CD4 and total lymphocyte counts as predictors of HIV disease progression

SARS-CoV-2-associated lymphopenia: possible mechanisms and the role of CD147

T lymphocytes play a primary role in the adaptive antiviral immunity. Both lymphocytosis and lymphopenia were found to be associated with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). While lymphocytosis indicates an active anti-viral response, lymphopenia is a sign of poor prognosis. T-cells, in essence, rarely express ACE2 receptors, making the cause of cell depletion enigmatic. Moreover, emerging strains posed an immunological challenge, potentially alarming for the next pandemic. Herein, we review how possible indirect and direct key mechanisms could contribute to SARS-CoV-2-associated-lymphopenia. The fundamental mechanism is the inflammatory cytokine storm elicited by viral infection, which alters the host cell metabolism into a more acidic state. This "hyperlactic acidemia" together with the cytokine storm suppresses T-cell proliferation and triggers intrinsic/extrinsic apoptosis. SARS-CoV-2 infection also results in a shift from steady-state hematopoiesis to stress hematopoiesis. Even with low ACE2 expression, the presence of cholesterol-rich lipid rafts on activated T-cells may enhance viral entry and syncytia formation. Finally, direct viral infection of lymphocytes may indicate the participation of other receptors or auxiliary proteins on T-cells, that can work alone or in concert with other mechanisms. Therefore, we address the role of CD147-a novel route-for SARS-CoV-2 and its new variants. CD147 is not only expressed on T-cells, but it also interacts with other co-partners to orchestrate various biological processes. Given these features, CD147 is an appealing candidate for viral pathogenicity. Understanding the molecular and cellular mechanisms behind SARS-CoV-2-associated-lymphopenia will aid in the discovery of potential therapeutic targets to improve the resilience of our immune system against this rapidly evolving virus.

Multicenter Study of Controlling Nutritional Status (CONUT) Score as a Prognostic Factor in Patients With HIV-Related Renal Cell Carcinoma

Objective

In recent years, the controlled nutritional status (CONUT) score has been widely recognized as a new indicator for assessing survival in patients with urological neoplasms, including renal, ureteral, and bladder cancer. However, the CONUT score has not been analyzed in patients with HIV-related urological neoplasms. Therefore, we aimed to evaluate the prognostic significance of the CONUT score in patients with HIV-related renal cell carcinoma (RCC).

Methods

A total of 106 patients with HIV-related RCC were recruited from four hospitals between 2012 and 2021, and all included patients received radical nephrectomy or partial nephrectomy. The CONUT score was calculated by serum albumin, total lymphocyte counts, and total cholesterol concentrations. Patients with RCC were divided into two groups according to the optimal cutoff value of the CONUT score. Survival analysis of different CONUT groups was performed by the Kaplan–Meier method and a log rank test. A Cox proportional risk model was used to test for correlations between clinical variables and cancer-specific survival (CSS), overall survival (OS), and disease-free survival (DFS). Clinical variables included age, sex, hypertension, diabetes, tumor grade, Fuhrman grade, histology, surgery, and CD4+ T lymphocyte count.

Result

The median age was 51 years, with 93 males and 13 females. At a median follow-up of 41 months, 25 patients (23.6%) had died or had tumor recurrence and metastasis. The optimal cutoff value for the CONUT score was 3, and a lower CONUT score was associated with the Fuhrman grade (P=0.024). Patients with lower CONUT scores had better CSS (HR 0.197, 95% CI 0.077-0.502, P=0.001), OS (HR 0.177, 95% CI 0.070-0.446, P<0.001) and DFS (HR 0.176, 95% CI 0.070-0.444, P<0.001). Multivariate Cox regression analysis indicated that a low CONUT score was an independent predictor of CSS, OS and DFS (CSS: HR=0.225, 95% CI 0.067-0.749, P=0.015; OS: HR=0.201, 95% CI 0.061-0.661, P=0.008; DFS: HR=0.227, 95% CI 0.078-0.664, P=0.007). In addition, a low Fuhrman grade was an independent predictor of CSS (HR 0.192, 95% CI 0.045-0.810, P=0.025), OS (HR 0.203, 95% CI 0.049-0.842, P=0.028), and DFS (HR 0.180, 95% CI 0.048-0.669, P=0.010), while other factors, such as age, sex, hypertension, diabetes, tumor grade, histology, surgery, and CD4+ T lymphocyte count, were not associated with survival outcome.

Conclusion

The CONUT score, an easily measurable immune-nutritional biomarker, may provide useful prognostic information in HIV-related RCC.

Substance use and HIV stage at entry into care among people with HIV

BACKGROUND

Information regarding the impact of substance use on the timing of entry into HIV care is lacking. Better understanding of this relationship can help guide approaches and policies to improve HIV testing and linkage.

METHODS

We examined the effect of specific substances on stage of HIV disease at entry into care in over 5000 persons with HIV (PWH) newly enrolling in care. Substance use was obtained from the AUDIT-C and ASSIST instruments. We examined the association between early entry into care and substance use (high-risk alcohol, methamphetamine, cocaine/crack, illicit opioids, marijuana) using logistic and relative risk regression models adjusting for demographic factors, mental health symptoms and diagnoses, and clinical site.

RESULTS

We found that current methamphetamine use, past and current cocaine and marijuana use was associated with earlier entry into care compared with individuals who reported no use of these substances.

CONCLUSION

Early entry into care among those with substance use suggests that HIV testing may be differentially offered to people with known HIV risk factors, and that individuals with substances use disorders may be more likely to be tested and linked to care due to increased interactions with the healthcare system.

Objective digital phenotypes of worry severity, pain severity and pain chronicity in persons living with HIV

Persons living with HIV report experiencing disproportionally severe and chronic pain and worry. However, no objective biomarkers of these subjective experiences have been developed. To address the lack of objective measures and assist in treatment planning, this study examined whether digital biomarkers of pain severity, pain chronicity and worry could be developed, using passive wearable sensors that continuously monitor movement. Results suggest that digital biomarkers can predict pain severity (r[35] = 0.690), pain chronicity (74.63% accuracy) and worry severity (r[65] = 0.642) with high precision, suggesting that objective digital biomarkers alone accurately capture internal symptom experiences in persons living with HIV.

DECLARATION OF INTEREST

N.C.J. is the owner of a free application published on the Google Play Store entitled 'Mood Triggers'. He does not receive any direct or indirect revenue from his ownership of the application (i.e. the application is free, there are no advertisements and the data is only being used for research purposes). C.O. has no conflicts to declare.

COVID-19 in Hospitalized Adults With HIV

BACKGROUND

The spread of SARS-CoV-2 and the COVID-19 pandemic have caused significant morbidity and mortality worldwide. The clinical characteristics and outcomes of hospitalized patients with SARS-CoV-2 and HIV co-infection remain uncertain.

METHODS

We conducted a matched retrospective cohort study of adults hospitalized with a COVID-19 illness in New York City between March 3, 2020, and May 15, 2020. We matched 30 people with HIV (PWH) with 90 control group patients without HIV based on age, sex, and race/ethnicity. Using electronic health record data, we compared demographic characteristics, clinical characteristics, and clinical outcomes between PWH and control patients.

RESULTS

In our study, the median age (interquartile range) was 60.5 (56.6-70.0) years, 20% were female, 30% were black, 27% were white, and 24% were of Hispanic/Latino/ethnicity. There were no significant differences between PWH and control patients in presenting symptoms, duration of symptoms before hospitalization, laboratory markers, or radiographic findings on chest x-ray. More patients without HIV required a higher level of supplemental oxygen on presentation than PWH. There were no differences in the need for invasive mechanical ventilation during hospitalization, length of stay, or in-hospital mortality.

CONCLUSIONS

The clinical manifestations and outcomes of COVID-19 among patients with SARS-CoV-2 and HIV co-infection were not significantly different than patients without HIV co-infection. However, PWH were hospitalized with less severe hypoxemia, a finding that warrants further investigation.

Causes and Timing of Mortality and Morbidity Among Late Presenters Starting Antiretroviral Therapy in the REALITY Trial

Background

In sub-Saharan Africa, 20%-25% of people starting antiretroviral therapy (ART) have severe immunosuppression; approximately 10% die within 3 months. In the Reduction of EArly mortaLITY (REALITY) randomized trial, a broad enhanced anti-infection prophylaxis bundle reduced mortality vs cotrimoxazole. We investigate the contribution and timing of different causes of mortality/morbidity.

