Interferon-gamma release assay as a diagnostic test for tuberculosis-associated uveitis.

Eye (Lond). 2012 Feb 3;

Authors: Ang M, Wong W, Ngan CC, Chee SP

Abstract
BackgroundTo study the use of interferon-gamma release assay (IFN-γ) (IGRAs) as a diagnostic test for tuberculosis (TB)-associated uveitis (TAU).DesignProspective cohort study.ParticipantsConsecutive new patients (n=162) with clinical ocular signs suggestive of TAU, seen >1 year period at a single tertiary center.MethodsAll subjects underwent investigations to rule out underlying disease, including T-SPOT.TB and tuberculin skin test (TST). Twenty-one subjects with underlying disease and three with interdeterminate T-SPOT.TB results were excluded. Those with T-SPOT.TB- or TST-positive results were referred to infectious diseases physician for evaluation. Anti-TB therapy (ATT) was prescribed if required. Patients' treatment response and recurrence were monitored for six months after completion of ATT, if given; or 1 year if no ATT was given.Main outcome measureDiagnosis of TAU.ResultsMean age of study cohort (n=138) was 46.8±15.3 years. Majority were Chinese (n=80, 58.0%) and female (n=75, 54.3%). TST was more sensitive than T-SPOT.TB (72.0% vs36.0%); but T-SPOT.TB was more specific (75.0% vs51.1%) for diagnosing TAU. Patients with either a T-SPOT.TB (1.44; 95% confidence intervals (CI), 0.86-2.42) or TST (1.47; 95% CI, 1.12-1.94)-positive result are more likely to have TAU. The accuracy of diagnosing TAU increases when both tests are used in combination (area under the receiver operator curve=0.665; 95% CI, 0.533-0.795). Patients with both tests positive are 2.16 (95% CI, 1.23-3.80) times more likely to have TAU. Negative T-SPOT.TB or TST results do not exclude TAU (negative likelihood ratios <1.0).ConclusionsWe recommend using a combination of clinical signs, IGRA, and TST to diagnose TAU.Eye advance online publication, 3 February 2012; doi:10.1038/eye.2012.1.

PMID: 22302066 [PubMed - as supplied by publisher]

Improved Skin Test for the Differential Diagnosis of Bovine Tuberculosis by the Addition of Rv3020c-Derived Peptides.

Clin Vaccine Immunol. 2012 Feb 1;

Authors: Jones GJ, Whelan A, Clifford D, Coad M, Vordermeier HM

Abstract
A peptide cocktail derived from the mycobacterial antigens ESAT-6, CFP-10 and Rv3615c allowed the differentiation between Mycobacterium bovis-infected and BCG-vaccinated cattle when used as a DIVA skin test reagent. Addition of the antigen Rv3020c improves the diagnostic sensitivity without compromising specificity in the face of BCG or Johne's disease vaccination.

PMID: 22301696 [PubMed - as supplied by publisher]

Anti-tuberculosis IgG antibodies as a marker of active Mycobacterium tuberculosis disease.

Clin Vaccine Immunol. 2012 Feb 1;

Authors: Welch RJ, Lawless KM, Litwin CM

Abstract
Anti-Mycobacterium tuberculosis IgG antibodies may aid in the diagnosis of active M. tuberculosis disease. We studied whether anti-M. tuberculosis IgG antibodies are elevated in active M. tuberculosis disease and assessed factors contributing to false positive and negative results. A retrospective study of 2,150 individuals tested by the QuantiFERON-TB Gold In-Tube (QFT-GIT) assay was conducted at University of Utah, ARUP Laboratories, November 2008 to December 2010. All samples were tested with the InBios Active TbDetect™anti-TB IgG antibody assay. Of 1,044 patients with a positive QFT-GIT, 59 (5.7%) were positive for M. tuberculosis antibodies. Fourteen of 1,106 (1.3%) with a negative or indeterminate QFT-GIT were positive for M. tuberculosis antibodies. M. tuberculosis antibody tests were positive in 61.5% with confirmed active M. tuberculosis disease and other mycobacterial infections. Over half of the false negative M. tuberculosis antibody tests occurred in patients ≥ 90 years of age. False positives were seen in 12.9% of autoimmune patients. The odds ratio of being positive on the QFT-GIT and the InBios TB IgG assay increased with confirmed M. tuberculosis disease or highly suspected M. tuberculosis disease and was 86.7 (95% confidence interval [CI], 34.4-218.5) in these two groups when compared to patients negative on both tests. Although anti-M. tuberculosis antibodies can be detected in patients with active M. tuberculosis disease, caution should be used in patients where immunoglobulin levels may be decreased or in patients with autoantibodies.

