Occult hepatitis B in persons infected with HIV is associated with low CD4 counts and resolves during antiretroviral therapy

Occult hepatitis B virus (HBV) is defined by the presence of plasma HBV DNA in individuals with HBV core antibodies (anti‐HBc), but without HBV surface antigen (HBsAg). The prevalence of occult HBV in HIV‐infected patients remains controversial, and the risk factors, clinical significance and effect of highly active antiretroviral therapy (HAART) are unknown. The aim of this study was to determine prevalence, risk factors, and clinical significance of occult HBV in HIV‐infected patients and to evaluate the effect of HAART. Plasma HBV DNA levels were determined in 191 HIV positive, antiretroviral naïve patients, who were anti‐HBc positive and HBsAg negative. Quantitative HBV DNA was determined using a Taqman real‐time nested PCR. Additionally, plasma HIV RNA levels, CD4 cell counts, anti‐HBs‐antibodies, anti‐HCV‐antibodies, ALT, AST, and γGT were determined. Occult HBV (a plasma HBV DNA level >50 copies/ml) was detected in 9/191 (4.7%) of the patients. Among 45 anti‐HBs‐negative patients (isolated anti‐HBc positive), the prevalence was 11.1%. Patients with occult HBV had significantly lower CD4 count compared to anti‐HBc‐positive/HBsAg negative/HBV DNA‐negative patients (105 ± 157 (median ± SD) vs. 323 ± 299 cells/mm³, P = 0.019). When HAART (including lamivudine) was initiated in the patients with occult HBV, HBV DNA was no longer detectable in any of the patients during 3 years of follow‐up. In conclusion, occult HBV was associated with low CD4 counts and may be viewed as opportunistic reactivation of HBV that resolves as a consequence of HAART induced immune reconstitution and/or the effect of lamivudine. J. Med. Virol. 81:441–445, 2009. © 2009 Wiley‐Liss, Inc.     

A high HIV DNA level in PBMCs at antiretroviral treatment interruption predicts a shorter time to treatment resumption,independently of the CD4 nadir

This study aimed to evaluate the safety of antiretroviral treatment interruption (TI) in HIV‐infected patients who started treatment based on earlier guidelines, and to identify baseline factors predictive of the time to reach fixed criteria for treatment resumption. Prospective, open‐label, multicenter trial. Patients were eligible if they had a CD4 cell count >350/mm³ and plasma HIV RNA <50,000 copies/ml when they first started antiretroviral therapy (ART); and if they had a CD4 count >450/mm³ and stable plasma HIV RNA <5,000 copies/ml for at least 6 months prior to enrolment. The criteria for ART resumption were a CD4 cell count <300/mm³ and/or a CDC stage B or C event. 116 patients had received ART for a median of 5.3 years. The median CD4 cell count and plasma HIV RNA values at inclusion were 809/mm³ and 2.6 log copies/ml, respectively. Median HIV DNA load at inclusion was 2.3 log copies/10⁶ peripheral blood mononuclear cells (PBMCs). Thirty‐six months after TI, 63.9% of the patients had not yet reached the criteria for ART resumption, and 55.9% of patients had not resumed ART. In Cox multivariable analysis, a high HIV DNA level at TI, a low CD4 nadir, and pre‐existing AIDS status were the only significant risk factors for reaching the criteria for ART resumption (hazards ratio: 2.15 (1.02–4.53), 4.59 (1.22–17.24), and 5.74 (1.60–20.56), respectively). Patients who started ART with a CD4 cell count above 350/mm³ were able to interrupt treatment for long periods without a high absolute risk of either AIDS or severe non‐AIDS morbidity/mortality. A high PBMC HIV DNA level at TI was a strong predictor for more rapid treatment resumption. J. Med. Virol. 82:1819–1828, 2010. © 2010 Wiley‐Liss, Inc.     

