Effects of Enzyme Induction and Polymorphism on the Pharmacokinetics of Isoniazid and Rifampin in Tuberculosis/HIV Patients.

Tuberculosis is the most common cause of death in HIV-infected individuals. Rifampin and isoniazid are the backbones of the current first-line antitubercular therapy. The aim of the present study was to describe the time-dependent pharmacokinetics and pharmacogenetics of rifampin and isoniazid and to quantitatively evaluate the drug-drug interaction between rifampin and isoniazid in patients coinfected with HIV. Plasma concentrations of isoniazid, acetyl-isoniazid, isonicotinic acid, rifampin, and 25-desacetylrifampin from 40 HIV therapy-naive patients were determined by liquid chromatography-tandem mass spectrometry (LC-MS/MS) after the first dose and at steady state of antitubercular therapy. Patients were genotyped for determination of acetylator status and CYP2C19 phenotype. Nonlinear mixed-effects models were developed to describe the pharmacokinetic data. The model estimated an autoinduction of both rifampin bioavailability (0.5-fold) and clearance (2.3-fold). 25-Desacetylrifampin clearance was 2.1-fold higher at steady state than after the first dose. Additionally, ultrarapid CYP2C19 metabolizers had a 2-fold-higher rifampin clearance at steady state than intermediate or extensive metabolizers. An induction of isonicotinic acid formation from isoniazid dependent on total rifampin dose was estimated. Simulations indicated a 30% lower isoniazid exposure at steady state during administration of standard rifampin doses than isoniazid exposure in noninduced individuals. Rifampin exposure was correlated with CYP2C19 polymorphism, and rifampin administration may increase exposure to toxic metabolites by isoniazid in patients. Both findings may influence the risk of treatment failure, resistance development, and toxicity and require further investigation, especially with regard to ongoing high-dose rifampin trials.

A CD4+ TNF+ monofunctional memory T-cell response to BCG vaccination is associated with Mycobacterium tuberculosis infection in infants exposed to HIV.

BACKGROUND: The immunologic correlates of risk of Mycobacterium tuberculosis (Mtb) infection after BCG vaccination are unknown. The mechanism by which BCG influences the tuberculin skin test (TST) remains poorly understood. We evaluated CD4+ T-cell responses in infants exposed to HIV and uninfected (HEU) who received BCG at birth and examined their role in susceptibility to Mtb infection and influence on TST induration. METHODS: HEU infants were enrolled in a randomised clinical trial of isoniazid (INH) to prevent Mtb infection in Kenya. We measured mycobacterial antigen-specific Th1 and Th17 cytokine responses at 6-10 weeks of age prior to INH randomisation and compared responses between Mtb infected and uninfected infants. Outcomes at 14 months of age included TST, QuantiFERON-Plus (QFT-Plus), and ESAT-6/CFP-10-specific non-IFN-γ cytokines measured in QFT-Plus supernatants. FINDINGS: A monofunctional mycobacterial antigen-specific TNF+ CD4+ effector memory (CCR7-CD45RA-) T-cell response at 6-10 weeks of age was associated with Mtb infection at 14 months of age as measured by ESAT-6/CFP-10-specific IFN-γ and non-IFN-γ responses (Odds Ratio 2.26; Confidence Interval 1.27-4.15; P = 0.006). Mycobacterial antigen-specific polyfunctional effector memory Th1 responses at 6-10 weeks positively correlated with TST induration in infants without evidence of Mtb infection at 14 months, an association which was diminished by INH therapy. INTERPRETATION: Induction of monofunctional TNF+ CD4+ effector memory T-cell responses may be detrimental in TB vaccine development. This study also provides mechanistic insight into the association of BCG-induced immune responses with TST induration and further evidence that TST-based diagnoses of Mtb infection in infants are imprecise. FUNDING: Thrasher Research Fund.

Molecular insights into the differential efflux mechanism of Rv1634 protein, a multidrug transporter of major facilitator superfamily in Mycobacterium tuberculosis.

