Tuberculosis treatment intermittency in the continuation phase and mortality in HIV-positive persons receiving antiretroviral therapy.

BACKGROUND: Some tuberculosis (TB) treatment guidelines recommend daily TB treatment in both the intensive and continuation phases of treatment in HIV-positive persons to decrease the risk of relapse and acquired drug resistance. However, guidelines vary across countries, and treatment is given 7, 5, 3, or 2 days/week. The effect of TB treatment intermittency in the continuation phase on mortality in HIV-positive persons on antiretroviral therapy (ART), is not well-described. METHODS: We conducted an observational cohort study among HIV-positive adults treated for TB between 2000 and 2018 and after enrollment into the Caribbean, Central, and South America network for HIV epidemiology (CCASAnet; Brazil, Chile, Haiti, Honduras, Mexico and Peru). All received standard TB therapy (2-month initiation phase of daily isoniazid, rifampin or rifabutin, pyrazinamide ± ethambutol) and continuation phase of isoniazid and rifampin or rifabutin, administered concomitantly with ART. Known timing of ART and TB treatment were also inclusion criteria. Kaplan-Meier and Cox proportional hazards methods compared time to death between groups. Missing model covariates were imputed via multiple imputation. RESULTS: 2303 patients met inclusion criteria: 2003(87%) received TB treatment 5-7 days/week and 300(13%) 2-3 days/week in the continuation phase. Intermittency varied by site: 100% of patients from Brazil and Haiti received continuation phase treatment 5-7 days/week, followed by Honduras (91%), Peru (42%), Mexico (7%), and Chile (0%). The crude risk of death was lower among those receiving treatment 5-7 vs. 2-3 days/week (HR = 0.68; 95% CI = 0.51-0.91; P = 0.008). After adjusting for age, sex, CD4, ART use at TB diagnosis, site of TB disease (pulmonary vs. extrapulmonary), and year of TB diagnosis, mortality risk was lower, but not significantly, among those treated 5-7 days/week vs. 2-3 days/week (HR 0.75, 95%CI 0.55-1.01; P = 0.06). After also stratifying by study site, there was no longer a protective effect (HR 1.42, 95%CI 0.83-2.45; P = 0.20). CONCLUSIONS: TB treatment 5-7 days/week was associated with a marginally decreased risk of death compared to TB treatment 2-3 days/week in the continuation phase in multivariable, unstratified analyses. However, little variation in TB treatment intermittency within country meant the results could have been driven by other differences between study sites. Therefore, randomized trials are needed, especially in heterogenous regions such as Latin America.

Virologic failure and mortality in older ART initiators in a multisite Latin American and Caribbean Cohort.

INTRODUCTION: The "greying" of the HIV epidemic necessitates a better understanding of the healthcare needs of older HIV-positive adults. As these individuals age, it is unclear whether comorbidities and their associated therapies or the ageing process itself alter the response to antiretroviral therapy (ART). In this study, HIV treatment outcomes and corresponding risk factors were compared between older ART initiators and those who were younger using data from the Caribbean, Central and South America Network for HIV Epidemiology (CCASAnet). METHODS: HIV-positive adults (≥18 years) initiating ART at nine sites in Argentina, Brazil, Chile, Haiti, Honduras, Mexico and Peru were included. Patients were classified as older (≥50 years) or younger (<50 years) based on age at ART initiation. ART effectiveness was measured using three outcomes: death, virologic failure and ART treatment modification. Cox regression models for each outcome compared risk between older and younger patients, adjusting for other covariates. RESULTS: Among 26,311 patients initiating ART between 1996 and 2016, 3389 (13%) were ≥50 years. The majority of patients in both ≥50 and <50 age groups received a non-nucleoside reverse transcriptase inhibitor-based regimen (89% vs. 87%), did not have AIDS at baseline (63% vs. 62%), and were male (59% vs. 58%). Older patients had a higher risk of death (adjusted hazard ratio (aHR) 1.64; 95% confidence intervals (CI): 1.48 to 1.83) and a lower risk of virologic failure (aHR: 0.73; 95% CI: 0.63 to 0.84). There was no difference in risk of ART modification (aHR: 1.00; 95% CI: 0.94 to 1.06). Risk factors for death, virologic failure and treatment modification were similar for each group. CONCLUSIONS: Older age at ART initiation was associated with increased mortality and decreased risk of virologic failure in our cohort of more than 26,000 ART initiators in Latin America and the Caribbean. To the best of our knowledge this is the first study from the region to evaluate ART outcomes in this growing and important population. Given the complexity of issues related to ageing with HIV, a greater understanding is needed in order to properly respond to this shifting epidemic.

Time to HAART Initiation after Diagnosis and Treatment of Opportunistic Infections in Patients with AIDS in Latin America.