Methods

Participants started ART with a CD4 count <100 cells/µL; enhanced prophylaxis comprised cotrimoxazole plus 12 weeks of isoniazid + fluconazole, single-dose albendazole, and 5 days of azithromycin. A blinded committee adjudicated events and causes of death as (non-mutually exclusively) tuberculosis, cryptococcosis, severe bacterial infection (SBI), other potentially azithromycin-responsive infections, other events, and unknown.

Results

Median pre-ART CD4 count was 37 cells/µL. Among 1805 participants, 225 (12.7%) died by week 48. Fatal/nonfatal events occurred early (median 4 weeks); rates then declined exponentially. One hundred fifty-four deaths had single and 71 had multiple causes, including tuberculosis in 4.5% participants, cryptococcosis in 1.1%, SBI in 1.9%, other potentially azithromycin-responsive infections in 1.3%, other events in 3.6%, and unknown in 5.0%. Enhanced prophylaxis reduced deaths from cryptococcosis and unknown causes (P < .05) but not tuberculosis, SBI, potentially azithromycin-responsive infections, or other causes (P > .3); and reduced nonfatal/fatal tuberculosis and cryptococcosis (P < .05), but not SBI, other potentially azithromycin-responsive infections, or other events (P > .2).

Conclusions

Enhanced prophylaxis reduced mortality from cryptococcosis and unknown causes and nonfatal tuberculosis and cryptococcosis. High early incidence of fatal/nonfatal events highlights the need for starting enhanced-prophylaxis with ART in advanced disease.

Clinical Trials Registration

ISRCTN43622374.

Laboratory Accuracy Improvement in the UK NEQAS Leucocyte Immunophenotyping Immune Monitoring Program: An Eleven-Year Review via Longitudinal Mixed Effects Modeling

BACKGROUND

The United Kingdom National External Quality Assessment Service (UK NEQAS) for Leucocyte Immunophenotyping Immune Monitoring Programme, provides external quality assessment (EQA) to non-U.S. laboratories affiliated with the NIH NIAID Division of AIDS (DAIDS) clinical trials networks. Selected laboratories are required to have oversight, performance monitoring, and remediation undertaken by Immunology Quality Assessment (IQA) staff under the DAIDS contract. We examined whether laboratory accuracy improves with longer EQA participation and whether IQA remediation is effective.

METHODS

Laboratory accuracy, defined by the measurement residuals from trial sample medians, was measured on four outcomes: both CD4+ absolute counts (cells/μL) and percentages; and CD8+ absolute counts (cells/μL) and percentages. Three laboratory categories were defined: IQA monitored (n = 116), United Kingdom/non-DAIDS (n = 137), and non-DAIDS/non-UK (n = 1034). For absolute count outcomes, the groups were subdivided into single platform and dual platform users.

RESULTS

Increasing EQA duration was found to be associated with increasing accuracy for all groups in all four lymphocyte subsets (P < 0.0001). In the percentage outcomes, the typical IQA group laboratory improved faster than laboratories from the other two groups (P < 0.005). No difference in the overall rate of improvement was found between groups for absolute count outcomes. However, in the DPT subgroup the IQA group ultimately showed greater homogeneity.

CONCLUSIONS

EQA participation coupled with effective laboratory monitoring and remedial action is strongly associated with improved laboratory accuracy, both incrementally and in the proportion of laboratories meeting suggested standards. Improvement in accuracy provides more reliable laboratory information facilitating more appropriate patient treatment decisions. © 2017 International Clinical Cytometry Society.

Improved prognostic stratification power of CIBMTR risk score with the addition of absolute lymphocyte and eosinophil counts at the onset of chronic GVHD

The CIBMTR chronic graft-versus-host disease (cGVHD) risk score can be refined and improved for better prognostic stratification. Three hundred and seven consecutive patients diagnosed with cGVHD by the NIH consensus criteria were retrospectively reviewed and had the CIBMTR risk score applied and analyzed. The CIBMTR risk score was successfully validated in our cohort (n = 307). The 3-year overall survival (OS) rates in each risk group (RG) were 82.5 ± 11.3% (RG1), 79.4 ± 3.0% (RG2), 71.8 ± 6.3% (RG3), and 27.3 ± 13.4% (RG4). A significantly lower OS rate and higher non-relapse mortality (NRM) were noted in RG4 compared to the other RGs. However, there were no differences in OS or NRM among RG1 to 3. To improve prognostic stratification power of the CIBMTR risk score, we incorporated the absolute lymphocyte (ALC) and eosinophil count (EC) at time of cGVHD into the CIBMTR risk score. Lower ALC (<1.0 × 10⁹/L, HR 1.94, p = 0.014) and lower EC (<0.5 × 10⁹/L, HR 3.27, p = 0.014) were confirmed as adverse risk factors for OS. Patients were stratified into four revised risk groups (rRG). The 3-year OS rates were 93.3 ± 6.4% (rRG1, score 0-3), 84.9 ± 3.4% (rRG2, score 4-6), 70.9 ± 4.4% (rRG3, score 7-9), and 32.0 ± 1.1% (rRG4, score ≥ 10) (p < 0.001). The 3-year NRM rates were 0.0% (rRG1), 6.7 ± 0.4% (rRG2), 18.4 ± 0.7% (rRG3), and 57.7 ± 5.1% (rRG4) (p < 0.001). The revised CIBMTR risk score was superior to the original CIBMTR risk score for OS (p < 0.001). The revised CIBMTR risk score including ALC and EC at the onset of cGVHD improved the prognostic stratification power of the CIBMTR risk score for long-term outcomes.

Performance Evaluation of the MyT4 Technology for Determining ART Eligibility

Background

In resource-limited countries, CD4 T-cell (CD4) testing continues to be used for determining antiretroviral therapy (ART) initiation eligibility and opportunistic infection monitoring. To support expanded access to CD4 testing, simple and robust technologies are necessary. We conducted this study to evaluate the performance of a new Point-of-Care (POC) CD4 technology, the MyT4, compared to conventional laboratory CD4 testing.

Methods

EDTA venous blood from 200 HIV-positive patients was tested in the laboratory using the MyT4 and BD FACSCalibur^™.

Results

The MyT4 had an r² of 0.82 and a mean bias of 12.3 cells/μl. The MyT4 had total misclassifications of 14.7% and 8.8% when analyzed using ART eligibility thresholds of 350 and 500 cells/μl, respectively.

Conclusions

We conclude that the MyT4 performed well in classifying patients using the current ART initiation eligibility thresholds in Mozambique when compared to the conventional CD4 technology.

POC CD4 Testing Improves Linkage to HIV Care and Timeliness of ART Initiation in a Public Health Approach: A Systematic Review and Meta-Analysis

BACKGROUND

CD4 cell count is an important test in HIV programs for baseline risk assessment, monitoring of ART where viral load is not available, and, in many settings, antiretroviral therapy (ART) initiation decisions. However, access to CD4 testing is limited, in part due to the centralized conventional laboratory network. Point of care (POC) CD4 testing has the potential to address some of the challenges of centralized CD4 testing and delays in delivery of timely testing and ART initiation. We conducted a systematic review and meta-analysis to identify the extent to which POC improves linkages to HIV care and timeliness of ART initiation.

METHODS

We searched two databases and four conference sites between January 2005 and April 2015 for studies reporting test turnaround times, proportion of results returned, and retention associated with the use of point-of-care CD4. Random effects models were used to estimate pooled risk ratios, pooled proportions, and 95% confidence intervals.

RESULTS

We identified 30 eligible studies, most of which were completed in Africa. Test turnaround times were reduced with the use of POC CD4. The time from HIV diagnosis to CD4 test was reduced from 10.5 days with conventional laboratory-based testing to 0.1 days with POC CD4 testing. Retention along several steps of the treatment initiation cascade was significantly higher with POC CD4 testing, notably from HIV testing to CD4 testing, receipt of results, and pre-CD4 test retention (all p<0.001). Furthermore, retention between CD4 testing and ART initiation increased with POC CD4 testing compared to conventional laboratory-based testing (p = 0.01). We also carried out a non-systematic review of the literature observing that POC CD4 increased the projected life expectancy, was cost-effective, and acceptable.

CONCLUSIONS

POC CD4 technologies reduce the time and increase patient retention along the testing and treatment cascade compared to conventional laboratory-based testing. POC CD4 is, therefore, a useful tool to perform CD4 testing and expedite result delivery.

Simple markers for the detection of severe immunosuppression in children with HIV infection in highly resource-scarce settings: experience from the Democratic Republic of Congo

OBJECTIVES

The decision to initiate the antiretroviral therapy in HIV-infected children living in poor countries is compromised by lack of resources. The objective of this study is to identify simple clinical and biological markers other than CD4+ count and viral load measurement that could help the decision to introduce antiretroviral treatment and to monitor patients.

