared to 41% and 24% in older AIS patients respectively. Similarly, serum NSE, S100ßß and ITIH4 levels showed a distinct pattern of expression at discharge time in AIS patients with improved and dependent outcome in both the age groups. CONCLUSION: Young males with hypertension and smoking habits are at a high risk of AIS while old AIS patients are at a greater risk of worse long term outcome. Serum levels of NSE and S100ßß are independent predictors of outcome in AIS patients. Similarly, it also suggests that serum ITIH4 levels could be used as a potential biomarker for predicting the outcome in AIS patients.

The assessment of cytokines in Quantiferon supernatants for the diagnosis of latent TB infection in a tribal population of Melghat, India.

The tuberculin skin test (TST) and interferon-gamma release assays (IGRA), namely, the QuantiFERON-TB Gold test (QFT), remain the standard immunological diagnostic tools for latent tuberculosis (TB) infection (LTBI). However, the sub-optimal detection rates of both of these tests are major impediments in recognizing the population at risk. This study was aimed at evaluating additional cytokines besides interferon-gamma (IFN-γ) as biomarkers for improving LTBI diagnosis in the tribal population of Melghat, India. Seventy-four close TB contacts were stratified by QFT and TST results into: (i) QFT+/TST+ (n = 26), (ii) QFT+/TST- (n = 12), (iii) QFT-/TST- (n = 35) and (iv) QFT-/TST+ (n = 1) groups. A panel of cytokines (IL-6, IL-10, TNF-α and IL-2R) was then evaluated in antigen-stimulated QFT cell-free culture supernatants using IMMULITE-1000, an automated immunoassay analyzer. Cytokine estimation showed significantly higher levels of IL-6 in the QFT+/TST+ group, while significantly higher levels of IL-10 were found in the QFT-/TST- group. Correlation analysis identified a positive correlation between IL-6 and the QFT response (r = 0.6723, P < 0.0001), while a negative correlation was seen between QFT and IL-10 expression (r = -0.3271, P = 0.0044). Similarly, IL-6 was positively correlated with TST levels (r = 0.6631, P <0 .0001), and conversely, a negative correlation was found between TST and IL-10 expression (r = -0.5698, P < 0.0001). The positive and negative predictive values of IL-6 were found to be 92.59 and 93.33%, respectively, and the positive and negative predictive values of IL-10 were 96.55 and 91.18%, respectively. No significant impact of the demographic characteristics on cytokine positivity was observed. Our preliminary results suggest that the evaluation of additional cytokines in QFT cell-free culture supernatants may be valuable for the identification of LTBI. Combining IL-6 and IL-10 with QFT and/or TST could markedly improve the detection accuracy of LTBI. Our observations require investigation in larger well-characterized cohorts along with follow-up studies to further confirm the study outcome.

Laboratory investigations on the diagnosis of tuberculosis in the malnourished tribal population of melghat, India.

BACKGROUND: Malnutrition is a major risk factor for the development of tuberculosis (TB). In India, Melghat is among the tribal regions which consist of highest number of malnutrition cases. Because of the paucity of TB data from these malnourished areas there is an urgent need for the development and evaluation of improved TB diagnostic tests. In the present study, three in house developed diagnostic tests namely TB-Ag(antigen) ELISA, Adenosine deaminase (ADA) estimation and IS6110 polymerase chain reaction (PCR) assay were investigated for the detection of Mycobacterium tuberculosis (M. tb.) infection. METHODS: For investigation, blood samples were collected from 128 study subjects from six villages of Melghat tribal area and evaluated using three in house developed assays, namely TB-Ag ELISA, ADA estimation and IS6110 PCR. RESULTS: The TB-Ag ELISA method yielded 83% sensitivity and 94% specificity. The ADA and PCR assay gave a sensitivity of 61% and 49% and specificity of 62% and 98% respectively. A considerable good agreement of 82.81% (k=0.472) between TB-Ag ELISA and PCR was observed. The overall sensitivity of TB-Ag ELISA was significantly higher (p<0.05) than the ADA and PCR while PCR yielded highest specificity among all the three evaluated tests. CONCLUSIONS: We concluded that the routine use of TB-Ag ELISA can be useful for screening of suspected TB patients in the malnourished population where sophisticated laboratory set up is difficult.

Diagnosis of tuberculosis infection based on synthetic peptides from Mycobacterium tuberculosis antigen 85 complex.

AIM: The laboratory diagnosis of pulmonary tuberculosis (TB) and tuberculous meningitis (TBM) is particularly challenging. The aim of the present work is to develop an immunoassay for the diagnosis of TB infection, using synthetic peptides of antigen (Ag) 85 complex of M. tuberculosis (Mtb) H37Rv. METHODS: Four peptides (7-10 amino acids long) corresponding to group-specific epitopes of Ag 85 complex of Mtb were synthesized. All peptides were evaluated by enzyme-linked immunosorbent assay (ELISA) for immunoreactivity with sera and CSF samples of TB and TBM patients respectively. The diagnostic value of the four peptides was evaluated in both the samples. RESULTS: It was observed that Ag 85 peptide 1, 3 and 4 had the highest positive rates in the pulmonary patients; however, Ag 85 peptide 1 and 2 had shown good positivity in the TBM subjects. CONCLUSIONS: The synthetic peptide based ELISA using Ag 85 complex peptides is a sensitive, specific, rapid and cost effective immunoassay for early diagnosis of pulmonary and extrapulmonary TB. In addition, these synthetic peptides are comparatively easy to produce in a reproducible manner compared with the whole antigen.