PMID: 22301692 [PubMed - as supplied by publisher]

Impaired Fitness of Mycobacterium africanum Despite Secretion of ESAT-6.

J Infect Dis. 2012 Feb 1;

Authors: Bold TD, Davis DC, Penberthy KK, Cox LM, Ernst JD, de Jong BC

Abstract
Background. When compared with Mycobacterium tuberculosis, individuals that live in the same household as an active case of smear-positive pulmonary tuberculosis exposed to M. africanum progress less frequently to active disease within 2 years. A putative ESX-1 secretion apparatus member, Rv3879c, is mutated in M. africanum, and individuals infected with M. africanum less frequently demonstrate T-cell responses to the ESX-1-secreted virulence factor ESAT-6 than those infected with M. tuberculosis. We hypothesized that less frequent progression is caused by impaired secretion of ESAT-6.Methods. We analyzed in vivo growth and in vitro secretion of ESAT-6 and CFP-10, comparing M. tuberculosis to M. africanum and a strain of M. africanum complemented with M. tuberculosis Rv3879c.Results. ESAT-6 and CFP-10 secretion were similar for all strains, although these were enriched in M. africanum cell lysates, suggesting a modest ESX-1 secretion defect unrelated to the Rv3879c mutation. In mice, M. africanum demonstrated smaller bacterial population sizes than M. tuberculosis but similar numbers and frequencies of ESAT-6-responsive T cells in the lungs.Conclusions. These results confirm impaired fitness of M. africanum in vivo and indicate that Rv3879c is not required for secretion of ESAT-6 or for its presentation as an antigen to T cells in vivo.

PMID: 22301632 [PubMed - as supplied by publisher]

Pathogen prevalence may determine maintenance of antigen-specific T-cell responses in HIV-infected individuals.

AIDS. 2012 Feb 1;

Authors: Schuetz A, Dirks J, Sester U, Haule A, Elias N, Geldmacher C, Sanga E, Maboko L, Reither K, Hoelscher M, Meyerhans A, Sester M

Abstract
OBJECTIVE:: To assess the effect of antigen-exposure on the T-cell repertoire in the chronic phase of HIV-infection. DESIGN:: This is a prospective cross-sectional study. METHODS:: HIV-seropositive patients and immunocompetent controls from tuberculosis low and high-endemic countries were recruited. Mycobacterium tuberculosis (purified protein derivative; PPD)-specific CD4 T-cell responses were quantified directly from whole blood using flow-cytometric analysis of intracellular cytokines after specific stimulation. T-cell reactivity toward cytomegalovirus (CMV) or Staphylococcus aureus Enterotoxin B (SEB) served as control. RESULTS:: In a low-endemic region, HIV-seropositive patients showed lower frequencies of PPD-specific T-cells compared to immunocompetent individuals. This was not due to a general loss of immunity toward recall antigens, as T-cell immunity toward CMV or SEB was preserved. In line with continuous antigen exposure, HIV-seropositive patients from a high-endemic region showed preserved PPD-specific T-cell frequencies that were not different from those found in HIV-seronegative controls. Likewise, both groups did not differ in recall T-cell responses toward CMV or SEB. CONCLUSION:: A lower prevalence and frequency of PPD-specific immunity is a typical feature of HIV-related immunosuppression in low-endemic regions. In contrast, PPD-specific responses are maintained in HIV-seropositive individuals in regions with high tuberculosis prevalence. This suggests constant skewing and restriction of specific T-cell immunity toward environmental antigens in HIV-seropositive individuals.

PMID: 22301414 [PubMed - as supplied by publisher]

A metabolomics approach to characterise and identify various Mycobacterium species.

