Eduardo Gotuzzo

Rapid Molecular Detection of Tuberculosis and Rifampin Resistance

BACKGROUNDnGlobal control of tuberculosis is hampered by slow, insensitive diagnostic methods, particularly for the detection of drug-resistant forms and in patients with human immunodeficiency virus infection. Early detection is essential to reduce the death rate and interrupt transmission, but the complexity and infrastructure needs of sensitive methods limit their accessibility and effect.nnnMETHODSnWe assessed the performance of Xpert MTB/RIF, an automated molecular test for Mycobacterium tuberculosis (MTB) and resistance to rifampin (RIF), with fully integrated sample processing in 1730 patients with suspected drug-sensitive or multidrug-resistant pulmonary tuberculosis. Eligible patients in Peru, Azerbaijan, South Africa, and India provided three sputum specimens each. Two specimens were processed with N-acetyl-L-cysteine and sodium hydroxide before microscopy, solid and liquid culture, and the MTB/RIF test, and one specimen was used for direct testing with microscopy and the MTB/RIF test.nnnRESULTSnAmong culture-positive patients, a single, direct MTB/RIF test identified 551 of 561 patients with smear-positive tuberculosis (98.2%) and 124 of 171 with smear-negative tuberculosis (72.5%). The test was specific in 604 of 609 patients without tuberculosis (99.2%). Among patients with smear-negative, culture-positive tuberculosis, the addition of a second MTB/RIF test increased sensitivity by 12.6 percentage points and a third by 5.1 percentage points, to a total of 90.2%. As compared with phenotypic drug-susceptibility testing, MTB/RIF testing correctly identified 200 of 205 patients (97.6%) with rifampin-resistant bacteria and 504 of 514 (98.1%) with rifampin-sensitive bacteria. Sequencing resolved all but two cases in favor of the MTB/RIF assay.nnnCONCLUSIONSnThe MTB/RIF test provided sensitive detection of tuberculosis and rifampin resistance directly from untreated sputum in less than 2 hours with minimal hands-on time. (Funded by the Foundation for Innovative New Diagnostics.)

Feasibility, diagnostic accuracy, and effectiveness of decentralised use of the Xpert MTB/RIF test for diagnosis of tuberculosis and multidrug resistance: a multicentre implementation study

Summary Background The Xpert MTB/RIF test (Cepheid, Sunnyvale, CA, USA) can detect tuberculosis and its multidrug-resistant form with very high sensitivity and specificity in controlled studies, but no performance data exist from district and subdistrict health facilities in tuberculosis-endemic countries. We aimed to assess operational feasibility, accuracy, and effectiveness of implementation in such settings. Methods We assessed adults (≥18 years) with suspected tuberculosis or multidrug-resistant tuberculosis consecutively presenting with cough lasting at least 2 weeks to urban health centres in South Africa, Peru, and India, drug-resistance screening facilities in Azerbaijan and the Philippines, and an emergency room in Uganda. Patients were excluded from the main analyses if their second sputum sample was collected more than 1 week after the first sample, or if no valid reference standard or MTB/RIF test was available. We compared one-off direct MTB/RIF testing in nine microscopy laboratories adjacent to study sites with 2–3 sputum smears and 1–3 cultures, dependent on site, and drug-susceptibility testing. We assessed indicators of robustness including indeterminate rate and between-site performance, and compared time to detection, reporting, and treatment, and patient dropouts for the techniques used. Findings We enrolled 6648 participants between Aug 11, 2009, and June 26, 2010. One-off MTB/RIF testing detected 933 (90·3%) of 1033 culture-confirmed cases of tuberculosis, compared with 699 (67·1%) of 1041 for microscopy. MTB/RIF test sensitivity was 76·9% in smear-negative, culture-positive patients (296 of 385 samples), and 99·0% specific (2846 of 2876 non-tuberculosis samples). MTB/RIF test sensitivity for rifampicin resistance was 94·4% (236 of 250) and specificity was 98·3% (796 of 810). Unlike microscopy, MTB/RIF test sensitivity was not significantly lower in patients with HIV co-infection. Median time to detection of tuberculosis for the MTB/RIF test was 0 days (IQR 0–1), compared with 1 day (0–1) for microscopy, 30 days (23–43) for solid culture, and 16 days (13–21) for liquid culture. Median time to detection of resistance was 20 days (10–26) for line-probe assay and 106 days (30–124) for conventional drug-susceptibility testing. Use of the MTB/RIF test reduced median time to treatment for smear-negative tuberculosis from 56 days (39–81) to 5 days (2–8). The indeterminate rate of MTB/RIF testing was 2·4% (126 of 5321 samples) compared with 4·6% (441 of 9690) for cultures. Interpretation The MTB/RIF test can effectively be used in low-resource settings to simplify patients access to early and accurate diagnosis, thereby potentially decreasing morbidity associated with diagnostic delay, dropout and mistreatment. Funding Foundation for Innovative New Diagnostics, Bill & Melinda Gates Foundation, European and Developing Countries Clinical Trials Partnership (TA2007.40200.009), Wellcome Trust (085251/B/08/Z), and UK Department for International Development.

