Gene expression responses to anti-tuberculous drugs in a whole blood model.

BACKGROUND: There is a need for better tools to evaluate new or repurposed TB drugs. The whole blood bactericidal activity (WBA) assay has been advocated for this purpose. We investigated whether transcriptional responses in the WBA assay resemble TB responses in vivo, and whether the approach might additionally reveal mechanisms of action. RESULTS: 1422 of 1798 (79%) of differentially expressed genes in WBA incubated with the standard combination of rifampicin, isoniazid, pyrazinamide and ethambutol were also expressed in sputum (P < 0.0001) obtained from patients taking the same combination of drugs; these comprised well-established treatment-response genes. Gene expression profiles in WBA incubated with the standard drugs individually, or with moxifloxacin or faropenem (with amoxicillin and clavulanic acid) clustered by individual drug exposure. Distinct pathways were detected for individual drugs, although only with isoniazid did these relate to known mechanisms of drug action. CONCLUSIONS: Substantial agreement between whole blood cultures and sputum and the ability to differentiate individual drugs suggest that transcriptomics may add value to the whole blood assay for evaluating new TB drugs

Neurocognitive Function at the First-Line Failure and on the Second-Line Antiretroviral Therapy in Africa: Analyses From the EARNEST Trial.

OBJECTIVE: To assess neurocognitive function at the first-line antiretroviral therapy failure and change on the second-line therapy. DESIGN: Randomized controlled trial was conducted in 5 sub-Saharan African countries. METHODS: Patients failing the first-line therapy according to WHO criteria after >12 months on non-nucleoside reverse transcriptase inhibitors-based regimens were randomized to the second-line therapy (open-label) with lopinavir/ritonavir (400 mg/100 mg twice daily) plus either 2-3 clinician-selected nucleoside reverse transcriptase inhibitors, raltegravir, or as monotherapy after 12-week induction with raltegravir. Neurocognitive function was tested at baseline, weeks 48 and 96 using color trails tests 1 and 2, and the Grooved Pegboard test. Test results were converted to an average of the 3 individual test z-scores. RESULTS: A total of 1036 patients (90% of those >18 years enrolled at 13 evaluable sites) had valid baseline tests (58% women, median: 38 years, viral load: 65,000 copies per milliliter, CD4 count: 73 cells per cubic millimeter). Mean (SD) baseline z-score was -2.96 (1.74); lower baseline z-scores were independently associated with older age, lower body weight, higher viral load, lower hemoglobin, less education, fewer weekly working hours, previous central nervous system disease, and taking fluconazole (P < 0.05 in multivariable model). Z-score was increased by mean (SE) of +1.23 (0.04) after 96 weeks on the second-line therapy (P < 0.001; n = 915 evaluable), with no evidence of difference between the treatment arms (P = 0.35). CONCLUSIONS: Patients in sub-Saharan Africa failing the first-line therapy had low neurocognitive function test scores, but performance improved on the second-line therapy. Regimens with more central nervous system-penetrating drugs did not enhance neurocognitive recovery indicating this need not be a primary consideration in choosing a second-line regimen

Severe Acute Respiratory Syndrome (SARS) in Singapore: Clinical Features of Index Patient and Initial Contacts

Severe acute respiratory syndrome (SARS) is an emerging viral infectious disease. One of the largest outbreaks of SARS to date began in Singapore in March 2003. We describe the clinical, laboratory, and radiologic features of the index patient and the patient’s initial contacts affected with probable SARS

Factors associated with virological rebound in HIV-infected patients receiving protease inhibitor monotherapy

OBJECTIVE: The Protease Inhibitor Monotherapy Versus Ongoing Triple Therapy (PIVOT) trial found that protease inhibitor monotherapy as a simplification strategy is well tolerated in terms of drug resistance but less effective than combination therapy in suppressing HIV viral load. We sought to identify factors associated with the risk of viral load rebound in this trial. METHODS: PIVOT was a randomized controlled trial in HIV-positive adults with suppressed viral load for at least 24 weeks on combination therapy comparing a strategy of physician-selected ritonavir-boosted protease inhibitor monotherapy versus ongoing triple therapy. In participants receiving monotherapy, we analysed time to confirmed viral load rebound and its predictors using flexible parametric survival models. RESULTS: Of 290 participants initiating protease inhibitor monotherapy (80% darunavir, 14% lopinavir, and 6% other), 93 developed viral load rebound on monotherapy. The risk of viral load rebound peaked at 9 months after starting monotherapy and then declined to approximately 5 per 100 person-years from 18 months onwards. Independent predictors of viral load rebound were duration of viral load suppression before starting monotherapy (hazard ratio 0.81 per additional year <50 copies/ml; P < 0.001), CD4+ cell count (hazard ratio 0.73 per additional 100 cells/µl for CD4+ nadir; P = 0.008); ethnicity (hazard ratio 1.87 for nonwhite versus white, P = 0.025) but not the protease inhibitor agent used (P = 0.27). Patients whose viral load was analysed with the Roche TaqMan-2 assay had a 1.87-fold risk for viral load rebound compared with Abbott RealTime assay (P = 0.012). CONCLUSION: A number of factors can identify patients at low risk of rebound with protease inhibitor monotherapy, and this may help to better target those who may benefit from this management strategy