CD4/CD8 ratio,comorbidities, and aging in treated HIV infected individuals on viral suppression

The progression of the human immunodeficiency virus (HIV) infection to acquired immunodeficiency syndrome (AIDS) can be efficiently interrupted by antiretroviral therapy (ART). However, even successfully treated HIV-infected individuals are prone to develop non-AIDS-related diseases that affect the metabolism and several organs and systems. Biomarkers that predict the occurrence of comorbidities may help develop preventive measures. Current research shows that CD4⁺ T cell counts and viral load do not predict the development of non-AIDS-related diseases. The CD4/CD8 ratio has been indicated as a suitable marker of persistent immune dysfunction and the occurrence of non-AIDS-related events in treated HIV-positive patients. In this study, we explored the relationship between CD4/CD8 ratios, comorbidities, and aging in ART-treated HIV patients on viral suppression. We collected and evaluated data from 352 HIV-positive adults who were virologically suppressed (<40 copies/mL) on ART and with CD4 counts above 350 cells/mm³. The median age for participants was 46 years, 218 individuals had at least one comorbidity, and 239 had inverted CD4/CD8 ratios (<1). Current CD4/CD8 ratios were predicted by baseline CD4/CD8 ratios and nadir CD4 counts. Despite the high rates of inverted CD4/CD8 ratios and prevalence of comorbidities, no association between them was observed. The prevalence of comorbidities was significantly higher in older individuals, though aging alone did not explain the rate of all individual comorbidities. Low CD4/CD8 ratios were linked to neurocognitive disorders, suggesting that persistent T cell dysfunction contributes to neurocognitive decline.     

Prognostic factors of long‐term CD4+count‐guided interruption of antiretroviral treatment

Aim of the study was to determine predictors of the duration of antiretroviral treatment interruption in patients infected with HIV. This pilot prospective, open‐label, multicenter trial comprised 62 HIV‐seropositive subjects who decided voluntarily to interrupt therapy after two or more years of successful HAART. The primary end‐point was the time to patients being free of therapy before reaching a CD4+ cell count ≤350/µl. Fifteen of 62 patients remained in treatment interruption for more than 180 days. Patients restarting therapy had higher HIV‐DNA levels (P = 0.05), were treated more frequently with NNRTI‐drugs (P = 0.02), had a shorter period of HAART (P = 0.046), and lower CD4+ cell counts after day 14 of interruption of treatment (P = 0.04). Multivariate regression analysis showed that less than 323 baseline proviral HIV‐DNA cp/10⁶ PBMCs and more than 564 CD4 cells/µl at day 14 after interruption were associated independently with a reduced risk of restarting treatment (P = 0.041 and P = 0.012, respectively). A score based on CD4+ cell counts at nadir, at baseline, at week 2 of treatment interruption, and on baseline HIV‐DNA values can identify patients with a prolonged period free safely of treatment. J. Med. Virol. 81:481–487, 2009. © 2009 Wiley‐Liss, Inc.     

Evidence for lower CD4+ T cell and higher viral load in asymptomatic HIV-1 infected individuals of India: implications for therapy initiation

PURPOSE: We have earlier documented that the south Indian population had lower CD4 counts. The aim of this study was to investigate a previous suggestion on a new CD4+ T cell cut off and association with HIV-1 RNA levels for decision on anti retroviral therapy in India (south). METHODS: We evaluated a new methodology i.e., artus real-time PCR and CD4+ T cell count by Guava EasyCD4 system. From 146 HIV infected individuals seen at a tertiary care centre, blood was collected for CD4+ T cell and HIV-1 RNA estimation. RESULTS: The receiver operating characteristic curve cut off value for the CD4 counts to distinguish between CDC clinical categories A and B was 243 cells/microL, and to distinguish B and C was 153 cells/microL. The RNA level that differentiated CDC A and B was 327473 RNA copies/mL, while for CDC B and C was 688543 copies/mL. There was a significant negative correlation (r = -0.55, P + T cell counts in HIV infected individuals. CONCLUSIONS: A majority with CD4 counts of 201-350 cells/microL in our population had higher viral load than the treatment threshold suggested by the International AIDS society and the above two methodologies are useful in monitoring HIV infections.     

