Optimising DTwP-containing vaccine infant immunisation schedules (OptImms) - a protocol for two parallel, open-label, randomised controlled trials

BACKGROUND

Universal immunisation is the cornerstone of preventive medicine for children, The World Health Organisation (WHO) recommends diphtheria-tetanus-pertussis (DTP) vaccine administered at 6, 10 and 14 weeks of age as part of routine immunisation. However, globally, more than 17 unique DTP-containing vaccine schedules are in use. New vaccines for other diseases continue to be introduced into the infant immunisation schedule, resulting in an increasingly crowded schedule. The OptImms trial will assess whether antibody titres against pertussis and other antigens in childhood can be maintained whilst adjusting the current Expanded Programme on Immunisation (EPI) schedule to provide space for the introduction of new vaccines.

METHODS

The OptImms studies are two randomised, five-arm, non-inferiority clinical trials in Nepal and Uganda. Infants aged 6 weeks will be randomised to one of five primary vaccination schedules based on age at first DTwP-vaccination (6 versus 8 weeks of age), number of doses in the DTwP priming series (two versus three), and spacing of priming series vaccinations (4 versus 8 weeks). Additionally, participants will be randomised to receive their DTwP booster at 9 or 12 months of age. A further sub-study will compare the co-administration of typhoid vaccine with other routine vaccines at one year of age. The primary outcome is anti-pertussis toxin IgG antibodies measured at the time of the booster dose. Secondary outcomes include antibodies against other vaccine antigens in the primary schedule and their safety.

DISCUSSION

These data will provide key data to inform policy decisions on streamlining vaccination schedules in childhood.

TRIAL REGISTRATIONS

ISRCTN12240140 (Nepa1, 7th January 2021) and ISRCTN6036654 (Uganda, 17th February 2021).

A qualitative study of the development and utilization of health facility-based immunization microplans in Uganda

Background

In 2006, Uganda adopted the Reaching Every District strategy with the goal of attaining at least 80% coverage for routine immunizations in every district. The development and utilization of health facility/district immunization microplans is the key to the strategy. A number of reports have shown suboptimal development and use of microplans in Uganda. This study explores factors associated with suboptimal development and use of microplans in two districts in Uganda to pinpoint challenges encountered during the microplanning process.

Methods

A qualitative study was conducted comparing two districts: Kapchorwa, with low immunization coverage, and Luwero with high immunization coverage. Data were collected through multilevel observation of health facilities, planning sessions and planning meetings; records review of microplans, micromaps and meeting minutes; 57 interviews with health workers at the ministry level and lower-level health facility workers. Data were analysed using NVivo 8 qualitative text analysis software. Transcripts were coded, and memos and display matrices were developed to examine the process of developing and utilizing microplans, including experiences of health workers (implementers).

Results

Three key findings emerged from this study. First, there are significant knowledge gaps with regard to the microplanning process among health workers at all levels (community and district health facility and nationally). Limited knowledge about communities and programme catchment areas greatly hinders the planning process by limiting the ability to identify hard-to-reach areas and to prioritize areas according to need. Secondly, the microplanning tool is bulky and complex. Finally, microplanning is being implemented in the context of already overtasked health personnel who have to conduct several other activities as part of their daily routines.

Conclusions

In order to achieve quality improvement as outlined in the Reaching Every District campaign, the microplanning process should be revised. Health workers’ misunderstanding and limited knowledge about the microplanning process, especially at peripheral health facilities, coupled with the complex, bulky nature of the microplanning tool, reduces the effectiveness of microplanning in improving routine immunization in Uganda. This study reveals the need to reduce the complexity of the tool and to identify ways to train and support workers in the use of the revised tool, including support in incorporating the microplanning process into their busy schedules.

Evaluating a Mobile Phone-Delivered Text Message Reminder Intervention to Reduce Infant Vaccination Dropout in Arua, Uganda: Protocol for a Randomized Controlled Trial

Background

Globally, suboptimal vaccine coverage is a public health concern. According to Uganda’s 2016 Demographic and Health Survey, only 49% of 12- to 23-month-old children received all recommended vaccinations by 12 months of age. Innovative ways are needed to increase coverage, reduce dropout, and increase awareness among caregivers to bring children for timely vaccination.