Neurocognitive function in HIV infected patients on antiretroviral therapy

OBJECTIVE To describe factors associated with neurocognitive (NC) function in HIV-positive patients on stable combination antiretroviral therapy. DESIGN We undertook a cross-sectional analysis assessing NC data obtained at baseline in patients entering the Protease-Inhibitor-Monotherapy-Versus-Ongoing-Triple therapy (PIVOT) trial. MAIN OUTCOME MEASURE NC testing comprised of 5 domains. Raw results were z-transformed using standard and demographically adjusted normative datasets (ND). Global z-scores (NPZ-5) were derived from averaging the 5 domains and percentage of subjects with test scores >1 standard deviation (SD) below population means in at least two domains (abnormal Frascati score) calculated. Patient characteristics associated with NC results were assessed using multivariable linear regression. RESULTS Of the 587 patients in PIVOT, 557 had full NC results and were included. 77% were male, 68% Caucasian and 28% of Black ethnicity. Mean (SD) baseline and nadir CD4+ lymphocyte counts were 553(217) and 177(117) cells/µL, respectively, and HIV RNA was <50 copies/mL in all. Median (IQR) NPZ-5 score was -0.5 (-1.2/-0) overall, and -0.3 (-0.7/0.1) and -1.4 (-2/-0.8) in subjects of Caucasian and Black ethnicity, respectively. Abnormal Frascati scores using the standard-ND were observed in 51%, 38%, and 81%, respectively, of subjects overall, Caucasian and Black ethnicity (p<0.001), but in 62% and 69% of Caucasian and Black subjects using demographically adjusted-ND (p = 0.20). In the multivariate analysis, only Black ethnicity was associated with poorer NPZ-5 scores (P<0.001). CONCLUSIONS In this large group of HIV-infected subjects with viral load suppression, ethnicity but not HIV-disease factors is closely associated with NC results. The prevalence of abnormal results is highly dependent on control datasets utilised. TRIAL REGISTRY ClinicalTrials.gov, NCT01230580

Absence of Neisseria meningitidis W-135 Electrophoretic Type 37 during the Hajj, 2002

We document the absence of carriage of Neisseria meningitidis W-135 of the sequence type 11 in returning pilgrims after the Hajj 2002. This finding contrasts with the 15% carriage rate we previously reported in pilgrims returning from the Hajj 2001. The epidemiology of carriage may be changing or may have been controlled by vaccination and a policy of administering antibiotics to pilgrims from countries with a high incidence of meningococcal disease

Nucleoside reverse-transcriptase inhibitor cross-resistance and outcomes from second-line antiretroviral therapy in the public health approach: an observational analysis within the randomised, open-label, EARNEST trial.