Currently, multidrug-resistant tuberculosis (MDR-TB) is a public health crisis and a major health security threat globally. In Mycobacterium tuberculosis (Mtb), major facilitator superfamily (MFS) is the largest group of secondary active transporters. Along with the transport of their natural substrates, MFS proteins were involved in a drug efflux mechanism that ultimately lead to resistance against available anti-TB drugs in Mtb. In the present study, the three-dimensional structure model of an MFS protein, Rv1634, a probable multidrug transporter from Mtb, was generated using homology modeling. The protein structure model was found in inward-open conformation having 14 transmembrane helices. In addition, a central transport channel was deduced across the protein, and a single binding pocket was identified halfway through the central cavity by structural alignment with the homologous protein structures. Further, Rv1634 protein was studied based on the differential structural behavior of apo and ligand-bound forms. All the protein systems were inserted into a phospholipid bilayer to characterize the conformational dynamics of the protein using molecular dynamics (MD) simulations. Detailed analysis of the MD trajectories showed the diverse substrate specificity of the binding pocket for the antibiotics that caused differential movement in the ciprofloxacin and norfloxacin, to which Mtb strains have now become resistant. The expulsion of the drugs outside the bacterial cell occurs through the alternating-access mechanism of N and C-terminal domains, which is intriguing and essential to the understanding the drug resistance mechanism in pathogenic bacteria.

Field evaluation of a prototype tuberculosis lipoarabinomannan lateral flow assay on HIV-positive and HIV-negative patients.

Detection of tuberculosis at the point-of-care (POC) is limited by the low sensitivity of current commercially available tests. We describe a diagnostic accuracy field evaluation of a prototype urine Tuberculosis Lipoarabinomannan Lateral Flow Assay (TB-LAM LFA) in both HIV-positive and HIV-negative patients using fresh samples with sensitivity and specificity as the measures of accuracy. This prototype combines a proprietary concentration system with a sensitive LFA. In a prospective study of 292 patients with suspected pulmonary tuberculosis in Uganda, the clinical sensitivity and specificity was compared against a microbiological reference standard including sputum Xpert MTB/RIF Ultra and solid and liquid culture. TB-LAM LFA had an overall sensitivity of 60% (95%CI 51-69%) and specificity of 80% (95%CI 73-85%). When comparing HIV-positive (N = 86) and HIV-negative (N = 206) patients, there was no significant difference in sensitivity (sensitivity difference 8%, 95%CI -11% to +24%, p = 0.4351) or specificity (specificity difference -9%, 95%CI -24% to +4%, p = 0.2051). Compared to the commercially available Alere Determine TB-LAM Ag test, the TB-LAM LFA prototype had improved sensitivity in both HIV-negative (difference 49%, 95%CI 37% to 59%, p<0.0001) and HIV-positive patients with CD4+ T-cell counts >200cells/µL (difference 59%, 95%CI 32% to 75%, p = 0.0009). This report is the first to show improved performance of a urine TB LAM test for HIV-negative patients in a high TB burden setting. We also offer potential assay refinement solutions that may further improve sensitivity and specificity.

Monkeying around with MAIT Cells: Studying the Role of MAIT Cells in SIV and Mtb Co-Infection.

There were an estimated 10 million new cases of tuberculosis (TB) disease in 2019. While over 90% of individuals successfully control Mycobacterium tuberculosis (Mtb) infection, which causes TB disease, HIV co-infection often leads to active TB disease. Despite the co-endemic nature of HIV and TB, knowledge of the immune mechanisms contributing to the loss of control of Mtb replication during HIV infection is lacking. Mucosal-associated invariant T (MAIT) cells are innate-like T cells that target and destroy bacterially-infected cells and may contribute to the control of Mtb infection. Studies examining MAIT cells in human Mtb infection are commonly performed using peripheral blood samples. However, because Mtb infection occurs primarily in lung tissue and lung-associated lymph nodes, these studies may not be fully translatable to the tissues. Additionally, studies longitudinally examining MAIT cell dynamics during HIV/Mtb co-infection are rare, and lung and lymph node tissue samples from HIV+ patients are typically unavailable. Nonhuman primates (NHP) provide a model system to characterize MAIT cell activity during Mtb infection, both in Simian Immunodeficiency Virus (SIV)-infected and SIV-naïve animals. Using NHPs allows for a more comprehensive understanding of tissue-based MAIT cell dynamics during infection with both pathogens. NHP SIV and Mtb infection is similar to human HIV and Mtb infection, and MAIT cells are phenotypically similar in humans and NHPs. Here, we discuss current knowledge surrounding MAIT cells in SIV and Mtb infection, how SIV infection impairs MAIT cell function during Mtb co-infection, and knowledge gaps to address.