Multidrug-Resistant Tuberculosis and Culture Conversion with Bedaquiline

BACKGROUNDnBedaquiline (Sirturo, TMC207), a diarylquinoline that inhibits mycobacterial ATP synthase, has been associated with accelerated sputum-culture conversion in patients with multidrug-resistant tuberculosis, when added to a preferred background regimen for 8 weeks.nnnMETHODSnIn this phase 2b trial, we randomly assigned 160 patients with newly diagnosed, smear-positive, multidrug-resistant tuberculosis to receive either 400 mg of bedaquiline once daily for 2 weeks, followed by 200 mg three times a week for 22 weeks, or placebo, both in combination with a preferred background regimen. The primary efficacy end point was the time to sputum-culture conversion in liquid broth. Patients were followed for 120 weeks from baseline.nnnRESULTSnBedaquiline reduced the median time to culture conversion, as compared with placebo, from 125 days to 83 days (hazard ratio in the bedaquiline group, 2.44; 95% confidence interval, 1.57 to 3.80; P<0.001 by Cox regression analysis) and increased the rate of culture conversion at 24 weeks (79% vs. 58%, P=0.008) and at 120 weeks (62% vs. 44%, P=0.04). On the basis of World Health Organization outcome definitions for multidrug-resistant tuberculosis, cure rates at 120 weeks were 58% in the bedaquiline group and 32% in the placebo group (P=0.003). The overall incidence of adverse events was similar in the two groups. There were 10 deaths in the bedaquiline group and 2 in the placebo group, with no causal pattern evident.nnnCONCLUSIONSnThe addition of bedaquiline to a preferred background regimen for 24 weeks resulted in faster culture conversion and significantly more culture conversions at 120 weeks, as compared with placebo. There were more deaths in the bedaquiline group than in the placebo group. (Funded by Janssen Pharmaceuticals; TMC207-C208 ClinicalTrials.gov number, NCT00449644.).

Mortality during the first year of potent antiretroviral therapy in HIV-1-infected patients in 7 sites throughout Latin America and the Caribbean.

Background:Although nearly 2 million people live with HIV in Latin America and the Caribbean, mortality rates after initiation of highly active antiretroviral therapy (HAART) have not been well described. Methods:Five thousand one hundred fifty-two HIV-infected, antiretroviral-naive adults from clinics in Argentina, Brazil, Chile, Haiti, Honduras, Mexico, and Peru starting HAART during 1996-2007 were included. First-year mortality rates and their association with demographics, regimen, baseline CD4, and clinical stage were assessed. Results:Overall 1-year mortality rate was 8.3% [95% confidence interval (CI): 7.6% to 9.1%], although variable across sites: 2.6%, 3.7%, 6.0%, 13.0%, 10.8%, 3.5%, and 9.8% for clinics in Argentina, Brazil, Chile, Haiti, Honduras, Mexico, and Peru, respectively. Eighty percent of deaths occurred within the first 6 months. Median baseline CD4 was 107 cells per milliliter, ranging from 79 (Peru) to 163 (Argentina). Mortality estimates adjusting for CD4 were similar across sites (1.1%-2.8% for CD4 = 200), except for Haiti, 7.5%, and Honduras, 7.0%. Death was associated with lower CD4 [adjusted hazard ratio for CD4 = 200 vs. CD4 = 50 was 0.58; 95% CI: 0.40 to 0.85] and clinical AIDS (hazard ratio = 3.1; 95% CI: 2.1 to 4.5). Conclusions:Mortality rates were similar to those reported elsewhere for resource-limited settings. Disease stage at HAART initiation, treatment eligibility criteria, program age, and background mortality rates may explain some variability in prognosis between sites.

