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"Magambo, Brian"
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Virological Response and Antiretroviral Drug Resistance Emerging during Antiretroviral Therapy at Three Treatment Centers in Uganda
by
Kaleebu, Pontiano
,
Hladik, Wolfgang
,
Asio, Juliet
in
Acquired immune deficiency syndrome
,
Adult
,
AIDS
2015
With the scale-up of antiretroviral therapy (ART), monitoring programme performance is needed to maximize ART efficacy and limit HIV drug resistance (HIVDR).
We implemented a WHO HIVDR prospective survey protocol at three treatment centers between 2012 and 2013. Data were abstracted from patient records at ART start (T1) and after 12 months (T2). Genotyping was performed in the HIV pol region at the two time points.
Of the 425 patients enrolled, at T2, 20 (4.7%) had died, 66 (15.5%) were lost to follow-up, 313 (73.6%) were still on first-line, 8 (1.9%) had switched to second-line, 17 (4.0%) had transferred out and 1 (0.2%) had stopped treatment. At T2, 272 out of 321 on first and second line (84.7%) suppressed below 1000 copies/ml and the HIV DR prevention rate was 70.1%, just within the WHO threshold of ≥ 70%. The proportion of participants with potential HIVDR was 20.9%, which is higher than the 18.8% based on pooled analyses from African studies. Of the 35 patients with mutations at T2, 80% had M184V/I, 65.7% Y181C, and 48.6% (54.8% excluding those not on Tenofovir) had K65R mutations. 22.9% had Thymidine Analogue Mutations (TAMs). Factors significantly associated with HIVDR prevention at T2 were: baseline viral load (VL) <100,000 copies/ml [Adjusted odds ratio (AOR) 3.13, 95% confidence interval (CI): 1.36-7.19] and facility. Independent baseline predictors for HIVDR mutations at T2 were: CD4 count < 250 cells/μl (AOR 2.80, 95% CI: 1.08-7.29) and viral load ≥ 100,000 copies/ml (AOR 2.48, 95% CI: 1.00-6.14).
Strengthening defaulter tracing, intensified follow-up for patients with low CD4 counts and/or high VL at ART initiation together with early treatment initiation above 250 CD4 cells/ul and adequate patient counselling would improve ART efficacy and HIVDR prevention. The high rate of K65R and TAMs could compromise second line regimens including NRTIs.
Journal Article
Effect of HIV-1 Subtypes on Disease Progression in Rural Uganda: A Prospective Clinical Cohort Study
by
Kaleebu, Pontiano
,
Nsubuga, Rebecca N.
,
Mayanja, Billy N.
in
Acquired immune deficiency syndrome
,
Adolescent
,
Adult
2013
We examined the association of HIV-1 subtypes with disease progression based on three viral gene regions.
A prospective HIV-1 clinical cohort study in rural Uganda.
Partial gag, env and pol genes were sequenced. Cox proportional hazard regression modelling was used to estimate adjusted hazard ratios (aHRs) of progression to: CD4≤250, AIDS onset and death, adjusted for sex, age and CD4 count at enrolment.
Between 1990 and 2010, 292 incident cases were subtyped: 25% had subtype A, 45% had D, 26% had A/D recombinants, 1% had C and 4% were other recombinant forms. Of the 278 incident cases included in the disease progression analysis, 62% progressed to CD4≤250, 32% to AIDS, and 34% died with a higher proportion being among subtype D cases. The proportions of individuals progressing to the three endpoints were significantly higher among individuals infected with subtype D. Throughout the study period, individuals infected with subtype D progressed faster to CD4≤250, adjusted HR (aHR), (95% CI) = 1.72 (1.16-2.54), but this was mainly due to events in the period before antiretroviral therapy (ART) introduction, when individuals infected with subtype D significantly progressed faster to CD4≤250 than subtype A cases; aHR (95% CI) = 1.78 (1.01-3.14).
In this population, HIV-1 subtype D was the most prevalent and was associated with faster HIV-1 disease progression than subtype A. Further studies are needed to examine the effect of HIV-1 subtypes on disease progression in the ART period and their effect on the virological and immunological ART outcomes.
