Development of tuberculosis in human immunodeficiency virus infected patients receiving antiretroviral therapy

HLA-B*13, B*35 and B*39 Alleles Are Closely Associated With the Lack of Response to ART in HIV Infection: A Cohort Study in a Population of Northern Brazil

Introduction

Immune reconstitution failure after HIV treatment is a multifactorial phenomenon that may also be associated with a single polymorphism of human leukocyte antigen (HLA); however, few reports include patients from the Brazilian Amazon. Our objective was to evaluate the association of the immunogenic profile of the “classical” HLA-I and HLA-II loci with treatment nonresponse in a regional cohort monitored over 24 months since HIV diagnosis.

Materials and Methods

Treatment-free participants from reference centers in the state of Pará, Brazil, were enrolled. Infection screening was performed using enzyme immunoassays (Murex AG/AB Combination DiaSorin, UK) and confirmed by immunoblots (Bio-Manguinhos, FIOCRUZ). Plasma viral load was quantified by real-time PCR (ABBOTT, Chicago, Illinois, USA). CD4⁺/CD8⁺ T lymphocyte quantification was performed by immunophenotyping and flow cytometry (BD Biosciences, San Jose, CA, USA). Infection was monitored via test and logistics platforms (SISCEL and SICLOM). Therapeutic response failure was inferred based on CD4⁺ T lymphocyte quantification after 1 year of therapy. Loci A, B and DRB1 were genotyped using PCR-SSO (One Lambda Inc., Canoga Park, CA, USA). Statistical tests were applied using GENEPOP, GraphPad Prism 8.4.3 and BioEstat 5.3.

Results

Of the 270 patients monitored, 134 responded to treatment (CD4⁺ ≥ 500 cells/µL), and 136 did not respond to treatment (CD4⁺ < 500 cells/µL). The allele frequencies of the loci were similar to heterogeneous populations. The allelic profile of locus B was statistically associated with treatment nonresponse, and the B*13, B*35 and B*39 alleles had the greatest probabilistic influence. The B*13 allele had the highest risk of treatment nonresponse, and carriers of the allele had a detectable viral load and a CD4+ T lymphocyte count less than 400 cells/µL with up to 2 years of therapy. The B*13 allele was associated with a switch in treatment regimens, preferably to efavirenz (EFZ)-based regimens, and among those who switched regimens, half had a history of coinfection with tuberculosis.

Conclusions

The allelic variants of the B locus are more associated with non-response to therapy in people living with HIV (PLHIV) from a heterogeneous population in the Brazilian Amazon.

Prevalence and associated risk factors for tuberculosis among people living with HIV in Nepal

Background

Worldwide tuberculosis (TB) takes more lives than any other infectious diseases. WHO estimates around 68,000 incident TB cases in Nepal. However, in 2018 only around 27,232 new TB cases were reported in the national system, resulting around 40,768 incident TB cases missing every year in Nepal. National Tuberculosis Control Center carried out this study in anti-retroviral therapy (ART) sites to estimate the prevalence of TB and identify the associated risk factors for TB among the people living with Human Immunodeficiency Virus (PLHIVs) in Nepal.

Methods

It was a cross-sectional institution-based study conducted between March and August 2018. Six ART sites with high caseloads of PLHIVs were selected. PLHIVs who were equal or above 18 years of age and were in ART program at the selected study sites were considered eligible for the study. Diagnosis of tuberculosis among PLHIVs who agreed to participate in the study was carried out as per the National Tuberculosis Management Guideline of National Tuberculosis Program of Nepal.

Results

Among 403 PLHIVs, tuberculosis was diagnosed in 40 (9.9%) individuals. Median age of the participants was 36 (30–43) years. Prevalence of TB was significantly higher among male PLHIVs than female PLHIVs (13.6% Vs 5.8%; P = 0.02) and Dalit ethnic group compared to Brahmin/Chettri (22.0%Vs5.9%, P = 0.01). The risk of developing TB was found significant among those with HIV stage progressed to WHO stage 3 and 4 (OR = 4.85, P<0.001) and with the family history of TB (OR = 4.50, P = 0.002).

