Highly active antiretroviral therapy restores in vitro mitogen and antigen-specific T-lymphocyte responses in HIV-1 perinatally infected children despite virological failure

To analyse the effect of highly active antiretroviral therapy (HAART) on T-lymphocyte functions we selected seven HIV-1 perinatally infected children (CDC immunological category 1 or 2) who had neither a fall in their plasma HIV-1 RNA levels nor a significant rise in CD4+ lymphocyte counts while receiving HAART. Clinical signs and symptoms were monitored monthly. Plasma viral load, CD4+, CD8+, CD19+ lymphocyte counts and in vitro T-lymphocyte proliferative responses to mitogens (anti-CD3, phytohaemoagglutinin, concanavalin A and pokeweed mitogen) and recall antigens (Candida albicans and tetanus toxoid) were tested at baseline and after 1, 3, 6 and 12 months of HAART. Twenty-two healthy age-matched children were studied as controls. A gain in body weight, no worsening of the disease and no recurrence of opportunistic infections were observed. At baseline, the majority of the children had low responses to mitogens, and all of them had a defective in vitro antigen-specific T-lymphocyte response (<2 standard deviations below the mean result for controls). During HAART, a significant increase in the response to mitogens and antigens was observed in all the patients. The T-lymphocyte response was restored more consistently against antigens to which the immune system is constantly exposed (Candida albicans, baseline versus 12 months: P < 0.001) compared with a low-exposure antigen (tetanus toxoid, baseline versus 12 months: P < 0.01). HAART restores in vitro T-lymphocyte responses even in the absence of a significant viral load decrease and despite any significant increase in CD4+ lymphocyte counts. It implies that a direct mechanism might be involved in the overall immune recovery under HAART.     

Cytokine profiles in highly active antiretroviral treatment non-adherent,adherent and naive HIV-1 infected patients in Western Kenya

BackgroundCytokines play an important role in signaling the immune system to build an adequate immune response against HIV. HIV distorts the balance between pro and anti-inflammatory cytokines causing viral replication. Highly active antiretroviral treatment (HAART) acts by trying to restore pro and anti-inflammatory cytokine balance. It is not clear how HAART non-adherence influences circulating cytokine levels. This study therefore determined cytokine levels in HAART non-adherent individuals.MethodsThis cross-sectional study recruited 163 participants (51 controls, 23 HIV-1+ HAART naive, 28 HAART-adherent 6 months, 19 HAART-adherent 12 months and 42 HAART non-adherent). Cytokines were analyzed by ELISA while CD4 T cells determined in 3.0 µl of whole blood using BD FACSCaliburTM and viral load in 0.2ml plasma sample using Abbott Molecular m2000sp sample preparation and m2000rt real-time amplification and detection systems (Abbott Molecular Inc., Illinois, USA) according to the manufacturer''s methods.ResultsIL-4, IL-6, IL-10, TNF-α and TGF-β were significantly elevated in HIV-1 HAART non-adherent compared with HIV-1 HAART adherent and healthy controls P<0.01. IFN- γ was significantly decreased in HIV-1 HAART non-adherent compared with HIV-1 HAART adherent and healthy controls P<0.01. TNF-α and TGF-β were significantly reduced in HIV-1 HAART adherent patients at 12 months compared to those at 6 months P<0.01. IL-4 and IL-10 correlated positively with viral load. IL-4, IL-6, IL-10, TNF-α and TGF- β associated inversely with CD4 T cell counts and body mass index (BMI).ConclusionThis study established that HAART adherence is immunologically beneficial to the pro and anti-inflammatory cytokine balance milieu while non-adherence appears to cause alterations in pro and anti-inflammatory cytokines warping the balance in this dichotomy.     

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.     

Immunological and virological consequences of patient-directed antiretroviral therapy interruption during chronic HIV-1 infection

Increasing numbers of patients are choosing to interrupt highly active antiretroviral therapy (HAART). We describe the effect of patient-directed treatment interruption (PDTI) on plasma viral loads (pVL), proviral DNA (pDNA), lymphocyte subsets and immune responses in 24 chronically HIV-1 infected individuals. Patients were divided into group A with pVL > 50 copies/ml and group B with pVL < 50 copies/ml, prior to the PDTI. pVL rose significantly in group B during the first month off HAART and was associated with a significant decrease in CD4 T-cell count. At baseline there was a significant difference in HIV-1 pDNA levels between groups A and B, however, levels significantly increased in group B, but not in group A during PDTI becoming equivalent after 1 month PDTI. We have previously shown no increase in pDNA over the time of substitution in patients switching HAART regimens despite a small rebound in pVL. These observations indicate that to protect low pDNA levels PDTI should be discouraged and that changing regimen at the first sign of failure should be advised where possible. Only transient, no longer than 4 week, HIV-1-specific responses were observed during PDTI in 5/24 patients, 2 from group A and 3 from group B. The low numbers of responders and the transient nature of the anti-HIV-1 immune responses do not favour the auto-vaccination hypothesis.     