Objective

This study evaluates a personalized, automated caregiver mobile phone–delivered text message reminder intervention to reduce the proportion of children who start but do not complete the vaccination series for children aged 12 months and younger in select health facilities in Arua district.

Methods

A two-arm, multicenter, parallel group randomized controlled trial was conducted in four health facilities providing vaccination services in and around the town of Arua. Caregivers of children between 6 weeks and 6 months of age at the time of their first dose of pentavalent vaccine (Penta1; containing diphtheria, tetanus, pertussis, hepatitis B, and Haemophilus influenzae type b antigens) were recruited and interviewed. All participants received the standard of care, defined as the health worker providing child vaccination home-based records to caregivers as available and providing verbal instruction of when to return for the next visit. At the end of each day, caregivers and their children were randomized by computer either to receive or not receive personalized, automated text message reminders for their subsequent vaccination visits according to the national schedule. Text message reminders for Penta2 were sent 2 days before, on the day of, and 2 days after the scheduled vaccination visit. Reminders for Penta3 and the measles-containing vaccine were sent on the scheduled day of vaccination and 5 and 7 days after the scheduled day. Study personnel conducted postintervention follow-up interviews with participants at the health facilities during the children’s measles-containing vaccine visit. In addition, focus group discussions were conducted to assess caregiver acceptability of the intervention, economic data were collected to evaluate the incremental costs and cost-effectiveness of the intervention, and health facility record review forms were completed to capture service delivery process indicators.

Results

Of the 3485 screened participants, 1961 were enrolled from a sample size of 1962. Enrollment concluded in August 2016. Follow-up interviews of study participants, including data extraction from the children’s vaccination cards, data extraction from the health facility immunization registers, completion of the health facility record review forms, and focus group discussions were completed by December 2017. The results are expected to be released in 2021.

Conclusions

Prompting health-seeking behavior with reminders has been shown to improve health intervention uptake. Mobile phone ownership continues to grow in Uganda, so their use in vaccination interventions such as this study is logical and should be evaluated with scientifically rigorous study designs.

Trial Registration

ClinicalTrials.gov NCT04177485; https://clinicaltrials.gov/ct2/show/NCT04177485

International Registered Report Identifier (IRRID)

DERR1-10.2196/17262

Population differences in vaccine responses (POPVAC): scientific rationale and cross-cutting analyses for three linked, randomised controlled trials assessing the role, reversibility and mediators of immunomodulation by chronic infections in the tropics

INTRODUCTION

Vaccine-specific immune responses vary between populations and are often impaired in low income, rural settings. Drivers of these differences are not fully elucidated, hampering identification of strategies for optimising vaccine effectiveness. We hypothesise that urban-rural (and regional and international) differences in vaccine responses are mediated to an important extent by differential exposure to chronic infections, particularly parasitic infections.

METHODS AND ANALYSIS

Three related trials sharing core elements of study design and procedures (allowing comparison of outcomes across the trials) will test the effects of (1) individually randomised intervention against schistosomiasis (trial A) and malaria (trial B), and (2) Bacillus Calmette-Guérin (BCG) revaccination (trial C), on a common set of vaccine responses. We will enrol adolescents from Ugandan schools in rural high-schistosomiasis (trial A) and rural high-malaria (trial B) settings and from an established urban birth cohort (trial C). All participants will receive BCG on day '0'; yellow fever, oral typhoid and human papilloma virus (HPV) vaccines at week 4; and HPV and tetanus/diphtheria booster vaccine at week 28. Primary outcomes are BCG-specific IFN-γ responses (8 weeks after BCG) and for other vaccines, antibody responses to key vaccine antigens at 4 weeks after immunisation. Secondary analyses will determine effects of interventions on correlates of protective immunity, vaccine response waning, priming versus boosting immunisations, and parasite infection status and intensity. Overarching analyses will compare outcomes between the three trial settings. Sample archives will offer opportunities for exploratory evaluation of the role of immunological and 'trans-kingdom' mediators in parasite modulation of vaccine-specific responses.