Conclusions

Prevalence of TB among PLHIVs in Nepal was found 9.9%. Risk of developing TB was higher among PLHIVs who were male, Dalit, with HIV stage progressed to WHO stage 3 and 4 and with family history of TB. Hence, targeted interventions are needed to prevent the risk of developing TB among PLHIVs. Similarly, integrated, and comprehensive TB and HIV diagnosis and treatment services are needed for the management of TB/HIV co-infection in Nepal.

Tuberculosis incidence in country of origin is a key determinant of the risk of active tuberculosis in people living with HIV: Data from a 30-year observational cohort study

INTRODUCTION

People living with HIV (PLWH) are at high risk of active tuberculosis (TB) but this risk in the era of antiretroviral treatment (ART) remains unclear. It is critical to identify the groups who should be prioritised for latent TB (LTBI) screening. In this study we identified the risk factors associated with developing incident TB disease, by analysing a 30-year observational cohort.

METHODS

We evaluated PLWH in Leicester, UK, between 1983 and 2017 to ascertain those who developed active TB and the timing of this in relation to HIV diagnosis; whether before, concurrently with, or more than 3 months after the diagnosis of HIV (incident TB). Predictors of incident TB were ascertained using Cox proportional hazards models.

RESULTS

In all, 325 out of 2158 (15.1%) PLWH under care had had active TB; 64/325 (19.7%) prior to HIV diagnosis, 161/325 (49.5%) concurrently with/within 3 months of HIV diagnosis and 100/325 (30.8%) had incident TB. Incident TB risk was 4.57/1000 person-years. Increased TB incidence in the country of birth was associated with an increased risk of developing incident TB [50-149/100 000 population, adjusted hazard ratio (AHR) = 3.10, 95% CI: 0.94-10.20; 150-249/100 000 population, AHR = 7.14, 95% CI: 3.46-14.74; 250-349/100 000 population, AHR = 5.90, 95% CI: 2.32-14.99; ≥ 350/100 000 population, AHR = 3.96, 95% CI: 1.39-11.26].

CONCLUSIONS

Tuberculosis risk remains high among PLWH and is related to TB incidence in the country of birth. Further work is required to determine whether specific groups of PLWH should be targeted for programmatic LTBI screening, and whether it will result in high uptake and completion of chemoprophylaxis and is cost-effective for widespread implementation.

HIV-associated tuberculosis

Tuberculosis (TB) remains a leading cause of morbidity and mortality among people living with HIV. HIV-associated TB disproportionally affects African countries, particularly vulnerable groups at risk for both TB and HIV. Currently available TB diagnostics perform poorly in people living with HIV; however, new diagnostics such as Xpert Ultra and lateral flow urine lipoarabinomannan assays can greatly facilitate diagnosis of TB in people living with HIV. TB preventive treatment has been underutilized despite its proven benefits independent of antiretroviral therapy (ART). Shorter regimens using rifapentine can support increased availability and scale-up. Mortality is high in people with HIV-associated TB, and timely initiation of ART is critical. Programs should provide decentralized and integrated TB and HIV care in settings with high burden of both diseases to improve access to services that diagnose TB and HIV as early as possible. The new prevention and diagnosis tools recently recommended by WHO offer an immense opportunity to advance our fight against HIV-associated TB. They should be made widely available and scaled up rapidly supported by adequate funding with robust monitoring of the uptake to advance global TB elimination.

Magnitude and Associated Factors of Pulmonary Tuberculosis Among HIV/AIDS Patients Attending Antiretroviral Therapy Clinic at Debre Tabor Specialized Hospital, Northwest Ethiopia, 2019

Background

Tuberculosis (TB) has remained as a top global public health concern of the 21st century. It is the leading cause of morbidity and mortality among people living with human immunodeficiency virus (HIV) worldwide.

Objective

The study aimed to investigate the magnitude of pulmonary tuberculosis and its associated factors among HIV-positive patients attending antiretroviral treatment (ART) clinic in Debre Tabor specialized hospital, Northwest, Ethiopia.

