Determinants of CD4 Counts Among HIV-Negative Ethiopians: Role of Body Mass Index, Gender, Cigarette Smoking, Khat (Catha Edulis) Chewing, and Possibly Altitude?

Chronic Immune Activation and CD4+ T Cell Lymphopenia in Healthy African Individuals: Perspectives for SARS-CoV-2 Vaccine Efficacy

Chronic immune activation has been considered as the driving force for CD4+ T cell depletion in people infected with HIV-1. Interestingly, the normal immune profile of adult HIV-negative individuals living in Africa also exhibit chronic immune activation, reminiscent of that observed in HIV-1 infected individuals. It is characterized by increased levels of soluble immune activation markers, such as the cytokines interleukin (IL)-4, IL-10, TNF-α, and cellular activation markers including HLA-DR, CD-38, CCR5, coupled with reduced naïve and increased memory cells in CD4+ and CD8+ subsets. In addition, it is accompanied by low CD4+ T cell counts when compared to Europeans. There is also evidence that mononuclear cells from African infants secrete less innate cytokines than South and North Americans and Europeans in vitro. Chronic immune activation in Africans is linked to environmental factors such as parasitic infections and could be responsible for previously observed immune hypo-responsiveness to infections and vaccines. It is unclear whether the immunogenicity and effectiveness of anti-SARS-CoV-2 vaccines will also be reduced by similar mechanisms. A review of studies investigating this phenomenon is urgently required as they should inform the design and delivery for vaccines to be used in African populations.

A mechanistic model for long-term immunological outcomes in South African HIV-infected children and adults receiving ART

Long-term effects of the growing population of HIV-treated people in Southern Africa on individuals and the public health sector at large are not yet understood. This study proposes a novel ‘ratio’ model that relates CD4+ T-cell counts of HIV-infected individuals to the CD4+ count reference values from healthy populations. We use mixed-effects regression to fit the model to data from 1616 children (median age 4.3 years at ART initiation) and 14,542 adults (median age 36 years at ART initiation). We found that the scaled carrying capacity, maximum CD4+ count relative to an HIV-negative individual of similar age, and baseline scaled CD4+ counts were closer to healthy values in children than in adults. Post-ART initiation, CD4+ growth rate was inversely correlated with baseline CD4+ T-cell counts, and consequently higher in adults than children. Our results highlight the impacts of age on dynamics of the immune system of healthy and HIV-infected individuals.

The human immunodeficiency virus (HIV) remains an ongoing global pandemic. There is currently no cure for HIV, but antiretroviral therapies can keep the virus in check and allow individuals with HIV to live longer, healthier lives. These drugs work in two ways. They block the ability of the virus to multiply and they allow numbers of an important type of infection-fighting cell called CD4+ T cells to rebound.

As more patients with HIV survive and transition from one life stage to the next, it is critical to understand how long-term antiretroviral therapies will affect normal age-related changes in their immune systems. The health of an immune system can be evaluated by looking at the number of CD4+ T cells an individual has, though this will vary by age and location. Clinicians use the same metrics to assess the immune health of individuals with HIV, however, as they age, it becomes a challenge to identify if a patient’s immune system recovers normally or insufficiently. Thus, learning more about age-related differences in CD4+ T cells in people living with HIV may help improve their care.

Using data from 1,616 children and 14,542 adults from South Africa, Ujeneza et al. created a simple mathematical model that can compare the immune system of person with HIV with the immune system of a similarly aged healthy individual. The model shows that among individuals with HIV receiving antiretroviral therapies, children have CD4+ T-cell numbers that are closest to the numbers seen in healthy individuals of the same age. This suggests that children may be more able to recover immune system function than adults after beginning treatment. Children also start antiretroviral therapies before their immune system has been severely damaged, while adults tend to start treatment much later when they have fewer CD4+ T cells left.

Ujeneza et al. show that the fewer CD4+ T cells a person has when they start treatment, the faster the number of these cells grows after starting treatment. This suggests that the more damaged the immune system is, the harder it works to recover. This reinforces the need to identify people infected with HIV as soon as possible through testing and to begin treatment promptly. The new model may help clinicians and policy makers develop screening and treatment protocols tailored to the specific needs of children and adults living with HIV.