Time course of inflammatory cytokines in acute ischemic stroke patients and their relation to inter-alfa trypsin inhibitor heavy chain 4 and outcome.

BACKGROUND: Biomarker for prognosis of stroke is urgently needed for the management of acute ischemic stroke (AIS) patients. OBJECTIVE: To evaluate the course of inflammatory cytokines in AIS patients and its comparison with inter-alfa trypsin inhibitor heavy chain 4 (ITIH4) and outcome after AIS. MATERIALS AND METHODS: A panel of 12 inflammatory cytokines and ITIH4 were estimated in serial blood samples collected at admission, 24 h, 48 h, 72 h, 144 h and at discharge of AIS patients (n = 5). RESULTS: Out of the 12 cytokines, only interleukin (IL)-2, tumor necrosis factor-alfa (TNF-α), IL-10, IL-6, IL-1B and IL-8 were in the measurable range of the kit (10 pg/mL). We found high IL-2 at admission, which decreased (P < 0.05) in the follow-up samples. TNF-α initially increases (P < 0.05) at 24 h followed by gradual decrease (P < 0.05) after 72 h. IL-10 decreases initially (P < 0.05) till 72 h as compared with its level at admission and then increases (P < 0.05) after 144 h. Similarly, ITIH4 was down-regulated in the early 72 h followed by further increase with improvement of the patient. ITIH4 correlates with IL-10 and computed tomography scan infarct volume. Serum IL-6, IL-1B and IL-8 increased in the AIS patients, but did not show any pattern. CONCLUSIONS: Serial measurement of IL-10, IL-2 and TNF-α and ITIH4 may be useful for the follow-up of clinical outcome after AIS.

Improved laboratory diagnosis of tuberculosis--the Indian experience.

Tuberculosis (TB) is the leading cause of death worldwide attributable to a single infectious disease agent. India has more new TB cases annually than any other country. In 2008, India accounted for a fifth of the estimated 9.4 million TB cases globally. There is an overwhelming need for improving TB diagnostics in India through the use of cost effective, patient-friendly methods appropriate to different tiers of the country health system. Substantial progress has been made in India in the field of TB diagnosis and serious efforts have been made to herald the development of diagnostic tests for pulmonary TB, extra pulmonary TB and MDR-TB. Diverse approaches have been attempted towards improving smear microscopy, rapid culture and for differentiation between the Mycobacterium tuberculosis complex and non-tuberculous mycobacteria. Several laboratories have developed in-house PCR assays for diagnosing TB with high accuracy. Approaches for distinguishing M. tuberculosis and/or Mycobacterium bovis infection and disseminated Mycobacterium avium complex infection in HIV-AIDS patients have also been described. Serological tests to detect antigens or antibodies to M. tuberculosis specific components by using cocktails of Excretory/Secretory protein antigens, Ag85 complex antigens, Hsp 65 antigen, RD1 antigens and Rapid Reverse Line Blot Hybridization assays to detect MDR-TB (mutations to rifampicin, isoniazid and streptomycin) have also been developed. Other methods like measurement of adenosine deaminase activity and use of luciferase reporter phages have also been explored for TB diagnosis. These advances in the Indian context are detailed in the present chapter. The validation and application of these methods in laboratory and public health settings is likely to result in improved TB diagnosis and contribute to effective disease management in India.

An approach towards peptide-based antibody detection for diagnosis of Chikungunya infection.

Chikungunya infection, although rarely fatal, is associated with significant morbidity which necessitates its diagnosis in the initial stages. Currently for diagnosis, together with clinical symptoms, immunological methods such as IgG/IgM detection, molecular methods such as real-time reverse transcriptase-polymerase chain reaction and viral isolation methods are available but they are either not very specific or they require high-level sophisticated infrastructures. In the present study, an enzyme-linked immunosorbent assay to evaluate antibody responses to peptides designed from the CHIKV E2 envelope glycoprotein was performed. Synthesized peptides were evaluated with confirmed Chikungunya and non-Chikungunya serum samples for antibody detection. The results demonstrate that the synthetic peptide-based diagnosis of Chikungunya can be an efficient and a more accessible approach in immunodiagnostics.

Protection of PC12 cells from chemical ischemia induced oxidative stress by Fagonia arabica.

