Effect of HIV-1 subtypes on disease progression in rural Uganda: a prospective clinical cohort study

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≤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≤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).

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.

Effect of pregnancy on immunological and virological outcomes of women on ART: a prospective cohort study in rural Uganda, 2004-2009

OBJECTIVES

Before antiretroviral therapy (ART) introduction, pregnancy was associated with a sustained drop in CD4 cell count in HIV-infected women. We examined the effects of pregnancy on immunological and virological ART outcomes.

METHODS

Between January 2004 and March 2009, we studied HIV-infected women receiving ART in a prospective open cohort study in rural Uganda. We used random effects regression models to compare the CD4 counts of women who became pregnant and those who did not, and among the pregnant women before and after pregnancy. CD4 count and proportions with detectable viral load (≥400 copies/ml) were compared between the two groups using the Mann-Whitney rank sum test and logistic regression respectively.

RESULTS

Of 88 women aged 20-40 years receiving ART, 23 became pregnant. At ART initiation, there were no significant differences between those who became pregnant and those who did not in clinical, immunological and virological parameters. Among women who became pregnant, CD4 cell count increased before pregnancy (average 75.9 cells/mm(3) per year), declined during pregnancy (average 106.0) but rose again in the first year after delivery (average 88.6). Among women who did not become pregnant, the average CD4 cell count rise per year for the first 3 years was 88.5. There was no significant difference in the proportions of women with detectable viral load at last clinic visit among those who became pregnant (8.7%) and those who did not (16.1%), P = 0.499.

CONCLUSION

Pregnancy had no lasting effect on the immunological and virological outcomes of HIV-infected women on ART.

Using verbal autopsy to assess the prevalence of HIV infection among deaths in the ART period in rural Uganda: a prospective cohort study, 2006-2008

Background

Verbal autopsy is important for detecting causes of death including HIV in areas with inadequate vital registration systems. Before antiretroviral therapy (ART) introduction, a verbal autopsy study in rural Uganda found that half of adult deaths assessed were in HIV-positive individuals. We used verbal autopsy to compare the proportion of HIV-positive adult deaths in the periods before and after ART introduction.

Methods

Between 2006 and 2008, all adult (≥ 13 years) deaths in a prospective population-based cohort study were identified by monthly death registration, and HIV serostatus was determined through annual serosurveys. A clinical officer interviewed a relative of the deceased using a verbal autopsy questionnaire. Two clinicians independently reviewed the questionnaires and classified the deaths as HIV-positive or not. A third clinician was the tie-breaker in case of nonagreement. The performance of the verbal autopsy tool was assessed using HIV serostatus as the gold standard of comparison. We compared the proportions of HIV-positive deaths as assessed by verbal autopsy in the early 1990s and the 2006-2008 periods.

Results

Of 333 deaths among 12,641 adults of known HIV serostatus, 264 (79.3%) were assessed by verbal autopsy, of whom 59 (22.3%) were HIV-seropositive and 68 (25.8%) were classified as HIV-positive by verbal autopsy. Verbal autopsy had a specificity of 90.2% and positive predictive value of 70.6% for identifying deaths among HIV-infected individuals, with substantial interobserver agreement (80.3%; kappa statistic = 0.69). The HIV-attributable mortality fraction estimated by verbal autopsy decreased from 47.0% (pre-ART period) to 25.8% (ART period), p < 0.001.

Conclusions

In resource-limited settings, verbal autopsy can provide a good estimate of the prevalence of HIV infection among adult deaths. In this rural population, the proportion of deaths identified by verbal autopsy as HIV-positive declined between the early 1990s and the 2006-2008 period. Verbal autopsy findings can inform policy on HIV health care needs.

Coreceptor and cytokine concentrations may not explain differences in disease progression observed in HIV-1 clade A and D infected Ugandans

Background

The use of cellular coreceptors and modulation of cytokine concentrations by HIV to establish a productive infection is well documented. However, it is unknown whether the expression of these proteins affects the course of HIV clade A and D disease, reported to have different progression rates.

Methodology/Principal Findings

We investigated whether the number of CD4⁺ T-cells expressing CCR5 or CXCR4, the density of these coreceptors and concentrations of specific immune proteins linked to HIV pathogenesis vary between individuals infected with HIV clade A or D. We undertook additional analyses stratifying participants by early (CD4>500 cells/µl) or late (CD4<200 cells/µl) disease stage. Whole blood samples were taken from 50 HIV-1 infected individuals drawn from cohorts in rural south-west Uganda. Late stage participants had less than half the number of CD4⁺/CCR5⁺ T-cells (p = 0.0113) and 5.6 times fewer CD4⁺/CXCR4⁺ cells (p<0.0001) than early stage participants. There was also a statistically significant difference in the density of CXCR4 on CD4⁺ cells between clade A and D infected early stage participants (142 [A] vs 84 [D]; p = 0.0146). Across all participants we observed significantly higher concentration of Th₁ cytokines compared to Th₂ (66.4 vs 23.8 pg/ml; p<0.0001). Plasma concentrations of IFNγ and IL-2 were 1.8 and 2.4 fold lower respectively in Late-D infected participants compared to Late-A participants. MIP-1β levels also decreased from 118.0 pg/ml to 47.1 pg/ml (p = 0.0396) as HIV disease progressed.