BACKGROUND: Since 2009, earlier initiation of highly active antiretroviral therapy (HAART) after an opportunistic infection (OI) has been recommended based on lower risks of death and AIDS-related progression found in clinical trials. Delay in HAART initiation after OIs may be an important barrier for successful outcomes in patients with advanced disease. Timing of HAART initiation after an OI in "real life" settings in Latin America has not been evaluated. METHODS: Patients in the Caribbean, Central and South America network for HIV Epidemiology (CCASAnet) ≥18 years of age at enrolment, from 2001-2012 who had an OI before HAART initiation were included. Patients were divided in an early HAART (EH) group (those initiating within 4 weeks of an OI) and a delayed HAART (DH) group (those initiating more than 4 weeks after an OI). All patients with an AIDS-defining OI were included. In patients with more than one OI the first event reported was considered. Calendar trends in the proportion of patients in the EH group (before and after 2009) were estimated by site and for the whole cohort. Factors associated with EH were estimated using multivariable logistic regression models. RESULTS: A total of 1457 patients had an OI before HAART initiation and were included in the analysis: 213 from Argentina, 686 from Brazil, 283 from Chile, 119 from Honduras and 156 from Mexico. Most prevalent OI were Tuberculosis (31%), followed by Pneumocystis pneumonia (24%), Invasive Candidiasis (16%) and Toxoplasmosis (9%). Median time from OI to HAART initiation decreased significantly from 5.7 (interquartile range [IQR] 2.8-12.1) weeks before 2009 to 4.3 (IQR 2.0-7.1) after 2009 (p<0.01). Factors associated with starting HAART within 4 weeks of OI diagnosis were lower CD4 count at enrolment (p-<0.001), having a non-tuberculosis OI (p<0.001), study site (p<0.001), and more recent years of OI diagnosis (p<0.001). DISCUSSION: The time from diagnosis of an OI to HAART initiation has decreased in Latin America coinciding with the publication of evidence of its benefit. We found important heterogeneity between sites which may reflect differences in clinical practices, local guidelines, and access to HAART. The impact of the timing of HAART initiation after OI on patient survival in this "real life" context needs further evaluation.

Temporal Trends in Age at HIV Diagnosis in Cohorts in the United States, the Caribbean, and Central and South America.

In the United States (USA), the age of those newly diagnosed with HIV is changing, particularly among men who have sex with men (MSM). A retrospective analysis included HIV-infected adults from seven sites in the Caribbean, Central and South America network (CCASAnet) and the Vanderbilt Comprehensive Care Clinic (VCCC-Nashville, Tennessee, USA). We estimated the proportion of patients <25 years at HIV diagnosis by calendar year among the general population and MSM. 19,466 (CCASAnet) and 3,746 (VCCC) patients were included. The proportion <25 years at diagnosis in VCCC increased over time for both the general population and MSM (p < 0.001). Only in the Chilean site for the general population and the Brazilian site for MSM were similar trends seen. Subjects <25 years of age at diagnosis were less likely to be immunocompromised at enrollment at both the VCCC and CCASAnet. Recent trends in the USA of greater numbers of newly diagnosed young patients were not consistently observed in Latin America and the Caribbean. Prevention efforts tailored to young adults should be increased.

Duration of anti-tuberculosis therapy and timing of antiretroviral therapy initiation: association with mortality in HIV-related tuberculosis.

BACKGROUND: Antiretroviral therapy (ART) decreases mortality risk in HIV-infected tuberculosis patients, but the effect of the duration of anti-tuberculosis therapy and timing of anti-tuberculosis therapy initiation in relation to ART initiation on mortality, is unclear. METHODS: We conducted a retrospective observational multi-center cohort study among HIV-infected persons concomitantly treated with Rifamycin-based anti-tuberculosis therapy and ART in Latin America. The study population included persons for whom 6 months of anti-tuberculosis therapy is recommended. RESULTS: Of 253 patients who met inclusion criteria, median CD4+ lymphocyte count at ART initiation was 64 cells/mm(3), 171 (68%) received >180 days of anti-tuberculosis therapy, 168 (66%) initiated anti-tuberculosis therapy before ART, and 43 (17%) died. In a multivariate Cox proportional hazards model that adjusted for CD4+ lymphocytes and HIV-1 RNA, tuberculosis diagnosed after ART initiation was associated with an increased risk of death compared to tuberculosis diagnosis before ART initiation (HR 2.40; 95% CI 1.15, 5.02; P = 0.02). In a separate model among patients surviving >6 months after tuberculosis diagnosis, after adjusting for CD4+ lymphocytes, HIV-1 RNA, and timing of ART initiation relative to tuberculosis diagnosis, receipt of >6 months of anti-tuberculosis therapy was associated with a decreased risk of death (HR 0.23; 95% CI 0.08, 0.66; P=0.007). CONCLUSIONS: The increased risk of death among persons diagnosed with tuberculosis after ART initiation highlights the importance of screening for tuberculosis before ART initiation. The decreased risk of death among persons receiving > 6 months of anti-tuberculosis therapy suggests that current anti-tuberculosis treatment duration guidelines should be re-evaluated.

The role of biologically active peptides in tissue repair using umbilical cord mesenchymal stem cells.

The role of bioactive compounds in wound repair is critical. The preliminary work described herein includes the study of the effects of second degree burns in a Rex rabbit model and the action of human umbilical cord cells on the regulation and secretion of bioactive compounds. When applied on blood scaffolds as heterograft matrices, fibroblasts proliferate from these primary cultures and release biologically active peptides under tight control. Our work in progress indicates that mesenchymal stem cell (MSC)-mediated therapy provides better quality and more efficient burn reepithelialization of injured tissues by controlling the release of these peptides. Improvement of wound aesthetics is achieved in less time than without MSC-mediated therapy. Well-organized epidermal regeneration and overall better quality of reepithelialization, with no rejection, can be demonstrated consistently with periodic biopsies. Our studies indicate that MSCs have the capacity to produce, regulate, and deliver biologically active peptides that result in superior regeneration, compared with conventional treatments.

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/mm(3) 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); p = 0.0002]. 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.

Human herpesvirus-8 in Peruvian blood donors: a population with hyperendemic disease?

Serum samples from 128 blood donors were tested for antibodies specific for human herpesvirus-8 by an immunofluorescence assay that detects antibodies against mainly lytic antigens. An overall seroprevalence of 56.25% was found (male donors, 54.68%; female donors, 57.11%). These findings indicate that human herpesvirus-8 infection is hyperendemic in Peruvian blood donors.