Advancing our understanding of HIV co-infections and neurological disease using the humanized mouse.

Humanized mice have become an important workhorse model for HIV research. Advances that enabled development of a human immune system in immune deficient mouse strains have aided new basic research in HIV pathogenesis and immune dysfunction. The small animal features facilitate development of clinical interventions that are difficult to study in clinical cohorts, and avoid the high cost and regulatory burdens of using non-human primates. The model also overcomes the host restriction of HIV for human immune cells which limits discovery and translational research related to important co-infections of people living with HIV. In this review we emphasize recent advances in modeling bacterial and viral co-infections in the setting of HIV in humanized mice, especially neurological disease, and Mycobacterium tuberculosis and HIV co-infections. Applications of current and future co-infection models to address important clinical and research questions are further discussed.

Structure and dynamics of a mycobacterial type VII secretion system.

Mycobacterium tuberculosis is the cause of one of the most important infectious diseases in humans, which leads to 1.4 million deaths every year1. Specialized protein transport systems-known as type VII secretion systems (T7SSs)-are central to the virulence of this pathogen, and are also crucial for nutrient and metabolite transport across the mycobacterial cell envelope2,3. Here we present the structure of an intact T7SS inner-membrane complex of M. tuberculosis. We show how the 2.32-MDa ESX-5 assembly, which contains 165 transmembrane helices, is restructured and stabilized as a trimer of dimers by the MycP5 protease. A trimer of MycP5 caps a central periplasmic dome-like chamber that is formed by three EccB5 dimers, with the proteolytic sites of MycP5 facing towards the cavity. This chamber suggests a central secretion and processing conduit. Complexes without MycP5 show disruption of the EccB5 periplasmic assembly and increased flexibility, which highlights the importance of MycP5 for complex integrity. Beneath the EccB5-MycP5 chamber, dimers of the EccC5 ATPase assemble into three bundles of four transmembrane helices each, which together seal the potential central secretion channel. Individual cytoplasmic EccC5 domains adopt two distinctive conformations that probably reflect different secretion states. Our work suggests a previously undescribed mechanism of protein transport and provides a structural scaffold to aid in the development of drugs against this major human pathogen.

Coronavirus Activates an Altruistic Stem Cell-Mediated Defense Mechanism that Reactivates Dormant Tuberculosis: Implications in Coronavirus Disease 2019 Pandemic.

We postulate that similar to bacteria, adult stem cells may also exhibit an altruistic defense mechanism to protect their niche against external threat. Herein, we report mesenchymal stem cell (MSC)-based altruistic defense against a mouse model of coronavirus, murine hepatitis virus-1 (MHV-1) infection of lung. MHV-1 infection led to reprogramming of CD271+ MSCs in the lung to an enhanced stemness phenotype that exhibits altruistic behavior, as per previous work in human embryonic stem cells. The reprogrammed MSCs exhibited transient expansion for 2 weeks, followed by apoptosis and expression of stemness genes. The conditioned media of the reprogrammed MSCs exhibited direct antiviral activity in an in vitro model of MHV-1-induced toxicity to type II alveolar epithelial cells by increasing their survival/proliferation and decreasing viral load. Thus, the reprogrammed MSCs can be identified as altruistic stem cells (ASCs), which exert a unique altruistic defense against MHV-1. In a mouse model of MSC-mediated Mycobacterium tuberculosis (MTB) dormancy, MHV-1 infection in the lung exhibited 20-fold lower viral loads than the MTB-free control mice on the third week of viral infection, and exhibited six-fold increase of ASCs, thereby enhancing the altruistic defense. Notably, these ASCs exhibited intracellular replication of MTB, and their extracellular release. Animals showed tuberculosis reactivation, suggesting that dormant MTB may exploit ASCs for disease reactivation.