Journal Article
Frequencies of Gag-restricted T-cell escape “footprints” differ across HIV-1 clades A1 and D chronically infected Ugandans irrespective of host HLA B alleles
by
Kaleebu, Pontiano
,
Mugaba, Susan
,
Ndembi, Nicaise
in
Acquired immune deficiency syndrome
,
Adult
,
AIDS
2015
•A and D infected subjects even though they bear the same presenting HLA alleles, and live in the same environment. Escape mutations that are known to confer survival advantage were more frequent in clade A-infected subjects irrespective of host HLA alleles.•There was no evidence to link this difference in outcome to the evaluated adaptive T-Cell responses (IFN-γ responses and polyfunctional responses) to those key structurally constrained Gag epitopes.•However, we have demonstrated that there was significantly greater selective pressure on the Gag protein of clade A than that of clade D.•The data are in line with the known faster disease progression in clade D than clade A infected individuals.•The data also highlight that the current difficulties in formulating a global HIV vaccine design will be further challenged by clade associated differences in outcome.
We evaluated relationships between critical Gag T-cell escape mutations and concomitant T-cell responses to determine whether HLA-restricted Gag mutations that confer protection, occur at similar rates in a population infected with mixed HIV-1 clades A1 and D viruses.
Assessment of Gag selective pressure, and adaptive T-cell functions to KAFSPEVIPMF (KF11), ISPRTLNAW (ISW9) and TSTLQEQIGW (TW10) Gag epitopes were combined with host HLA to assess correlations with rates of critical epitope escape mutations in clades A1- (n=23) and D- (n=21) infected, untreated subjects. Infecting clades and selection pressure were determined from the gag sequences.
Overall, Gag escape mutations A163X in KF11 were detected in 61% (14/23) A1- infected compared to 5% (1/21) in D-infected subjects (p=0.00015). Gag mutations I147X in the ISW9 epitope were seen in 43%: (10/23) clade A compared to 5%: (1/21) clade D infected subjects, p=0.007, Fisher's Exact test. Both mutations were more frequent in clade A1 infection. Frequencies of the measured epitope-specific T-cell responses were comparable across clades. Peptide binding affinities for the restricting HLA alleles did not differ across clades. Overall, selection pressure on the Gag protein was significantly greater in clade A than in clade D sequences.
These findings imply that HIV-1 vaccine strategies designed to target structurally constrained T-cell epitopes may be further challenged by clade-driven outcomes in specific HLA-restricted Gag epitopes. Equally, the data are line with slower HIV-1 disease progression in clade A infection; and raise hope that increased selective pressure on Gag may be protective irrespective of host HLA alleles.
Journal Article
Early virological failure and HIV drug resistance in Ugandan adults co-infected with tuberculosis
by
Sekaggya-Wiltshire, Christine
,
Kambugu, Andrew
,
Fehr, Jan
in
Adult
,
Anti-HIV Agents - therapeutic use
,
Antiretroviral agents
2017
Purpose
This cross-sectional study took place in the integrated tuberculosis (TB) clinic of a large outpatient clinic for HIV-infected patients in Kampala, Uganda. The purpose of this study was to describe the proportion of TB/HIV co-infected adults with virological failure, type and frequency of HIV drug resistance-associated mutations, and the proportion of patients with suboptimal efavirenz levels.
Methods
HIV-1 plasma viral loads, CD4 cell count measurements, and efavirenz serum concentrations were done in TB/HIV co-infected adults. Genotypic resistance testing was performed in case of confirmed virological failure.
Results
After a median time on ART of 6 months, virological failure was found in 22/152 patients (14.5%). Of 147 participants with available efavirenz serum concentration, 26 (17.6%) had at least one value below the reference range, including 20/21 (95.2%) patients with confirmed virological failure. Genotypic resistance testing was available for 16/22 (72.7%) patients, of which 15 (93.8%) had at least one major mutation, most commonly M184V (81.2%) and K103NS (68.8%).
Conclusion
We found a high proportion of TB/HIV co-infected patients with virological failure, the majority of which had developed relevant resistance-mutations after a median time on anti-retroviral treatment (ART) of 6 months. Virological monitoring should be prioritized in TB/HIV co-infected patients in resource-limited settings.
Journal Article
Transmitted Antiretroviral Drug Resistance Among Drug-Naive Female Sex Workers With Recent Infection in Kampala, Uganda
2012
During 2006—2007, transmitted human immunodeficiency virus (HIV) drug resistance (TDR) among drug-naive women with newly diagnosed HIV infection and likely to be recently infected when attending antenatal clinics in Entebbe was found to be <5% with use of the World Health Organization (WHO) survey method. Using the same method, we attempted to classify TDR among women who seroconverted during 2008—2010 and who were identified from a cohort of recently infected sex workers in Kampala, Uganda. TDR mutations were identified using the 2009 WHO TDR mutations list. The WHO survey method could not be used to classify TDR because the necessary sample size was not reached during the survey period. However, a point prevalence estimate of 2.6% (95% confidence interval, 0.07%—13.8%) nonnucleoside reverse-transcriptase inhibitor TDR was determined.
