Persistently low CD4 cell counts are associated with hepatic events in HCV/HIV coinfected patients: data from the national free antiretroviral treatment program of China

BACKGROUND

Chronic liver disease has emerged as a leading cause of non-acquired immune deficiency syndrome (AIDS)-related mortality in hepatitis C virus (HCV)/human immunodeficiency virus (HIV)-coinfected patients. The relationship between CD4 cell count and HIV-related opportunistic infections and tumors has been well characterized; however, it is unclear whether CD4 cell count is associated with HCV-related hepatic events.

METHODS

This observational cohort study enrolled HCV/HIV-coinfected patients from the National Free Antiretroviral Treatment Program of China from 2004 to 2019 in Guangzhou. The primary outcome was a composite of hepatic events, including cirrhosis complications, hepatocellular carcinoma (HCC), and liver-related mortality. Kaplan-Meier survival and multivariate logistic regression analyses were performed.

RESULTS

Among the 793 patients, 43 developed hepatic events during a median follow-up of 6.7 years, including 35 cirrhosis complications, 13 HCC cases, and 14 cases of liver-related mortality. The 5-year and 10-year cumulative incidences of hepatic events were 4.2% and 9.3%, respectively. Patients who developed hepatic events had a less satisfactory increase in CD4 cell count, lower peak CD4 (354.5 cells/μL vs. 560.0 cells/μL, P < 0.001), and lower percentage of peak CD4 > 500 cells/μL (30.2% vs. 60.7%, P < 0.001) after the initiation of antiretroviral therapy (ART) than those who did not. The cumulative incidences of hepatic events were higher in patients with lower peak CD4 levels with adjusted odds ratios of 3.96 (95% confidence interval [CI]: 1.51-10.40), 2.25 (95% CI: 0.87-5.86), and 0.98 (95% CI: 0.35-2.74) for patients with peak CD4 at <200 cells/μL, 200-350 cells/μL, and 351 to 500 cells/μL, respectively, relative to those with peak CD4 > 500 cells/μL. Peak CD4 was negatively associated with the risk of hepatic events in a dose-response manner ( P -value for trend = 0.004).

CONCLUSION

Persistently low CD4 cell counts after ART are independently associated with a high risk of hepatic events in HCV/HIV-coinfected patients, highlighting the important role of immune reconstitution in improving liver outcomes.

Humoral Immune Response to Inactivated COVID-19 Vaccination at the 3rd Month among People Living with HIV

Background: Research on the immune response to inactivated COVID-19 vaccination among people living with HIV (PLWH) is limited, especially among those with low CD4+ T lymphocyte (CD4 cell) count. This cross-sectional study aimed to assess the humoral immune response to inactivated COVID-19 vaccination among PLWH compared to HIV negative controls (HNC) and to determine the impact of CD4 cell count on vaccine response among PLWH. Methods: The neutralizing antibodies (nAbs) and the specific IgM and IgG-binding antibody responses to the inactivated COVID-19 vaccine at the third month after the second dose of inactivated COVID-19 vaccination were measured among 138 PLWH and 35 HNC. Multivariable logistic regression and multiple linear regression models were conducted to identify factors associated with the seroconversion rate of antibodies and the magnitude of anti-SARS-CoV-2 antibody titers, respectively. Results: At the end of the third month after two doses of vaccination, the seroconversion rates of IgG were comparable between PLWH (8.7%; 95%CI, 3.9-13.5%) and HNC (11.4%; 95%CI, 0.3-22.5%), respectively. The median titers and seroconversion rate of nAbs among PLWH were 0.57 (IQR: 0.30-1.11) log 10 BAU/mL and 29.0% (95%CI: 21.3-36.8%), respectively, both lower than those in HNC ( P ＜0.05). After adjusting for age, sex, comorbidities, and CD4 cell count, the titers and seroconversion rate of nAbs were comparable between PLWH and HNC (P＞0.05). Multivariable regression analyses showed that CD4 cell count＜200 /μL was independently associated with lower titers and seroconversion rate of nAbs among PLWH ( P ＜0.05). A positive correlation was observed between the CD4 cell count and nAbs titers in PLWH (Spearman'sρ=0.25, P =0.034). Conclusion: Our study concluded that the immune response to inactivated COVID-19 vaccination among PLWH was independently associated with CD4 cell count, PLWH with lower CD4 cell count showed a weaker humoral immune response, especially those with CD4 cell count＜200 /μL. This finding suggests that expanding COVID-19 vaccination coverage among PLWH is impendency. In addition, aggressive ART should be carried out for PLWH, especially for those with low CD4 cell count, to improve the immune response to vaccines.