Immune recovery in HIV-1 infected patients with sustained viral suppression under long-term antiretroviral therapy in Ethiopia

BACKGROUND

There is very little data on long-term immune recovery responses in patients on suppressive antiretroviral therapy (ART) in the setting of sub-Saharan Africa (SSA). Thus, we sought to determine CD4+ T-cell, CD8+ T-cell and CD4/CD8 ratio responses in a cohort of HIV infected individuals on sustained suppressive ART followed up for more than a decade.

METHODS

The cohort comprised adult patients who started ART between 2001 and 2007 and followed for up to 14 years. Trends in median CD4+ T-cells, CD8+ T-cells and CD4/CD8 ratio were reviewed retrospectively. Poisson regression models were used to identify factors associated with achieving normalized T-cell biomarkers. Kaplan-Meier curves were used to estimate the probability of attaining normalized counts while on suppressive ART.

RESULTS

A total of 227 patients with a median duration of follow-up on ART of 12 (IQR: 10.5-13.0) years were included. CD4 cell count increased from baseline median of 138 cells (IQR: 70-202) to 555 cells (IQR: 417-830). CD4 cell increased continuously up until 5 years, after which it plateaued up until 14 years of follow up. Only 69.6% normalized their CD4 cell count within a median of 6.5 (IQR: 3.0-10.5) years. In addition, only 15.9% of the cohort were able to achieve the median reference CD4+ T-cell threshold count in Ethiopians (≈760 cells/μL). CD8+ T-cell counts increased initially until year 1, after which continuous decrease was ascertained. CD4/CD8 ratio trend revealed continuous increase throughout the course of ART, and increased from a median baseline of 0.14 (IQR: 0.09-0.22) to a median of 0.70 (IQR: 0.42-0.95). However, only 12.3% normalized their ratio (≥ 1.0) after a median of 11.5 years. In addition, only 8.8% of the cohort were able to achieve the median reference ratio of healthy Ethiopians.

CONCLUSION

Determination of both CD4+ and CD8+ T-cells, along with CD4/CD8 ratio is highly relevant in long-term follow-up of patients to assess immune recovery. Monitoring ratio levels may serve as a better biomarker risk for disease progression among patients on long-term ART. In addition, the findings emphasize the relevance of initiation of ART at the early stage of HIV-1 infection.

Anemia, Iron Status, and HIV: A Systematic Review of the Evidence

People living with HIV (PLWHIV) are at high risk of anemia due to inadequate iron intake, HIV and opportunistic infections, and inflammation, and as a side effect of antiretroviral therapy. Though iron supplementation can reduce iron deficiency anemia (IDA) in the general population, its role in anemia and in the health of PLWHIV is unclear due to concerns that iron supplementation may increase HIV replication and risk of opportunistic infections. We systematically reviewed the evidence on indicators of iron status, iron intake, and clinical outcomes among adults and children with HIV. The evidence suggests that anemia is associated with an increased risk of all-cause mortality and incident tuberculosis among HIV-infected individuals, regardless of anemia type, and the magnitude of the risk is greater with more severe anemia. High serum ferritin is associated with adverse clinical outcomes, although it is unclear if this is due to high iron or inflammation from disease progression. One large observational study found an increased risk of all-cause mortality among HIV-infected adults if they received iron supplementation. Published randomized controlled trials of iron supplementation among PLWHIV tend to have small sample sizes and have been inconclusive in terms of effectiveness and safety. Large randomized trials exploring approaches to safely and effectively provide iron supplementation to PLWHIV are warranted.

Health outcomes of asymptomatic HIV-infected pregnant women initiating antiretroviral therapy at different baseline CD4 counts in Ethiopia

OBJECTIVE

To compare health outcomes following initiation of antiretroviral therapy (ART) for asymptomatic HIV-infected pregnant women at different CD4 levels.

METHODS

We analyzed data from 706 asymptomatic HIV-infected Ethiopian women initiating ART during pregnancy between February 2012 and October 2016. The outcomes evaluated were CD4 gain, CD4 normalization (CD4 count ≥750cells/mm3) and occurrence of HIV-related clinical events after twelve months of treatment.