High proportion of PD‐1‐expressing CD4+ T cells in adipose tissue constitutes an immunomodulatory microenvironment that may support HIV persistence

We and others have demonstrated that adipose tissue is a reservoir for HIV. Evaluation of the mechanisms responsible for viral persistence may lead to ways of reducing these reservoirs. Here, we evaluated the immune characteristics of adipose tissue in HIV‐infected patients receiving antiretroviral therapy (ART) and in non‐HIV‐infected patients. We notably sought to determine whether adipose tissue's intrinsic properties and/or HIV induced alteration of the tissue environment may favour viral persistence. ART‐controlled HIV infection was associated with a difference in the CD4/CD8 T‐cell ratio and an elevated proportion of Treg cells in subcutaneous adipose tissue. No changes in Th1, Th2 and Th17 cell proportions or activation markers expression on T cell (Ki‐67, HLA‐DR) could be detected, and the percentage of CD69‐expressing resident memory CD4⁺ T cells was not affected. Overall, our results indicate that adipose‐tissue‐resident CD4⁺ T cells are not extensively activated during HIV infection. PD‐1 was expressed by a high proportion of tissue‐resident memory CD4⁺ T cells in both HIV‐infected patients and non‐HIV‐infected patients. Our findings suggest that adipose tissue's intrinsic immunomodulatory properties may limit immune activation and thus may strongly contribute to viral persistence.     

High frequency and proliferation of CD4+FOXP3+ Treg in HIV‐1‐infected patients with low CD4 counts

The frequency of Treg is reported to be higher in patients with chronic HIV type 1 (HIV‐1) infection and CD45RA⁺ Treg exist in normal adults. In this study, we found a lower absolute number (15 cells/μL) but a higher proportion (16.2%) of FOXP3⁺ cells (Treg) in the CD4⁺ population in treatment‐naïve HIV‐1 patients with low CD4 (<200 cells/μL) counts than in those with high CD4 counts (34 cells/μL and 9.3%) or healthy adults (48 cells/μL and 7.5%). In HIV‐1 patients, CD45RA⁺CCR7⁺, CD45RA^?CCR7⁺, and CD45RA^?CCR7^? subsets were identified in the Treg population, and the proportion of CD45RA^?CCR7^? Treg was higher (57.9%) in patients with low CD4 than high CD4 counts (38.3%). Treg were in a high proliferation state especially in patients with low CD4 counts. HIV viral load correlated positively with the Treg proliferation rate and the proportion of CD45RA^?CCR7^? Treg. Furthermore, the proliferation of Treg correlated positively with the CD45RA^?CCR7^? Treg proportion but negatively with Treg numbers. Successful antiretroviral therapy resulted in a limited increase in Treg numbers, but their frequency was reduced in 1–2 months due to a rapid rebound of FOXP3^? CD4⁺cells. Our results suggest that HIV‐activating Treg may be a reason for the high frequencies of Treg and CD45RA^?CCR7^? Treg in the peripheral blood of late‐stage HIV‐1‐infected patients.     

CD4+ NK cells can be productively infected with HIV, leading to downregulation of CD4 expression and changes in function

NK cells mediate the innate immune response, and HIV-infected individuals demonstrate altered NK cell phenotype and function. We find that CD4+ NK cells are susceptible to HIV infection; this could account for the NK cell dysfunction seen in HIV-infected individuals. CD4+ NK cells express CXCR4 and can be infected with X4-tropic viruses and some primary R5-utilizing viral isolates. Treatment with the CXCR4 ligands AMD3100 and SDF-1α partially blocks infection with X4-tropic virus, treatment with anti-CCL Igs upregulates CCR5 surface expression and enables infection with HIV-Bal. HIV infection of NK cells results in CD4 downregulation and the production of infectious virus. HIV-infected CD4+ NK cells mediate NK cell cytotoxicity, however, HIV infection is associated with decreased chemotaxis towards IL-16. Thus, HIV infection of CD4+ NK cells could account for the NK cell dysfunction observed in HIV-infected individuals. Furthermore infected NK cells could serve as a viral reservoir of HIV in vivo.     