CD4 Trends With Evolving Treatment Initiation Policies Among Children Living With HIV in Zambézia Province, Mozambique, 2012-2018

BACKGROUND

Historically, antiretroviral therapy (ART) initiation was based on CD4 criteria, but this has been replaced with "Test and Start" wherein all people living with HIV are offered ART. We describe the baseline immunologic status among children relative to evolving ART policies in Mozambique.

METHODS

This retrospective evaluation was performed using routinely collected data. Children living with HIV (CL aged 5-14 years) with CD4 data in the period of 2012-2018 were included. ART initiation "policy periods" corresponded to implementation of evolving guidelines: in period 1 (2012-2016), ART was recommended for CD4 <350 cells/mm3; during period 2 (2016-2017), the CD4 threshold increased to <500 cells/mm3; Test and Start was implemented in period 3 (2017-2018). We described temporal trends in the proportion of children with severe immunodeficiency (CD4 <200 cells/mm3) at enrollment and at ART initiation. Multivariable regression models were used to estimate associations with severe immunodeficiency.

RESULTS

The cohort included 1815 children with CD4 data at enrollment and 1922 at ART initiation. The proportion of children with severe immunodeficiency decreased over time: 20% at enrollment into care in period 1 vs. 16% in period 3 (P = 0.113) and 21% at ART initiation in period 1 vs. 15% in period 3 (P = 0.004). Children initiating ART in period 3 had lower odds of severe immunodeficiency at ART initiation compared with those in period 1 [adjusted odds ratio (aOR) = 0.67; 95% CI: 0.51 to 0.88]. Older age was associated with severe immunodeficiency at enrollment (aOR = 1.13; 95% CI: 1.06 to 1.20) and at ART initiation (aOR = 1.14; 95% CI: 1.08 to 1.21).

CONCLUSIONS

The proportion of children with severe immunodeficiency at ART initiation decreased alongside more inclusive ART initiation guidelines. Earlier treatment of children living with HIV is imperative.

Treatment outcomes and HIV drug resistance of patients switching to second-line regimens after long-term first-line antiretroviral therapy: An observational cohort study

To investigate the responses to switching to second-line regimens among patients who had received a long-term first-line antiretroviral therapy.Patients switching to second-line regimens from June 2008 to June 2015 were enrolled from an observational cohort. In addition, patients continuing first-line therapy and had a viral load <1000 copies/mL were included as controls in July 2012. All these patients were followed-up for 36 months or until June 2016. The virological, immunological outcomes, and drug resistance were evaluated. Virological failure was defined as viral load ≥1000 copies/mL after 6 months of treatment since the start of the study.There were 304 patients switching to second-line regimens and 46 patients remaining on first-line therapy enrolled while having received first-line therapy for a median of 7.6 years. Patients with plasma viral load (VL) ≥1000 copies/mL before switching to second-line regimens had a sharp decline in the proportion of virological failure with 26.7%, 20.4%, and 17.0% at 12, 24, and 36 months after regimen switch, respectively (trend test, P < .001). Among these patients, individuals with drug resistance (DR) had a better virological responses as compared with those without DR after regimen switching. While patients with VL <1000 copies/mL at inclusion remained a high rate of viral suppression after switching to second-line regimens. So did patients continuing first-line therapy. Among patients with VL ≥1000 copies/mL before switching to second-line regimens, the rates of drug resistance were decreased from 79.4% at inclusion to 7.5% at 36 months of regimen switch, with the proportion of NRTI- and NNRTI-related drug resistance from 67.2% and 79.4% to 5.4% and 7.5%, respectively. No PI-related resistance was found. Having self-reported missing doses within a month at follow-ups were independently associated with virological failure at 36 months of switching.HIV-infected patients had viral load ≥1000 copies/mL at regimen switch after a long duration of first-line therapy had good virological responses to second-line regimens, especially those harbored drug resistant variants at regimen switch. However, patients with suppressive first-line therapy did not appear to benefit virologically from switching to second-line regimens.