Pharmacogenetic predictors of nevirapine pharmacokinetics in Ghanaian children living with HIV with or without TB coinfection.

Nevirapine (NVP) is a non-nucleoside reverse transcriptase inhibitor that is used in the treatment of human immunodeficiency virus (HIV) infection in children younger than 3 years old. Identifying genetic predictors of NVP pharmacokinetics (PK) in young children is important because inter-individual variability in NVP concentrations contributes to variable treatment response and the information may be used to individualize dosing decisions. We examined the relationship between genetic variations in relevant drug disposition genes and NVP PK parameters in Ghanaian children living with HIV eligible to initiate NVP-based antiretroviral therapy. Participants received NVP plus zidovudine and lamivudine or abacavir and lamivudine twice daily, and those with tuberculosis (TB) coinfection received concurrent anti-TB therapy with NVP. Pharmacokinetic sampling was performed after at least 4 weeks of antiretroviral therapy. Nevirapine minimum concentration (Cmin), area under the concentration-time curve from time 0 to 12 h (AUC0-12h), and apparent clearance (CL/F) were calculated using non-compartmental analysis using Phoenix v8.0 software. Genotyping for CYP2B6, CYP2A6, CYP3A5, ABCB1, NR1I2, and NR1I3 single nucleotide polymorphism (SNPs) was performed by TaqMan® allelic discrimination method. The median (range) NVP dose received was 10 (7-14) mg/kg. Of the 53 participants, the median (range) Cmin was 3.3 (0.0-14.0) mg/L and AUC0-12h was 56.0 (16.7-202.6) mg.hr/L. Using step-wise regression, CYP2B6 rs3745274 and NR1I2 rs6785049 SNPs were independent as well as joint predictors of NVP AUC0-12h, Cmin, and CL/F. We concluded that genotyping for CYP2B6 rs3745274, and the NR1I2 rs6785049 G > A SNP (which encodes the transcriptional factor, pregnane X receptor), could improve prediction of NVP PK for individualized therapy.

Early-phase scale-up of isoniazid preventive therapy for people living with HIV in two districts in Malawi (2017).

BACKGROUND: Isoniazid preventive therapy (IPT) against tuberculosis (TB) is a life-saving intervention for people living with HIV (PLHIV). In September 2017, Malawi began programmatic scale-up of IPT to eligible PLHIV in five districts with high HIV and TB burden. We measured the frequency and timeliness of early-phase IPT implementation to inform quality-improvement processes. METHODS AND FINDINGS: We applied a two-stage cluster design with systematic, probability-proportional-to-size sampling of six U.S. Centers for Disease Control and Prevention (CDC)-affiliated antiretroviral therapy (ART) centers operating in the urban areas of Lilongwe and Blantyre, Malawi (November 2017). ART clinic patient volume determined cluster size. Within each cluster, we sequentially sampled approximately 50 PLHIV newly enrolled in ART care. We described a quality-of-care cascade for intensive TB case finding (ICF) and IPT in PLHIV. PLHIV newly enrolled in ART care were eligibility-screened for hepatitis and peripheral neuropathy, as well as for TB disease using a standardized four-symptom screening tool. Among eligible PLHIV, the overall weighted IPT initiation rate was 70% (95% CI: 46%-86%). Weighted IPT initiation among persons aged <15 years (30% [95% CI: 12%-55%]) was significantly lower than among persons aged ≥15 years (72% [95% CI: 47%-89%]; Rao-Scott chi-square P = 0.03). HIV-positive children aged <5 years had a weighted initiation rate of only 13% (95% CI: 1%-79%). For pregnant women, the weighted initiation rate was 67% (95% CI: 32%-90%), similar to non-pregnant women aged ≥15 years (72% [95% CI: 49%-87%]). Lastly, 95% (95% CI: 92%-97%) of eligible PLHIV started ART within one week of HIV diagnosis, and 92% (95% CI: 73%-98%) of patients receiving IPT began on the same day as ART. CONCLUSIONS: Early-phase IPT uptake among adults at ART centers in Malawi was high. Child uptake needed improvement. National programs could adapt this framework to evaluate their ICF-IPT care cascades.