Journal Article
COHORT PROFILE: The Complications of Long-Term Antiretroviral Therapy study in Uganda (CoLTART), a prospective clinical cohort
by
Kaleebu, Pontiano
,
Mayanja, Billy Nsubuga
,
Munderi, Paula
in
Acquired immune deficiency syndrome
,
Adolescent
,
Adult
2017
Background
Antiretroviral therapy (ART) improves the survival and quality of life of HIV-positive individuals, but the effects of long-term ART use do eventually manifest. The Complications of Long-Term Antiretroviral Therapy cohort study in Uganda (CoLTART) was established to investigate the metabolic and renal complications of long-term ART use among Ugandan adults. We describe the CoLTART study set-up, aims, objectives, study methods, and also report some preliminary cross–sectional study enrolment metabolic and renal complications data analysis results.
Methods
HIV-positive ART naïve and experienced adults (18 years and above) in Uganda were enrolled. Data on demographic, dietary, medical, social economic and behaviour was obtained; and biophysical measurements and a clinical examination were undertaken. We measured: fasting glucose and lipid profiles, renal and liver function tests, full blood counts, immunology, virology and HIV drug resistance testing. Plasma samples were stored for future studies.
Results
Between July 2013 and October 2014, we enrolled 1095 individuals, of whom 964 (88.0%) were ART experienced (6 months or more), with a median of 9.4 years (IQR 7.0–9.9) on ART. Overall, 968 (88.4%) were aged 35 years and above, 711 (64.9%) were females, 608 (59.6%) were or had ever been on a Tenofovir ART regimen and 236 (23.1%) on a Protease Inhibitor (PI) regimen. There were no differences in renal dysfunction between patients on Tenofovir and Non-Tenofovir containing ART regimens. Patients on PI regimens had higher total cholesterol, lower high density lipoprotein, higher low density lipoprotein, higher triglycerides, and a high atherogenic index for plasma than the non-PI regimen, p = 0.001 or < 0.001. Patients on Non-PI regimens had higher mean diastolic hypertension than patients on PI regimens, p < 0.001.
Conclusions
Our finding of no differences in renal dysfunction between patients on Tenofovir and those on Non-Tenofovir containing ART regimens means that Tenofovir based first line ART can safely be initiated even in settings without routine renal function monitoring. However, integration of cardiovascular risk assessment, preventive and curative measures against cardiovascular disease are required. The CoLTART cohort is a good platform to investigate the complications of long-term ART use in Uganda.
Journal Article
Transmitted Antiretroviral Drug Resistance Among Drug-Naive Female Sex Workers With Recent Infection in Kampala, Uganda
by
LUBEGA, George W
,
GROSSKURTH, Heiner
,
KAPAATA, Anne
in
Antibiotics. Antiinfectious agents. Antiparasitic agents
,
Antiviral agents
,
Biological and medical sciences
2012
Journal Article
PHYLOGENETIC AND DEMOGRAPHIC CHARACTERISATION OF HIV-1 TRANSMISSION NETWORKS IN A GENERAL POPULATION COHORT IN UGANDA
by
Kaleebu, Pontiano
,
Kapaata, Anne
,
Kirangwa, Joseph
in
Global health
,
Human immunodeficiency virus
,
Phylogenetics
2017
BackgroundThe General Population Cohort (GPC) in Southwestern Uganda is a low-risk population with low HIV incidence rates (<1%). Despite several interventions for close to 30 years, new cases of HIV continue to emerge. We set out to use phylogenetics and patients' demographic data to understand the HIV transmission dynamics in this population to inform prevention.MethodsA total of 2049 pol sequences of participants diagnosed from 2003–2015 were included in this analysis; pol sequences were from GPC (n=1049), Central Uganda (n=800) and Eastern Uganda (n=200). Phylogenetic analysis was used to identify transmission networks. The demographic and clinical characteristics of the transmission clusters were analysed.ResultsThe overall subtype distribution was: A (45%), C (3%), D (40%) and others (12%). The subtype distribution by region was for GPC: A (41%), C (2%), D (45%) and others (12%). For Central: A (49%), C (4%), D (35%) and others (12%). Eastern: A (60%), C (3%), D (24%) and others (13%). We identified 233 transmission clusters (cluster size variation 2–10) that comprised of 559 (27%) of the 2049 participants.The majority of clusters comprised transmission pairs (n=186) and triplets (n=30). The majority (∼60%) of the 233 clusters was from the GPC and all 13 large clusters (≥5) were also from the GPC. A significant number of clusters (n=25, 11%) was formed between individuals from different geographic locations. Participants in transmission networks were associated with high-risk sexual behaviour: low condom use, high alcohol use, and partner change even with known HIV-positives.ConclusionsThe transmission networks identified among individuals from the GPC and other populations or geographic regions may imply HIV introductions from outside communities. This suggests that HIV introductions into communities are common and account for a substantial number of new infections in the GPC. HIV prevention efforts should therefore target the broader communities beyond the GPC.