Global Trends in CD4 Cell Count at the Start of Antiretroviral Therapy: Collaborative Study of Treatment Programs

Background

Early initiation of combination antiretroviral therapy (cART), at higher CD4 cell counts, prevents disease progression and reduces sexual transmission of human immunodeficiency virus (HIV). We describe the temporal trends in CD4 cell counts at the start of cART in adults from low-income, lower-middle-income, upper-middle-income, and high-income countries (LICs, LMICs, UMICs, and HICs, respectively).

Methods

We included HIV-infected individuals aged ≥16 years who started cART between 2002 and 2015 in a clinic participating in the International epidemiology Databases to Evaluate AIDS (IeDEA) or the Collaboration of Observational HIV Epidemiological Research in Europe (COHERE). Missing CD4 cell counts at the start of cART were estimated through multiple imputation. Weighted mixed-effect models were used to smooth trends in median CD4 cell counts.

Results

A total of 951855 adults from 16 LICs, 11 LMICs, 9 UMICs, and 19 HICs were included. Overall, the modeled median CD4 cell count at the start of cART increased from 2002 to 2015, from 78/µL (95% confidence interval, 58-104/µL) to 287/µL (250-328/µL) in LICs, from 99/µL (71-140/µL) to 234/µL (192-285/µL) in LMICs, from 71/µL (49-104/µL) to 311/µL (255-379/µL) in UMICs, and from 161/µL (143-181/µL) to 327/µL (286-372/µL) in HICs. In LICs, LMICs, and UMICs, the increase was more pronounced in women; in HICs, the opposite was observed.

Conclusions

Median CD4 cell counts at the start of cART increased in all income groups, but generally remained below 350/μL in 2015. Substantial additional efforts and resources are required to achieve earlier diagnosis, linkage to care, and initiation of cART.

Persistent High Burden of Advanced HIV Disease Among Patients Seeking Care in South Africa's National HIV Program: Data From a Nationwide Laboratory Cohort

Background

The South African national HIV program has increased antiretroviral therapy (ART) coverage over the last decade, supported by policy changes allowing for earlier ART initiation. However, many patients still enter care with advanced (<200 cells/μL) and very advanced (<100 cells/μL) HIV disease. We assessed disease progression at entry to care using nationwide laboratory data.

Methods

We constructed a national HIV cohort using laboratory records containing HIV RNA loads and CD4 counts from 2004 to 2016 to determine entry into care. We estimated numbers and proportions of adults with the first CD4 count <100 cells/ μL or 100-199 cells/μL. We calculated relative risks of presenting with advanced disease associated with male sex.

Results

8.04 million first CD4 results were identified. From 2005 to 2011, the proportion of patients entering into care with CD4 count <200 cells/μL declined from 46.8% to 35.6%. From 2011 onward, the proportion of patients entering ART with advanced HIV disease has remained relatively unchanged. In 2016, we estimated that of 654 868 patients entering care, 32.9% had advanced HIV disease, and 16.8% had very advanced HIV disease. Men were almost twice as likely as women (23.1% vs 12.6% ) to enter care with very advanced HIV disease.

Conclusions

The proportion of patients presenting with advanced HIV disease in South Africa remains consistently high despite ART scale-up, representing a large and avoidable burden of morbidity. Early HIV diagnosis, rapid linkage to ART and approaches to attract men into early ART initiation should be prioritized.

Effect of Immediate Initiation of Antiretroviral Treatment in HIV-Positive Individuals Aged 50 Years or Older

BACKGROUND

Clinical guidelines recommend immediate initiation of combined antiretroviral therapy for all HIV-positive individuals. However, those guidelines are based on trials of relatively young participants.