ETHICS AND DISSEMINATION

Ethics approval has been obtained from relevant Ugandan and UK ethics committees. Results will be shared with Uganda Ministry of Health, relevant district councils, community leaders and study participants. Further dissemination will be done through conference proceedings and publications.

TRIAL REGISTRATION NUMBERS

ISRCTN60517191, ISRCTN62041885, ISRCTN10482904.

Comparing static and outreach immunization strategies and associated factors in Uganda, Nov-Dec 2016

Introduction

the government of Uganda aims at reducing childhood morbidity through provision of immunization services. We compared the proportion of children 12-33 months reached using either static or outreach immunization strategies and factors affecting utilization of routine vaccination services in order to inform policy updates.

Methods

we adopted the 2015 vaccination coverage cluster survey technique. The sample selection was based on a stratified three-stage sample design. Using the Fleiss formula, a sample of 50 enumeration areas was sufficient to generate immunization coverages at each region. A total of 200 enumeration areas were selected for the survey. Thirty households were selected per enumeration area. Epi-Info software was used to calculate weighted coverage estimates. facility.

Results

among the 2231 vaccinated children aged 12-23 months who participated in the survey, 68.1% received immunization services from a health unit and 10.6% from outreaches. The factors that affected utilization of routine vaccination services were; accessibility, where 78.2% resided within 5km from a health. 29.7% missed vaccination due to lack of vaccines at the health facility. Other reasons were lack of supplies at 39.2% and because the caretaker had other things to do, 26.4%. The survey showed 1.8% (40/2271) respondents had not vaccinated their children. Among these, 70% said they had not vaccinated their child because they were busy doing other things and 27.5% had not done so because of lack of motivation.

Conclusion

almost 7 in 10 children aged 12-23 months access vaccination at health facilities. There is evidence of parental apathy as well as misconceptions about vaccination.

Building health workforce capacity for planning and monitoring through the Strengthening Technical Assistance for routine immunization training (START) approach in Uganda

INTRODUCTION

The Global Vaccine Action Plan identifies workforce capacity building as a key strategy to achieve strong immunization programs. The Strengthening Technical Assistance for Routine Immunization Training (START) approach aimed to utilize practical training methods to build capacity of district and health center staff to implement routine immunization (RI) planning and monitoring activities, as well as build supportive supervision skills of district staff.

METHODS

First implemented in Uganda, the START approach was executed by trained external consultants who used existing tools, resources, and experiences to mentor district-level counterparts and, with them, conducted on-the-job training and mentorship of health center staff over several site visits. Implementation was routinely monitored using daily activity reports, pre and post surveys of resources and systems at districts and health centers and interviews with START consultants.

RESULTS

From July 2013 through December 2014 three START teams of four consultants per team, worked 6 months each across 50 districts in Uganda including the five divisions of Kampala district (45% of all districts). They conducted on-the-job training in 444 selected under-performing health centers, with a median of two visits to each (range 1-7, IQR: 1-3). More than half of these visits were conducted in collaboration with the district immunization officer, providing the opportunity for mentorship of district immunization officers. Changes in staff motivation and awareness of challenges; availability and completion of RI planning and monitoring tools and systems were observed. However, the START consultants felt that potential durability of these changes may be limited by contextual factors, including external accountability, availability of resources, and individual staff attitude.

CONCLUSIONS

Mentoring and on-the-job training offer promising alternatives to traditional classroom training and audit-focused supervision for building health workforce capacity. Further evidence regarding comparative effectiveness of these strategies and durability of observed positive change is needed.

Enhancing Workforce Capacity to Improve Vaccination Data Quality, Uganda

In Uganda, vaccine dose administration data are often not available or are of insufficient quality to optimally plan, monitor, and evaluate program performance. A collaboration of partners aimed to address these key issues by deploying data improvement teams (DITs) to improve data collection, management, analysis, and use in district health offices and health facilities. During November 2014–September 2016, DITs visited all districts and 89% of health facilities in Uganda. DITs identified gaps in awareness and processes, assessed accuracy of data, and provided on-the-job training to strengthen systems and improve healthcare workers’ knowledge and skills in data quality. Inaccurate data were observed primarily at the health facility level. Improvements in data management and collection practices were observed, although routine follow-up and accountability will be needed to sustain change. The DIT strategy offers a useful approach to enhancing the quality of health data.