Conclusions/Significance

We observed specific alterations in the abundance of CD4⁺/CCR5⁺ and CD4⁺/CXCR4⁺ T-cells, and concentrations of immune proteins across different HIV clades and as infection progresses. Our results suggest that these changes are unlikely to explain the observed differences in disease progression between subtype A and D infections. However, our observations further the understanding of the natural progression of non-clade B HIV infection and how the virus adapts to exploit the host environment.

HIV-1 seroprevalence and risk factors for HIV infection among first-time psychiatric admissions in Uganda

This study investigated HIV seroprevalence and it's correlates among patients with first-time psychiatric admissions to two national referral hospitals in urban Kampala, Uganda. A structured standardised evaluation was used to assess patients for: Diagnostic and Statistical Manual IV psychiatric diagnosis, socio-demographics, sexual behaviour and HIV status (for those HIV-positive, CDC classification and CD4 cell counts). The HIV-1 seroprevalence was 18.4% (95% CI, 13.8-23.0%). Factors that were independently associated with HIV-1 seropositivity were female gender and older age (41+years) and after adjusting for sex and age group, the nature of the current episode (highest among those with first episode of mental illness) and psychiatric diagnoses (highest in the organic affective disorders and delirium, lowest in those with bipolar affective disorder and psychotic syndromes). These results demonstrate that the prevalence of HIV is high among patients with severe mental illness in Africa and that HIV/AIDS adds to the burden of mental illness in high HIV prevalence countries in sub-Saharan Africa. Both HIV care programmes and psychiatric care clinics should be made aware of the frequent association of HIV infection and mental illness, and adopt important diagnostic and care elements of these complementary disciplines in the training and the day-to-day work of clinicians, nurses and counsellors.

Duration from seroconversion to eligibility for antiretroviral therapy and from ART eligibility to death in adult HIV-infected patients from low and middle-income countries: collaborative analysis of prospective studies

BACKGROUND

Estimation of the number of people in need of antiretroviral therapy (ART) in resource-limited settings requires information on the time from seroconversion to ART eligibility and from ART eligibility to death.

OBJECTIVES

To estimate duration from seroconversion to different ART eligibility criteria and from ART eligibility to death in HIV-infected adults in low-income and middle-income countries.

METHODS

Participants with documented seroconversion from five cohorts (two cohorts from Uganda, two from Thailand and one from Côte d'Ivoire) were analysed. We used Weibull survival models and Bayesian simulation methods to model true (unobserved) first time of treatment eligibility. We set a consistency constraint so that the mean duration from seroconversion to death was equal to the mean from seroconversion to ART eligibility plus the mean from eligibility to death.

RESULTS

We analysed data from 2072 participants, 16 157 person-years of follow-up and 794 deaths. For the criterion CD4 T-lymphocyte count <200 cells x10(6)/l, the median duration from seroconversion to ART eligibility was 6.1 years (95% credibility interval 3.3-10.4) for all studies and 7.6 years (95% credibility interval 3.4-15.2) for all but the Thai cohorts. Corresponding estimates for the time from CD4 T-lymphocyte count <200 cells x10(6)/l to death were 2.1 years (0.7-4.8) and 2.7 years (0.8-8.4). When including all cohorts, the mean time from serconversion to CD4 T-lymphocyte count <200 cells x10(6)/l and from CD4 T-lymphocyte count <200 cells x10(6)/l to death represented 66% (38-87%) and 34% (13-62%), respectively of the total survival time.

CONCLUSIONS

The duration of different ART eligibility criteria to death was longer than the estimates used in previous calculations of the number of people needing ART. However, uncertainty in estimates was considerable and heterogeneity across cohorts important.

Anaemia in a rural Ugandan HIV cohort: prevalence at enrolment, incidence, diagnosis and associated factors

OBJECTIVES

To determine the prevalence and incidence of anaemia in HIV-positive and negative individuals; to identify risk factors for anaemia, prior to the introduction of HAART; and to determine the validity of the clinical diagnosis of anaemia.

METHODS

Between 1990 and 2003, we followed a rural population based cohort of HIV-infected and uninfected participants. Prevalence and incidence of anaemia were determined clinically and by laboratory measurements. The sensitivity, specificity and predictive values of clinical diagnosis were calculated.