Fagonia arabica (Zygophyllaceae) is an important Ayurvedic herb, grows throughout arid regions of India, has been widely used as a folk remedy by the indigenous people for its anti-inflammatory, analgesic and antipyretic effects. In the present study, antioxidant potential of F. arabica and the associated mechanism of antioxidant defence in rat pheochromocytoma (PC12) cells subjected to chemical ischemia was studied. Effect of total extract of F. arabica was studied for its antioxidant potential on the chemical ischemia induced PC12 cells. Alterations in the activities of cellular antioxidant enzymes (SOD, CAT, GSH-Px and GSH-R) were measured. Antioxidant potential of herb (ABTS), extent of lipid peroxidation (MDA and 4-HAE), total antioxidant status (TAS) and total glutathione (reduced, oxidized and their ratio) were evaluated. F. arabica scavenges the free radicals (ABTS(.)+), and showed a concentration dependent antioxidant activity, highest being at 1000 microg/ml. Its treatment with ischemic cells ameliorates the GSH and TAS levels and also helps the cells to restore the activities of the cellular antioxidative enzymes and also reduced the degree of lipid peroxidation. F. arabica scavenges the free radicals and attenuates oxidative stress mediated cell injury during ischemia.

Comparison of an adenosine deaminase assay with ELISA for the diagnosis of tuberculous meningitis infection.

BACKGROUND: Diagnosing tuberculous meningitis (TBM) remains problematic despite many new advanced diagnostic methods. Adenosine deaminase (ADA) assays have emerged as novel alternatives to other costly and time-consuming methods for TBM diagnosis. In the present study the usefulness of the ADA method was assessed for the diagnosis of TBM and compared with an in-house developed ELISA method for detecting the antigen 85 (Ag 85) complex of M. tuberculosis in cerebrospinal fluid (CSF) samples of suspected and culture-confirmed TBM patients. MATERIAL/METHODS: ADA activity in CSF was determined at 37 degrees C according to the method of Guisti and Galanti. ELISA, employing monoclonal antibodies against the purified Ag 85 complex, was used to demonstrate Ag 85 complex in CSF from TBM patients. CSF samples were obtained from 153 patients in three different groups: confirmed TBM (n=27), clinically suspected TBM (n=39), and non-TBM (n=87). RESULTS: The ADA method yielded sensitivity and specificity of 83% and 86%, which are similar to those of the ELISA method (89% and 90%). The correlation between the Ag 85 complex activity in absorbance by ELISA and the ADA activity obtained in units per liter per minute (U/l/min) was also positive and significant. (Pearson's correlation coefficient r=0.3234, 95%CI: 0.1621-0.4679, p<0.001). CONCLUSIONS: This study suggests that the ADA method can be performed for TBM diagnosis in low-income TB-affected regions where more sophisticated facilities are generally not available.

Secretory factors of human neuroblastoma (IMR-32) and human glioblastoma (U87MG) cell lines induce neurite outgrowths in PC12 cells.

Neurite outgrowth is essential for the communication of the nervous system. The rat Pheochromocytoma (PC12) cells are commonly used in the neuronal cell study. It is well known that exogenous stimuli such as Nerve Growth Factor (NGF) induce neurite outgrowth. In the present study it has been investigated whether or not the conditioned medium from human neuroblastoma cell line (IMR-32) and human glioblastoma cell line (U87MG) may augment neurite outgrowth in PC12 cells. PC12 were cultured with and without conditioned media of IMR-32 and U87MG. The result showed that both the conditioned media induce neurite outgrowth within 48 hr and stops further proliferation of PC12 cells. However no outgrowth was noted in PC12 cells incubated without conditioned medium. In conclusion, it is shown that both the conditioned media (IMR-32 and U87MG) have the potential to induce the neurite outgrowth in the PC12 cells.

Cerebrospinal fluid adenosine deaminase activity: a complimentary tool in the early diagnosis of tuberculous meningitis.

BACKGROUND: Tuberculous meningitis (TBM) is the commonest form of neurotuberculosis caused by Mycobacterium tuberculosis bacilli (MTB). The diagnosis of TBM is often difficult. A reliable, cost-effective and rapid diagnostic test, which can be performed in any standard pathology laboratory, could be of help in the diagnosis of TBM. In the present study we measured the adenosine deaminase (ADA) activity in cerebrospinal fluid (CSF) of TBM and non-TBM patients. METHOD: ADA activity in CSF was determined according to a method based on the Berthlot reaction, which is the formation of a colored indophenol complex from ammonia liberated from adenosine, and quantified spectrophotometrically. RESULTS: The CSF ADA activity from TBM patients was compared with CSF ADA from non-TBM infectious meningitis patients, and from patients with non-infectious neurological disorders. The mean CSF ADA activity was found to be significantly higher in CSF of TBM patients, 14.31 +/- 3.87 (2.99-26.94), mean +/- SD with range, than in the CSF from non-TBM infectious meningitis, 9.25 +/- 2.14 (4.99-13.96) and from the non-infectious neurological disorders group, 2.71 +/- 1.96 (0.00-7.68), P < 0.0001 for both comparisons. A cut-off value of 11.39 U/L/min for the TBM patients was calculated from the mean + SD of the non-TBM patients. The ADA test gave a sensitivity of 82% and a specificity of 83% for infectious TBM when this cut-off value was used. CONCLUSION: This study demonstrated that ADA activity in the CSF of TBM patients, using a cut-off value 11.39 U/L/min, can be useful for the early differential diagnosis of TBM. This test can be performed in any pathology laboratory where more sophisticated methods are not available.