Understanding the policy environment for immunization supply chains: Lessons learned from landscape analyses in Uganda and Senegal

As immunization programs around the world undergo rapid change and expansion, supply chain and logistics systems have become strained, making it increasingly challenging for national public health systems to provide reliable, safe, and efficient access to vaccines. Governments and immunization partners have been aware of this problem for several years, and in 2010, the World Health Organization (WHO) launched the Effective Vaccine Management (EVM) process to help countries identify shortcomings in their immunization supply chains and develop plans for systematic improvement. EVM improvement plans now exist in all Gavi-eligible countries plus many middle- and upper-income countries; however, implementation has been slow and in many cases fraught with financial, managerial, structural, and political roadblocks. Recognizing that significant change of any kind requires a supportive policy environment and strong leadership, PATH began working in Uganda and Senegal to landscape the policy environment around immunization and identify relevant policies, administrative and technical roles and responsibilities, and other issues that may be affecting the supply chain for immunization. The policy landscape assessments included a desk review and a series of structured, in-depth interviews with key international, national, and local stakeholders. The findings highlighted a number of critical issues and challenges in both countries that may be preventing supply chains from functioning optimally. These challenges include a need for better coordination and planning between immunization programs and supply chain managers; the need for sufficient, timely and reliable financing for all aspects of immunization programs; the need for high-level managers trained in immunization supply chain management; and an urgent need for better, more timely data for decision-making. Overcoming these challenges will require the involvement of high-level political actors-including ministers of health and finance, parliamentarians, and other officials who have the ability to approve and influence policy, personnel, and structural changes; ensure work plans are backed with adequate resources for implementation; and hold program managers accountable for achieving agreed indicators.

Yield of undetected tuberculosis and human immunodeficiency virus coinfection from active case finding in urban Uganda

OBJECTIVES

To determine the yield of undetected active tuberculosis (TB), TB and human immunodeficiency virus (HIV) coinfection and the number needed to screen (NNS) to detect a case using active case finding (ACF) in an urban community in Kampala, Uganda.

METHODS

In a door-to-door survey conducted in Rubaga community from January 2008 to June 2009, residents aged ≥15 years were screened for chronic cough (≥2 weeks) and tested for TB disease using smear microscopy and/or culture. Rapid testing was used to screen for HIV infection. The NNS to detect one case was calculated based on population screened and undetected cases found.

RESULTS

Of 5102 participants, 3868 (75.8%) were females; the median age was 24 years (IQR 20-30). Of 199 (4%) with chronic cough, 160 (80.4%) submitted sputum, of whom 39 (24.4%, 95%CI 17.4-31.5) had undetected active TB and 13 (8.1%, 95%CI 6.7-22.9) were TB-HIV co-infected. The NNS to detect one TB case was 131 in the whole study population, but only five among the subgroup with chronic cough.

CONCLUSION

ACF obtained a high yield of previously undetected active TB and TB-HIV cases. The NNS in the general population was 131, but the number needed to test in persons with chronic cough was five. These findings suggest that boosting the identification of persons with chronic cough may increase the overall efficiency of TB case detection at a community level.

Relapse more common than reinfection in recurrent tuberculosis 1-2 years post treatment in urban Uganda

OBJECTIVE

To determine the proportion of recurrent tuberculosis (TB) due to relapse with the patient's initial strain or reinfection with a new strain of Mycobacterium tuberculosis 1-2 years after anti-tuberculosis treatment in Uganda, a sub-Saharan TB-endemic country.

DESIGN

Records of patients with culture-confirmed TB who completed treatment at an urban Ugandan clinic were reviewed. Restriction fragment length polymorphism (RFLP) patterns were used to determine relapse or reinfection. Associations between human immunodeficiency virus (HIV) positivity and type of TB recurrence were determined.

RESULTS

Of 1701 patients cured of their initial TB episode with a median follow-up of 1.24 years, 171 (10%) had TB recurrence (8.4 per 100 person-years). Rate and risk factors for recurrence were similar to other studies from sub-Saharan Africa. Insertion sequence (IS) 6110-based RFLP of paired isolates from 98 recurrences identified 80 relapses and 18 reinfections. Relapses among HIV-positive and -negative patients were respectively 79% and 85% of recurrences.