METHODS

We included HIV-positive antiretroviral therapy-naive, AIDS-free individuals aged 50-70 years after 2004 in the HIV-CAUSAL Collaboration. We used the parametric g-formula to estimate the 5-year risk of all-cause and non-AIDS mortality under (1) immediate initiation at baseline and initiation at CD4 count, (2) <500 cells/mm, and (3) <350 cells/mm. Results were presented separately for the general HIV population and for a US Veterans cohort with high mortality.

RESULTS

The study included 9596 individuals (28% US Veterans) with median (interquantile range) age of 55 (52-60) years and CD4 count of 336 (182-513) at baseline. The 5-year risk of all-cause mortality was 0.40% (95% confidence interval (CI): 0.10 to 0.71) lower for the general HIV population and 1.61% (95% CI: 0.79 to 2.67) lower for US Veterans when comparing immediate initiation vs initiation at CD4 <350 cells/mm. The 5-year risk of non-AIDS mortality was 0.17% (95% CI: -0.07 to 0.43) lower for the general HIV population and 1% (95% CI: 0.31 to 2.00) lower for US Veterans when comparing immediate initiation vs initiation at CD4 <350 cells/mm.

CONCLUSIONS

Immediate initiation seems to reduce all-cause and non-AIDS mortality in patients aged 50-70 years.

Comparison of dynamic monitoring strategies based on CD4 cell counts in virally suppressed, HIV-positive individuals on combination antiretroviral therapy in high-income countries: a prospective, observational study

BACKGROUND

Clinical guidelines vary with respect to the optimal monitoring frequency of HIV-positive individuals. We compared dynamic monitoring strategies based on time-varying CD4 cell counts in virologically suppressed HIV-positive individuals.

METHODS

In this observational study, we used data from prospective studies of HIV-positive individuals in Europe (France, Greece, the Netherlands, Spain, Switzerland, and the UK) and North and South America (Brazil, Canada, and the USA) in The HIV-CAUSAL Collaboration and The Centers for AIDS Research Network of Integrated Clinical Systems. We compared three monitoring strategies that differ in the threshold used to measure CD4 cell count and HIV RNA viral load every 3-6 months (when below the threshold) or every 9-12 months (when above the threshold). The strategies were defined by the threshold CD4 counts of 200 cells per μL, 350 cells per μL, and 500 cells per μL. Using inverse probability weighting to adjust for baseline and time-varying confounders, we estimated hazard ratios (HRs) of death and of AIDS-defining illness or death, risk ratios of virological failure, and mean differences in CD4 cell count.

FINDINGS

47 635 individuals initiated an antiretroviral therapy regimen between Jan 1, 2000, and Jan 9, 2015, and met the eligibility criteria for inclusion in our study. During follow-up, CD4 cell count was measured on average every 4·0 months and viral load every 3·8 months. 464 individuals died (107 in threshold 200 strategy, 157 in threshold 350, and 200 in threshold 500) and 1091 had AIDS-defining illnesses or died (267 in threshold 200 strategy, 365 in threshold 350, and 459 in threshold 500). Compared with threshold 500, the mortality HR was 1·05 (95% CI 0·86-1·29) for threshold 200 and 1·02 (0·91·1·14) for threshold 350. Corresponding estimates for death or AIDS-defining illness were 1·08 (0·95-1·22) for threshold 200 and 1·03 (0·96-1·12) for threshold 350. Compared with threshold 500, the 24 month risk ratios of virological failure (viral load more than 200 copies per mL) were 2·01 (1·17-3·43) for threshold 200 and 1·24 (0·89-1·73) for threshold 350, and 24 month mean CD4 cell count differences were 0·4 (-25·5 to 26·3) cells per μL for threshold 200 and -3·5 (-16·0 to 8·9) cells per μL for threshold 350.