METHODS

A cross sectional study was conducted between January and March 2005 in Kinshasa, Democratic Republic of Congo.

RESULTS

Eighty-four children infected with HIV were recruited. In this cohort, the lymphocytes (P = 0.001) and CD4 (P = 0.0001) were significantly lower in children with immunological stage 3 and viral load (P = 0.027) was significantly higher in children at the same immunological stage. Reticulocytes (r = +0.440), white blood cells count (r = +0.560), total lymphocytes (r = +0.675) and albumin (r = +0.381) showed positive significant correlations with CD4. Haemoglobin (r = - 0.372), Haematocrit (r = - 0.248), red blood cells (r = - 0.278) and CD4 (r = - 0.285) showed negative significant correlations with viral load. Neutropaenia (P = 0.02), enlarged nodes (P = 0.005) and oral candidiasis (P = 0.04) were associated with viral load >10,000 copies/ml. Oral candidiasis (P = 0.02) was associated with CD4 level < 15%.

CONCLUSION

Oral candidiasis, enlarged nodes, total lymphocytes count, neutropaenia and albumin predict severe immunodepression. These clinical and biological markers may guide the clinician in making the decision to initiate antiretroviral therapy in highly resource-scarce settings.

Current laboratory practices in flow cytometry for the enumeration of CD 4(+) T-lymphocyte subsets

BACKGROUND

CD4(+) T-lymphocyte subset enumeration is routinely used for monitoring HIV disease progression, with approximately 300,000 tests performed annually in the UK alone. Technical variables can impact upon any laboratory test and therefore the final result obtained. Here, we report the findings of a survey questionnaire issued to 1,587 clinical flow cytometry laboratories to: (a) determine if the UK NEQAS for Leucocyte Immunophenotyping (UK NEQAS LI) lymphocyte subset external quality assessment (EQA) programme was suitable for current laboratory needs and practices; and (b) assess the impact of these responses on clinical practice where CD4(+) T-lymphocyte subsets analysis is undertaken. The survey covered areas not traditionally examined by EQA such as: staffing numbers, flow cytometer age and service intervals, plus six test specific sections covering: leukaemia immunophenotyping, CD4(+) T-lymphocyte subsets analysis (reported here), CD34(+) stem cell testing, low level leucocyte enumeration, minimal residual disease testing and PNH testing.

RESULTS

The responses revealed major methodological variations between centres undertaking CD4(+) T-lymphocyte subset analysis. Significant differences existed in basic laboratory practices such as: normal range derivation; pipetting techniques; instrument maintenance and units of reporting, all of which results in non-adherence to international guidelines.

DISCUSSION

Despite the availability of international guidelines our survey highlighted a lack of concordance amongst laboratory techniques. Such variation could adversely impact on patient care and clinical trial data. Therefore, it is recommended centres undertaking flow cytometric CD4(+) T-lymphocyte subsets analysis urgently review their methodologies and normal ranges to ensure they are fit for purpose and meet current international guidelines.

Evaluation of Non-Viral Surrogate Markers as Predictive Indicators for Monitoring Progression of Human Immunodeficiency Virus Infection: An Eight-Year Analysis in a Regional Center

Suitable methods for clinical monitoring of HIV-infected patients are crucial in resource-poor settings. Demographic data, clinical staging, and laboratory findings for 112 asymptomatic subjects positive for HIV were assessed at the first admission and the last visit from 2002 to 2010. Cox regression analysis showed hemoglobin (Hb) (HR = 0.643, P = 0.021) to be a predictive indicator for disease progression, while CD4, CD8, and platelet counts showed low HRs, despite having significant probability values. Hb and total lymphocyte count (TLC) rapidly declined from stage II to III (10.9 and 29.6%, respectively). Reduced CD4 and platelet counts and Hb during stage I were associated with disease progression, and TLC was correlated with CD4 counts at the last follow-up (P < 0.001). However, WHO TLC cutoff of 1,200 cell/mm(3) had 26.1% sensitivity and 98.6% specificity. ROC curve analysis suggested that a TLC cutoff of 1,800 cell/mm(3) was more reliable in this region. Statistical analysis and data mining findings showed that Hb and TLC, and their rapid decline from stage II to III, in addition to reduced platelet count, could be valuable markers for a surrogate algorithm for monitoring of HIV-infected subjects and starting anti-viral therapy in the absence of sophisticated detection assays.

Technical performance evaluation of the MyT4 point of care technology for CD4+ T cell enumeration

Objective

Though absolute CD4+ T cell enumeration is the primary gateway to antiretroviral therapy initiation for HIV-positive patients in all developing countries, patient access to this critical diagnostic test is relatively poor. We technically evaluated the performance of a newly developed point-of-care CD4+ T cell technology, the MyT4, compared with conventional CD4+ T cell testing technologies.

Design

Over 250 HIV-positive patients were consecutively enrolled and their blood tested on the MyT4, BD FACSCalibur, and BD FACSCount.

Results

Compared with the BD FACSCount, the MyT4 had an r² of 0.7269 and a mean bias of −23.37 cells/µl. Compared with the BD FACSCalibur, the MyT4 had an r² of 0.5825 and a mean bias of −46.58 cells/µl. Kenya currently uses a CD4+ T cell test threshold of 350 cells/µl to determine patient eligibility for antiretroviral therapy. At this threshold, the MyT4 had a sensitivity of 95.3% (95% CI: 88.4–98.7%) and a specificity of 87.9% (95% CI: 82.3–92.3%) compared with the BD FACSCount and sensitivity and specificity of 88.2% (95% CI: 79.4–94.2%) and 84.2% (95% CI: 78.2–89.2%), respectively, compared with the BD FACSCalibur. Finally, the MyT4 had a coefficient of variation of 12.80% compared with 14.03% for the BD FACSCalibur.

Conclusions

We conclude that the MyT4 performed well at the current 350 cells/µl ART initiation eligibility threshold when used by lower cadres of health care facility staff in rural clinics compared to conventional CD4+ T cell technologies.

High Rate of Non-detectable HIV-1 RNA Among Antiretroviral Drug Naive HIV Positive Individuals in Nigeria

Plasma HIV-1 RNA concentration, or viral load, is an indication of the magnitude of virus replication and largely correlates with disease progression in an infected person. It is a very useful guide for initiation of therapy and monitoring of response to antiretroviral drugs. Although the majority of patients who are not on antiretroviral therapy (ART) have a high viral load, a small proportion of ART naive patients are known to maintain low levels or even undetectable viral load levels. In this study, we determined the rate of undetectable HIV-1 RNA among ART naive HIV positive patients who presented for treatment at the University College Hospital (UCH), Ibadan, Nigeria from 2005 to 2011. Baseline viral load and CD4 lymphocyte cell counts of 14,662 HIV positive drug naive individuals were determined using the Roche Amplicor version 1.5 and Partec easy count kit, respectively. The detection limits of the viral load assay are 400 copies/mL and 750,000 copies/mL for lower and upper levels, respectively. A total of 1,399 of the 14,662 (9.5%) HIV-1 positive drug naive individuals had undetectable viral load during the study period. In addition, the rate of non-detectable viral load increased over the years. The mean CD4 counts among HIV-1 infected individuals with detectable viral load (266 cells/μL; range = 1 to 2,699 cells/μL) was lower than in patients with undetectable viral load (557 cells/μL; range = 1 to 3,102 cells/μL). About 10% of HIV-1 infected persons in our study population had undetectable viral load using the Roche Amplicor version 1.5.

Prevalence of Anemia and Immunological Markers in HIV-Infected Patients on Highly Active Antiretroviral Therapy in Northeastern Nigeria

BACKGROUND

There are conflicting reports on the impact of highly active antiretroviral therapy (HAART) in resolving hematological complications. Whereas some studies have reported improvements in hemoglobin and other hematological parameters resulting in reduction in morbidity and mortality of HIV patients, others have reported no improvement in hematocrit values of HAART-treated HIV patients compared with HAART-naïve patients.

OBJECTIVE

This current study was designed to assess the impact of HAART in resolving immunological and hematological complications in HIV patients by comparatively analyzing the results (immunological and hematological) of HAART-naive patients and those on HAART in our environment.

METHODS

A total of 500 patients participated, consisting of 315 HAART-naive (119 males and 196 females) patients and 185 HAART-experienced (67 males and 118 females) patients. Hemoglobin (Hb), CD4+ T-cell count, total white blood count (WBC), lymphocyte percentage, plateletes, and plasma HIV RNA were determined.