RESULT

On average, CD4 count (cells/mm3) increased from 391 (95% CI: 372-409) at baseline to 523 (95% CI: 495-551) after twelve months of treatment. Rate of CD4 gain was higher among women with baseline CD4 between 350 and 499 compared to CD4 ≥500 (207 versus 6, p<0.001). But women with baseline CD4 between 350 and 499 could not catch up with women with CD4 ≥500. Women with baseline CD4 ≥500 had significantly higher likelihood of achieving CD4 normalization as compared to those with CD4 between 350 and 499 (AOR=0.32, 95% CI: 0.13-0.76). No strong evidence of differential risk in the occurrence of HIV-related clinical events.

CONCLUSION

Starting ART for asymptomatic HIV-infected women with CD4 count ≥500cells/mm3 was beneficial to preserve or recover immunity after 12 months of treatment in a resource limited setting.

CD4 Variability in Malawi: Implications for Use of a CD4 Threshold of 500 Cells/mm3 Versus Universal Eligibility for Antiretroviral Therapy

Background.  Given the uncertainty about the ability of a single CD4 count to accurately classify a patient as antiretroviral therapy (ART) eligible, we sought to understand the extent to which CD4 variability results in misclassification at a CD4 threshold of 500 cells/mm³. Methods.  We performed a prospective study of CD4 variability in Malawian human immunodeficiency virus-infected, ART-naive, World Health Organization (WHO) stage 1 or 2, nonpregnant adults. CD4 counts were performed daily for 8 days. We fit a Bayesian linear mixed-effects model of log-transformed CD4 cell counts to the data. We used Monte Carlo approximations to estimate misclassification rates for different observed values of CD4. The misclassification rate was calculated based on the conditional probability of true CD4 given the geometric mean of observed CD4 measurements. Results.  Fifty patients were enrolled from 2 sites. The median age was 33.5 years (interquartile range, 27.5-40.0) and 34 (68%) were female. Misclassification rates were <1% when the observed CD4 counts were ≤250 or ≥750 cells/mm³. Rates of misclassification were high at observed CD4 counts between 350 and 650 cells/mm³, particularly when a single measurement was used (up to 46.7%). Conclusions.  Our data show that ART eligibility based on a single CD4 count results in highest risk of misclassification when observed CD4 counts are in the range of 350-650 cells/mm³. Given the benefits of early ART, countries should weigh the costs and complexity of CD4 testing using a 500 cell/mm³ threshold against the cost savings and public health benefits of universal eligibility.

CD4 Cell Count: Declining Value for Antiretroviral Therapy Eligibility

Antiretroviral therapy (ART) policy for people living with human immunodeficiency virus (HIV) has historically been based on clinical indications, such as opportunistic infections and CD4 cell counts. Studies suggest that CD4 counts early in HIV infection do not predict relevant public health outcomes such as disease progression, mortality, and HIV transmission in people living with HIV. CD4 counts also vary widely within individuals and among populations, leading to imprecise measurements and arbitrary ART initiation. To capture the clinical and preventive benefits of treatment, the global HIV response now focuses on increasing HIV diagnosis and ART coverage. CD4 counts for ART initiation were necessary when medications were expensive and had severe side effects, and when the impact of early ART initiation was unclear. However, current evidence suggests that although CD4 counts may still play a role in guiding clinical care to start prophylaxis for opportunistic infections, CD4 counts should cease to be required for ART initiation.

Sex and Urbanicity Contribute to Variation in Lymphocyte Distribution across Ugandan Populations

Management of patient care and interpretation of research data require evaluation of laboratory results in the context of reference data from populations with known health status to adequately diagnose disease or make a physiological assessment. Few studies have addressed the diversity of lymphocyte subsets in rural and urban Ugandan populations. Here, 663 healthy blood bank donors from semi-urban centers of Kampala consented to participate in a study to define lymphocyte reference ranges. Whole blood immunophenotyping was performed to determine the frequency and absolute counts of T, B, and NK cells using clinical flow cytometry. Results from blood bank donors were compared to a rural cohort from the district of Kayunga and more urban clinical trial participants from the capital city, Kampala. Relationships between hematological and lymphocyte parameters were also explored. In the semi-urban blood donors, females were significantly different from males in all parameters except the frequency of CD8 T and B cells. Females had higher absolute counts of CD4 T, CD8 T and B cells, whereas males had higher NK cell counts. NK cell frequency and counts were significantly higher in semi-urban blood donors, regardless of sex, compared to more urban study participants. CD8 T cell frequency and counts were significantly higher in the blood donors compared to the rural participants, irrespective of sex. Interestingly, basophil counts were positively associated with overall T cell counts. These findings suggest that both sex and level of cohort urbanicity may influence lymphocyte subset distributions in Ugandans.

