Establishing CD4 thresholds for highly active antiretroviral therapy initiation in a cohort of HIV-infected adult Chinese in Hong Kong

Diagnosis of Human Immunodeficiency Virus Infection

HIV diagnostics have played a central role in the remarkable progress in identifying, staging, initiating, and monitoring infected individuals on life-saving antiretroviral therapy. They are also useful in surveillance and outbreak responses, allowing for assessment of disease burden and identification of vulnerable populations and transmission "hot spots," thus enabling planning, appropriate interventions, and allocation of appropriate funding. HIV diagnostics are critical in achieving epidemic control and require a hybrid of conventional laboratory-based diagnostic tests and new technologies, including point-of-care (POC) testing, to expand coverage, increase access, and positively impact patient management. In this review, we provide (i) a historical perspective on the evolution of HIV diagnostics (serologic and molecular) and their interplay with WHO normative guidelines, (ii) a description of the role of conventional and POC testing within the tiered laboratory diagnostic network, (iii) information on the evaluations and selection of appropriate diagnostics, (iv) a description of the quality management systems needed to ensure reliability of testing, and (v) strategies to increase access while reducing the time to return results to patients. Maintaining the central role of HIV diagnostics in programs requires periodic monitoring and optimization with quality assurance in order to inform adjustments or alignment to achieve epidemic control.

Early initiation of antiretroviral therapy in HIV-infected adults and adolescents: a systematic review

OBJECTIVES

The objective of this review was to update evidence on when to initiate antiretroviral therapy (ART) to inform revision of the 2013 WHO guidelines for ART in low and middle-income countries.

DESIGN

A systematic review and meta-analysis.

METHODS

We comprehensively searchescohorts. Outcomes were mortality, clinical progression, virologic failure, immunologic recover, and severe adverse events. We pooled data across studies and estimated summary effect sizes. We graded the quality of evidence from the literature for each outcome.

RESULTS

We identified 24 studies; 3 were RCTs. Studies found reduced risk of mortality [1 RCT: hazard ratio 0.77, 95% confidence interval (CI) 0.34-1.76; 13 cohorts: relative risk (RR) 0.66, 95% CI 0.55-0.79], progression to AIDS or death (2 RCTs: RR 0.48, 95% CI 0.26-0.91; 9 cohorts: RR 0.70, 95% CI 0.40-1.24) and diagnosis of a non-AIDS-defining illness (1 RCT: RR 0.14, 95% CI 0.03-0.64; 1 cohort: RR 0.47, 95% CI 0.23-0.98), and an increased risk of grade 3/4 laboratory abnormalities in patients initiating ART at at least 350 cells/μl (1 RCT: RR 1.49, 95% CI 1.25-1.77). The quality of evidence was low or very low for clinical outcomes due to few events and imprecision, and high for adverse events.

CONCLUSIONS

Our findings contributed to the evidence base for the revised 2013 WHO guidelines on ART, which recommend initiating ART at CD4 T-cell counts of 350-500 cells/μl, but not above 500 cells/μl compared to initiating it later when CD4 T-cell counts fall below 350 cells/μl.

Rate of CD4 decline and HIV-RNA change following HIV seroconversion in men who have sex with men: a comparison between the Beijing PRIMO and CASCADE cohorts

OBJECTIVE

Little is known about the natural history of the HIV infection in men who have sex with men (MSM) in China.

METHODS

We compared changes in CD4+ T-cell count and HIV-RNA following seroconversion before starting antiretroviral therapy between MSM in China and in resource-rich countries using data from the Beijing PRIMO cohort and Concerted Action on SeroConversion to AIDS and Death in Europe (CASCADE), respectively. Linear mixed models were used to compare rates of CD4 decline (cubic root scale) and changes in HIV-RNA (log10 scale) in the first 3 years following seroconversion.

RESULTS

For 131 PRIMO and 3171 CASCADE MSM infected in 2001-2010, estimated CD4+ T-cell count at seroconversion was lower in PRIMO (504 cells/mm3; 95% confidence interval: 463 to 547) compared with CASCADE (554 cells/mm3; 544 to 564). CD4 decline was significantly faster for PRIMO men [-0.59 (-0.72 to -0.47) and - 0.41 (-0.44 to -0.38) cubic root of CD4 count/year for PRIMO and CASCADE, respectively], even after restricting to subtype B (P = 0.01). HIV-RNA at seroconversion was lower in PRIMO compared with CASCADE MSM [difference 0.425 log10/mL (0.249 to 0.603), P < 0.001]. After the first year of seroconversion, PRIMO MSM experienced a faster increase in HIV-RNA [0.830 log10/mL per year; (0.484 to 1.168)] compared with CASCADE MSM [0.018 (-0.035 to 0.067)] (P < 0.001).