RESULTS

HAART-experienced patients were older than their HAART-naive counterparts. In HAART-naive patients, the incidence of anemia (packed cell volume [PCV] <30%) was 57.5%, leukopenia (WBC < 2.5), 6.1%, and thrombocytopenia < 150, 9.6%; it was, significantly higher compared with their counterparts on HAART (24.3%, 1.7%, and 1.2%, respectively). The use of HAART was not associated with severe anemia. Of HAART-naive patients, 57.5% had a CD4 count < 200 cells/μL in comparison with 20.4% of HAART-experienced patients (P < 0.001). The mean viral load log10 was significantly higher in HAART-naive than in HAART-experienced patients (P < 0.001). Total lymphocyte count < 1.0 was a significant predictor of <CD4 counts < 200 cells/μL in HAART-naïve patients, but this relationship was not observed in HAART-experienced patients.

CONCLUSION

HAART has the capability of reducing the incidence of anemia, other deranged hematological and immunological parameters associated with disease progression, and death in HIV-infected patients. Total lymphocyte count fails to predict CD4 count < 200 cells/μL in our cohort; thus, its use in the management and monitoring of HIV-infected patients in our settings is not reliable.

HIV Drug-Resistant Patient Information Management, Analysis, and Interpretation

Introduction

The science of information systems, management, and interpretation plays an important part in the continuity of care of patients. This is becoming more evident in the treatment of human immunodeficiency virus (HIV) and acquired immune deficiency syndrome (AIDS), the leading cause of death in sub-Saharan Africa. The high replication rates, selective pressure, and initial infection by resistant strains of HIV infer that drug resistance will inevitably become an important health care concern. This paper describes proposed research with the aim of developing a physician-administered, artificial intelligence-based decision support system tool to facilitate the management of patients on antiretroviral therapy.

Methods

This tool will consist of (1) an artificial intelligence computer program that will determine HIV drug resistance information from genomic analysis; (2) a machine-learning algorithm that can predict future CD₄ count information given a genomic sequence; and (3) the integration of these tools into an electronic medical record for storage and management.

Conclusion

The aim of the project is to create an electronic tool that assists clinicians in managing and interpreting patient information in order to determine the optimal therapy for drug-resistant HIV patients.

Total lymphocyte count as a surrogate marker for CD4 count in resource-limited settings

BACKGROUND

CD4 testing is the recognized gold standard used to stage HIV/AIDS, guide treatment decisions for HIV-infected persons and evaluate effectiveness of therapy. The need for a less expensive surrogate marker that can be used in resource-limited setting is however necessary. The study sought to assess the suitability of Total lymphocyte count (TLC) as a surrogate marker for CD4 count in resource-limited localities in Ghana.

METHODS

This observational study was conducted at the Central Regional Hospital, which has one of the established antiretroviral therapy centres in Ghana. A total of one hundred and eighty-four (184) confirmed HIV I seropositive subjects were included in the study. Blood samples were taken from all the subjects for estimation of CD4 and total lymphocyte counts. The study subjects were further categorised into three (3) groups according to the Centers for Disease Control and Prevention (CDC) classification criteria as follows: CD4 counts (1) ≥ 500 cells/mm3 (2) 200-499 cells/mm3 and (3) <200 cells/mm3. Positive predictive value (PPV), negative predictive value (NPV), sensitivity and specificity of various TLC cut-offs were computed for three groups. Correlation and Receiver Operator Characteristic analysis was performed for the various CD4 counts and their corresponding Total Lymphocyte count obtained.

RESULTS

The sensitivity, specificity, positive and negative predictive values of TLC 1200 cells/ mm3 to predict CD4 count were <200 cells/mm3 72.2%, 100%, 100% and 95.7% respectively. A TLC of 1500 cells/ mm3 was found to have maximal sensitivity (96.67%), specificity (100%), PPV (100%) and NPV (75.0%) for predicting a CD4 cell count of 200-499 cell/mm3. A TLC of 1900 cells/mm3 was also found to have a maximal sensitivity (98.45%), specificity (100%), PPV (100%) and NPV (100%) for predicting CD4 count ≥500 cells/mm3. A positive correlation was noted between 184 paired CD4 and TLC counts (r = 0.5728).

CONCLUSION

Total Lymphocyte count can therefore adequately serve as a surrogate marker for CD4 count in HIV patients who are naïve for antiretroviral therapy in resource-limited areas.

Absolute lymphocyte count as a predictor of Pneumocystis pneumonia in patients previously unknown to have HIV

This is a retrospective review of patients admitted to an inner city community hospital with community-acquired pneumonia who were ultimately diagnosed with AIDS and Pneumocystis. Absolute lymphocyte count in our hospital is available immediately. In contrast, it can take 48 hours or longer to obtain more specific CD-4 counts and AIDS enzyme-linked immunosorbent assay (ELISA) serology. The association of lymphopenia with ultimate diagnosis of AIDS and Pneumocystis supports immediate empiric treatment for pneumocystis carinii pneumonia (PCP) in our highly HIV prevalent hospital.

Comparing absolute lymphocyte count to total lymphocyte count, as a CD4 T cell surrogate, to initiate antiretroviral therapy

Background:

The high cost of CD4 count estimation in resource-limited settings is a major obstacle in initiating patients on highly active antiretroviral therapy (HAART). Thus, there is a need to evaluate other less expensive surrogate markers like total lymphocyte count (TLC) and absolute lymphocyte count (ALC).

Objectives

To evaluate the correlation of TLC and ALC to CD4 count. To determine a range of TLC and ALC cut-offs for initiating HAART in HIV-infected patients in resource-limited settings.

Materials and Methods:

In a prospective observational cohort study of 108 ART-naive HIV-positive patients, Spearman correlation between ALC and CD4 cell count, and TLC and CD4 cell count were assessed. Sensitivity, specificity, positive and negative predictive values of various ALC and TLC cut-offs were computed for CD4 count <200 cells/cu.mm.

Results:

Good correlation was noted between ALC and CD4 (r=0.5604) and TLC and CD4 (r=0.3497). ALC of 1400 cells/cu.mm had a sensitivity of 71.08% and specificity of 78.26% for predicting CD4 cell counts less than 200 cells/cu.mm. Similarly, TLC of 1200 cells/cu.mm had a sensitivity of 63.41% and specificity of 69.57%.

Conclusion:

Either ALC or TLC may be helpful in deciding when to initiate antiretroviral therapy in resource-poor settings, though ALC is better than TLC as a surrogate for CD4 counts.

Total lymphocyte count is a good marker for HIV-related mortality and can be used as a tool for starting HIV treatment in a resource-limited setting

OBJECTIVES

Total lymphocyte counts (TLC) may be used as an alternative for CD4 cell counts to monitor HIV infection in resource-limited settings, where CD4 cell counts are too expensive or not available.

METHODS

We used prospectively collected patient data from an urban HIV clinic in Indonesia. Predictors of mortality were identified via Cox regression, and the relation between TLC and CD4 cell counts was calculated by linear regression. Receiver operating characteristics (ROC) curves were used to choose the cut-off values of TLC corresponding with CD4 cell counts <200 and ≤350 cells/μl. Based on these analyses, we designed TLC-based treatment algorithms.

RESULTS

Of 889 antiretroviral treatment (ART)-naïve subjects included, 66% had CD4 cell counts <200 and 81% had 350 ≤ cells/μl at baseline. TLC and CD4 cell count were equally strong predictors of mortality in our population, where ART was started based on CD4 cell count criteria. The correlation coefficient (R) between TLC and √CD4 was 0.70. Optimal cut-off values for TLC to identify patients with CD4 cell counts <200 and ≤350 cells/μl were 1500 and 1700 cells/μl, respectively. Treatment algorithms based on a combination of TLC, gender, oral thrush, anaemia and body mass index performed better in terms of predictive value than WHO staging or TLC alone. In our cohort, such an algorithm would on average have saved $14.05 per patient.

CONCLUSION

Total lymphocyte counts is a good marker for HIV-associated mortality. Simple algorithms including TLC can prioritize patients for HIV treatment in a resource-limited setting, until affordable CD4 cell counts will be universally available.

Equity and efficiency in HIV-treatment in South Africa: the contribution of mathematical programming to priority setting

The HIV-epidemic is one of the greatest public health crises to face South Africa. A health care response to the treatment needs of HIV-positive people is a prime example of the desirability of an economic, rational approach to resource allocation in the face of scarcity. Despite this, almost no input based on economic analysis is currently used in national strategic planning. While cost-utility analysis is theoretically able to establish technical efficiency, in practice this is accomplished by comparing an intervention's ICER to a threshold level representing society's maximum willingness to pay to avoid death and improve health-related quality of life. Such an approach has been criticised for a number of reasons, including that it is inconsistent with a fixed budget for health care and that equity is not taken into account. It is also impractical if no national policy on the threshold exists. As an alternative, this paper proposes a mathematical programming approach that is capable of highlighting technical efficiency, equity, the equity/efficiency trade-off and the affordability of alternative HIV-treatment interventions. Government could use this information to plan an HIV-treatment strategy that best meets equity and efficiency objectives within budget constraints.