HCV Seroprevalence among HIV Patients and Associated Comorbidities at One Primary Health Facility in Rwanda.

Hepatitis C virus (HCV) and HIV have emerged as major viral infections within the past two decades, and their coinfection poses a big challenge with a significant impact in terms of morbidity and mortality associated with liver disease and renal failure. The current study aimed at assessing the prevalence of HCV infection and associated comorbidities among HIV patients at one primary health facility in Rwanda. In total, 417 HIV-positive patients were recruited and included in the study from January 1, 2019 up to June 30, 2019. All participants were screened for HCV infection by using the SD Bioline HCV antibody rapid test. In addition, underlying medical conditions were also recorded as comorbidities. Among 417 participants, 52 exhibited HCV-positive results (12.5%). The group of 41- to 50- and 51- to 60-year-olds had higher prevalence of HIV/HCV coinfection than other age-groups with 3.6% and 4.6%, respectively. Furthermore, five underlying medical conditions were found as comorbidities among the study participants. Those with HIV/HCV coinfection showed higher comorbidities than those with mono-infection including liver toxicity, P value 0.005; tuberculosis, P value 0.005; renal failure, P value 0.003; hypertension, P value 0.001; and diabetes mellitus, P value 0.001. The relative risk ratio of having comorbidities in those groups was 4.09. To conclude, the prevalence of HCV/HIV coinfection is high, and there was a statistical significant association of having comorbidities in HIV/HCV-coinfected group compared with the group of HIV mono-infection, which suggests more intervention in this vulnerable group of patients.

A Two-Gene Signature for Tuberculosis Diagnosis in Persons With Advanced HIV.

Background: Transcriptomic signatures for tuberculosis (TB) have been proposed and represent a promising diagnostic tool. Data remain limited in persons with advanced HIV. Methods: We enrolled 30 patients with advanced HIV (CD4 <100 cells/mm3) in India; 16 with active TB and 14 without. Whole-blood RNA sequencing was performed; these data were merged with a publicly available dataset from Uganda (n = 33; 18 with TB and 15 without). Transcriptomic profiling and machine learning algorithms identified an optimal gene signature for TB classification. Receiver operating characteristic analysis was used to assess performance. Results: Among 565 differentially expressed genes identified for TB, 40 were shared across India and Uganda cohorts. Common upregulated pathways reflect Toll-like receptor cascades and neutrophil degranulation. The machine-learning decision-tree algorithm selected gene expression values from RAB20 and INSL3 as most informative for TB classification. The signature accurately classified TB in discovery cohorts (India AUC 0.95 and Uganda AUC 1.0; p < 0.001); accuracy was fair in external validation cohorts. Conclusions: Expression values of RAB20 and INSL3 genes in peripheral blood compose a biosignature that accurately classified TB status among patients with advanced HIV in two geographically distinct cohorts. The functional analysis suggests pathways previously reported in TB pathogenesis.

Determinants of coinfection tuberculosis and HIV in prisons in Brazil.

INTRODUCTION: Prisons context has the potential for the spread of infectious diseases, like HIV and tuberculosis, which prevalence is higher in the people deprived of liberty compared to the general population. OBJECTIVE: to analyze which are the determinants of coinfection tuberculosis and HIV in prisons. METHODOLOGY: Case-control study conducted in the state of São Paulo, Brazil. New cases of tuberculosis in the population deprived of liberty in the period between 2015 and 2017 were considered. Data were obtained through the notification and monitoring system for tuberculosis cases in the state of São Paulo and included sociodemographic and clinical variables and diagnosis and treatment information. The data were analyzed through frequency distribution and bivariate analysis, testing the association of the dependent variable (tuberculosis/HIV coinfection vs. tuberculosis/HIV non-coinfection) with independent variables (sociodemographic, clinical and diagnostics variables) by calculating the odds ratio and p-value. RESULTS: Among the determinants of tuberculosis/HIV coinfection in prisons, we identified: age between 26-35, 36-55 and 56-84 years, notification in hospitals, negative sputum smear microscopy and culture, X-ray suggestive of another pathology, extrapulmonary and mixed clinical form, and alcoholism. A high percentage of death was also identified among coinfected people. CONCLUSIONS: identifying the determinants of the tuberculosis/HIV coinfected individual can assist in the development and implementation of guidelines aimed at controlling both infections in the prison environment.