Durability of Initial Antiretroviral Therapy in a Resource-Constrained Setting and the Potential Need for Zidovudine Weight-Based Dosing

Background:Whereas access to antiretroviral therapy (ART) for HIV-infected individuals in the developing world is increasing, data on factors impacting initial regimen durability are lacking. Methods:Retrospective review patients starting initial ART at Instituto de Medicine Tropical (Lima, Peru) April 1, 2004 to December 30, 2007. Survival methods (Kaplan-Meier, Cox proportional hazard) assessed factors associated with regimen durability including an interaction term between nucleoside reverse transcriptase inhibitor backbone and time. Results:Decreased initial regimen durability was observed with weight <60 kg [hazards ratio (HR) = 1.77; 95% confidence interval (CI) = 1.25-2.51], CD4 <200 (HR = 1.73; 95% CI = 1.03-2.91), and zidovudine (AZT) use at <120 days (HR = 2.09; 95% CI = 1.22-3.57). In contrast, after 120 days, AZT use decreased risk of discontinuation (HR = 0.52; 95% CI = 0.28-0.95). Early (<120 days) toxicity-related discontinuation of AZT containing regimens was observed in 44% of patients <50 kg at baseline vs. 14% of those >70 kg. An increased risk of early toxicity-related discontinuation of AZT-containing regimens was observed for baseline weight <60 kg (HR = 2.52; 95% CI = 1.46-4.35). Conclusions:Lower baseline weight and lower CD4 values at ART initiation were associated with decreased regimen durability. Compared with didanosine/stavudine, AZT use initially increased, then subsequently (>120 days) lowered hazards for regimen discontinuation. Weight <60 kg was associated with an increased risk of toxicity-related AZT discontinuation. As ART use expands globally, further study into maximally durable, least toxic regimens, and the role of weight-based AZT dosing is imperative.BACKGROUNDnAnal intraepithelial neoplasia (AIN), particularly AIN 3 is a precursor to anal cancer. Most cases of AIN are intraanal, but few treatments for intraanal AIN are currently available. Topical 85% trichloroacetic acid (TCA) is an inexpensive method used to treat perianal condyloma, a form of AIN 1, but its efficacy to treat intraanal AIN as first-line therapy is unknown.nnnMETHODSnRetrospective review of medical records was performed for all patients with AIN treated at the University of California San Francisco Anal Neoplasia Clinic with TCA as the first-line therapy from January 2000 to December 2004. Clearance was defined as the absence of AIN confirmed by high-resolution anoscopy and cytology after up to 4 TCA treatments.nnnRESULTSnThirty-five HIV-positive men and 19 HIV-negative men met the enrollment criteria. In multivariate analysis, greater clearance was seen in patients 41-48 years of age versus >49 years [odds ratio (OR): 8.4, confidence interval (CI): 1.1 to 94, P: 0.04]. Among HIV-positive men, those with 2 or fewer lesions showed greater clearance (OR: 14.3, CI: 1.5 to 662, P: 0.01). 32% of patients with AIN 2/3 cleared to no lesions. On a per lesion basis, 73% of AIN 1 and 71% AIN 2/3 cleared to no lesion or AIN 1 or less, respectively.nnnCONCLUSIONSnTopical 85% TCA was safe and well tolerated. It was more effective in younger patients and among HIV-positive patients, those with 2 or fewer lesions. A high proportion of AIN 2/3 lesions responded to TCA treatment.

Cross-Sectional Analysis of Late HAART Initiation in Latin America and the Caribbean: Late Testers and Late Presenters