Incidence of Severe Malaria Syndromes and Status of Immune Responses among Khat Chewer Malaria Patients in Ethiopia

Although more emphasis has been given to the genetic and environmental factors that determine host vulnerability to malaria, other factors that might have a crucial role in burdening the disease have not been evaluated yet. Therefore, this study was designed to assess the effect of khat chewing on the incidence of severe malaria syndromes and immune responses during malaria infection in an area where the two problems co-exist. Clinical, physical, demographic, hematological, biochemical and immunological data were collected from Plasmodium falciparum mono-infected malaria patients (age ≥ 10 years) seeking medication in Halaba Kulito and Jimma Health Centers. In addition, incidences of severe malaria symptoms were assessed. The data were analyzed using SPSS (version 20) software. Prevalence of current khat chewer malaria patients was 57.38% (95%CI =53-61.56%). Malaria symptoms such as hyperpyrexia, prostration and hyperparasitemia were significantly lower (P<0.05) among khat chewer malaria patients. However, relative risk to jaundice and renal failure were significantly higher (P<0.05) in khat chewers than in non-khat chewer malaria patients. Longer duration of khat use was positively associated with incidence of anemia. IgM and IgG antibody titers were significantly higher (P<0.05) among khat chewer malaria patients than among malaria positive non-chewers. Although levels of IgG subclasses in malaria patients did not show significant differences (P>0.05), IgG3 antibody was significantly higher (P<0.001) among khat chewer malaria patients. Moreover, IgM, IgG, IgG1and IgG3 antibodies had significant negative association (P<0.001) with parasite burden and clinical manifestations of severe malaria symptoms, but not with severe anemia and hypoglycemia. Additionally, a significant increment (P<0.05) in CD4⁺ T-lymphocyte population was observed among khat users. Khat might be an important risk factor for incidence of some severe malaria complications. Nevertheless, it can enhance induction of humoral immune response and CD4⁺ T-lymphocyte population during malaria infection. This calls for further investigation on the effect of khat on parasite or antigen-specifc protective malaria immunity and analysis of cytokines released upon malaria infection among khat chewers.

Schistosoma haematobium infection and CD4+ T-cell levels: a cross-sectional study of young South African women

Schistosoma (S.) haematobium causes urogenital schistosomiasis and has been hypothesized to adversely impact HIV transmission and progression. On the other hand it has been hypothesized that HIV could influence the manifestations of schistosomiasis. In this cross-sectional study, we explored the association between urogenital S. haematobium infection and CD4 cell counts in 792 female high-school students from randomly selected schools in rural KwaZulu-Natal, South Africa. We also investigated the association between low CD4 cell counts in HIV positive women and the number of excreted schistosome eggs in urine. Sixteen percent were HIV positive and 31% had signs of urogenital schistosomiasis (as determined by genital sandy patches and / or abnormal blood vessels on ectocervix / vagina by colposcopy or presence of eggs in urine). After stratifying for HIV status, participants with and without urogenital schistosomiasis had similar CD4 cell counts. Furthermore, there was no significant difference in prevalence of urogenital schistosomiasis in HIV positive women with low and high CD4 cell counts. There was no significant difference in the number of eggs excreted in urine when comparing HIV positive and HIV negative women. Our findings indicate that urogenital schistosomiasis do not influence the number of circulating CD4 cells.

Evaluation of immunomodulatory activities of methanolic extract of khat (Catha edulis, Forsk) and cathinone in Swiss albino mice

Background

The objective of this study was to explore the immunomodulatory effect of khat and its active component, cathinone, using mice.

Materials and methods

Female Swiss albino mice aged 7–8 weeks weighing 25-30 g were used in the study. Mice were randomized into eight groups of 6 each and oral treatment of khat crude extract and cathinone were given daily for four weeks. Physical, hematological, biochemical, and immunological parameters were measured. Immunological studies included humeral immunity (IgG and IgM), cellular immune response (delay type hypersensitivity), phagocytic activities of reticuloendothelial system, and determination of T-lymphocyte population: CD3⁺, CD4⁺, CD8⁺ count and CD4⁺/CD8⁺ status.