J Microbiol Methods. 2012 Jan 24;

Authors: Olivier I, Loots DT

Abstract
We investigated the potential use of gas chromatography mass spectrometry (GC-MS), in combination with multivariate statistical data processing, to build a model for the classification of various tuberculosis (TB) causing, and non-TB Mycobacterium species, on the basis of their characteristic metabolite profiles. A modified Bligh-Dyer extraction procedure was used to extract lipid components from Mycobacterium tuberculosis, Mycobacterium avium, Mycobacterium bovis, and Mycobacterium kansasii cultures. Principle component analyses (PCA) of the GC-MS generated data showed a clear differentiation between all the Mycobacterium species tested. Subsequently, the 12 compounds best describing the variation between the sample groups were identified as potential metabolite markers, using PCA and partial least-squares discriminant analysis (PLS-DA). These metabolite markers were then used to build a discriminant classification model based on Bayes' theorem, in conjunction with multivariate kernel density estimation. This model subsequently correctly classified 2 "unknown" samples for each of the Mycobacterium species analysed, with probabilities ranging from 72 to 100%. Furthermore, Mycobacterium species classification could be achieved in less than 16h, and the detection limit for this approach was 1×10(3)bacteriamL(-1). This study proves the capacity of a GC-MS, metabolomics pattern recognition approach for its possible use in TB diagnostics and disease characterisation.

PMID: 22301369 [PubMed - as supplied by publisher]

1,4-Diarylpiperazines and analogs as anti-tubercular agents: Synthesis and biological evaluation.

Eur J Med Chem. 2012 Jan 21;

Authors: Forge D, Cappoen D, Laurent J, Stanicki D, Mayence A, Huang TL, Verschaeve L, Huygen K, Vanden Eynde JJ

Abstract
Despite progress in modern chemotherapy to combat tuberculosis, the causative pathogen Mycobacterium tuberculosis (M.tb.) is far from eradicated. Bacillary resistance to anti-mycobacterial agents, bacillary persistence and human immunodeficiency virus (HIV) co-infection hamper current drug treatment to completely cure the infection, generating a constant demand for novel drug candidates to tackle these problems. A small library of novel heterocyclic compounds was screened in a rapid luminometric in vitro assay against the laboratory M.tb. strain H37Rv. A group of amidines was found to have the highest potency and was further evaluated for acute toxicity against C3A hepatocytes. Next, the most promising compounds were evaluated for activity against a multi-drug resistant clinical isolate. The group of amidines was also tested for their ability to kill intracellular M.tb. residing in mouse J774A.1 macrophages. Finally, we report on a correlation between the structural differences of the compounds and their anti-mycobacterial activity.

PMID: 22301215 [PubMed - as supplied by publisher]

Performance of Tuberculosis Drug Susceptibility Testing in the United States Laboratories from 1994-2008.

J Clin Microbiol. 2012 Feb 1;

Authors: Angra PK, Taylor TH, Iademarco MF, Metchock B, Astles JR, Ridderhof JC

Abstract
We present a statistical summary of results from the Model Performance Evaluation Program (MPEP) for Mycobacterium tuberculosis Drug Susceptibility Testing, 1994-2008 implemented by the U.S. Centers for Disease Control and Prevention (CDC). During that period, a total of 57,733 test results for culture isolates were reported by 216 participating laboratories for the first-line anti-tuberculosis drugs used in the United States- isoniazid (INH), rifampin (RMP), ethambutol (EMB), and pyrazinamide (PZA). Using Clinical Laboratory and Standards Institute (CLSI) recommended concentrations for one or more of three methods, agar proportion (AP), BACTEC™460 (BACTEC), and MGIT™-960 (MGIT), yielded overall agreement of 97.0% for first-line drugs. For susceptible strains, agreement was 98.4%; for resistant strains, agreement was 91.0%, with significantly lower accuracy (Chi-sq p<0.0001). For resistant strains, overall agreement by methods was: AP 91.3%; BACTEC 93.0%; and MGIT 82.6% and by drugs was: INH 92.2%; RMP 91.5%; EMB 79.0%; and PZA 97.5%. For some strains, performance by method varied significantly. Use of duplicate strains in the same shipment and repeat strains over time, revealed consistent performance even for strains with higher levels of inter-laboratory discordance. No overall differences in performance between laboratories were observed based on volume of testing or type of facility (e.g., health department, hospital, independent). By all methods, decreased performance was observed for strains with low-level INH resistance, RMP resistance, and EMB-resistant strains. These results demonstrate a high level of performance in detection of drug resistant M. tuberculosis in U.S. laboratories.