Gut commensal microbes do not represent a dominant antigenic source for continuous CD4+ T‐cell activation during HIV‐1 infection

Chronic immune activation is a hallmark of HIV‐1 infection; specifically, the activation of T cells has predictive value for progression to AIDS. The majority of hyperactivated T cells are not HIV‐specific and their antigenic specificities remain poorly understood. Translocation of gut luminal microbial products to systemic sites contributes to chronic immune activation during HIV‐1 infection, but how it affects (TCR‐dependent) immune activation remains elusive. We hypothesized that gut luminal antigens foster activation of CD4⁺ T cells with specificities for commensal bacterial antigens, thereby contributing to the pool of activated CD4⁺ T cells in the circulation of HIV‐1 infected individuals. To test this hypothesis, we quantified the frequencies of gut microbe‐specific CD4⁺ T cells by cytokine production upon restimulation with selected gut commensal microbial antigens. Contrary to our hypothesis, we did not observe increased but rather decreased frequencies of gut microbe‐specific CD4⁺ T cells in HIV‐1 infected individuals compared to healthy controls. We conclude that the increased activation status of circulating CD4⁺ T cells in HIV‐1 infected individuals is not driven by CD4⁺ T cells with specificities for commensal bacterial antigens.     

CD4+ lymphocyte values and trends in individuals infected with Human Immunodeficiency Virus and/or co-infected with Hepatitis C Virus in The Gambia

Objectives

This study was undertaken to monitor the CD4+ lymphocyte count in individuals infected with Human Immunodeficiency Virus (HIV) and/or co-infected with Hepatitis C Virus (HCV) and to compare this with the counts in normal individuals in The Gambia.

Methods

Blood samples were taken from 1500 individuals referred for HIV serology at the Royal Victoria Teaching Hospital (RVTH) following informed consent. Samples were tested for antibodies to HIV by the Murex ELISA, antibodies to HCV by the Ortho ELISA, and CD4 counts determined by the Dynalimmunomagnetic cell isolation method

Results

Of the 1500 patients screened for HIV and HCV antibodies, 6.7% (101/1500) were infected with HIV, 0.6 % (9/1500) were co-infected with HCV and 1.5 % (22/1500) were infected with HCV alone. Almost half (44.6%; 25/56) of HIV-1 infected patients had a CD4+ lymphocyte count at diagnosis of 200 cells/µl or less as compared to 41.7 % (10/24) of HIV-2 and 75% (6/8) of HIV-D infected patients. The rate of CD4 decline was higher among HIV/HCV co-infected persons than individuals infected with HIV or HCV. The rate of decline was higher among men than women. These differences did not reach statistical significance due in large part to the small number of participants who completed the programme. The CD4+ lymphocyte count of apparently healthy Gambian male and females was 489 cells/µl and 496 cells/µl respectively. This rate is lower than that reported for Caucasians, but in agreement with the global range.

Conclusion

A significant progressive decline in CD4+ lymphocyte count was observed among the female control group who were negative for HIV and HCV. This finding is unclear and calls for a longitudinal study involving a cohort of women in this region.Short title: CD4+ counts in HIV/HCV co-infection     

Fas (CD95) expression on CD4+ T cells from HIV-infected patients increases with disease progression

Active T cell suicide (apoptosis) is supposed to be involved in the CD4⁺ T cell depletion in the course of HIV infection. We investigated the expression of the apoptosis-related antigen Fas on CD4⁺ T cells from 25 HIV-positive individuals (CDC I-III) and 8 HIV-negative controls by two-colour flowcytometry. In addition, we evaluated: total CD4 count, HIV p24 antigen concentration in serum after immune complex dissociation, and clinical course of infection in HIV-positive individuals. We found a significant increase in mean Fas expression on CD4⁺ T cells from HIV-positive individuals compared to HIV-negative individuals (85.84±14.92% vs. 64.28±7.59%, P<0.001). Within the HIV-positive group the increase in Fas expression was correlated with the decline in CD4 count (r=–0.76, P<0.001), p24 antigen concentration in serum after immune complex dissociation (r=0.67, P<0.001), and CDC stage (r=0.73, P<0.001). The upregulation of Fas antigen on CD4 cells is associated with CD4 depletion and other virological and clinical marker of disease progression in HIV infection.Abbreviations AIDS Acquired immunodeficiency syndrome - CDC Center of disease control - CTL Cytotoxic T lymphocyte - FasL Fas ligand - HIV Human immunodeficiency virus - MFI Mean fluorescence intensity     