Early severe morbidity and resource utilization in South African adults on antiretroviral therapy

Background

High rates of mortality and morbidity have been described in sub-Saharan African patients within the first few months of starting highly active antiretroviral therapy (HAART). There is limited data on the causes of early morbidity on HAART and the associated resource utilization.

Methods

A cross-sectional study was conducted of medical admissions at a secondary-level hospital in Cape Town, South Africa. Patients on HAART were identified from a register and HIV-infected patients not on HAART were matched by gender, month of admission, and age group to correspond with the first admission of each case. Primary reasons for admission were determined by chart review. Direct health care costs were determined from the provider's perspective.

Results

There were 53 in the HAART group with 70 admissions and 53 in the no-HAART group with 60 admissions. The median duration of HAART was 1 month (interquartile range 1-3 months). Median baseline CD4 count in the HAART group was 57 × 10⁶ cells/L (IQR 15-115). The primary reasons for admission in the HAART group were more likely to be due to adverse drug reactions and less likely to be due to AIDS events than the no-HAART group (34% versus 7%; p < 0.001 and 39% versus 63%; p = 0.005 respectively). Immune reconstitution inflammatory syndrome was the primary reason for admission in 10% of the HAART group. Lengths of hospital stay per admission and inpatient survival were not significantly different between the two groups. Five of the 15 deaths in the HAART group were due to IRIS or adverse drug reactions. Median costs per admission of diagnostic and therapeutic services (laboratory investigations, radiology, intravenous fluids and blood, and non-ART medications) were higher in the HAART group compared with the no-HAART group (US$190 versus US$111; p = 0.001), but the more expensive non-curative costs (overhead, capital, and clinical staff) were not significantly different (US$1199 versus US$1128; p = 0.525).

Conclusions

Causes of early morbidity are different and more complex in HIV-infected patients on HAART. This results in greater resource utilization of diagnostic and therapeutic services.

Total lymphocyte count: not a surrogate marker for risk of death in HIV-infected Ugandan children

OBJECTIVES

To determine the utility of total lymphocyte count (TLC) in predicting the 12-month mortality in HIV-infected Ugandan children and to correlate TLC and CD4 cell %.

DESIGN

This is a retrospective data analysis of clinical and laboratory data collected prospectively on 128 HIV-infected children in the HIV Network for Prevention Trials 012 trial.

METHODS

TLC and CD4 cell % measurements were obtained at birth, 14 weeks, and 12, 24, 36, 48, and 60 months of age and assessed with respect to risk of death within 12 months.

RESULTS

Median TLC per microliter (CD4 cell %) was 4150 (41%) at birth, 4900 (24%) at 12 months, 4300 (19%) at 24 months, 4150 (19%) at 36 months, 4100 (18%) at 48 months, and 3800 (20%) at 60 months. The highest risk of mortality within 12 months was 34% - 37% at birth and declined to 13%-15% at 24 months regardless of TLC measurement. The correlation between CD4 cell % and TLC was extremely low overall (r = 0.01).

CONCLUSIONS

The TLC did not predict a risk of progression to death within 12 months in HIV-infected Ugandan children. Therefore, TLC alone may not be a useful surrogate marker for determining those children at highest risk of death, who require antiretroviral therapy most urgently.

Assessing efficiency and costs of scaling up HIV treatment

INTRODUCTION

Whereas cost-effectiveness/utility analyses theoretically assess efficiency in HIV treatment, in practice they are of limited use to policy makers who are also concerned with the total costs of scaling up. This paper proposes an approach to simultaneously assessing both factors when setting priorities for HIV treatment.

METHODS

Three interventions were assessed: a no antiretroviral therapy (ART) status quo, ART including first-line only, and ART including first and second-line regimens. Data were from a cohort receiving healthcare in a poor South African setting. Markov modelling was used to calculate patient-level lifetime costs and quality-adjusted life-years (QALY) as well as population-level total costs and QALY in each intervention. Linear programming was used to assess efficiency at the population level.

RESULTS

First-line ART costs US$795 per QALY gained compared to no ART, while first and second-line costs US$1625 compared to first-line alone. The efficiency of either ART strategy depends on the HIV treatment budget. If this is less than US$10 billion during the planning period, first-line ART is most efficient. A combination of first-line with first and second-line treatment is most efficient if the budget is US$10-12 billion. Using both first and second-line treatment for everyone becomes efficient as the main strategy only at budgets greater than US$13 billion.

CONCLUSION

An approach has been developed to HIV treatment priority setting that simultaneously considers efficiency and the costs of scaling up. This can help to establish explicit and evidence-based priorities and budgets to meet scaling up challenges.

Correlation analysis on total lymphocyte count and CD4 count of HIV-infected patients

OBJECTIVE

To determine the relationship between CD4 count and other blood indices and to explore the prediction of total lymphocyte count (TLC) for CD4 count in HIV-infected patients.

METHODS

Cross-sectional study was performed for the prediction of TLC and other indices for CD4 count, and historical cohort study was performed for the TLC changes as a surrogate for CD4 changes of patients on antiretroviral therapy (ART) to further understanding the utility of TLC changes for AIDS patients' management.

RESULTS

In our cross-sectional study, both TLC and white blood corpuscle count positively correlated to CD4 count, but differed in these patients. For patients on ART, the prediction of TLC for CD4 count is better than that of patient without ART. Further investigation of historical cohort study indicated that, among AIDS patients on highly active antiretroviral therapy, their TLC and haemoglobin changes also positively correlated to CD4 change, with a total correlation coefficient of 0.31 (p < 0.01) and 0.19 (p < 0.01) respectively. The prediction of TLC change for CD4 change differed each time point when patients underwent ART.

CONCLUSIONS

Total lymphocyte count and its change can be used as alternative in conjunction with other indices to CD4 count and its change in the management of HIV-infected individuals in China.

Clinical applications and availability of CD4+ T cell count testing in sub-Saharan Africa

The absolute CD4+ T cell count in adults and CD4+ T cell percentage of lymphocytes (CD4%) in pediatrics compliment clinical history and physical examination to inform decisions about initiating antiretroviral therapy (ART). In addition, these immunologic markers predict host susceptibility to specific opportunistic infections, selected drug toxicities, and mortality. These benefits argue strongly for the availability of CD4+ T cell testing capacity in all settings where HIV infection is treated. Several currently available flow cytometry-based devices, and novel CD4+ T cell enumeration techniques such as the panleucogating CD4 are especially suitable for resource-constrained settings. At this time, unfortunately, the landscape of HIV care in sub-Saharan Africa is a mosaic characterized by large areas where CD4+ T cell testing capacity is limited or unavailable, and small, but growing, pockets where the capacity exists. Routine HIV quantification is currently unaffordable and unsustainable in the great majority of the region; therefore, a reliance on CD4+ T cell testing is inevitable for now. To this end, correcting the disparities in CD4+ T cell testing capacity and defining the minimum laboratory requirements for the safe use of antiretroviral drugs through well-designed clinical studies are some of the most urgent priorities of the ongoing global scale-up of ART.

Determining eligibility for antiretroviral therapy in resource-limited settings using total lymphocyte counts, hemoglobin and body mass index

BACKGROUND

CD4+ T lymphocyte (CD4) cell count testing is the standard method for determining eligibility for antiretroviral therapy (ART), but is not widely available in sub-Saharan Africa. Total lymphocyte counts (TLCs) have not proven sufficiently accurate in identifying subjects with low CD4 counts. We developed clinical algorithms using TLCs, hemoglobin (Hb), and body mass index (BMI) to identify patients who require ART.

METHODS

We conducted a cross-sectional study of HIV-infected adults in Uganda, who presented for assessment for ART-eligibility with WHO clinical stages I, II or III. Two by two tables were constructed to examine TLC thresholds, which maximized sensitivity for CD4 cell counts 350 cells microL. Hb and BMI values were then examined to try to improve model performance.

RESULTS

1787 subjects were available for analysis. Median CD4 cell counts and TLCs, were 239 cells/microL and 1830 cells/microL, respectively. Offering ART to all subjects with a TLCs 3000 cells/microL, and used Hb and/or BMI values to determine eligibility for those with TLC values between 2000 and 3000 cells/microL, marginally improved accuracy.