RESULTS

The prevalence of anaemia at enrolment was 18.9% among HIV-positive and 12.9% among HIV-negative participants (P = 0.065). Incidence of anaemia increased with HIV disease progression, from 103 per 1000 person-years of observation among those with CD4 counts >500 to 289 per 1000 person-years of observation among those with CD4 counts <200. Compared to laboratory diagnosis, the clinical diagnosis of anaemia had a sensitivity of 17.8%, specificity of 96.8%, a positive predictive value of 50.6% and a negative predictive value of 86.4%. Being female, low CD4 cell counts, HIV-positive, wasting syndrome, WHO stage 3 or 4, malaria, fever, pneumonia and oral candidiasis were associated with prevalent anaemia.

CONCLUSIONS

Anaemia prevalence and incidence were higher among HIV-positive than negative participants. Compared to laboratory diagnosis, clinical detection of anaemia had a low sensitivity. Clinicians working in settings with limited laboratory support must be conscious of the risk of anaemia when managing HIV/AIDS patients, particularly when using antiretroviral drugs which by themselves may cause anaemia as a side effect. We recommend that haemoglobin should be measured before starting ART and monthly for the first three months.

HIV incidence and recent injections among adults in rural southwestern Uganda

Thirty-six incident HIV cases were matched for age, sex and time period with 36 controls to examine associations with recent injections. A significant association between HIV incidence and a history of injections was detected that was not reduced after adjusting for available sexual behaviour variables. This association could either be the result of injections causing HIV infection or, more likely, injections for seroconversion illnesses or other consequences of unsafe sex.

Genotypic variation in the pol gene of HIV type 1 in an antiretroviral treatment-naive population in rural southwestern Uganda

The majority of studies of HIV-1 drug resistance have involved subtype B viruses. Here we have characterized subtype distribution and determined the levels of polymorphism at protease (PR) and reverse transcriptase (RT) drug resistance positions, in antiretroviral treatment-naive HIV-positive Ugandan patients. We have also investigated codon usage variability at these positions and assessed intersubtype recombination within the pol gene. The study population consisted of 187 patients, from a cohort established by the UK Medical Research Council Programme on AIDS in Uganda in 1990. Results indicate that 28.3% of patients were infected with subtype A (n = 53), 64.2% subtype D (n = 120), 6.4% A/D recombinant (n = 12), and 1.1% subtype C (n = 2). Variation in amino acid usage at drug resistance-associated positions was minimal between the two main subtypes (A and D) in RT, but there was appreciable variation in PR. Codon usage, however, was considerably more variable between subtypes A and D in both PR and RT. Thus, while no natural high-level resistance to antiretroviral therapy was detected in this cohort, subtypes A and D may possess different genetic barriers to be overcome in order to achieve resistance. With the increasing introduction of antiretroviral therapy into Africa, such information will be vital in our understanding and evaluation of the development of drug resistance as it occurs, and how to interpret resistance data the type of which has rarely previously been seen. This analysis also significantly increases the number of Ugandan PR and RT sequences characterized to date.

HIV-1 disease progression and fertility: the incidence of recognized pregnancy and pregnancy outcome in Uganda

OBJECTIVES

To estimate the association between HIV disease progression and the incidence of recognized pregnancy; to estimate the risk of subsequent fetal loss.

METHODS

A total of 191 women (92 HIV seropositive and 99 HIV seronegative at enrolment) aged 15-49 years in an HIV clinical cohort were invited to attend routine clinic visits every 3 months. Information on HIV progression collected at the visit was related to whether there was a pregnancy beginning in the following 3 months. Visits were excluded where the woman was already pregnant, lactating, using modern contraceptives or if there was inadequate follow-up.

RESULTS

There were 2524 eligible visits and 216 recognized pregnancies. The reported frequency of sexual intercourse diminished with advancing HIV disease. The adjusted odds ratio (OR) for pregnancy when the woman was in WHO stage 1 compared with HIV seronegatives was 0.58 [95% confidence interval (CI), 0.36-0.93]; stage 2, 0.47 (95% CI, 0.25-0.91); stage 3, 0.43 (95% CI, 0.25-0.74); and stage 4, (AIDS) 0.14 (95% CI, 0.02-1.09). The findings were similar for CD4 cell count, time from seroconversion and time before AIDS. There was an increase in fetal loss from the early stages of HIV infection (adjusted OR for stage 1, 5.38; 95% CI, 1.57-18.44), there were very few recognized pregnancies in the advanced stages.

CONCLUSIONS

Fertility is reduced from the earliest asymptomatic stage of HIV infection resulting from both a reduced incidence of recognized pregnancy and increased fetal loss. The greatest reduction in fertility was observed following progression to AIDS when there was a very low incidence of recognized pregnancies.