Results

Findings of this study showed that, khat and its major metabolite, cathinone, can positively affect immune system in dose dependent manner. When doses of crude khat extract and cathinone increase, the induction of humeral (IgG and IgM) and cellular immune responses were up-regulated significantly (P < 0.05), while at higher dose of khat (200 mg/kg) cellular immune response was suppressed. In support of this, as doses of the two test substances increased, the count of T helper cells (CD4⁺) was significantly increased (P < 0.05), while higher dose significantly reduced whole white blood cell (WBC), CD8⁺, and CD3⁺ counts.

Conclusion

At relatively lower dose (50-100 mg/kg), crude khat extract has immune stimulating property, although higher dose (200 mg/kg) leads to suppression of cellular immune response. Cathinone also share all immune modulating property of its parent compound, khat, but with intense strength. Thus, it calls for further detailed investigation of khat for practical application of the same in human medication.

Electronic supplementary material

The online version of this article (doi:10.1186/s12865-015-0072-5) contains supplementary material, which is available to authorized users.

Selected micronutrient levels and response to highly active antiretroviral therapy (HAART) among HIV/AIDS patients attending a teaching Hospital in Addis Ababa, Ethiopia

Poor micronutrient levels are associated with an increased risk of progression to AIDS and are also suggested to influence outcome of highly active antiretroviral therapy (HAART), though existing data are inconclusive to support the latter. Few published data are available on micronutrient levels in Ethiopian HIV/AIDS patients taking HAART. The objective of the study was to determine the association of micronutrient levels and response to HAART (CD4(+) T cell count) among adult HIV/AIDS patients attending a teaching Hospital in Addis Ababa. CD4(+) T cell counts and micronutrient (retinol, zinc, and iron) levels for 171 subjects were determined using standard procedures. Some proportions of the study participants were found deficient for retinol (14.03 %), zinc (47.3 %), and iron (2.8 %). Patients who were deficient in retinol had a significantly lower median CD4(+) T cell counts (P = 0.002) compared to non-deficient subjects. Association of micronutrient quartiles with CD4+ T cell count was assessed using adjusted multivariate regression by taking quartile 4 as a reference category. Accordingly, patients who had retinol levels in quartile 4 had a significantly lower mean CD4(+) T cell count compared to quartile 3 (P = 0.02). The significantly higher CD4(+) T cell counts in patients who were non-deficient in retinol imply the role of retinol in improving the production of CD4(+) T cells. However, both lower and higher retinol levels were associated with suppressed immunity (CD4 < 200 cells/mm(3)), suggesting an adverse effect of higher retinol levels. Thus, retinol may be potentially harmful depending on the dose, emphasizing the need for optimized level of retinol in nutrient supplements in patients taking HAART.

Cluster of differentiation 4+ cell count mean value, reference range and its influencing factors in Human Immunodeficiency Virus-seronegative pregnant women in Lagos

Background:

Immunity in pregnancy is physiologically compromised and this may affect cluster of differentiation four (CD4) count levels. It is well established that several factors affect CD4 count level in pregnancy. This study aims to determine the effects of maternal age, gestational age, parity and level of education as they influence CD4 count in pregnancy and also to determine the mean and reference range of CD4 count in pregnancy in Lagos, Nigeria.

Materials and Methods:

A descriptive cross-sectional study was carried out at Ante-natal clinics in Lagos State, Nigeria. About 5 mls of blood was collected into Ethylene Diamine Tetracetic Acid (EDTA) bottles from HIV-negative pregnant women in various gestational ages of pregnancy. CD4+ cell count and full blood count of all samples were done within 3 hours of collection. The descriptive data was given as means ± standard deviation (SD). Pearson's chi-squared test and correlation were used for analytical assessment.

Results:

A total of 74 pregnant women were recruited. The age range was 19–41 years and a mean age of 30.42 ± 5.34 years. The CD4+ cell count was not statistically significant when compared with participants ages P = 0.417, neither with gestational ages P = 0.323, nor with parity P = 0.247 nor level of education P = 0.96. An overall mean CD4+ cell count was 771.96 ± 250 cells/μl and the range was 193–1370 cells/μl.