CONCLUSIONS

Relapse was more common and presented earlier than reinfection in both HIV-positive and -negative TB patients 1-2 years after completing treatment. These findings impact both the choice of retreatment drug regimen, as relapsing patients are at higher risk for acquired drug resistance, and clinical trials of new TB regimens with relapse as clinical endpoint.

Influence of efavirenz pharmacokinetics and pharmacogenetics on neuropsychological disorders in Ugandan HIV-positive patients with or without tuberculosis: a prospective cohort study

Background

HIV infection, anti-tuberculosis and efavirenz therapy are associated with neuropsychological effects. We evaluated the influence of rifampicin cotreatment, efavirenz pharmacokinetics and pharmacogenetics on neuropsychiatric disorders in Ugandan HIV patients with or without tuberculosis coinfection.

Methods

197 treatment naïve Ugandan HIV patients, of whom 138 were TB co-infected, enrolled prospectively and received efavirenz based HAART. TB-HIV confected patients received concomitant rifampicin based anti-TB therapy. Genotypes for CYP2B6 (*6, *11), CYP3A5 (*3, *6, *7), ABCB1 (c.3435C>T and c.4036 A/G rs3842), CYP2A6 (*9, *17) and NR1I3 rs3003596 T/C were determined. Efavirenz plasma concentrations were serially quantified at 3rd day, 1st, 2nd, 4th, 6th, 8th and 12th weeks during therapy. Efavirenz neuropsychiatric symptoms were evaluated in terms of sleep disorders, hallucinations and cognitive effects at baseline, at two and twelve weeks of efavirenz treatment using a modified Mini Mental State Examination (MMSE) score.

Results

During the first twelve weeks of ART, 73.6% of the patients experienced at least one efavirenz related neuropsychiatric symptom. Commonest symptoms experienced were sleep disorders 60.5% (n=124) and hallucination 30.7% (n=63). Neuropsychiatric symptoms during HAART were significantly predicted by efavirenz plasma concentrations consistently. Rifampicin cotreatment reduced plasma efavirenz concentrations significantly only during the first week but not afterwards. There was no significant difference in the incidence of neuropsychiatric symptoms between patients receiving efavirenz with or without rifampicin cotreatment. CYP2B6*6 and ABCB1 c.4036 A/G genotype significantly predicted efavirenz concentrations. The tendency of CYP2B6*6 genotype association with higher incidence of having vivid dream (p=0.05), insomnia (p=0.19) and tactile hallucination (p=0.09) was observed mainly at week-2.

Conclusions

Efavirenz related neuropsychiatric symptoms are common among Ugandan HIV patients receiving ART and is mainly predicted by higher efavirenz plasma concentrations and CYP2B6 genotype but not by rifampicin based anti-TB co-treatment.

Elevated HIV seroprevalence and risk behavior among Ugandan TB suspects: implications for HIV testing and prevention

OBJECTIVES

Voluntary counseling and testing (VCT) for the human immunodeficiency virus (HIV) is recommended for persons treated for tuberculosis (TB). Opportunities to diagnose HIV may be missed by limiting HIV testing to only persons diagnosed with TB. Among TB suspects in Uganda, we determined HIV prevalence, risk behaviors, and willingness to refer family for VCT.

METHODS

Consenting adult patients presenting for evaluation at a referral TB clinic received same-day VCT. TB diagnosis data were abstracted from clinical records.

RESULTS

Among 665 eligible patients, 565 (85%) consented to VCT. Among these, 238 (42%) were HIV-positive. Of the HIV-infected patients, 37% had received a non-TB diagnosis. HIV seroprevalence was higher in patients with a non-TB diagnosis (49%) than those diagnosed with TB (39%) (P = 0.02). Fewer than 6% of HIV-infected patients reported always using condoms with sexual partners. The majority of patients (86%) reported being 'very willing' to refer family members for VCT.

CONCLUSIONS

Over 35% of HIV-infected cases in our population would have been undetected if HIV testing was limited to cases with diagnosed TB. The high HIV seroprevalence in both TB and non-TB cases merits HIV testing for all patients evaluated at TB clinics. HIV-infected TB suspects reporting high-risk behavior are at risk for HIV transmission, and should receive risk-reduction counseling.