Background Starting HAART in a very advanced stage of disease is assumed to be the most prevalent form of initiation in HIV-infected subjects in developing countries. Data from Latin America and the Caribbean is still lacking. Our main objective was to determine the frequency, risk factors and trends in time for being late HAART initiator (LHI) in this region. Methodology Cross-sectional analysis from 9817 HIV-infected treatment-naïve patients initiating HAART at 6 sites (Argentina, Chile, Haiti, Honduras, Peru and Mexico) from October 1999 to July 2010. LHI had CD4+ count ≤200cells/mm3 prior to HAART. Late testers (LT) were those LHI who initiated HAART within 6 months of HIV diagnosis. Late presenters (LP) initiated after 6 months of diagnosis. Prevalence, risk factors and trends over time were analyzed. Principal Findings Among subjects starting HAART (nu200a=u200a9817) who had baseline CD4+ available (nu200a=u200a8515), 76% were LHI: Argentina (56%[95%CI:52–59]), Chile (80%[95%CI:77–82]), Haiti (76%[95%CI:74–77]), Honduras (91%[95%CI:87–94]), Mexico (79%[95%CI:75–83]), Peru (86%[95%CI:84–88]). The proportion of LHI statistically changed over time (except in Honduras) (p≤0.02; Honduras pu200a=u200a0.7), with a tendency towards lower rates in recent years. Males had increased risk of LHI in Chile, Haiti, Peru, and in the combined site analyses (CSA). Older patients were more likely LHI in Argentina and Peru (OR 1.21 per +10-year of age, 95%CI:1.02–1.45; OR 1.20, 95%CI:1.02–1.43; respectively), but not in CSA (OR 1.07, 95%CI:0.94–1.21). Higher education was associated with decreased risk for LHI in Chile (OR 0.92 per +1-year of education, 95%CI:0.87–0.98) (similar trends in Mexico, Peru, and CSA). LHI with date of HIV-diagnosis available, 55% were LT and 45% LP. Conclusion LHI was highly prevalent in CCASAnet sites, mostly due to LT; the main risk factors associated were being male and older age. Earlier HIV-diagnosis and earlier treatment initiation are needed to maximize benefits from HAART in the region.

Induced Sputum MMP-1, -3 & -8 concentrations during treatment of tuberculosis

Introduction Tuberculosis (TB) destroys lung tissues and this immunopathology is mediated in part by Matrix Metalloproteinases (MMPs). There are no data on the relationship between local tissue MMPs concentrations, anti-tuberculosis therapy and sputum conversion. Materials and Methods Induced sputum was collected from 68 TB patients and 69 controls in a cross-sectional study. MMPs concentrations were measured by Luminex array, TIMP concentrations by ELISA and were correlated with a disease severity score (TBscore). 46 TB patients were then studied longitudinally at the 2nd, 8th week and end of treatment. Results Sputum MMP-1,-2,-3,-8,-9 and TIMP-1 and -2 concentrations are increased in TB. Elevated MMP-1 and -3 concentrations are independently associated with higher TB severity scores (p<0.05). MMP-1, -3 and -8 concentrations decreased rapidly during treatment (p<0.05) whilst there was a transient increase in TIMP-1/2 concentrations at week 2. MMP-2, -8 and -9 and TIMP-2 concentrations were higher at TB diagnosis in patients who remain sputum culture positive at 2 weeks and MMP-3, -8 and TIMP-1 concentrations were higher in these patients at 2nd week of TB treatment. Conclusions MMPs are elevated in TB patients and associate with disease severity. This matrix-degrading phenotype resolves rapidly with treatment. The MMP profile at presentation correlates with a delayed treatment response.

A diagnostic accuracy study of Xpert®MTB/RIF in HIV-positive patients with high clinical suspicion of pulmonary tuberculosis in Lima, Peru.

Background Diagnosis of pulmonary tuberculosis (TB) among human immunodeficiency virus (HIV) patients remains complex and demands easy to perform and accurate tests. Xpert®MTB/RIF (MTB/RIF) is a molecular TB diagnostic test which is rapid and convenient; the test requires minimal human resources and reports results within two hours. The majority of performance studies of MTB/RIF have been performed in high HIV burden settings, thus TB diagnostic studies among HIV patients in low HIV prevalence settings such as Peru are still needed. Methodology/Principal Findings From April 2010 to May 2011, HIV-positive patients with high clinical suspicion of TB were enrolled from two tertiary hospitals in Lima, Peru. Detection of TB by MTB/RIF was compared to a composite reference standard Löwenstein-Jensen (LJ) and liquid culture. Detection of rifampicin resistance was compared to the LJ proportion method. We included 131 patients, the median CD4 cell count was 154.5 cells/mm3 and 45 (34.4%) had TB. For TB detection among HIV patients, sensitivity of MTB/RIF was 97.8% (95% CI 88.4–99.6) (44/45); specificity was 97.7% (95% CI 91.9–99.4) (84/86); the positive predictive value was 95.7% (95% CI 85.5–98.8) (44/46); and the negative predictive value, 98.8% (95% CI 93.6–99.8) (84/85). MTB/RIF detected 13/14 smear-negative TB cases, outperforming smear microscopy [97.8% (44/45) vs. 68.9% (31/45); pu200a=u200a0.0002]. For rifampicin resistance detection, sensitivity of MTB/RIF was 100% (95% CI 61.0–100.0) (6/6); specificity was 91.0% (95% CI 76.4–96.9) (30/33); the positive predictive value was 66.7% (95% CI 35.4–87.9) (6/9); and the negative predictive value was 100% (95% CI 88.7 –100.0) (30/30). Conclusions/Significance In HIV patients in our population with a high clinical suspicion of TB, MTB/RIF performed well for TB diagnosis and outperformed smear microscopy.