CONCLUSIONS

CD4 decline and HIV-RNA increase are faster between MSM in China compared with MSM from resource-rich settings. Whether this is due to differences in host immunity or viral characteristics requires further exploration.

Race and CD4+ T-cell count in HIV prognosis and treatment

CD4+ T-cell count is known to vary by race in HIV-negative individuals. While people of certain races, such as blacks and Asians, continue to be disproportionately burdened by HIV/AIDS, they remain under-represented in most HIV clinical studies. Recent studies suggest that CD4+ count evolution in HIV, before and after therapy, may differ by race. In this review, we summarize the evidence from prospective cohorts comparing CD4+ count trajectories by race, and whether it is of any clinical significance. We find that although minor differences in CD4+ count trajectories exist between people of diverse races, socioeconomic, cultural and environmental differences are far more important in predicting clinical outcomes than racial differences in CD4+ count. Furthermore, current evidence does not support the need for any race or ethnicity-specific CD4+ thresholds for ART and prophylactic therapy initiation. Future long-term trials in racially diverse populations are required to substantiate these findings.

The Clinical Significance of CD4 Counts in Asian and Caucasian HIV-Infected Populations: Results from TAHOD and AHOD

The significance of interethnic variation in CD4 counts between Asian and Caucasian populations is not known. Patients on combination antiretroviral therapy from Treat Asia and Australian HIV Observational Databases (TAHOD, predominantly Asian, n = 3356; and AHOD, predominantly Caucasian, n = 2312, respectively) were followed for 23 144 person-years for AIDS/death and all-cause mortality endpoints. We calculated incidence-rates and used adjusted Cox regression to test for the interaction between cohort (TAHOD/AHOD) and time-updated CD4 count category (lagged by 3 months) for each of the endpoints. There were 382 AIDS/death events in TAHOD (rate: 4.06, 95%CI: 3.68-4.50) and 305 in AHOD (rate: 2.39, 95%CI: 2.13-2.67), per 100 person-years. At any given CD4 count category, the incidence-rates of endpoints were found to be similar between TAHOD and AHOD (in the adjusted models, P > .05 for the interaction term between cohort type and latest CD4 counts). At any given CD4 count, risk of AIDS or death was not found to vary by ethnicity, suggesting that the CD4 count thresholds for predicting outcomes defined in Caucasian populations may be equally valid in Asian populations.

Stable and low prevalence of transmitted HIV type 1 drug resistance despite two decades of antiretroviral therapy in Hong Kong

Transmitted HIV resistance is of both clinical and public health importance. Baseline genotypic resistance testing was performed for HIV-1-infected treatment-naive patients who were newly diagnosed between 2003 and 2007 and attended the government HIV clinic in Hong Kong. International AIDS Society-USA mutation figures and the Stanford resistance interpretation algorithm were used to identify resistance mutations and drug susceptibility, respectively. The pattern and factors associated with resistance were examined. The presence of one or more IAS-USA resistance mutations was found in 26 (3.6%) of 731 patients over the 5-year study period. Overall, protease inhibitor (PI) resistance mutations were most common (16), followed by nucleoside reverse transcriptase inhibitors (NRTIs) (8) and nonnucleoside reverse transcriptase inhibitors (NNRTIs) (3). Resistance to drugs in one, two, and three classes was present in 25 (3.4%), 1 (0.1%), and 0, respectively. Seventy-eight (10.7%) had strains of reduced susceptibility, as predicted by the Stanford algorithm to display at least low-level resistance to one or more drugs of the three classes. Intermediate or high-level resistance was found in 1.6% overall, and in descending order for NRTIs, PIs, and NNRTIs. There was no temporal trend of increase in resistance. Sex between men, Chinese ethnicity, and lower baseline CD4 were associated with harboring resistant strains as elucidated by either method. We conclude that transmitted HIV-1 drug resistance is uncommon in up to two decades of antiretroviral therapy in Hong Kong. The situation has to be continually monitored for any change in significance.

Economic evaluation of ART in resource-limited countries

PURPOSE OF REVIEW

In the face of increasing economic constraints, it is critically important to evaluate how best to utilize available resources. In this article, we review the growing number of cost-effectiveness analyses of HIV treatment with antiretroviral therapy (ART) in resource-limited settings. We focus on studies that evaluate when to start therapy, what therapy to start with and what to switch to based on what criteria.