Comparison of intermittent ethambutol with rifampicin-based regimens in HIV-infected adults with PTB, Kampala

BACKGROUND

The human immunodeficiency virus (HIV) is a key factor responsible for the high rates of tuberculosis (TB) in sub-Saharan Africa. Treatment of TB with rifampicin (R, RMP) containing short-course regimens is highly effective in HIV-infected adults. We conducted a study to compare the efficacy and safety of intermittent ethambutol (E, EMB) with two RMP-containing regimens to treat pulmonary TB in HIV-infected patients.

SETTING

National Tuberculosis Treatment Centre, Mulago Hospital, Kampala, Uganda.

DESIGN

This was a prospective cohort compared to two non-randomised control groups. The study group and the two control arms were treated with 2 months of isoniazid (H), RMP, pyrazinamide (Z) and EMB followed by 6 E3H3 for the study group and 4HR or 6HR for controls.

RESULTS

Between April 1993 and March 2000, 136 patients were enrolled in the 2EHRZ/E3H3 arm, 147 in the 2EHRZ/4HR arm and 266 in the 2EHRZ/6HR arm. The relapse rate was 18.2 per 100 person-years observation (PYO) for the study regimen compared to 9.7/100 PYO (P = 0.0063) and 4.8/100 PYO (P = 0.0001) in patients treated with 2 EHRZ/4HR or 2EHRZ/6HR, respectively.

CONCLUSION

The 2EHRZ/6E3H3 regimen is safe and effective but has a significant risk of relapse.

A Randomized, Double‐Blind, Placebo‐Controlled Trial of the Use of Prednisolone as an Adjunct to Treatment in HIV‐1–Associated Pleural Tuberculosis

BACKGROUND

Active tuberculosis may accelerate progression of human immunodeficiency virus (HIV) infection by promoting viral replication in activated lymphocytes. Glucocorticoids are used in pleural tuberculosis to reduce inflammation-induced pathology, and their use also might reduce progression of HIV by suppressing immune activation. We examined the effect that prednisolone has on survival in HIV-1-associated pleural tuberculosis.

METHODS

We conducted a randomized, double-blind, placebo-controlled trial of prednisolone as an adjunct to tuberculosis treatment, in adults with HIV-1-associated pleural tuberculosis. The primary outcome was death. Analysis was by intention to treat.

RESULTS

Of 197 participants, 99 were assigned to the prednisolone group and 98 to the placebo group. The mortality rate was 21 deaths/100 person-years (pyr) in the prednisolone group and 25 deaths/100 pyr in the placebo group (age-, sex-, and initial CD4+ T cell count-adjusted mortality rate ratio, 0.99 [95% confidence interval, 0.62-1.56] [P =.95]). Resolution of tuberculosis was faster in the prednisolone group, but recurrence rates were slightly (though not significantly) higher, and use of prednisolone was associated with a significantly higher incidence of Kaposi sarcoma (4.2 cases/100 pyr, compared with 0 cases/100 pyr [P =.02]).

CONCLUSIONS

In view of the lack of survival benefit and the increased risk of Kaposi sarcoma, the use of prednisolone in HIV-associated tuberculous pleurisy is not recommended.

Human immunodeficiency virus type 1 (HIV-1) quasispecies at the sites of Mycobacterium tuberculosis infection contribute to systemic HIV-1 heterogeneity