Methods

A hospital-based cross-sectional study was conducted among 362 HIV-positive adult participants attending the ART clinic from October 1st to December 30th 2019. Socio-demographic data were collected using a pre-tested questionnaire. Sputum was collected aseptically into a sterile and leak-proof container. Following aseptic techniques, each sample was processed using the GeneXpert assay based on the manufacturer’s instructions. Similarly, about 3–5 mL of whole blood was drawn for CD4+ T-cell count and plasma viral load tests following standard blood collection procedures. CD4+ T-cell count was performed using the BD FACS caliber flow cytometry while the plasma viral load was performed by using a quantitative real-time polymerase chain reaction. Then, collected data were double-checked, cleaned and entered into Epi-Info version 7.2.0.1 and exported to SPSS version 20.0 for further statistical analysis. The bivariate and multivariate logistic regression were conducted to address risk factor analysis. The 95%confidence interval with its corresponding cure and adjusted odds ratio was computed. Finally, p-value ≤0.05 was considered as a statistically significant association.

Results

In this study, the overall prevalence of tuberculosis among HIV-positive patients was 18 [(5%), 95% CI: 2.8–7.5]. A high viral load (≥1000 copies/mL) was positively associated [AOR (95% CI: 6.4 (1.6–25.7)), p < 0.001] with developing tuberculosis among HIV-positive patients.

Conclusion

The prevalence of TB is low among ART-receiving patients in our study site.

Role of CD4/CD8 ratio on the incidence of tuberculosis in HIV-infected patients on antiretroviral therapy followed up for more than a decade

Background

The role of CD4/CD8 ratio on the incidence of tuberculosis (TB) in patients on antiretroviral therapy (ART) is unknown. Thus, we sought to determine whether the CD4/CD8 ratio was associated with development of TB in a cohort of HIV infected individuals on ART followed up for more than a decade in the setting of sub-Saharan Africa (SSA).

Methods

The cohort comprised adult patients who started ART between 2001 and 2007 and followed for up to 15 years. Clinical data were collected in retrospective manner. Patients with an AIDS defining illness or a CD4 count <200 cell/μL were started with a combination of ART. The participants have clinic visits every 6 months and/or as needed. Poisson regression models were used to identify factors associated with development of incident TB. Kaplan-Meier curves were used to estimate the probability of incident TB while on ART.

Results

A total of 347 patients with a median duration of follow-up on ART of 11.5 (IQR: 10.0–12.5) years were included. Incident TB developed in 47 patients during the 3259 person-years of follow-up, the majority (76.6%) occurred within five year of ART initiation. On univariate analysis, poor ART adherence (RR:2.57, 95% CI: 1.28–5.17), time-updated CD4 cell count of lower than 200 (RR: 4.86, 95%CI 2.33–10.15), or CD4 cell count between 200 and 500 (RR: 4.68, 95% CI: 2.17–10.09), time-updated CD8 cell count lower than 500 (RR: 2.83 95% CI 1.31–6.10), or CD8 cell count over 1000 (RR: 2.23, 95% CI: 1.12–4.45), time-updated CD4/CD8 ratio of less than 0.30 (RR: 6.00, 95% CI: 2.96–12.14), lack of normalization of CD4 T-cell count (RR: 6.13, 95% CI: 2.20–17.07), and virological failure (RR: 2.35 (95% CI: 1.17–4.71) were all associated with increased risk of incident TB. In multivariate analysis, however, time-updated CD4/CD8 ratio of less than 0.30 (adjusted RR: 4.08, 95% CI: 1.31–12.68) was the only factor associated with increased risk of developing incident TB (p = 0.015). Similar results were obtained in a sensitivity analysis by including only those virally suppressed patients (n = 233, 69% of all patients). In this group, CD4/CD8 ratio of less than 0.30 was associated with development of incident TB (adjusted RR: 4.02, 95% CI: 1.14–14.19, p = 0.031). Overall, the incidence rate of TB in patients with an updated CD4/CD8 ratio of less than 0.30 was more than 5-fold higher when compared with those with a ratio more than 0.45.

Conclusion

Low CD4/CD8 ratio is independently associated with an increased risk of incident TB despite viral suppression. CD4/CD8 ratio may serve as a biomarker for identifying patients at risk of TB in patients on ART in the setting of SSA.