RECENT FINDINGS

Recent findings show that earlier ART initiation based on CD4 cell count criteria (CD4 cell counts <350 cells/microl) can be cost effective in most resource-limited settings. They also suggest that initiating ART with tenofovir as a component of the first-line regimen is an efficient use of resources compared with initiating ART with stavudine. Finally, they show that HIV RNA monitoring combined with CD4 monitoring is more effective than CD4 monitoring alone, although this strategy was not yet found to be cost effective in all studies. Nearly all studies demonstrate, however, that the cost-effectiveness ratio of HIV RNA monitoring will become more attractive as the cost of HIV RNA tests and second-line ART regimens decrease.

SUMMARY

Substantial research shows that ART for HIV disease in resource-limited settings is cost effective. Improved initial regimens and increased laboratory monitoring may provide both clinical benefit and good value for money. Further price reductions of laboratory tests and recent antiretroviral drugs are needed to guarantee the cost-effectiveness of these required improvements.

CD4 Count and Anti Retroviral Therapy for HIV Positive Patients With Cancer in Nigeria -A Pilot Study

Background:

Highly Active Anti Retroviral Treatment (HAART) improves the outcome of HIV positive patients treated for cancer. In our center HAART is only commenced in HIV positive patients with malignancy if the CD4 T lymphocyte count is less than 200 cells/ul. Presently, the outcome of treatment in these patients is poor.

Objective:

To evaluate the influence of CD4 T-cell count and HAART on treatment outcome of HIV positive patients with cancer managed at the oncology service of The University College Hospital, Ibadan-South West Nigeria.

Patients and methods:

Twenty two adult HIV positive patients with malignancies who presented for treatment at our hospital from 2007 to 2009 were closely monitored by the investigators. Relevant clinical data collected included age, sex, HIV status, type of malignancy, CD4 counts, history of ART, ECOG performance status, prescribed oncology treatment with regularity of treatment and to follow up conditions.

Results:

Twenty two patients aged between 26 and 67 years were evaluated. The performance status of all patients was at least ECOG 2. Three ART naive patients with initial CD4 counts 450 cells/ul and above were able to complete oncology treatment without HAART with good malignant disease control. Five other patients on HAART before the diagnosis of malignancy with CD4 counts 350 cells/ul and above were also able to complete their treatments on schedule with good outcome. Eight HAART naive patients with initial CD4 counts less than 370 cells/ul had inconsistent treatments with poor outcome.

Conclusion:

Based on these observations, we propose that HAART should be commenced on all HIV positive patients diagnosed with malignancy with an initial CD4 count less than 450 cells/ul in our environment. Further studies in low resource settings with appropriate sample sizes are however needed to validate these findings.

Optimal time for initiation of antiretroviral therapy in asymptomatic, HIV-infected, treatment-naive adults

BACKGROUND

According to consensus, initiation of therapy is best based on CD4 cell count, a marker of immune status, rather than on viral load, a marker of virologic replication. For patients with advanced symptoms, treatment should be started regardless of CD4 count. However, the point during the course of HIV infection at which antiretroviral therapy (ART) is best initiated in asymptomatic patients remains unclear. Guidelines issued by various agencies provide different initiation recommendations according to resource availability. This can be confusing for clinicians and policy-makers when determining the best time to initiate therapy. Optimizing the initiation of ART is clearly complex and must, therefore, be balanced between individual and broader public health needs.

OBJECTIVES

To assess the evidence for the optimal time to initiate ART in treatment-naive, asymptomatic, HIV-infected adults

SEARCH STRATEGY

We formulated a comprehensive and exhaustive search strategy in an attempt to identify all relevant studies regardless of language or publication status (published, unpublished, in press, and in progress). In August 2009, we searched the following electronic journal and trial databases: MEDLINE, EMBASE, and CENTRAL. We also searched the electronic conference database of NLM Gateway, individual conference proceedings and prospective trials registers. We contacted researchers and relevant organizations and checked reference lists of all included studies.

SELECTION CRITERIA

Randomized controlled trials that compared the effect of ART consisting of three drugs initiated early in the disease at high CD4 counts as defined by the trial. Early initiation could be at levels of 201-350, 351-500, or >500 cells/microL, with the comparison group initiating ART at CD4 counts below 200 x 10(6) cells/microL or as defined by the trial.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed study eligibility, extracted data, and graded methodological quality. Data extraction and methodological quality were checked by a third author who resolved differences when these arose. Where clinically meaningful to do so, we meta-analysed dichotomous outcomes using the relative risk (RR) and report the 95% confidence intervals (95% CIs).