HIV Stigma as a Barrier to Retention in HIV Care at a General Hospital in Lima, Peru: a Case-Control Study

HIV stigma as a barrier to retention in HIV care has not been well-studied outside the United States. We conducted a case–control study in Lima, Peru to examine this issue. Cases were out-of-care for ≥12xa0months (nxa0=xa066) and controls were recruited from patients in active care presenting for a clinic visit (nxa0=xa0110). A previously validated HIV stigma scale with four domains was used. Associations between being out-of-care and each stigma domain were assessed using multivariable logistic regression. Stigma scores were highest for disclosure concerns. Modest associations were found for greater disclosure concerns (OR 1.16; 95xa0% CI 0.99, 1.36) and concerns with public attitudes (OR 1.20; 95xa0% CI 1.03, 1.40). Enacted stigma and negative self-image showed non-linear associations with being out-of-care that plateaued or declined, respectively, at higher levels of stigma. The threshold effect for enacted stigma warrants further exploration, while disclosure concerns may be especially amenable to intervention in this population.ResumenEl rol del estigma social asociado al VIH, como una barrera para la retención en el cuidado de VIH, no ha sido bien estudiado fuera de los Estados Unidos. Para examinar este problema, se realizó un estudio de casos y controles en Lima, Perú. Los casos fueron aquellos pacientes que estuvieron fuera del cuidado para VIH por ≥12 meses (nxa0=xa066) y los controles aquellos que se encontraban bajo cuidado activo para el VIH (nxa0=xa0110). Se utilizó una escala para estigma en VIH previamente validada con cuatro dominios. Las asociaciones entre estar fuera del cuidado y cada dominio de estigma fueron evaluadas mediante una regresion logistica multivariable. Los puntajes más altos de estigma fueron para la preocupacion sobre divulgacion de estatus. Se encontraron asociaciones modestas para la preocupacion de divulgación de estatus (OR 1,16; 95xa0% CI 0,99, 1,36) y la preocupacion por las actitudes publicas (OR 1,20; 95xa0% IC 1,03 a 1,40). El estigma establecido y la auto-imagen negativa mostraron asociaciones no lineales con estar fuera del cuidado. Estas se estabilizaron o se redujeron, respectivamente, con niveles más altos de estigma. El efecto umbral del estigma declarado merece una mayor exploración, mientras que la preocupacion de divulgación de estatus puede ser un foco de especial atencion en esta población.

Sustained efficacy and safety of raltegravir after 5 years of combination antiretroviral therapy as initial treatment of HIV-1 infection: final results of a randomized, controlled, phase II study (Protocol 004).

Abstract:Raltegravir as initial HIV therapy was examined in a double-blind study; 160 patients were randomized to raltegravir (400 mg bid after dose-ranging), 38 to efavirenz, both with tenofovir/lamivudine. At week 240, HIV-RNA remained <50 copies per milliliter in 68.8% (raltegravir) versus 63.2% (efavirenz), and CD4 increases were 302 versus 276 cells per microliter, respectively. Early HIV-RNA decline predicted later CD4 increases in both groups. Raltegravir resistance was observed in 3 of 10 raltegravir recipients with virologic failure. Few drug-related adverse events were reported after week 48. Raltegravir had minimal effect on laboratory values, including lipids. Raltegravir with tenofovir/lamivudine showed durable efficacy and good tolerability over 5 years.