BACKGROUND: Cross-resistance after first-line antiretroviral therapy (ART) failure is expected to impair activity of nucleoside reverse-transcriptase inhibitors (NRTIs) in second-line therapy for patients with HIV, but evidence for the effect of cross-resistance on virological outcomes is limited. We aimed to assess the association between the activity, predicted by resistance testing, of the NRTIs used in second-line therapy and treatment outcomes for patients infected with HIV. METHODS: We did an observational analysis of additional data from a published open-label, randomised trial of second-line ART (EARNEST) in sub-Saharan Africa. 1277 adults or adolescents infected with HIV in whom first-line ART had failed (assessed by WHO criteria with virological confirmation) were randomly assigned to a boosted protease inhibitor (standardised to ritonavir-boosted lopinavir) with two to three NRTIs (clinician-selected, without resistance testing); or with raltegravir; or alone as protease inhibitor monotherapy (discontinued after week 96). We tested genotypic resistance on stored baseline samples in patients in the protease inhibitor and NRTI group and calculated the predicted activity of prescribed second-line NRTIs. We measured viral load in stored samples for all patients obtained every 12-16 weeks. This trial is registered with Controlled-Trials.com (number ISRCTN 37737787) and ClinicalTrials.gov (number NCT00988039). FINDINGS: Baseline genotypes were available in 391 (92%) of 426 patients in the protease inhibitor and NRTI group. 176 (89%) of 198 patients prescribed a protease inhibitor with no predicted-active NRTIs had viral suppression (viral load <400 copies per mL) at week 144, compared with 312 (81%) of 383 patients in the protease inhibitor and raltegravir group at week 144 (p=0·02) and 233 (61%) of 280 patients in the protease inhibitor monotherapy group at week 96 (p<0·0001). Compared with results with no active NRTIs, 95 (85%) of 112 patients with one predicted-active NRTI had viral suppression (p=0·3) and 20 (77%) of 26 patients with two or three active NRTIs had viral suppression (p=0·08). Over all follow-up, greater predicted NRTI activity was associated with worse viral load suppression (global p=0·0004). INTERPRETATION: Genotypic resistance testing might not accurately predict NRTI activity in protease inhibitor-based second-line ART. Our results do not support the introduction of routine resistance testing in ART programmes in low-income settings for the purpose of selecting second-line NRTIs. FUNDING: European and Developing Countries Clinical Trials Partnership, UK Medical Research Council, Institito de Salud Carlos III, Irish Aid, Swedish International Development Cooperation Agency, Instituto Superiore di Sanita, WHO, Merck

Persistence of W135 Neisseria meningitidis Carriage in Returning Hajj Pilgrims: Risk for Early and Late Transmission to Household Contacts

After an outbreak of meningococcal disease caused by Neisseria meningitidis W135, associated with the Hajj pilgrimage in 2001, 15% of returning vaccinated pilgrims carried a single W135 clone, and 55% were still carriers 6 months later. Transmission to 8% of their unvaccinated household contacts occurred within a few weeks, but no late transmission took place. Public health interventions are needed to protect household contacts

Neurocognitive function in HIV-infected patients: comparison of two methods to define impairment.

OBJECTIVE: To compare two definitions of neurocognitive impairment (NCI) in a large clinical trial of effectively-treated HIV-infected adults at baseline. METHODS: Hopkins Verbal Learning test-Revised (HVLT-R), Colour Trail (CTT) and Grooved Pegboard (GPT) tests were applied exploring five cognitive domains. Raw scores were transformed into Z-scores and NCI defined as summary NPZ-5 score one standard deviation below the mean of the normative dataset (i.e. <-1SD) or Z-scores <-1SD in at least two individual domains (categorical scale). Principal component analysis (PCA) was performed to explore the contribution of individual tests to the total variance. RESULTS: Mean NPZ-5 score was -0.72 (SD 0.98) and 178/548 (32%) participants had NPZ-5 scores <-1SD. When impairment was defined as <-1SD in at least two individual tests, 283 (52%) patients were impaired. Strong correlations between the two components of the HVLT-R test (learning/recall) (r = 0.73), and the CTT and (attention/executive functioning) (r = 0.66) were observed. PCA showed a clustering with three components accounting for 88% of the total variance. When patients who scored <-1SD only in two correlated tests were considered as not impaired, prevalence of NCI was 43%. When correlated test scores were averaged, 36% of participants had NPZ-3 scores <-1SD and 32% underperformed in at least two individual tests. CONCLUSION: Controlling for differential contribution of individual test-scores on the overall performance and the level of correlation between components of the test battery used appear to be important when testing cognitive function. These two factors are likely to affect both summary scores and categorical scales in defining cognitive impairment. TRIAL REGISTRATION: EUDRACT: 2007-006448-23 and ISRCTN04857074

A blood RNA transcript signature for TB exposure in household contacts.

BACKGROUND: Current tools for diagnosing latent TB infection (LTBI) detect immunological memory of past exposure but are unable to determine whether exposure is recent. We sought to identify a whole-blood transcriptome signature of recent TB exposure. METHODS: We studied household contacts of TB patients; healthy volunteers without recent history of TB exposure; and patients with active TB. We performed whole-blood RNA sequencing (in all), an interferon gamma release assay (IGRA; in contacts and healthy controls) and PET/MRI lung scans (in contacts only). We evaluated differentially-expressed genes in household contacts (log2 fold change ≥1 versus healthy controls; false-discovery rate  0.19). CONCLUSIONS: Transcriptomics can detect TB exposure and, with further development, may be an approach of value for epidemiological research and targeting public health interventions