Progressive CD127 down‐regulation correlates with increased apoptosis of CD8 T cells during chronic HIV‐1 infection

Chronic HIV‐1 infection can induce a significant decrease in CD127 expression on CD8 T cells, but the underlying mechanisms and immunological consequences are unclear. In this study, we investigated CD127 expression on CD8 T cells from a total of 51 HIV‐1‐infected subjects and 16 healthy individuals and analyzed the association between CD127 expression and CD8 T‐cell apoptosis in these HIV‐1‐infected subjects. We found that CD127 expression on total CD8 T cells was significantly down‐regulated, which was correlated with the increased CD8 T‐cell apoptosis and disease progression of chronic HIV‐1 infection. The in vitro addition of IL‐7 efficiently rescued the spontaneous apoptosis of CD8 T cells from HIV‐1‐infected individuals. IL‐7 stimulation also transiently down‐regulated CD127 expression, whereas some of the CD127^? CD8 T cells regained CD127 expression soon after IL‐7 was retracted from the incubation medium. Thus, IL‐7 stimulation reduced apoptosis of both CD127⁺ and CD127^?CD8 T cells to some degree. These data indicate that CD127 loss might impair IL‐7 signaling and increase CD8 T‐cell apoptosis during HIV‐1 infection. This study, therefore, will extend the notion that IL‐7 could be a good candidate for immunotherapy in HIV‐1‐infected patients.     

Factors influencing the normalization of CD4+ T-cell count, percentage and CD4+/CD8+ T-cell ratio in HIV-infected patients on long-term suppressive antiretroviral therapy

We evaluated factors associated with normalization of the absolute CD4+ T-cell counts, per cent CD4+ T cells and CD4+/CD8+ T-cell ratio. A multicentre observational study was carried out in patients with sustained HIV-RNA <50 copies/mL. Outcomes were: CD4-count >500/mm³ and multiple T-cell marker recovery (MTMR), defined as CD4+ T cells >500/mm³ plus %CD4 T cells >29% plus CD4+/CD8+ T-cell ratio >1. Kaplan-Meier survival analysis and Cox regression analyses to predict odds for achieving outcomes were performed. Three hundred and fifty-two patients were included and followed-up for a median of 4.1 (IQR 2.1–5.9) years, 270 (76.7%) achieving a CD4+ T-cell count >500 cells/mm³ and 197 (56%) achieving MTMR. Using three separate Cox models for both outcomes we demonstrated that independent predictors were: both absolute CD4+ and CD8+ T-cell counts, %CD4+ T cells, a higher CD4+/CD8+ T-cell ratio, and age. A likelihood-ratio test showed significant improvements in fitness for the prediction of either CD4+ >500/mm³ or MTMR by multivariable analysis when the other immune markers at baseline, besides the absolute CD4+ count alone, were considered. In addition to baseline absolute CD4+ T-cell counts, pretreatment %CD4+ T cells and the CD4+/CD8+ T-cell ratio influence recovery of T-cell markers, and their consideration should influence the decision to start antiretroviral therapy. However, owing to the small sample size, further studies are needed to confirm these results in relation to clinical endpoints.     

Impaired CD4+ cell recovery during antiretroviral therapy in patients with HIV resistance mutations

Antiretroviral therapy is limited by the development of human immunodeficiency virus (HIV) resistance mutations. Although resistance testing is recommended during therapy failure, little is known about the optimal time points for testing or its impact on treatment. In this study, we investigated HIV polymorphisms and mutations and assessed their influence on the outcome of highly active antiretroviral therapy (HAART). We focused on viral load and CD4+ cell counts as the most important parameters for therapy response. Resistance mutations were present in 19% of all patients prior to antiretroviral treatment. Mutations causing direct antiretroviral drug resistance were observed in 10%. Analyzing therapy response, we found a significant correlation between resistance mutations and impaired CD4+ cell recovery six months after the initiation of antiretroviral treatment. Lower CD4+  cell counts were also observed in a subgroup of patients infected with a virus presenting mutations that directly lowered drug susceptibility.     