Prevalence and Risk Factors of Active TB among Adult HIV Patients Receiving ART in Northwestern Tanzania: A Retrospective Cohort Study

INTRODUCTION

Although ART has improved the outcome of people living with HIV/AIDS, still some patients develop TB while receiving ART. The literature on the magnitude of this problem is still scarce in our setting especially northwestern Tanzania. This study was designed to determine the prevalence of active TB among HIV patients on ART and assess its potential risk factors.

METHODS

A retrospective cohort study was done among adult HIV-positive patients initiated on ART at Bugando Medical Centre. Patients who were TB positive before ART initiation were excluded. Data regarding demographic, clinical, and laboratory information, TB status on receipt of ART, and time on ART were collected and analyzed using STATA 11 to determine the prevalence of TB and its associated factors.

RESULTS

In total, 391 patients were enrolled in this study. The median age was 39 (32-46) years, and a total of 129 (32.99%) participants had CD4 counts <200 cells/µl and 179 (45.78%) had WHO stage 3 and 4 illnesses. A total of 43 (11.0%) participants developed TB while receiving ART which was independently associated with male gender (OR = 2.9; p=0.007), WHO clinical stage 3 and 4 (OR = 1.4; p=0.029), baseline CD4 count <200 cells/µl (OR = 9.1; p < 0.001), and having not used IPT (OR = 3.1; p=0.05).

CONCLUSIONS

Active TB is prevalent among HIV patients while receiving ART in northwestern Tanzania which is independently associated with male gender, advanced HIV disease, and nonuse of IPT. Universal HIV testing could reduce late HIV diagnosis and hence reduce the risk of developing TB while receiving ART in our setting. Also IPT should be widely used for those who are negative for TB on screening.

The Immune Interaction between HIV-1 Infection and Mycobacterium tuberculosis

The modulation of tuberculosis (TB)-induced immunopathology caused by human immunodeficiency virus (HIV)-1 coinfection remains incompletely understood but underlies the change seen in the natural history, presentation, and prognosis of TB in such patients. The deleterious combination of these two pathogens has been dubbed a "deadly syndemic," with each favoring the replication of the other and thereby contributing to accelerated disease morbidity and mortality. HIV-1 is the best-recognized risk factor for the development of active TB and accounts for 13% of cases globally. The advent of combination antiretroviral therapy (ART) has considerably mitigated this risk. Rapid roll-out of ART globally and the recent recommendation by the World Health Organization (WHO) to initiate ART for everyone living with HIV at any CD4 cell count should lead to further reductions in HIV-1-associated TB incidence because susceptibility to TB is inversely proportional to CD4 count. However, it is important to note that even after successful ART, patients with HIV-1 are still at increased risk for TB. Indeed, in settings of high TB incidence, the occurrence of TB often remains the first presentation of, and thereby the entry into, HIV care. As advantageous as ART-induced immune recovery is, it may also give rise to immunopathology, especially in the lower-CD4-count strata in the form of the immune reconstitution inflammatory syndrome. TB-immune reconstitution inflammatory syndrome will continue to impact the HIV-TB syndemic.

Tuberculosis Incidence and Risk Factors Among Human Immunodeficiency Virus (HIV)-Infected Adults Receiving Antiretroviral Therapy in a Large HIV Program in Nigeria

Background. Despite the benefits of antiretroviral therapy (ART), tuberculosis (TB) is the leading cause of mortality among human immunodeficiency virus (HIV)-infected persons in Africa. Nigeria bears the highest TB burden in Africa and second highest HIV burden globally. This long-term multicenter study aimed to determine the incidence rate and predictors of TB in adults in the Harvard/AIDS Prevention Initiative in Nigeria (APIN) and President's Emergency Plan for AIDS Relief (PEPFAR) Nigeria ART program.

Methods. This retrospective evaluation used data collected from 2004 to 2012 through the Harvard/APIN PEPFAR program. Risk factors for incident TB were determined using multivariate Cox proportional hazards regression with time-dependent covariates.