PMID: 22301024 [PubMed - as supplied by publisher]

First evaluation of an improved assay for molecular genetic detection of tuberculosis as well as RMP and INH resistances.

J Clin Microbiol. 2012 Feb 1;

Authors: Crudu V, Stratan E, Romancenco E, Allerheiligen V, Hillemann A, Moraru N

Abstract
The commercially available Line Probe Assay Genotype MTBDRplus VER2.0 (Hain Lifescience, Nehren, Germany) was evaluated for its ability to detect Mycobacterium tuberculosis complex (MTBC) and simultaneously mutations conferring resistance to rifampicin (RMP) and isoniazid (INH) directly in smear-negative and smear-positive pulmonary clinical specimens under routine laboratory conditions. A total of 348 samples originating from Moldova, a high incidence country for TB, were investigated. 257 (73.9%) were smear-negative, 12 samples were excluded, and 81 (23.3%) were smear-positive. Two DNA extraction methods were applied. Referred to culture and clinical data as reference standard (adapted from Vadwai, V., Boehme, C., Nabeta, P., Anjali, S., Alland, D., and C. Rodrigues. 2011. J. Clin. Microbiol., in press) overall sensitivity and specificity were 87.6% and 99.2%, respectively.104 of the 257 smear-negative samples turned out to be culture-positive and 20 were MTBC culture-negative, but positive based on clinical symptoms. The combined sensitivity and specificity in the subgroup of smear negative samples were calculated to 79.8% and 99.2%, respectively.The MTBDRplus VER2.0 detected RMP and INH resistances with a sensitivity and specificity of 94.3% and 96.0%, respectively.In conclusion, the MTBDRplus VER2.0 assay is a rapid and highly sensitive test for the detection of M. tuberculosis strains from smear positive and negative clinical specimens, with the additional information on RMP and INH resistance status, which can easily be included in a routine laboratory work flow.

PMID: 22301019 [PubMed - as supplied by publisher]

Three-Year Outcomes From BENEFIT-EXT: A Phase III Study of Belatacept Versus Cyclosporine in Recipients of Extended Criteria Donor Kidneys.

Am J Transplant. 2012 Feb 2;

Authors: Pestana JO, Grinyo JM, Vanrenterghem Y, Becker T, Campistol JM, Florman S, Garcia VD, Kamar N, Lang P, Manfro RC, Massari P, Rial MD, Schnitzler MA, Vitko S, Duan T, Block A, Harler MB, Durrbach A

Abstract
Recipients of extended-criteria donor (ECD) kidneys have poorer long-term outcomes compared to standard-criteria donor kidney recipients. We report 3-year outcomes from a randomized, phase III study in recipients of de novo ECD kidneys (n = 543) assigned (1:1:1) to either a more intensive (MI) or less intensive (LI) belatacept regimen, or cyclosporine. Three hundred twenty-three patients completed treatment by year 3. Patient survival with a functioning graft was comparable between groups (80% in MI, 82% in LI, 80% in cyclosporine). Mean calculated GFR (cGFR) was 11 mL/min higher in belatacept-treated versus cyclosporine-treated patients (42.7 in MI, 42.2 in LI, 31.5 mL/min in cyclosporine). More cyclosporine-treated patients (44%) progressed to GFR <30 mL/min (chronic kidney disease [CKD] stage 4/5) than belatacept-treated patients (27-30%). Acute rejection rates were similar between groups. Posttransplant lymphoproliferative disorder (PTLD) occurrence was higher in belatacept-treated patients (two in MI, three in LI), most of which occurred during the first 18 months; four additional cases (3 in LI, 1 in cyclosporine) occurred after 3 years. Tuberculosis was reported in two MI, four LI and no cyclosporine patients. In conclusion, at 3 years after transplantation, immunosuppression with belatacept resulted in similar patient survival, graft survival and acute rejection, with better renal function compared with cyclosporine. As previously reported, PTLD and tuberculosis were the principal safety findings associated with belatacept in this study population.