MAIN RESULTS

One completed trial (N = 816) and one sub-group (N = 249) of a larger trial met inclusion criteria. We combined the mortality data for both trials comparing initiating ART at CD4 levels at 350 cells/microL or between 200 and 350 cells/microL with deferring initiation of ART to CD4 levels of 250 cells/microL or 200 cells/microL. There was a statistically significant reduction in death when starting ART at higher CD4 counts. Risk of death was reduced by 74% (RR = 0.26; 95% CI: 0.11, 0.62; P = 0.002). Risk of tuberculosis was reduced by 50% in the groups starting ART early; this was not statistically significant, with the reduction as much as 74% or an increased risk of up to 12% (RR = 0.54; 95% CI: 0.26, 1.12; P = 0.01). Starting ART at enrollment (when participants had CD4 counts of 350 cells/microL) rather than deferring to starting at a CD4 count of 250 cells/microL reduced the risk of disease progression by 70%; this was not statistically significant, with the reduction in risk as much as 97% or an increased risk of up to 185% (RR = 0.30; 95% CI: 0.03, 2.85; P = 0.29).One RCT found no statistically significant difference in the number of independent Grade 3 or 4 adverse events occurring in the early and standard ART groups when we conducted an intention-to-treat analysis (RR = 1.72; 95% CI: 0.98, 3.03; P = 0.06). However, when analyzing only participants who actually commenced ART in the deferred group (n = 160), the trial authors report a statistically significant increase in the incidence of zidovudine-related anaemia (8.1%) compared with those in the early initiation group (3.4%) (RR = 0.42; 95% CI: 0.20, 0.88; P = 0.02).

AUTHORS' CONCLUSIONS

There is evidence of moderate quality that initiating ART at CD4 levels higher than 200 or 250 cells/microL reduces mortality rates in asymptomatic, ART-naive, HIV-infected people. Practitioners and policy-makers may consider initiating ART at levels </= 350 cells/microL for patients who present to health services and are diagnosed with HIV early in the infection.

Social network methodology for studying HIV epidemiology in men having sex with men

A self-administered network-based questionnaire survey was conducted on 91 HIV-positive Chinese men having sex with men (MSM). Affiliation matrices were created to assess their networking pattern. The individuals' preferential use of venues for sex partnership before HIV infection has changed over three time periods of 1997-2000, 2001-2003 and 2004-2006. Over time, there was a parallel increase in network density (density scores from 0.26, through 0.36, to 0.53) and degree centrality (from a median score of 9, through 12, to 16), suggesting that connectivity of MSM was becoming higher through sexual networks. The overall practice of unprotected sex has, however, remained the same. The study demonstrated how the application of social network analysis could enrich the epidemiologic description of HIV infection in the population.

Clinical prognostic value of RNA viral load and CD4 cell counts during untreated HIV-1 infection--a quantitative review

Background

The prognostic value of CD4 counts and RNA viral load for identifying treatment need in HIV-infected individuals depends on (a) variation within and among individuals, and (b) relative risks of clinical progression per unit CD4 or RNA difference.

Methodology/Principal Findings

We reviewed these measurements across (a) 30 studies, and (b) 16 cohorts of untreated seropositive adults. Median within-population interquartile ranges were 74,000 copies/mL for RNA with no significant change during the course of infection; and 330 cells/µL for CD4, with a slight proportional increase over infection. Applying measurement and physiological fluctuations observed on chronically infected patients, we estimate that 45% of population-level variation in RNA, and 25% of variation in CD4, were due to within-patient fluctuations. Comparing a patient with RNA at upper 75^th centile with a patient at median RNA, 5-year relative risks were 1.4 (95% CI 1.2–1.7) for AIDS and 1.5 (1.3–1.9) for death, without change over the course of infection. In contrast, for a patient with CD4 count at the lower 75^th centile, relative risks increased from 1.0 at seroconversion to maxima of 6.3 (4.4–8.9) for AIDS and 5.5 (2.7–10.1) for death by year 6, when the population median had fallen to 300 cells/µL. Below 300 cells/µL, prognostic power did not increase, due to a narrower CD4 range.

Conclusions

Findings support the current WHO recommendation (used with clinical criteria) to start antiretroviral treatment in low-income settings at CD4 thresholds of 200–350 cells/µL, without pre-treatment RNA monitoring – while not precluding earlier treatment based on clinical, socio-demographic or public health criteria.