Antiretroviral therapy among patients with HIV in Almaty, Kazakhstan: the implication for HIV-associated tuberculosis control.

INTRODUCTION: Antiretroviral therapy (ART) is an effective preventive strategy against tuberculosis (TB) in people living with HIV (PLWH). In Kazakhstan, according to the revised HIV treatment guideline (2017), ART should be initiated immediately after HIV diagnosis established, regardless of CD4+ count. AIM: To evaluate the impact of early initiation of ART on TB infection in PLWH registered in the Center of Prevention and Control of AIDS, Almaty, Kazakhstan, between 2008 and 2018. METHODOLOGY: A retrospective cohort study was conducted using the data of 4,053 patients from electronic HIV case management system (2008-2018) (EHCMS). RESULTS: The study revealed low rates (12.6%) of rapid ART (≤ 1 month after HIV diagnosis). Patients in the rapid ART initiation group were less likely to develop TB compared with those who started treatment >1 month after the HIV detection (odds ratio 1.6; 95% confidence interval [1.1, 2.2]; p = 0.00799). Interestingly, the risk for developing TB among patients receiving ART ≥ 1 month after HIV diagnosis was significantly higher compared with those not taking any treatment. The latter was explained by several confounding not addressed during the analysis, since ART was prescribed to patients with primarily deeper immunodeficiency, while the patients not receiving ART were less immunocompromised. CONCLUSION: Despite the recently changed HIV treatment guideline in Kazakhstan, ART is still initiated based on the disease severity. In 2018, the initiation of ART during the first month after HIV diagnosis increased by 50%. However, it is necessary to reduce the time to initiation of ART for all patients.

Plasma Levels of a Cleaved Form of Galectin-9 Are the Most Sensitive Biomarkers of Acquired Immune Deficiency Syndrome and Tuberculosis Coinfection.

Acquired immunodeficiency syndrome (AIDS) complicated with tuberculosis (TB) is a global public issue. Due to the paucity of bacteria in AIDS/TB, blood-based biomarkers that reflect disease severity are desired. Plasma levels of matricellular proteins, such as osteopontin (OPN) and galectin-9 (Gal-9), are known to be elevated in AIDS and TB. Therefore, full-length (FL)-Gal9 and FL-OPN, and their truncated forms (Tr-Gal9, Ud-OPN), and 38 cytokines/chemokines were measured in the plasma of 24 AIDS (other than TB), 49 TB, and 33 AIDS/TB patients. Receiver-operating characteristic analysis was used to screen molecules that could distinguish either between disease and normal group, among each disease group, or between deceased patients and survivors. Selected molecules were further analyzed for significant differences. Tr-Gal9 had the highest ability to differentiate TB from AIDS or AIDS/TB, while Ud-OPN distinguished multidrug resistance (MDR)-TB from non-MDR TB, and extra-pulmonary TB from pulmonary TB. Molecules significantly elevated in deceased patients included; FL-Gal9, Tr-Gal9, interleukin (IL)-1 receptor antagonist, IL-17A and transforming growth factor-α in AIDS; IL-6, granulocyte colony-stimulating factor and monocyte chemotactic protein-1 in TB; and macrophage inflammatory protein-1ß in AIDS/TB. From the sensitivity, specificity, and significant elevation, Tr-Gal9 is the best biomarker of inflammation and severity in AIDS and AIDS/TB.

Pre-HAART CD4+ T-lymphocytes as biomarkers of post-HAART immune recovery in HIV-infected children with or without TB co-infection.