Conclusion:

Maternal age, gestational age, parity and level of education had no significant effects on CD4+ cell count levels in pregnancy. The mean CD4+ cell count of HIV-negative pregnant women in Lagos is 771.96 ± 250 cells/μl.

The magnitude and risk factors of intestinal parasitic infection in relation to Human Immunodeficiency Virus infection and immune status, at ALERT Hospital, Addis Ababa, Ethiopia

Human Immunodeficiency Virus (HIV) and intestinal parasitic infections are among the main health problems in developing countries like Ethiopia. Particularly, co-infections of these diseases would worsen the progression of HIV to Acquired Immunodeficiency Syndrome (AIDS). The purpose of this study was to determine the magnitude and risk factors for intestinal parasites in relation to HIV infection and immune status. The study was conducted in (1) HIV positive on antiretroviral therapy (ART) and (2) ART naïve HIV positive patients, and (3) HIV-negative individuals, at All African Leprosy and Tuberculosis (TB) Eradication and Rehabilitation Training Center (ALERT) hospital in Addis Ababa, Ethiopia. Study participants were interviewed using structured questionnaires to obtain socio-demographic characteristics and assess risk factors associated with intestinal parasitic infection. Intestinal parasites were identified from fecal samples by direct wet mount, formol ether concentration, and modified Ziehl-Neelsen staining techniques. The immune status was assessed by measuring whole blood CD4 T-cell count. The overall magnitude of intestinal parasite was 35.08%. This proportion was different among study groups with 39.2% (69/176), 38.83% (40/103) and 27.14% (38/140) in ART naïve HIV positives patients, in HIV negatives, and in HIV positive on ART patients respectively. HIV positive patients on ART had significantly lower magnitude of intestinal parasitic infection compared to HIV negative individuals. Intestinal helminths were significantly lower in HIV positive on ART and ART naïve patients than HIV negatives. Low monthly income, and being married, divorced or widowed were among the socio-demographic characteristics associated with intestinal parasitic infection. No association was observed between the magnitude of intestinal parasites and CD4 T-cell count. However, Cryptosporidium parvum, and Isospora belli were exclusively identified in individuals with CD4 T-cell count of ≤ 350 cells/mm(3). Regular provision of mass preventive chemotherapy and extended health education will curb the burden of intestinal parasitic infection in the community. Emphasis should also be given to laboratory diagnosis and identification of opportunistic intestinal parasites in patients with lower CD4-Tcell count.

CD4 cell levels during treatment for tuberculosis (TB) in Ethiopian adults and clinical markers associated with CD4 lymphocytopenia

Background

The clinical correlations and significance of subnormal CD4 levels in HIV-negative patients with TB are unclear. We have determined CD4 cell levels longitudinally during anti-tuberculosis treatment (ATT) in patients, with and without HIV co-infection, and their associations with clinical variables.

Method

Adults diagnosed with TB (maximum duration of ATT for 2 weeks, and with no history of antiretroviral therapy (ART) in HIV-positive subjects) were included consecutively in eight out-patient clinics in Ethiopia. Healthy individuals were recruited for comparison at one of the study health centers. Data on patient characteristics and physical findings were collected by trained nurses following a structured questionnaire at inclusion and on follow-up visits at 2 and 6 months. In parallel, peripheral blood CD4 cell levels were determined. The evolution of CD4 cell levels during ATT was assessed, and the association between clinical characteristics and low CD4 cell levels at baseline was investigated using regression analysis.

Results

In total, 1116 TB patients were included (307 HIV-infected). Among 809 HIV-negative patients, 200 (25%) had subnormal CD4 cell counts (<500 cells/mm³), with <350 cells/mm³ in 82 (10%) individuals. CD4 cell levels increased significantly during the course of ATT in both HIV+ and HIV- TB-patients, but did not reach the levels in healthy subjects (median 896 cells/mm³). Sputum smear status, signs of wasting (low mid upper arm circumference (MUAC)), and bedridden state were significantly associated with low CD4 cell counts.