CONCLUSION

TLCs appear useful in predicting who would be eligible for ART based on CD4 cell count criteria. Hb and BMI values may be useful in prioritizing patients for ART, but did not improve model accuracy.

The cost-effectiveness of antiretroviral treatment in Khayelitsha, South Africa--a primary data analysis

Background

Given the size of the HIV epidemic in South Africa and other developing countries, scaling up antiretroviral treatment (ART) represents one of the key public health challenges of the next decade. Appropriate priority setting and budgeting can be assisted by economic data on the costs and cost-effectiveness of ART. The objectives of this research were therefore to estimate HIV healthcare utilisation, the unit costs of HIV services and the cost per life year (LY) and quality adjusted life year (QALY) gained of HIV treatment interventions from a provider's perspective.

Methods

Data on service utilisation, outcomes and costs were collected in the Western Cape Province of South Africa. Utilisation of a full range of HIV healthcare services was estimated from 1,729 patients in the Khayelitsha cohort (1,146 No-ART patient-years, 2,229 ART patient-years) using a before and after study design. Full economic costs of HIV-related services were calculated and were complemented by appropriate secondary data. ART effects (deaths, therapy discontinuation and switching to second-line) were from the same 1,729 patients followed for a maximum of 4 years on ART. No-ART outcomes were estimated from a local natural history cohort. Health-related quality of life was assessed on a sub-sample of 95 patients. Markov modelling was used to calculate lifetime costs, LYs and QALYs and uncertainty was assessed through probabilistic sensitivity analysis on all utilisation and outcome variables. An alternative scenario was constructed to enhance generalizability.

Results

Discounted lifetime costs for No-ART and ART were US$2,743 and US$9,435 over 2 and 8 QALYs respectively. The incremental cost-effectiveness ratio through the use of ART versus No-ART was US$1,102 (95% CI 1,043-1,210) per QALY and US$984 (95% CI 913-1,078) per life year gained. In an alternative scenario where adjustments were made across cost, outcome and utilisation parameters, costs and outcomes were lower, but the ICER was similar.

Conclusion

Decisions to scale-up ART across sub-Saharan Africa have been made in the absence of incremental lifetime cost and cost-effectiveness data which seriously limits attempts to secure funds at the global level for HIV treatment or to set priorities at the country level. This article presents baseline cost-effectiveness data from one of the longest running public healthcare antiretroviral treatment programmes in Africa that could assist in enhancing efficient resource allocation and equitable access to HIV treatment.

Can routine clinical markers be used longitudinally to monitor antiretroviral therapy success in resource-limited settings?

Although routine clinical markers are used routinely to determine the stage of human immunodeficiency virus (HIV) disease, their use in monitoring response to antiretroviral therapy is poorly defined. Selected clinical markers were evaluated for their ability to predict first-line antiretroviral therapy success. No clinically meaningful variables were identified that predicted virologic or immunological success, implying that the CD4+ cell count and HIV type 1 RNA level data are required for optimal management of antiretroviral therapy.

Validation of Primary CD4 Gating as an Affordable Strategy for Absolute CD4 Counting in Cambodia

OBJECTIVE

To validate primary CD4 gating in lysed whole blood for absolute CD4 counts in fresh and aged blood using an affordable compact volumetric commercial flow cytometer.

DESIGN

Comparison of CD4 counts between the FACSCount and the 2-parameter CyFlow SL Green.

METHODS

One hundred twenty fresh blood samples from patients likely to be infected with HIV were simultaneously run on a FACSCount at the Pasteur Institute of Cambodia and on a CyFlow SL Green at the Sihanouk Hospital Center of Hope (SHCH), Phnom Penh, Cambodia. Intra- and interrun precision was assessed using 2 blood samples. Stability of CD4 counting in blood stored up to 96 hours at room temperature was assessed using 27 blood samples.

RESULTS

CD4 counts on the CyFlow SL Green and on the FACSCount correlated well apart from a relative bias (R = 0.993, bias of -9.5%, 95% confidence interval [CI]: -11.8% to -7.1%, limits of agreement: -32.5% to 13.6%). Intra- and interrun variability ranged from 3% to 5% and from 5% to 6%, respectively. CD4 counts on aged blood using the CyFlow SL Green showed an interassay variability of <10%.

CONCLUSIONS

Primary CD4 gating in lysed whole blood using the CyFlow SL Green is an affordable and precise method for CD4 counting. Because the fluorescence (FL) and light scatter signals have to be analyzed manually, however, intensive training of the technician and/or operator is imperative.

The Added Value of a CD4 Count to Identify Patients Eligible for Highly Active Antiretroviral Therapy Among HIV-Positive Adults in Cambodia

In a retrospective study of 648 persons with HIV infection in Cambodia, we determined the sensitivity, specificity, and accuracy of the 2003 World Health Organization (WHO) criteria to start antiretroviral treatment based on clinical criteria alone or based on a combination of clinical symptoms and the total lymphocyte count. As a reference test, we used the 2003 WHO criteria, including the CD4 count. The 2003 WHO clinical criteria had a sensitivity of 96%, a specificity of 57%, and an accuracy of 89% to identify patients who need highly active antiretroviral therapy (HAART). In our clinic, with a predominance of patients with advanced disease, the 2003 WHO clinical criteria alone was a good predictor of those needing HAART. A total lymphocyte count as an extra criterion did not improve the accuracy. Nine percent of patients were wrongly identified to be in need of HAART. Among them, almost 50% had a CD4 count of more than 500 cells/muL, and 73% had weight loss of more than 10% as a stage-defining condition. Our data suggest that, in settings with limited access to CD4 count testing, it might be useful to target this test to patients in WHO stage 3 whose staging is based on weight loss alone, to avoid unnecessary treatment.

A new model to monitor the virological efficacy of antiretroviral treatment in resource-poor countries

Monitoring the efficacy of antiretroviral treatment in developing countries is difficult because these countries have few laboratory facilities to test viral load and drug resistance. Those that exist are faced with a shortage of trained staff, unreliable electricity supply, and costly reagents. Not only that, but most HIV patients in resource-poor countries do not have access to such testing. We propose a new model for monitoring antiretroviral treatment in resource-limited settings that uses patients' clinical and treatment history, adherence to treatment, and laboratory indices such as haemoglobin level and total lymphocyte count to identify virological treatment failure, and offers patients future treatment options. We believe that this model can make an accurate diagnosis of treatment failure in most patients. However, operational research is needed to assess whether this strategy works in practice.

Use of total lymphocyte count for informing when to start antiretroviral therapy in HIV-infected children: a meta-analysis of longitudinal data

BACKGROUND

Total lymphocyte count has been proposed as an alternative to the percentage of CD4+ T-cells to indicate when antiretroviral therapy should be started in children with HIV in resource-poor settings. We aimed to assess thresholds of total lymphocyte count at which antiretroviral therapy should be considered, and compared monitoring of total lymphocyte count with monitoring of CD4-cell percentage.

METHODS

Longitudinal data on 3917 children with HIV infection were pooled from observational and randomised studies in Europe and the USA. The 12-month risks of death and AIDS by most recent total lymphocyte count and age were estimated by parametric survival models, based on measurements before antiretroviral therapy or during zidovudine monotherapy. Risks were derived and compared at thresholds of total lymphocyte count and CD4-cell percentage for starting antiretroviral therapy recommended in WHO 2003 guidelines.

FINDINGS

Total lymphocyte count was a powerful predictor of the risk of disease progression despite a weak correlation with CD4-cell percentage (r=0.08-0.19 dependent on age). For children older than 2 years, the 12-month risk of death and AIDS increased sharply at values less than 1500-2000 cells per muL, with little trend at higher values. Younger children had higher risks and total lymphocyte count was less prognostic. Mortality risk was substantially higher at thresholds of total lymphocyte count recommended by WHO than at corresponding thresholds of CD4-cell percentage. When the markers were compared at the threshold values at which mortality risks were about equal, total lymphocyte count was as effective as CD4-cell percentage for identifying children before death, but resulted in an earlier start of antiretroviral therapy.

INTERPRETATION

In this population, total lymphocyte count was a strong predictor of short-term disease progression, being only marginally less predictive than CD4-cell percentage. Confirmatory studies in resource-poor settings are needed to identify the most cost-effective markers to guide initiation of antiretroviral therapy.

Total lymphocyte count, hemoglobin, and delayed-type hypersensitivity as predictors of death and AIDS illness in HIV-1-infected women receiving highly active antiretroviral therapy

BACKGROUND

Total lymphocyte count (TLC) and hemoglobin level have been suggested as useful and inexpensive parameters to indicate need for HAART in settings in which CD4 cell counts are unavailable. If delayed-type hypersensitivity (DTH) response predicts clinical response in persons using highly active antiretroviral therapy (HAART), it may also prove useful in resource-poor settings.