BACKGROUND: Infection with the Human Immunodeficiency Virus (HIV) dramatically increases the risk of developing active tuberculosis (TB). Several studies have indicated that co-infection with TB increases the risk of HIV progression and death. Sub-Saharan Africa bears the brunt of these dual epidemics, with about 2.4 million HIV-infected people living with TB. The main objective of our study was to assess whether the pre-HAART CD4+ T-lymphocyte counts and percentages could serve as biomarkers for post-HAART treatment immune-recovery in HIV-positive children with and without TB co-infection. METHODS: The data analyzed in this retrospective study were collected from a cohort of 305 HIV-infected children being treated with HAART. A Lehmann family of ROC curves were used to assess the diagnostic performance of pre- HAART treatment CD4+ T-lymphocyte count and percentage as biomarkers for post-HAART immune recovery. The Kaplan-Meier estimator was used to compare differences in post-HAART recovery times between patients with and without TB co-infection. RESULTS: We found that the diagnostic performance of both pre-HARRT treatment CD4+ T-lymphocyte count and percentage was comparable and achieved accuracies as high as 74%. Furthermore, the predictive capability of pre-HAART CD4+ T-lymphocyte count and percentage were slightly better in TB-negative patients. Our analyses also indicate that TB-negative patients have a shorter recovery time compared to the TB-positive patients. CONCLUSIONS: Pre-HAART CD4+ T-lymphocyte count and percentage are stronger predictors of immune recovery in TB-negative pediatric patients, suggesting that TB co-infection complicates the treatment of HIV in this cohort. These findings suggest that the detection and treatment of TB is essential for the effectiveness of HAART in HIV-infected pediatric patients.

Mortality and risk of tuberculosis among people living with HIV in whom TB was initially ruled out.

Tuberculosis (TB) misdiagnosis remains a public health concern, especially among people living with HIV (PLHIV), given the high mortality associated with missed TB diagnoses. The main objective of this study was to describe the all-cause mortality, TB incidence rates and their associated risk factors in a cohort of PLHIV with presumptive TB in whom TB was initially ruled out. We retrospectively followed a cohort of PLHIV with presumptive TB over a 2 year-period in a rural district in Southern Mozambique. During the study period 382 PLHIV were followed-up. Mortality rate was 6.8/100 person-years (PYs) (95% CI 5.2-9.2) and TB incidence rate was 5.4/100 PYs (95% CI 3.9-7.5). Thirty-six percent of deaths and 43% of TB incident cases occurred in the first 12 months of the follow up. Mortality and TB incidence rates in the 2-year period after TB was initially ruled out was very high. The TB diagnostic work-up and linkage to HIV care should be strengthened to decrease TB burden and all-cause mortality among PLHIV with presumptive TB.

Previous and active tuberculosis increases risk of death and prolongs recovery in patients with COVID-19.

BACKGROUND: There is a growing literature on the association of SARS-CoV-2 and other chronic conditions, such as noncommunicable diseases. However, little is known about the impact of coinfection with tuberculosis. We aimed to compare the risk of death and recovery, as well as time-to-death and time-to-recovery, in COVID-19 patients with and without tuberculosis. METHODS: We created a 4:1 propensity score matched sample of COVID-19 patients without and with tuberculosis, using COVID-19 surveillance data in the Philippines. We conducted a longitudinal cohort analysis of matched COVID-19 patients as of May 17, 2020, following them until June 15, 2020. The primary analysis estimated the risk ratios of death and recovery in patients with and without tuberculosis. Kaplan-Meier curves described time-to-death and time-to-recovery stratified by tuberculosis status, and differences in survival were assessed using the Wilcoxon test. RESULTS: The risk of death in COVID-19 patients with tuberculosis was 2.17 times higher than in those without (95% CI: 1.40-3.37). The risk of recovery in COVID-19 patients with tuberculosis was 25% lower than in those without (RR = 0.75,05% CI 0.63-0.91). Similarly, time-to-death was significantly shorter (p = .0031) and time-to-recovery significantly longer in patients with tuberculosis (p = .0046). CONCLUSIONS: Our findings show that coinfection with tuberculosis increased morbidity and mortality in COVID-19 patients. Our findings highlight the need to prioritize routine and testing services for tuberculosis, although health systems are disrupted by the heavy burden of the SARS-CoV-2 pandemic.