INTERPRETATION

Decreasing monitoring to annually when CD4 count is higher than 200 cells per μL compared with higher than 500 cells per μL does not worsen the short-term clinical and immunological outcomes of virally suppressed HIV-positive individuals. However, more frequent virological monitoring might be necessary to reduce the risk of virological failure. Further follow-up studies are needed to establish the long-term safety of these strategies.

FUNDING

National Institutes of Health.

When to Monitor CD4 Cell Count and HIV RNA to Reduce Mortality and AIDS-Defining Illness in Virologically Suppressed HIV-Positive Persons on Antiretroviral Therapy in High-Income Countries: A Prospective Observational Study

OBJECTIVE

To illustrate an approach to compare CD4 cell count and HIV-RNA monitoring strategies in HIV-positive individuals on antiretroviral therapy (ART).

DESIGN

Prospective studies of HIV-positive individuals in Europe and the USA in the HIV-CAUSAL Collaboration and The Center for AIDS Research Network of Integrated Clinical Systems.

METHODS

Antiretroviral-naive individuals who initiated ART and became virologically suppressed within 12 months were followed from the date of suppression. We compared 3 CD4 cell count and HIV-RNA monitoring strategies: once every (1) 3 ± 1 months, (2) 6 ± 1 months, and (3) 9-12 ± 1 months. We used inverse-probability weighted models to compare these strategies with respect to clinical, immunologic, and virologic outcomes.

RESULTS

In 39,029 eligible individuals, there were 265 deaths and 690 AIDS-defining illnesses or deaths. Compared with the 3-month strategy, the mortality hazard ratios (95% CIs) were 0.86 (0.42 to 1.78) for the 6 months and 0.82 (0.46 to 1.47) for the 9-12 month strategy. The respective 18-month risk ratios (95% CIs) of virologic failure (RNA >200) were 0.74 (0.46 to 1.19) and 2.35 (1.56 to 3.54) and 18-month mean CD4 differences (95% CIs) were -5.3 (-18.6 to 7.9) and -31.7 (-52.0 to -11.3). The estimates for the 2-year risk of AIDS-defining illness or death were similar across strategies.

CONCLUSIONS

Our findings suggest that monitoring frequency of virologically suppressed individuals can be decreased from every 3 months to every 6, 9, or 12 months with respect to clinical outcomes. Because effects of different monitoring strategies could take years to materialize, longer follow-up is needed to fully evaluate this question.

Multiple facets of HIV-associated renal disease

HIV infection has a broad spectrum of renal manifestations. This study examined the clinical and histological manifestations of HIV-associated renal disease, and predictors of renal outcomes. Sixty-one (64% male, mean age 45 years) HIV patients were retrospectively evaluated. Clinical presentation and renal histopathology were assessed, as well as CD4 T-cell count and viral load. The predictive value of histological lesion, baseline CD4 cell count and viral load for end-stage renal disease (ESRD) or death were determined using the Cox regression model. The outcomes of chronic kidney disease (CKD) and ESRD or death were evaluated by baseline CD4 cell count. The percent distribution at initial clinical presentation was non-nephrotic proteinuria (54%), acute kidney injury (28%), nephrotic syndrome (23%), and chronic kidney disease (22%). Focal segmental glomerulosclerosis (28%), mainly the collapsing form (HIVAN), acute interstitial nephritis (AIN) (26%), and immune complex-mediated glomerulonephritis (ICGN) (25%) were the predominant renal histology. Baseline CD4 cell count ≥ 200 cells/mm3 was a protective factor against CKD (hazard ratio=0.997; 95%CI=0.994-0.999; P=0.012). At last follow-up, 64% of patients with baseline CD4 ≥ 200 cells/mm3 had eGFR >60 mL·min-1·(1.73 m2)-1 compared to the other 35% of patients who presented with CD4 <200 cells/mm3 (log rank=9.043, P=0.003). In conclusion, the main histological lesion of HIV-associated renal disease was HIVAN, followed by AIN and ICGN. These findings reinforce the need to biopsy HIV patients with kidney impairment and/or proteinuria. Baseline CD4 cell count ≥ 200 cells/mm3 was associated with better renal function after 2 years of follow-up.