Prevalence and impact of hepatitis B and C virus co-infections in antiretroviral treatment naïve patients with HIV infection at a major treatment center in Ghana

Data on the effects of the presence of hepatitis B virus (HBV) and hepatitis C virus (HCV) in patients co‐infected with these viruses and HIV in West Africa are conflicting and little information is available in Ghana. A cohort of 138 treatment naïve individuals infected with HIV was screened for HBV and HCV serologic markers; HBsAg positive patients were tested for HBeAg, anti‐HBe, and anti‐HBc IgM. The viral load of HIV‐1 in the plasma was determined in 81 patients. Eighteen of the 138 patients (13%) and 5 (3.6%) had HBsAg and anti‐HCV, respectively. None of the patients had anti‐HBc IgM, but 10 (55.6%) and 8 (44.4%) of the 18 patients who were HBsAg positive had HBeAg and anti‐HBe, respectively. In patients with measurement of CD4⁺ undertaken within 1 month (n = 83), CD4⁺ count was significantly lower in patients with HBeAg (median [IQR], 81 [22–144]) as compared to those with anti‐HBe (median [IQR], 210 [197–222]) (P = 0.002, CI: ?96.46 to 51.21). However, those with HIV mono‐infection had similar CD4⁺ counts (median [IQR], 57 [14–159]) compared to those with HBeAg (P = 1.0, CI: ?71.75 to 73.66). Similar results were obtained if CD4⁺ count was measured within 2 months prior to initiation of HAART (n = 119). Generally, HBV and anti‐HCV did not affect CD4⁺ and viral loads of HIV‐1 in plasma but patients with HIV and HBV co‐infection who had HBeAg had more severe immune suppression as compared to those with anti‐HBe. This may have implication for initiating HAART in HBV endemic areas. J. Med. Virol. 84:6–10, 2011. © 2011 Wiley Periodicals, Inc.     

Baseline CD4 T Cell Level Predicts Recovery Rate after Initiation of ART in HIV Infected Nigerians

The most characteristic immunologic disorder in HIV infection is the progressive loss of CD4 T lymphocytes, thus, it remains the most important and commonly used marker for monitoring of immune status of HIV-infected individuals. This study monitored CD4 T lymphocyte cell dynamics among HIV patients on ART, and consequently defined an optimal baseline level required for enhanced ARV treatment. Ninety-eight (M = 33; F = 65) out of 106 consenting HIV-infected ARV-naïve patients enrolled and monitored for 24 months were considered in the analysis. The patients were classified into four groups based on baseline CD4 T lymphocyte cell levels, and specific parameters were evaluated at interval. Median CD4 T lymphocyte increased from 114 (Range: 6–330) at baseline to highest 357 (Range: 15–1036) cells/μL at 18 months of therapy. Fifty (51.0%), 58(59.2%), 75(76.5%), 69(70.4%), 63(64.3%), and 69(70.4%) doubled their preceding CD4 levels during the 3^rd, 6^th, 9^th, 12^th, 18^th, and 24^th months of ART, respectively. Maximum 337, 302, 360, and 475 cells/μL of blood were attained by groups commenced on ART with baseline CD4 ≤ 50, 51–100, 101–200, and 201–350 cells/μL of blood, respectively. The results show that higher baseline CD4 T lymphocyte cell level correlates with enhanced restoration and plateau after commencement of ART.     