We have recently reported an increased heterogeneity in the human immunodeficiency virus type 1 (HIV-1) envelope gene (env) in HIV-1-infected patients with pulmonary tuberculosis (TB) compared to patients with HIV-1 alone. This increase may be a result of dissemination of lung-derived HIV-1 isolates from sites of Mycobacterium tuberculosis infection and/or the systemic activation of the immune system in response to TB. To distinguish between these two mechanisms, blood and pleural fluid samples were obtained from HIV-1-infected patients with active pleural TB in Kampala, Uganda (CD4 cell counts of 34 to 705 cells/microl, HIV-1 plasma loads of 2,400 to 280,000 RNA copies/ml, and HIV-1 pleural loads of 7,600 to 4,500,000 RNA copies/ml). The C2-C3 coding region of HIV-1 env was PCR amplified from lysed peripheral blood mononuclear cells and pleural fluid mononuclear cells and reverse transcriptase-PCR amplified from plasma and pleural fluid HIV-1 virions of eight HIV-1 patients with pleural TB. Phylogenetic and phenetic analyses revealed a compartmentalization of HIV-1 quasispecies between blood and pleural space in four of eight patients, with migration events between the compartments. There was a trend for a greater genetic heterogeneity in the pleural space, which may be the result of an M. tuberculosis-mediated increase in HIV-1 replication and/or selection pressure at the site of infection. Collectively, these findings suggest that HIV-1 quasispecies in the M. tuberculosis-infected pleural space may leak into the systemic circulation and lead to increased systemic HIV-1 heterogeneity during TB.

Increased replication of HIV-1 at sites of Mycobacterium tuberculosis infection: potential mechanisms of viral activation

Tuberculosis (TB) enhances HIV-1 replication and the progression to AIDS in dually infected patients. We employed pleural TB as a model to understand the interaction of the host with HIV-1 during active TB, at sites of Mycobacterium tuberculosis (MTB) infection. HIV-1 replication was enhanced both in the cellular (pleural compared with blood mononuclear cells) and acellular (pleural fluid compared with plasma) compartments of the pleural space. Several potential mechanisms for expansion of HIV-1 in situ were found, including augmentation in expression of tumor necrosis factor (TNF)-alpha and the HIV-1 noninhibitory beta-chemokine (MCP-1), low presence of HIV-1 inhibitory beta-chemokines (MIP-1 alpha, MIP-1 beta, and RANTES [regulated on activation, normal T expressed and secreted]), and upregulation in expression of the HIV-1 coreceptor, CCR5, by pleural fluid mononuclear cells. Thus, at sites of MTB infection, conditions are propitious both for transcriptional activation of HIV-1 in latently infected mononuclear cells, and facilitation of viral infection of newly recruited cells. These mechanisms may contribute to enhanced viral burden and dissemination during TB infection.

Evaluation of suspected tuberculous pleurisy: clinical and diagnostic findings in HIV-1-positive and HIV-negative adults in Uganda

SETTING

National Tuberculosis Treatment Centre, Mulago Hospital, Kampala, Uganda.

OBJECTIVES

To compare clinical and radiographic presentation, and diagnostic methods, in adults with tuberculous pleurisy who are negative and positive for the human immunodeficiency virus (HIV).

DESIGN

Adults with suspected pleural tuberculosis were screened by clinical examination, thoracocentesis and closed pleural biopsy. Biopsy material was cultured on Middlebrook 7H-10 solid medium and in BACTEC 12B radiometric vials. Pleural fluid was cultured using Löwenstein-Jensen slants, BACTEC and Kirchner liquid medium.

RESULTS

Of 156 individuals enrolled, 142 had tuberculosis, of whom 80% were HIV-positive. Among those with tuberculosis, HIV-positive patients bad a more severe and longer illness. The size of effusions was similar in HIV-positive and HIV-negative patients. A higher proportion of HIV-positive patients had parenchymal infiltrates but this difference was not statistically significant. Pleural fluid lymphocytosis was present in all HIV-negative and 97% of the HIV-positive patients. HIV-positive patients had lower pleural fluid lymphocyte counts. Pleural fluid cultures were more often positive in HIV-positive patients. BACTEC and Kirchner liquid media gave higher yields than solid media.

CONCLUSION

HIV-positive patients with tuberculous pleurisy had a more severe illness than HIV-negative patients. Mycobacterial cultures from HIV-positive patients were more often positive, suggesting more mycobacterial extension from the lungs into the pleural space. Liquid culture media were superior to solid media with regard to diagnostic yield and time until diagnosis.