PMID: 22300431 [PubMed - as supplied by publisher]

Neurotuberculosis: An Overview.

Cent Nerv Syst Agents Med Chem. 2012 Jan 31;

Authors: Rodrigues MG, da Rocha AJ, Masruha MR, Minett TS

Abstract
Although pulmonary tuberculosis is the most common form of this disease, neurotuberculosis is more severe and presents higher morbidity and mortality. Its diagnosis continues to challenge physicians all over the world. Contributing to this fact is the nonspecificity of its clinical manifestations, the low density of bacilli in the cerebrospinal fluid (CSF), and the delayed recovery of Mycobacterium tuberculosis through culture techniques. Thus, the diagnosis is largely based on suspicious symptoms, and the prognosis is directly related to the stage of the disease at the beginning of treatment. Even thought there is no consensus regarding the best therapeutic regimen, the WHO recommends using the same regimen used for pulmonary tuberculosis with a longer treatment time. It is important to note that in most cases, the doctor will not have a definite diagnosis at the beginning of the treatment. However, this should not delay the initiation of therapy. A delay in initiating treatment, in most cases, is directly associated with a poor prognosis. This review gives an overview of the current state of the neurotuberculosis research. It covers the epidemiological aspects of the infection, pathogenesis, principal clinical presentations, diagnosis highlighting neuroimaging, where a series of imaging are presented, prognosis, prevention and therapeutic regimens.

PMID: 22300226 [PubMed - as supplied by publisher]

Clinical signs of uveitis associated with latent tuberculosis.

Clin Experiment Ophthalmol. 2012 Feb 2;

Authors: Ang M, Hedayatfar A, Zhang R, Chee SP

Abstract
Background:  To identify the clinical ocular signs of uveitis associated with latent tuberculosis (TB). Design:  Retrospective case-control study. Participants:  Consecutive patients from Singapore National Eye Centre Uveitis over 9 years. We compared 62 patients with uveitis associated with latent TB (LTBU) to 72 matched controls diagnosed with other known uveitides. Methods:  Patients were categorized as: (A) predominantly anterior segment inflammation (anterior uveitides) and (B) predominantly posterior segment inflammation (intermediate, posterior or pan-uveitides). The diagnostic performance of combining these clinical signs with investigations such as interferon-gamma release assay (IGRA) positivity and chest X-ray results suggestive of pulmonary tuberculosis (TB) was done using area under the receiver operator characteristic curve (AUC). Main Outcome Measures:  Sensitivity, specificity and likelihood of association with TB of various clinical signs. Results:  Extensive posterior synechiae and concomitant anterior scleritis in group A; low-grade anterior chamber activity, retinal phlebitis and severe vitritis in Group B were significantly associated with LTBU. Combining these clinical signs with a positive IGRA and tuberculin skin test (TST) improved the diagnostic performance in both groups (AUC for group A = 0.779; group B = 0.789). Conclusions:  Patients with a combination of suggestive clinical signs with positive IGRA and TST are more likely to be accurately diagnosed with uveitis associated with latent TB, which responds to anti-TB therapy. © 2012 The Authors. Journal compilation © 2012 Royal Australian and New Zealand College of Ophthalmologists.

PMID: 22299676 [PubMed - as supplied by publisher]

Inhibition of the β-class carbonic anhydrases from Mycobacterium tuberculosis with carboxylic acids.

J Enzyme Inhib Med Chem. 2012 Feb 3;