Interleukin‐4 downregulates CD127 expression and activity on human thymocytes and mature CD8+ T cells

Signaling via the IL‐7 receptor complex (IL‐7Rα/CD127 and IL‐2Rγ/CD132) is required for T‐cell development and survival. Decreased CD127 expression has been associated with persistent viral infections (e.g. HIV, HCV) and cancer. Many IL‐2Rγ‐sharing (γ_C) cytokines decrease CD127 expression on CD4⁺ and CD8⁺ T cells in mice (IL‐2, IL‐4, IL‐7, IL‐15) and in humans (IL‐2, IL‐7), suggesting a common function. IL‐4 is of particular interest as it is upregulated in HIV infection and in thyroid and colon cancers. The role of IL‐4 in regulating CD127 expression and IL‐7 activity in human thymocytes and mature CD8⁺ T cells is unknown and was therefore investigated. IL‐4 decreased CD127 expression on all thymocyte subsets tested and only on naïve (CD45RA⁺) CD8⁺ T cells, without altering membrane‐bound CD127 mRNA expression. Pre‐treatment of thymocytes or CD8⁺ T cells with IL‐4 inhibited IL‐7‐mediated phosphorylation of STAT5 and decreased proliferation of CD8⁺ T cells. By downregulating CD127 expression and signaling on developing thymocytes and CD8⁺ T cells, IL‐4 is a potential contributor to impaired CD8⁺ T‐cell function in some anti‐viral and anti‐tumor responses. These findings are of particular consequence to diseases such as HIV, HCV, RSV, measles and cancer, in which CD127 expression is decreased, IL‐7 activity is impaired and IL‐4 concentrations are elevated.     

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.     

Determination of cell expansion and surface molecule expression on anti‐CD3/28 expanded CD4+ T cells

CD4⁺ T cell immunotherapy has potential for treatment in HIV‐infected patients. A large number of expanded CD4⁺ T cells and confirmation of functional‐related phenotypes are required for ensuring the successful outcomes of treatment. Freshly isolated CD4⁺ T cells from healthy donors were activated with anti‐CD3/28‐coated magnetic beads at different bead‐to‐cell ratios and cultured in the absence and presence of IL‐2 supplementation for 3 weeks. Fold expansion, cell viability, growth kinetic and lymphocyte subset identities were determined. Data demonstrated that a 1:1 bead‐to‐cell ratio rendered the highest expansion of 1044‐fold with 88% viability and 99.5% purity followed by the 2:1 and 0.5:1 ratios. No significant difference in proliferation and phenotypes was found between non–IL‐2 and IL‐2 supplementation groups. Several specific surface molecule expressions of the expanded cells including chemokine receptors, adhesion molecules, co‐stimulatory molecules, activation molecules, maturation markers, cytokine receptors and other molecules were altered when compared to the unexpanded cells. This optimized expansion protocol using the 1:1 bead‐to‐cell ratio of anti‐CD3/28‐coated magnetic beads and culture condition without IL‐2 supplementation provided the satisfactory yield with good reproducibility. Specific surface molecule expressions of the expanded cells presented potential roles in proliferation, differentiation, homeostasis, apoptosis and organ homing.     

Dynamics of CD4 cell count among HIV-infected individuals in Lagos,Nigeria

Human immunodeficiency virus (HIV) infection leads to progressive loss of CD4 T cells. Antiretroviral therapy has been able to inhibit this process, resulting in significant level of immune recovery and function. Our aim is to investigate the dynamics of CD4 recovery among HIV patients in Lagos, Nigeria. A total of 213 HIV-positive individuals were enrolled between October 2007 and May 2008, and followed up for 9 months based on CD4 count. CD4 analysis was done by flow cytometry at enrollment and after every 3 months. Data were grouped according to age range, antiretroviral treatment (ART), and time between infection and diagnosis. Kaplan–Meier survival analysis was used for data analysis. There was a significant difference in CD4 count between antiretroviral (ART) naïve and ART experienced subjects (P < 0.001). About 50% of the ART experienced population was identified to show poor CD4 reconstitution unable to achieve a CD4 of 500 cells/µl after 9 months of therapy. Time interval between infection and therapy was also identified to contribute to poor CD4 restoration. Further studies need to be done to classify immunological nonresponders among HIV patients in Nigeria. We also recommend introduction of programs that will facilitate early detection of HIV infection.