Macrophage‐Activating Cytokines in Human Immununodeficiency Virus Type 1–Infected and –Uninfected Patients with Pulmonary Tuberculosis

Tuberculosis (TB) is the most common opportunistic infection in human immunodeficiency virus type 1 (HIV-1)-infected patients globally and occurs throughout the course of HIV-1 disease. Here the production of interferon (IFN)-gamma and tumor necrosis factor (TNF)-alpha by peripheral blood mononuclear cells (PBMC) of HIV-1-infected versus -uninfected patients with newly diagnosed pulmonary TB (PTB) was compared. Findings were correlated with cytokine profiles, clinical presentation, and expression of inducible nitric oxide (iNOS). Most HIV-1/PTB patients with a CD4 cell count of 200-500 cells/microL had high IFN-gamma production and radiographic evidence of atypical PTB. Low IFN-gamma production and radiographic evidence of reactivated PTB characterized both HIV-1/PTB patients with a CD4 cell count >or=500 cells/microL and HIV-1-uninfected patients. TNF-alpha levels were similar in all HIV-1/PTB patients, regardless of CD4 cell count. Induction of iNOS in PBMC was low and was associated with low IFN-gamma production. These data underscore the potential pathogenic role of macrophage-activating cytokines in TB in HIV-1-infected patients.

HIV-1-related pleural tuberculosis: elevated production of IFN-gamma, but failure of immunity to Mycobacterium tuberculosis

BACKGROUND

Pleural tuberculosis can resolve spontaneously, suggesting that the inflammatory process may represent a protective immune response. However, pleural tuberculosis is strongly associated with HIV infection. It has been suggested that cell-mediated immune responses may be reduced, and direct bacterial invasion may have a role in pathogenesis, in HIV-positive cases. To test this hypothesis, we compared production of the pro-inflammatory cytokines, interferon (IFN)-gamma and tumour necrosis factor(TNF)-alpha, production of the immunosuppressive cytokine, interleukin (IL)-10, and mycobacterial culture positivity, in HIV-negative and HIV-positive patients with pleural tuberculosis.

METHODS

Cytokine levels were measured in serum and pleural fluid, and in supernatants of blood and pleural fluid stimulated in vitro using mycobacterial antigens. Intracellular IFN-gamma and TNF-alpha production was measured after stimulation with phorbol myristate acetate and ionomycin in vitro.

RESULTS

IFN-gamma was strikingly elevated in serum and pleural fluid in HIV-positive, compared to HIV-negative subjects (P < or = 0.02). TNF-alpha was elevated, but this was not statistically significant. IL-10 levels were higher in serum (P < 0.001), but similar in pleural fluid. IFN-gamma responses to soluble mycobacterial antigen in vitro were reduced in peripheral blood (P = 0.006), but not pleural fluid, of HIV-positive subjects. Intracellular cytokine staining suggested that CD8+ T cells were a major source of IFN-gamma in HIV-positive subjects. The proportion of subjects with a positive culture for Mycobacterium tuberculosis from pleural fluid was higher in the HIV-positive group.

CONCLUSIONS

HIV-positive patients with pleural tuberculosis show elevated production of IFN-gamma, for which CD8+ T cells may be a major source. Mycobacterium tuberculosis can proliferate despite high levels of pro-inflammatory cytokines.

Augmentation of apoptosis and interferon-gamma production at sites of active Mycobacterium tuberculosis infection in human tuberculosis

Pleural tuberculosis (TB) was employed as a model to study T cell apoptosis at sites of active Mycobacterium tuberculosis (MTB) infection in human immunodeficiency virus (HIV)-coinfected (HIV/TB) patients and patients infected with TB alone. Apoptosis in blood and in pleural fluid mononuclear cells and cytokine immunoreactivities in plasma and in pleural fluid were evaluated. T cells were expanded at the site of MTB infection, irrespective of HIV status. Apoptosis of CD4 and non-CD4 T cells in the pleural space occurred in both HIV/TB and TB. Interferon (IFN)-gamma levels were increased in pleural fluid, compared with plasma. Spontaneous apoptosis correlated with specific loss of MTB-reactive, IFN-gamma-producing pleural T cells. Immunoreactivities of molecules potentially involved in apoptosis, such as tumor necrosis factor-alpha, Fas-ligand, and Fas, were increased in pleural fluid, compared with plasma. These data suggest that continued exposure of immunoreactive cells to MTB at sites of infection may initiate a vicious cycle in which immune activation and loss of antigen-responsive T cells occur concomitantly, thus favoring persistence of MTB infection.