Authors: Maresca A, Vullo D, Scozzafava A, Manole G, Supuran CT

Abstract
The growth of Mycobacterium tuberculosis is strongly inhibited by weak acids although the mechanism by which these compounds act is not completely understood. A series of substituted benzoic acids, nipecotic acid, ortho- and para-coumaric acid, caffeic acid and ferulic acid were investigated as inhibitors of three β-class carbonic anhydrases (CAs, EC 4.2.1.1) from this pathogen, mtCA 1 (Rv1284), mtCA 2 (Rv3588c) and mtCA 3 (Rv3273). All three enzymes were inhibited with efficacies between the submicromolar to the micromolar one, depending on the scaffold present in the carboxylic acid. mtCA 3 was the isoform mostly inhibited by these compounds (K(I)s in the range of 0.11-0.97 µM); followed by mtCA 2 (K(I)s in the range of 0.59-8.10 µM), whereas against mtCA 1, these carboxylic acids showed inhibition constants in the range of 2.25-7.13 µM. This class of relatively underexplored β-CA inhibitors warrant further in vivo studies, as they may have the potential for developing antimycobacterial agents with a diverse mechanism of action compared to the clinically used drugs for which many strains exhibit multi-drug or extensive multi-drug resistance.

PMID: 22299588 [PubMed - as supplied by publisher]

Differences in patient profiles of abdominal and pulmonary tuberculosis: a comparative study.

Med J Malaysia. 2011 Oct;66(4):318-21

Authors: Chong VH

Abstract
OBJECTIVES: Tuberculosis remains a common infection and is often associated with non-specific constitutional symptoms or laboratory investigations regardless of site of manifestations. This study compares the profiles of abdominal tuberculosis (ATB) and pulmonary tuberculosis (PTB).
METHODS: Patients with ATB (n=34, male-21, mean age 43.3 +/- 16.0 years) diagnosed over a nine year period were identified from the National Tuberculosis registry and retrospectively reviewed. Comparisons were made with patients treated for PTB (n=163).
RESULTS: The most commonly affected sites were the ileocecal regions, peritoneum and hepatobiliary system. Common clinical presentations were abdominal pain (61.8%), anorexia (44.1%), weight loss (55.9%), fever (41.1%) and abdominal distension (29.4%). Four patients had concomitant active PTB. Compared to PTB, patients with ATB had significantly lower serum haemoglobin (11.6 +/- 2.4 vs. 12.6 +/- 2.0 gm/dL, p=0.036) and higher rate of adverse events of antituberculous treatment (50% vs. 15.4%, p < 0.001). There were no difference in prevalence of constitutional symptoms (fever, weight loss and anorexia), platelet level, albumin, total protein and erythrocyte sedimentation rate. Importantly, there was no difference in the treatment response. More patients with ATB and concomitant active PTB had reported weight loss (100% versus 36.7%, p = 0.017).
CONCLUSION: There are differences in the profiles of ATB and PTB. Awareness of such differences can help to improve the understanding and management of this infection.

PMID: 22299550 [PubMed - in process]

Association between circulating full-length osteopontin and IFN-gamma with disease status of tuberculosis and response to successful treatment.

Southeast Asian J Trop Med Public Health. 2011 Jul;42(4):876-89

Authors: Ridruechai C, Sakurada S, Yanai H, Yamada N, Kantipong P, Piyaworawong S, Dhepakson P, Khusmith S, Keicho N

Abstract
The T helper type 1 (Th1) immune response plays an important role in protective immunity, pathophysiology and development of tuberculosis (TB). To investigate whether osteopontin (OPN) and other Th1 response-related molecules are associated withTB disease status, including co-infection with HIV, and response to anti-TB treatment, circulating levels of full-length OPN (F-OPN), thrombin-cleaved N-terminal fragment of OPN (N-half OPN), IFN-gamma, IP-10, IL-18, IL-12/ IL-23 (p40), IL-10, IL-15 and C-reactive protein (CRP) were measured before and after anti-TB treatment. Patients with newly active pulmonary TB had significantly higher plasma levels of F-OPN, IFN-gamma and CRP than healthy controls (HC). F-OPN, N-half OPN, IFN-gamma, IP-10, IL-18 and IL-10 levels were higher in patients with extensive TB/HIV co-infection than in patients with a single disease of TB or HIV. Plasma levels of F-OPN correlated well with those of IP-10, IL-18 and N-half OPN among patients with active TB. The F-OPN, IFN-gamma, IP-10 and CRP levels decreased significantly after effective anti-TB treatment. These data suggest that circulating OPN and Th1 response-related molecules, including IFN-gamma, may be regulated in response to expansion of active TB and could serve as markers of disease activity before and during treatment.

PMID: 22299470 [PubMed - in process]