Conclusion

A high proportion of Ethiopian TB patients have subnormal CD4 cell counts before starting treatment. Low CD4 cell levels are associated with smear positive disease and signs of wasting. The continuous increase of CD4 cell counts during the course of ATT suggest a reversible impact of active TB on CD4 cell homeostasis, which may be considered in interpretation of CD4 cell counts in HIV/TB co-infected subjects.

Population-based CD4 counts in a rural area in South Africa with high HIV prevalence and high antiretroviral treatment coverage

Background

Little is known about the variability of CD4 counts in the general population of sub-Saharan Africa countries affected by the HIV epidemic. We investigated factors associated with CD4 counts in a rural area in South Africa with high HIV prevalence and high antiretroviral treatment (ART) coverage.

Methods

CD4 counts, health status, body mass index (BMI), demographic characteristics and HIV status were assessed in 4990 adult resident participants of a demographic surveillance in rural KwaZulu-Natal in South Africa; antiretroviral treatment duration was obtained from a linked clinical database. Multivariable regression analysis, overall and stratified by HIV status, was performed with CD4 count levels as outcome.

Results

Median CD4 counts were significantly higher in women than in men overall (714 vs. 630 cells/µl, p<0.0001), both in HIV-uninfected (833 vs. 683 cells/µl, p<0.0001) and HIV-infected adults (384.5 vs. 333 cells/µl, p<0.0001). In multivariable regression analysis, women had 19.4% (95% confidence interval (CI) 16.1–22.9) higher CD4 counts than men, controlling for age, HIV status, urban/rural residence, household wealth, education, BMI, self-reported tuberculosis, high blood pressure, other chronic illnesses and sample processing delay. At ART initiation, HIV-infected adults had 21.7% (95% CI 14.6–28.2) lower CD4 counts than treatment-naive individuals; CD4 counts were estimated to increase by 9.2% (95% CI 6.2–12.4) per year of treatment.

Conclusions

CD4 counts are primarily determined by sex in HIV-uninfected adults, and by sex, age and duration of antiretroviral treatment in HIV-infected adults. Lower CD4 counts at ART initiation in men could be a consequence of lower CD4 cell counts before HIV acquisition.

Profound reduction of CD4+ lymphocytes without HIV infection: two cases from the horn of Africa

Idiopathic CD4+ lymphocytopenia is a disorder associated with low CD4+ T cell count and opportunistic infections resembling AIDS. Most cases are described in developed countries. We report two HIV-negative patients with idiopathic CD4+ lymphocytopenia and AIDS-defining events diagnosed in Djibouti. The first patient developed lesions of Kaposi's sarcoma and the second one presented with pulmonary tuberculosis. Both patients died with severe immunodepression. In poor resource-areas where HIV testing may not be available it is important to bear in mind that severe immunodepression and a clinical presentation compatible with AIDS do not necessary carry the diagnosis of AIDS.

Campylobacter fetus bacteremia in a young healthy adult transmitted by khat chewing

Campylobacter fetus is a pathogen affecting almost exclusively patients with immunosuppression and chronic debilitating diseases. We report the case of a healthy young man with C. fetus bacteremia presenting with fever, hypotension and meningitis. The patient had no exposure to contaminated sources except from khat chewing, which we describe as a possible source of transmission for the first time.

Role of selenium in HIV infection

HIV infection is a global disease that disproportionately burdens populations with nutritional vulnerabilities. Laboratory experiments have shown that selenium has an inhibitory effect on HIV in vitro through antioxidant effects of glutathione peroxidase and other selenoproteins. Numerous studies have reported low selenium status in HIV-infected individuals, and serum selenium concentration declines with disease progression. Some cohort studies have shown an association between selenium deficiency and progression to AIDS or mortality. In several randomized controlled trials, selenium supplementation has reduced hospitalizations and diarrheal morbidity, and improved CD4(+) cell counts, but the evidence remains mixed. Additional trials are recommended to study the effect of selenium supplementation on opportunistic infections, and other HIV disease-related comorbidities in the context of highly active antiretroviral therapy in both developing and developed countries.