Results. Of 50 320 adults enrolled from 2005 to 2010, 11 092 (22%) had laboratory-confirmed active TB disease at ART initiation, and 2021 (4%) developed active TB after commencing ART. During 78 228 total person-years (PY) of follow-up, the TB incidence rate was 25.8 cases per 1000 PY (95% confidence interval [CI], 24.7–27.0) overall, and it decreased significantly both with duration on ART and calendar year. Risk factors at ART initiation for incident TB included the following: earlier ART enrollment year, tenofovir-containing initial ART regimen, and World Health Organization clinical stage above 1. Time-updated risk factors included the following: low body mass index, low CD4⁺ cell count, unsuppressed viral load, anemia, and ART adherence below 80%.

Conclusions. The rate of incident TB decreased with longer duration on ART and over the program years. The strongest TB risk factors were time-updated clinical markers, reinforcing the importance of consistent clinical and laboratory monitoring of ART patients in prompt diagnosis and treatment of TB and other coinfections.

Tuberculosis incidence rate and risk factors among HIV-infected adults with access to antiretroviral therapy

OBJECTIVE

The objective of this study is to determine the incidence rate and risk factors of tuberculosis (TB) among HIV-infected adults accessing antiretroviral therapy (ART) in Tanzania.

DESIGN

A prospective observational study among HIV-infected adults attending HIV clinics in Dar es Salaam.

METHODS

We estimated TB incidence rates among HIV-infected patients prior to and after ART initiation. We used Cox proportional hazard regressions to determine the predictors of incident TB among HIV-infected adults enrolled in the HIV care and treatment programme.

RESULTS

We assessed 67 686 patients for a median follow-up period of 24 (interquartile range: 8-49) months; 7602 patients were diagnosed with active TB. The TB incidence rate was 7.9 [95% confidence interval (95% CI), 7.6-8.2] per 100 person-years prior to ART initiation, and 4.4 (95% CI, 4.2-4.4) per 100 person-years for patients receiving ART. In multivariate analyses, patients on ART in the first 3 months had a 57% higher risk of TB (hazard ratio: 1.57, 95% CI, 1.47-1.68) than those not on ART, but the risk significantly decreased with increasing duration of ART. Risk factors for incident TB included being male, having low BMI or middle upper arm circumference, lower CD4 cell count and advanced WHO disease stage. There was seasonal variation for incident TB, with higher risk observed following the rainy seasons (May, June and November).

CONCLUSION

In TB endemic regions, HIV-infected patients initiating ART, particularly men and those with poor nutritional status, should be closely monitored for active TB at ART initiation. In addition to increasing the access to ART, interventions should be considered to improve nutritional status among HIV-infected patients.

Cytokine and chemokine expression profiles in response to Mycobacterium tuberculosis stimulation are altered in HIV-infected compared to HIV-uninfected subjects with active tuberculosis

Mycobacterium tuberculosis (Mtb) infects nearly 2 million people annually and is the most common cause of death in HIV-infected individuals. Tuberculosis (TB) diagnostics cater to HIV-uninfected individuals in non-endemic countries, are expensive, slow, and lack sensitivity for those most affected. Patterns of soluble immune markers from Mtb-stimulated immune cells are not well defined in HIV co-infection. We assessed immune differences between HIV-infected and HIV-uninfected individuals with active TB utilizing IFNγ-based QuantiFERON®-TB Gold In-Tube (QFT) testing in Nairobi, Kenya. Excess QFT supernatants were used to measure cytokine and chemokine responses by a 17-plex bead array. Mtb/HIV co-infected participants were significantly less likely to be QFT+ (47.2% versus 84.2% in the HIV-uninfected group), and demonstrated lower expression of all cytokines except for IFNα2. Receiver operator characteristic analyses identified IL-1α as a potential marker of co-infection. Among HIV-infected individuals, CD4+ T cell count correlated weakly with the expression of several analytes. Co-expression analysis highlighted differences in immune profiles between the groups. These data suggest that there is a unique and detectable Mtb-specific immune response in co-infection. A better understanding of Mtb immunology can translate into much needed immunodiagnostics with enhanced sensitivity in HIV-infected individuals, facilitating their opportunity to obtain live-saving treatment.