OBJECTIVE

To examine whether TLC, hemoglobin, and DTH response observed prior to initiation of HAART predict post-HAART clinical response.

DESIGN

Prospective cohort study.

PARTICIPANTS

873 women in the Women's Interagency HIV Study.

MEASUREMENTS

TLC, hemoglobin, CD4 cell counts, and DTH testing using mumps, candida, and tetanus toxoid antigens, performed within 1 year prior to HAART initiation; death; self-report of initiation of HAART use and AIDS-defining illness (ADI).

RESULTS

Three different multivariate analyses were performed: 2 models that excluded CD4 cell count and assessed TLC at either < 850 or < 1250 cells/microL, and 1 model that excluded TLC and included CD4 < 200 cells/microL. TLC < 850, TLC < 1250, CD4 < 200 cells/microL, anergy to DTH testing, hemoglobin < 10.6 g/dL, and a pre-HAART report of ADI were each consistently independently associated both with death and with incident ADI. Log likelihood chi2 values suggested similar power among the 3 models in predicting both death and incident ADI.

CONCLUSIONS

Pre-HAART TLC, hemoglobin level, anergy to DTH testing, and clinical disease each independently predicted morbidity and death after HAART initiation. These findings support the use of TLC to guide decision-making for HAART initiation and suggest that further study of TLC, hemoglobin level, and DTH responses as an indication to provide HAART may be useful in resource-limited settings.

Changes in Total Lymphocyte Count as a Surrogate for Changes in CD4 Count Following Initiation of HAART: Implications for Monitoring in Resource-Limited Settings

BACKGROUND

A major obstacle to the administration of highly active antiretroviral therapy (HAART) in resource-limited settings is the high cost of CD4 count testing. The total lymphocyte count (TLC) has been proposed as a surrogate marker to monitor immune response to therapy.

OBJECTIVE

To assess, in a developed country setting, the capability and clinical utility of TLC change as a surrogate marker for CD4 count change in monitoring patients on HAART.

METHODS

Longitudinal co-variation between changes in TLC and concomitant changes in CD4 count following the initiation of HAART was examined using a retrospective cohort study of 126 HIV-positive patients attending The Miriam Hospital, Brown University, Providence, RI. Analyses included evaluation of the direction of TLC change as a marker for direction of CD4 change, using sensitivity and specificity; evaluation of absolute change in TLC as a marker for benchmark changes in CD4 (> or =50 over 6 months, > or =100 over 12 months), using receiver-operator characteristic (ROC) curves; and a regression model of change in TLC as a function of change in CD4, to understand within-individual variation of longitudinal TLC measures.

RESULTS

In the first 24 months of HAART, the sensitivity of a TLC increase as a marker for CD4 count increase over the same time period ranged from 86-94%, and the specificity ranged from 80-85%. The median change in TLC among patients with a CD4 count rise of > or =100 cells/mm at 1 year of HAART was +766 cells/mm while that of patients with a CD4 count rise of <100 cells/m was +100 cells/mm. The area under the corresponding ROC curve was 0.89, suggesting that change in TLC discriminates well between those with 1-year CD4 change of > or =100 vs. those with change <+100. From a regression analysis, we found that mean change in TLC per 1 cell/mm change in CD4 count was 7.3 (SE 1.2, P < 0.001). The degree of this association varied from individual to individual but was positive for all individuals.

CONCLUSIONS

Within the first 2 years of HAART, the direction of change in TLC appears to be a strong marker for direction of concomitant change in CD4 count (sensitivity 86-94% and specificity 80-85%, depending on length of interval). Positive and negative predictive values depend on the proportion of CD4 changes that are positive. In this cohort, that proportion is 87.9%, which yields high positive predictive value (96-98%) but lower negative predictive value (43-63%). Findings from the regression model suggest that taking multiple measurements of TLC at more frequent intervals may reduce variability and potentially improve predictive accuracy.

Outcomes after two years of providing antiretroviral treatment in Khayelitsha, South Africa

BACKGROUND

A community-based antiretroviral therapy (ART) programme was established in 2001 in a South African township to explore the operational issues involved in providing ART in the public sector in resource-limited settings and demonstrate the feasibility of such a service.

METHODS

Data was analysed on a cohort of patients with symptomatic HIV disease and a CD4 lymphocyte count < 200 x 10 cells/l. The programme used standardized protocols (using generic medicines whenever possible), a team-approach to clinical care and a patient-centred approach to promote adherence.

RESULTS

Two-hundred and eighty-seven adults naive to prior ART were followed for a median duration of 13.9 months. The median CD4 lymphocyte count was 43 x 10 cells/l at initiation of treatment, and the mean log10 HIV RNA was 5.18 copies/ml. The HIV RNA level was undetectable (< 400 copies/ml) in 88.1, 89.2, 84.2, 75.0 and 69.7% of patients at 3, 6, 12, 18 and 24 months respectively. The cumulative probability of remaining alive was 86.3% at 24 months on treatment for all patients, 91.4% for those with a baseline CD4 lymphocyte count > or =50 x 10 cells/l, and 81.8% for those with a baseline CD4 lymphocyte count < 50 x 10 cells/l. The cumulative probability of changing a single antiretroviral drug by 24 months was 15.1% due to adverse events or contraindications, and 8.4% due to adverse events alone.

CONCLUSIONS

ART can be provided in resource-limited settings with good patient retention and clinical outcomes. With responsible implementation, ART is a key component of a comprehensive response to the epidemic in those communities most affected by HIV.

Use of total lymphocyte count for monitoring response to antiretroviral therapy

The CD4 cell count has become a key laboratory measurement in the management of human immunodeficiency virus (HIV) disease. In ideal situations, HIV-infected persons are followed up longitudinally with serial CD4 cell counts to determine disease progression, risk for opportunistic infection, and the need for prophylactic or therapeutic intervention. However, the use of the CD4 cell count in resource-limited settings is often not possible because of lack of availability and high cost. Thus, other laboratory markers have been proposed as substitutes for the CD4 cell count. The data regarding the clinical utility of the total lymphocyte count (TLC) as a potential surrogate marker of immune function in patients with HIV disease are examined. The role of the TLC in the initiation of antiretroviral therapy and opportunistic infection prophylaxis, as well as the role of the TLC in monitoring the response to antiretroviral therapy, are also addressed.

Rapid declines in total lymphocyte counts and hemoglobin concentration prior to AIDS among HIV-1-infected men

OBJECTIVE

To describe temporal patterns in total lymphocyte count (TLC) and hemoglobin (Hgb) concentration during HIV infection and relate these patterns to changes in other markers and to clinical disease.

DESIGN

Prospective cohort study.

METHODS

Longitudinal trajectories of total lymphocyte count and hemoglobin from men in the Multicenter AIDS Cohort Study were studied by applying, to each individual, a segmented regression model to capture changes in marker trajectories at an inflection point. The estimated slope of these markers before and after the inflection point were examined to determine whether those with AIDS onset could be distinguished from those remaining free of AIDS through the use of receiver operating characteristic (ROC) curves.

RESULTS

Prior to the estimated inflection points, TLC and Hgb marker slopes were distributed around zero in all men; afterwards, those who developed AIDS showed rapid declines in both markers. A TLC decline greater than 10% and Hgb decline greater than 2.2% was present in over 77% of HIV-positive men who developed AIDS but only 23% of HIV-positive men who did not. Among those who developed AIDS, rapid declines in TLC and Hgb began as CD4+ cell counts fell from 350 to 200 x 106 cells/l and preceded clinical AIDS by a median of about 1.6 years.

CONCLUSIONS

Both TLC and Hgb showed a period of stability, which was followed by a rapid decline beginning shortly before the onset of AIDS. These results suggest that TLC and Hgb might be useful for monitoring disease progression in resource-limited settings.

Total Lymphocyte Count as a Possible Surrogate of Cd4 Cell Count to Prioritize Eligibility for Antiretroviral Therapy among HIV-Infected Individuals in Resource-Limited Settings

Objective

To characterize the value of total lymphocyte counts in predicting risk of death among patients initiating triple combination antiretroviral therapy.

Methods

Study subjects included antiretroviral-naive persons aged 18 years or older who initiated treatment with triple combination therapy between August 1 1996 and September 30 1999 in a population-based observational cohort of HIV-infected individuals. Total lymphocyte counts as well as CD4 count and plasma viral load were assessed at baseline. Separate Cox proportional hazards models were devised to evaluate the effect on survival of total lymphocyte count in lieu of or with CD4 count after adjustment for other prognostic factors including plasma viral load.