Journal Article
Virological Response and Antiretroviral Drug Resistance Emerging during Antiretroviral Therapy at Three Treatment Centers in Uganda: e0145536
2015
Background With the scale-up of antiretroviral therapy (ART), monitoring programme performance is needed to maximize ART efficacy and limit HIV drug resistance (HIVDR). Methods We implemented a WHO HIVDR prospective survey protocol at three treatment centers between 2012 and 2013. Data were abstracted from patient records at ART start (T1) and after 12 months (T2). Genotyping was performed in the HIV pol region at the two time points. Results Of the 425 patients enrolled, at T2, 20 (4.7%) had died, 66 (15.5%) were lost to follow-up, 313 (73.6%) were still on first-line, 8 (1.9%) had switched to second-line, 17 (4.0%) had transferred out and 1 (0.2%) had stopped treatment. At T2, 272 out of 321 on first and second line (84.7%) suppressed below 1000 copies/ml and the HIV DR prevention rate was 70.1%, just within the WHO threshold of greater than or equal to 70%. The proportion of participants with potential HIVDR was 20.9%, which is higher than the 18.8% based on pooled analyses from African studies. Of the 35 patients with mutations at T2, 80% had M184V/I, 65.7% Y181C, and 48.6% (54.8% excluding those not on Tenofovir) had K65R mutations. 22.9% had Thymidine Analogue Mutations (TAMs). Factors significantly associated with HIVDR prevention at T2 were: baseline viral load (VL) <100,000 copies/ml [Adjusted odds ratio (AOR) 3.13, 95% confidence interval (CI): 1.36-7.19] and facility. Independent baseline predictors for HIVDR mutations at T2 were: CD4 count <250 cells/Ml (AOR 2.80, 95% CI: 1.08-7.29) and viral load greater than or equal to 100,000 copies/ml (AOR 2.48, 95% CI: 1.00-6.14). Conclusion Strengthening defaulter tracing, intensified follow-up for patients with low CD4 counts and/or high VL at ART initiation together with early treatment initiation above 250 CD4 cells/ul and adequate patient counselling would improve ART efficacy and HIVDR prevention. The high rate of K65R and TAMs could compromise second line regimens including NRTIs.
Journal Article
Effect of HIV-1 Subtypes on Disease Progression in Rural Uganda: A Prospective Clinical Cohort Study. e71768
by
Kaleebu, Pontiano
,
Nsubuga, Rebecca N
,
Paal, Lieve Vander
in
Acquired immune deficiency syndrome
,
Human immunodeficiency virus 1
2013
Objective We examined the association of HIV-1 subtypes with disease progression based on three viral gene regions. Design A prospective HIV-1 clinical cohort study in rural Uganda. Methods Partial gag, env and pol genes were sequenced. Cox proportional hazard regression modelling was used to estimate adjusted hazard ratios (aHRs) of progression to: CD4 less than or equal to 250, AIDS onset and death, adjusted for sex, age and CD4 count at enrolment. Results Between 1990 and 2010, 292 incident cases were subtyped: 25% had subtype A, 45% had D, 26% had A/D recombinants, 1% had C and 4% were other recombinant forms. Of the 278 incident cases included in the disease progression analysis, 62% progressed to CD4 less than or equal to 250, 32% to AIDS, and 34% died with a higher proportion being among subtype D cases. The proportions of individuals progressing to the three endpoints were significantly higher among individuals infected with subtype D. Throughout the study period, individuals infected with subtype D progressed faster to CD4 less than or equal to 250, adjusted HR (aHR), (95% CI) = 1.72 (1.16-2.54), but this was mainly due to events in the period before antiretroviral therapy (ART) introduction, when individuals infected with subtype D significantly progressed faster to CD4 less than or equal to 250 than subtype A cases; aHR (95% CI) = 1.78 (1.01-3.14). Conclusions In this population, HIV-1 subtype D was the most prevalent and was associated with faster HIV-1 disease progression than subtype A. Further studies are needed to examine the effect of HIV-1 subtypes on disease progression in the ART period and their effect on the virological and immunological ART outcomes.
Journal Article