Comparative effectiveness of immediate antiretroviral therapy versus CD4-based initiation in HIV-positive individuals in high-income countries: observational cohort study

BACKGROUND

Recommendations have differed nationally and internationally with respect to the best time to start antiretroviral therapy (ART). We compared effectiveness of three strategies for initiation of ART in high-income countries for HIV-positive individuals who do not have AIDS: immediate initiation, initiation at a CD4 count less than 500 cells per μL, and initiation at a CD4 count less than 350 cells per μL.

METHODS

We used data from the HIV-CAUSAL Collaboration of cohort studies in Europe and the USA. We included 55,826 individuals aged 18 years or older who were diagnosed with HIV-1 infection between January, 2000, and September, 2013, had not started ART, did not have AIDS, and had CD4 count and HIV-RNA viral load measurements within 6 months of HIV diagnosis. We estimated relative risks of death and of death or AIDS-defining illness, mean survival time, the proportion of individuals in need of ART, and the proportion of individuals with HIV-RNA viral load less than 50 copies per mL, as would have been recorded under each ART initiation strategy after 7 years of HIV diagnosis. We used the parametric g-formula to adjust for baseline and time-varying confounders.

FINDINGS

Median CD4 count at diagnosis of HIV infection was 376 cells per μL (IQR 222-551). Compared with immediate initiation, the estimated relative risk of death was 1·02 (95% CI 1·01-1·02) when ART was started at a CD4 count less than 500 cells per μL, and 1·06 (1·04-1·08) with initiation at a CD4 count less than 350 cells per μL. Corresponding estimates for death or AIDS-defining illness were 1·06 (1·06-1·07) and 1·20 (1·17-1·23), respectively. Compared with immediate initiation, the mean survival time at 7 years with a strategy of initiation at a CD4 count less than 500 cells per μL was 2 days shorter (95% CI 1-2) and at a CD4 count less than 350 cells per μL was 5 days shorter (4-6). 7 years after diagnosis of HIV, 100%, 98·7% (95% CI 98·6-98·7), and 92·6% (92·2-92·9) of individuals would have been in need of ART with immediate initiation, initiation at a CD4 count less than 500 cells per μL, and initiation at a CD4 count less than 350 cells per μL, respectively. Corresponding proportions of individuals with HIV-RNA viral load less than 50 copies per mL at 7 years were 87·3% (87·3-88·6), 87·4% (87·4-88·6), and 83·8% (83·6-84·9).

INTERPRETATION

The benefits of immediate initiation of ART, such as prolonged survival and AIDS-free survival and increased virological suppression, were small in this high-income setting with relatively low CD4 count at HIV diagnosis. The estimated beneficial effect on AIDS is less than in recently reported randomised trials. Increasing rates of HIV testing might be as important as a policy of early initiation of ART.

FUNDING

National Institutes of Health.

Sex-associated differences in pre-antiretroviral therapy plasma HIV-1 RNA in diverse areas of the world vary by CD4(+) T-cell count

BACKGROUND

Sex differences in the natural history of HIV infection may vary between resource-rich and resource-limited settings.

METHODS

Baseline characteristics from a randomized clinical trial of treatment-naive subjects conducted at sites in Africa, Asia, the Caribbean, and North and South America were analysed to determine if there were significant differences by sex.

RESULTS

Of the 1,571 participants, 740 (47.1%) were women. Women had higher mean screening CD4(+) T-cell counts (mean 15 cells higher; P<0.001), lower mean haemoglobin and creatinine clearance, a lower mean baseline HIV-1 viral load (4.85 log(10) versus 5.05 log₁₀ copies/ml; P<0.001) and were less likely to have a prior AIDS diagnosis than men. The sex difference in viral load was related to CD4(+) T-cell count; however, it was independent of country and persisted within the strata with CD4(+) T-cell count <200 cells/mm³.

CONCLUSIONS

Women in resource-limited settings have lower levels of plasma HIV-1 RNA and appear to present for enrolment into clinical trials at an earlier stage of disease than men. The biological basis for lower viral load in women compared to men remains unexplained. It will be important to determine if the sex differences observed at baseline impact clinical outcomes once the PEARLS clinical trial is completed.