Results

A total of 733 antiretroviral-naive persons initiated triple drug combination antiretroviral therapy over the study period with a median follow-up of 29.5 months. In the first analysis, only baseline CD4 cell counts of 50–199 cells/μl or less than 50 μl were associated with an increased risk of mortality [adjusted relative risk (ARR) 2.90; 95% CI: 1.40, 5.98] and (ARR 6.30; 95% CI: 2.93, 13.54), respectively. When CD4 counts were excluded from the analysis as if unavailable, total lymphocyte count of between 0.8 and 1.4 G/l, and less than 0.8 G/l were both significantly associated with an increased risk of mortality (ARR 2.36; 95% CI: 1.16, 4.78) and (ARR 6.17; 95% CI: 2.93, 13.01), respectively.

Conclusion

Total lymphocyte count may provide a simple and cost-effective alternative for prioritizing therapy initiation in resource-limited settings. Our results suggest that, if appropriately validated, judicious application of total lymphocyte counts could overcome one of the practical obstacles to more widespread provision of antiretroviral therapy in resource-poor settings.

Total lymphocyte count and hemoglobin combined in an algorithm to initiate the use of highly active antiretroviral therapy in resource-limited settings

OBJECTIVE

To develop clinical algorithms that improve the sensitivity of surrogate markers to initiate the use of highly active antiretroviral therapy (HAART) in resource-limited settings.

DESIGN

A retrospective evaluation of total lymphocyte counts (TLC) and hemoglobin to predict the CD4 lymphocyte count.

METHODS

A total of 3269 members of the Johns Hopkins HIV observational cohort contributed 22 690 paired observations of CD4 lymphocyte counts and TLC. Two methods were used to evaluate the effect of combining TLC and hemoglobin to predict CD4 cell counts below 200 cells/mm3 before the initiation of HAART in 1451 participants; 55.3% of participants had CD4 cell counts below 200 cells/mm3.

RESULTS

TLC below 1200 cells/mm3 and hemoglobin below 12 g/dl significantly predicted CD4 cell counts below 200 cells/mm3. For TLC alone sensitivity was 70.7% and specificity was 81.7%. For both men and women, we chose a TLC lower cutoff point of 1200 cells/mm3, an upper cutoff point of 2000 cells/mm3, and hemoglobin of 12 g/dl. For men, method I generated sensitivity of 78.0% and specificity of 77.5%. Method II improved specificity to 81.8%. For women, method I increased sensitivity to 85.6% and decreased specificity to 64.1%. Method II improved specificity to 81.4%.

CONCLUSION

TLC below 1200 cells/mm3 were associated with CD4 cell counts below 200 cells/mm3 as in the WHO guidelines, but sensitivity was low. Adding hemoglobin to TLC increased sensitivity, thereby reducing the risk of false-negative results. Our model may serve as a template for the development of algorithms to initiate the use of HAART in resource-limited settings.

Plasma vitamin A and zinc levels in HIV-infected adults in Cape Town, South Africa

A cross-sectional study of 132 adults attending an HIV clinic in Cape Town, South Africa, was conducted to determine predictors of low plasma vitamin A and Zn levels. No patients were on antiretroviral therapy. The possible confounding effect of the acute-phase response was controlled by including C-reactive protein levels in multivariate analysis and by excluding active opportunistic infections. Retinol levels were low (<1.05 micromol/l) in 39 % of patients with early disease (WHO clinical stages I and II) compared with 48 and 79 % of patients with WHO stage III and IV respectively (P<0.01). Plasma Zn levels were low (<10.7 micromol/l) in 20 % of patients with early disease v. 36 and 45 % with stage III and IV disease respectively (P<0.05). C-reactive protein levels were normal in 63 % of subjects. Weak, positive associations were found between CD4+ lymphocyte count and plasma levels of retinol (r 0.27; 95 % CI 0.1, 0.43) and Zn (r 0.31; 95 % CI 0.25, 0.46). Multivariate analysis showed the following independent predictors of low retinol levels: WHO stage IV (odds ratio 3.4; 95 % CI 2.1, 5.7) and body weight (odds ratio per 5 kg decrease 1.15; 95 % CI, 1.08, 1.25), while only body weight was significantly associated with low Zn levels (OR per 5 kg decrease 1.19; 95 % CI 1.09, 1.30). CD4+ lymphocyte count <200/microl was not significantly associated with either low retinol or Zn levels. In resource-poor settings, simple clinical features (advanced disease and/or weight loss) are associated with lowered blood concentrations of vitamin A and/or Zn. The clinical significance of low plasma retinol and/or Zn levels is unclear and more research is required to establish the role of multiple micronutrient intervention strategies in HIV disease.

Usefulness of total lymphocyte count in monitoring highly active antiretroviral therapy in resource-limited settings

OBJECTIVE

To assess the usefulness of total lymphocyte count (TLC) for monitoring HIV-infected patients receiving highly active antiretroviral therapy. DESIGN Observational cohort study.

METHODS

Correlation between difference (Delta) from baseline at week 4, 8, 12 and 48 in TLC, CD4 cell count and viral load was determined in patients initiating HAART in phase III clinical trials between 1995 and 2001 at the HIV Clinical Research Unit, Somerset Hospital, Cape Town.

RESULTS

The study included 266 patients. At weeks 4, 8, 12 and 48, median increase in TLC was 30, 52, 139 and 219 cells x 10 /l, median increase in CD4 cell count was 8, 48, 88, and 145 cells x 10 /l, and median decrease in viral load was -1.6, -2.2, -2.5 and -2.7 log copies/ml, respectively. The correlation between all pairs of DeltaTLC and DeltaCD4 cell counts was significant (r, 0.61; P < 0.0001), but between DeltaTLC and Delta viral load it was not (r, -0.014; P= 0.73). However, the correlation between median viral load reduction and median increase in both DeltaCD4 cell count (r, -0.96; P< 0.0001) and DeltaTLC (r, -0.89; P< 0.0001) was significant. The slope of DeltaCD4 cell count was [52.493 + 0.14(DeltaTLC)]. Sensitivity and specificity of an increase or decrease from baseline in TLC for similar trend in CD4 cell count during follow-up were 83.4% and 87.3% respectively.

CONCLUSION

TLC correlated well with changes in CD4 cell count and at a group level with viral load changes. TLC may have a role in inexpensive monitoring of the immunological response to highly active antiretroviral therapy in a resource-constrained setting.

Total lymphocyte count (TLC) is a useful tool for the timing of opportunistic infection prophylaxis in India and other resource-constrained countries

BACKGROUND

In most resource-constrained countries, CD4 cell count testing is prohibitively expensive for routine clinical use and is not widely available. As a result, physicians are often required to make decisions about opportunistic infection (OI) chemoprophylaxis without a laboratory evaluation of HIV stage and level of immunosuppression. OBJECTIVES To evaluate the correlation of total lymphocyte count (TLC), an inexpensive and widely available parameter, to CD4 count. To determine a range of TLC cutoffs for the initiation of OI prophylaxis that is appropriate for resource-constrained settings.

METHODS

Spearman correlation between CD4 count and TLC was assessed in patients attending an HIV/AIDS clinic in South India. Positive predictive value (PPV), negative predictive value (NPV), and sensitivity and specificity of various TLC cutoffs were computed for CD4 count <200 cells/mm3 and <350 cells/mm3. Correlation and statistical indices computed for all patients and for patients dually infected with HIV and active tuberculosis.

RESULTS

High degree of correlation was noted between 650 paired CD4 and TLC counts (r = 0.744). TLC <1400 cells/mm3 had a 76% PPV, 86% NPV, and was 73% sensitive, 88% specific for CD4 count <200 cells/mm3. TLC <1700 cells/mm3 had a 86% PPV, 69% NPV, and was 70% sensitive, 86% specific for CD4 count <350 cells/mm3. The cost of a single CD4 count in India is approximately 30 US dollars, whereas the cost of a single TLC is 0.80 US dollars.

CONCLUSION

TLC could serve as a low-cost tool for determining both a patient's risk of OI and when to initiate prophylaxis in resource-constrained settings. PPV, NPV, sensitivity, and specificity maximally aggregated at TLC <1400 cells/mm3 for CD4 <200 cell/mm3 and TLC <1700 cells/mm3 for CD4 <350 cells/mm3. Selection of appropriate TLC cutoffs for prophylaxis administration should be made on a regional basis depending on OI incidence, antimicrobial resistance patterns, and availability of the antimicrobials.