Variations in CD4 cell counts among HIV-uninfected and infected women in Uganda and Zimbabwe

We conducted a cross-sectional study with 208 HIV-uninfected and 188 HIV-infected women in Uganda and Zimbabwe to investigate differences in median CD4 counts. Absolute CD4 counts were determined by flow cytometry. Multivariate analyses were used to examine the association of country and HIV-infection status on CD4 counts. Median CD4 counts were significantly lower in Zimbabwe than in Uganda overall (649 and 783 cells/mm(3), P = 0.009) and among HIV-infected women (470 and 614 cells/mm(3), P = 0.003). In separate multivariable models, CD4 counts were significantly lower in Zimbabwe in HIV-uninfected (P = 0.014) and infected (P < 0.001) women, controlling for age, contraceptive method, education and living with partner status. In a model combining HIV-uninfected and infected women, there was no significant interaction between country and HIV infection status (P = 0.344), suggesting that the relationship between country and CD4 count was not significantly modified by HIV infection status. This study reinforces the importance of establishing country-specific reference CD4 levels as CD4 count continues to be used as a key biomarker in clinical decision-making for HIV-infected individuals in sub-Saharan Africa.

Factors associated with CD4 lymphocyte counts in HIV-negative Senegalese individuals

CD4+ lymphocytes are a primary target of the human immunodeficiency virus (HIV), and CD4 counts are one of the factors used to measure disease progression in HIV-positive individuals. CD4 counts vary in uninfected individuals and across populations due to a variety of demographic, environmental, immunological and genetic factors that probably persist throughout the course of HIV infection. This study sought to determine reference levels and identify factors that influence lymphocyte counts in 681 HIV-uninfected adults in Senegal, where residents are exposed to a variety of infectious diseases and other conditions that may affect CD4 counts. Lymphocyte counts were assessed in commercial sex workers, symptomatic men and women presenting to the University of Dakar infectious disease clinic for out-patient care and women seeking family planning services. CD4 and CD3 lymphocyte counts differed between the four study groups (P < 0.01). Men had the lowest mean CD4 count (711.6 cells/microl), while commercial sex workers had the highest levels (966.0 cells/microl). After adjustment for age and other behavioural and clinical factors, the difference in CD4 counts between the three groups of women did not remain. However, both gender and smoking were associated independently with CD4 counts, as men maintained lower mean CD4 counts (beta = -156.4 cells/microl, P < 0.01) and smokers had higher mean CD4 counts (beta = 124.0 cells/microl, P < 0.01) than non-smokers in multivariable analyses. This study is the first to explore factors that may influence CD4 levels in Senegal and to estimate baseline CD4 levels among HIV-negatives, information that may guide clinicians in interpreting CD4 counts.

Correlates of CD4+ and CD8+ lymphocyte counts in high-risk immunodeficiency virus (HIV)-seronegative women enrolled in the women's interagency HIV study (WIHS)

Studies of human immunodeficiency virus (HIV) infection often compare values from HIV-uninfected controls, including CD4 and CD8 lymphocyte counts. Nonetheless, little is known regarding factors associated with CD4 and CD8 cell numbers in HIV-uninfected individuals. To ascertain potential factors associated with differences in CD4 and CD8 cells among HIV negative women, we studied these cells in a group of 953 women, enrolled as HIV-negative comparators in the Women's Interagency HIV Study. Using standard techniques, we measured CD4 and CD8 cells obtained during study-related visits every six months through visit 20 (maximum of 9.5 years). Results were correlated with demographic and behavioral factors, and data were analyzed using a multiple linear regression approach with generalized estimating equations. At baseline, the median age was 32.4 years, body mass index (BMI) was 26.4 kg/m(2), CD4 cell count was 1010 (range 214-2705)/microL, and CD8 cell count was 542 (range 72-2448)/microL. African-Americans comprised 54%, 24% were Hispanic, and 19% were Caucasian. In multivariate analysis, increasing age (p = 0.0006), increasing BMI (p = 0.001), and current smoking status (p = 0.03) were independent predictors of higher CD4 counts. Multivariate analyses of CD8 cells revealed that lower age (p = 0.001), higher BMI (p = 0.03), Hispanic race/ethnicity (p = 0.01); current smoking (p = 0.006), injection drug use (p = 0.02), and Hepatitis C infection (p = 0.01) were independent predictors of higher CD8 cell counts. Multiple demographic and behavioral factors may influence CD4 and CD8 counts in HIV negative women. These factors must be considered in future analyses comparing lymphocyte subsets in HIV positive and negative women.