Towards a combined prognostic index for survival in HIV infection: the role of 'non-HIV' biomarkers

BACKGROUND

As those with HIV infection live longer, 'non-AIDS' condition associated with immunodeficiency and chronic inflammation are more common. We ask whether 'non-HIV' biomarkers improve differentiation of mortality risk among individuals initiating combination antiretroviral therapy (cART).

METHODS

Using Poisson models, we analysed data from the Veterans Aging Cohort Study (VACS) on HIV-infected veterans initiating cART between 1 January 1997 and 1 August 2002. Measurements included: HIV biomarkers (CD4 cell count, HIV RNA and AIDS-defining conditions); 'non-HIV' biomarkers (haemoglobin, transaminases, platelets, creatinine, and hepatitis B and C serology); substance abuse or dependence (alcohol or drug); and age. Outcome was all cause mortality. We tested the discrimination (C statistics) of each biomarker group alone and in combination in development and validation data sets, over a range of survival intervals, and adjusting for missing data.

RESULTS

Of veterans initiating cART, 9784 (72%) had complete data. Of these, 2566 died. Subjects were middle-aged (median age 45 years), mainly male (98%) and predominantly black (51%). HIV and 'non-HIV' markers were associated with each other (P < 0.0001) and discriminated mortality (C statistics 0.68-0.73); when combined, discrimination improved (P < 0.0001). Discrimination for the VACS Index was greater for shorter survival intervals [30-day C statistic 0.86, 95% confidence interval (CI) 0.80-0.91], but good for intervals of up to 8 years (C statistic 0.73, 95% CI 0.72-0.74). Results were robust to adjustment for missing data.

CONCLUSIONS

When added to HIV biomarkers, 'non-HIV' biomarkers improve differentiation of mortality. When evaluated over similar intervals, the VACS Index discriminates as well as other established indices. After further validation, the VACS Index may provide a useful, integrated risk assessment for management and research.

Total lymphocyte count of 1200 is not a sensitive predictor of CD4 lymphocyte count among patients with HIV disease in Kampala, Uganda

INTRODUCTION

Total Lymphocyte Count (TLC) has been found to be an inexpensive and useful marker for staging disease, predicting progression to AIDS and death and monitoring response to ART. However, the correlation between TLC and CD4 has not been consistent. Access to HAART is expanding in Kampala, Uganda, yet there are no published data evaluating the utility of TLC as inexpensive surrogate marker of CD4 cell count to help guide therapeutic decisions.

OBJECTIVE

To evaluate clinical illnesses and total lymphocyte count (TLC) as surrogate markers of the CD4 cell count in HIV infected persons being considered for ART.

METHODS

A total of 131 patients were enrolled and evaluated by clinical assessment, TLC and CD4 count. Clinical illnesses and TLC dichotomized at various cut-point values were used to determine the sensitivity, specificity, and positive and negative predictive values (PPV and NPV) for the diagnosis of CD4 count <200 cells/mm 3 among 100 participants fulfilling criteria for WHO clinical stage 2 and 3.

RESULTS

A strong correlation was observed between TLC and CD4 (r = 0.73, p<0.0001). For all clinical syndromes, except pulmonary tuberculosis, the positive predictive values (PPV) for a CD4 count <200 cells/mm 3 were high (>80%) but the negative predictive values (NPV) were low. Using the WHO recommended TLC cut-off of 1200 cells/mm 3 to diagnose a CD4 less than 200 cells/mm 3 , the PPV was 100%, and the NPV was 32%.

CONCLUSION

Our data showed a good correlation between TLC and CD4 cell count. However, the WHO recommended TLC cut-off of 1200 did not identify the majority of WHO stage 2 and 3 patients with CD4 counts less than 200 cells/mm 3 . A more rational use of TLC counts is to treat all patients with WHO stage 2 and 3 who have a TLC <1200 and to limit CD4 counts to patients who are symptomatic but have TLC of >1200.