Efficacy of antiretroviral therapy in individuals infected with HIV-1 non-B subtypes

The impact of HIV-1 subtype on clinical outcome following exposure to antiretroviral therapy is currently not well known. Natural polymorphisms are often present in HIV-1 non-B subtypes at positions known to be associated with drug resistance in clade B viruses. These changes might influence the emergence of drug-resistant viruses, modifying drug susceptibility and/or the virus replicative capacity. Moreover, different pathways may lead to drug resistance according to HIV-1 clade. Finally, the influence of subtype on the performance of phenotypic assays and in the interpretation of algorithms for genotypic resistance is currently a matter of debate. All these aspects explain why the response to antiretroviral therapy might vary in subjects infected with different HIV-1 clades.     

IL-2 and IL-10 serum levels in HIV-1-infected patients with or without active antiretroviral therapy

We analyzed IL-2 and IL-10 serum levels in 26 HIV-1-infected patients naive of antiretroviral treatment and in 34 patients receiving highly active antiretroviral therapy (HAART). All patients without treatment were asymptomatic. When they were stratified according to levels of CD4+ T cells, IL-2 levels were significantly increased in patients with > or =200 CD4+/microl and IL-10 levels were significantly increased in patients with <200 CD4+/microl compared to controls. A significant negative correlation was observed between IL10 levels and CD4+ T-cell counts. No correlation was observed between IL-2 and IL-10 levels and viral load due to the wide range of variability in the number of HIV copies/ml present in the different patients. However, IL-2 levels were higher in patients with high viral load than in patients with low viral load. In patients with HAART, IL-2 and IL-10 levels were similar to the control group and no differences were detected respecting CD4+ T cells counts and viral load. Our findings show that the modifications in IL-2 and IL-10 serum levels in HIV-1-infected patients naive of antiretroviral treatment are associated with the progression of immunological damage. Furthermore, they show a dysbalance of type-1/type-2 cytokines with an involvement of type-2 cytokines in later stages of HIV infection. Cytokine dysregulation can be reversed by HAART in the context of immune restoration and viral suppression.     

Lipodystrophy syndrome among HIV infected children on highly active antiretroviral therapy in northern India

Background

It is estimated that about 2.5 million people are living with HIV infection in India. Although antiretroviral drugs have been able to reduce the mortality, these drugs have serious side effects one of which is lipodystrophy syndrome. Most of the drugs used in HAART viz, protease inhibitors, stavudine and nevirapine are associated with lipodystrophy. Hence we conducted this study to assess the prevalence of lipodystrophy in HIV infected children on HAART and its associated risk factors.

Materials and methods

A cross sectional study was conducted on 80 HIV infected children aged 2–18 years of age who were on stavudine based HAART for ≥2 years. These children were assessed for presence of lipodystrophy, its metabolic complications and associated risk factors.

Results

Lipodystrophy was observed in 33.7% of children with lipoatrophy being the commonest subtype followed by lipohypertrophy. Older age, increased duration of treatment and dyslipidaemia were found to be associated in patients with lipodystrophy than those without. On further multivariate analysis of independent risk factors only increased duration of treatment was significantly associated with lipodystrophy. No association was found with insulin resistance.

Conclusion

We observed that lipodystrophy is a common finding in HIV patients treated with HAART for long duration.     

慢性HIV感染者抗逆转录病毒治疗过程中树突状细胞亚群的变化特点

目的 了解慢性人免疫缺陷病毒(HIV)感染者抗逆转录病毒治疗(ART)过程中树突状细胞(DC)亚群的变化特点.方法 选取ART治疗的慢性HIV感染者17例,分别于治疗0,4,8,12,24,48,60周采集静脉血,同时选取健康者、长期不进展者(LTNPs)各15例为对照.常规进行CD4+/CD8+T细胞计数和病毒载量测定;用流式细胞术测定DC亚群,ELISA测定血浆IFN-α水平;采用SPSS16.0软件分析数据特点.结果 (1) ART治疗前HIV感染者髓样树突状细胞(mDC)百分比及绝对计数明显低于健康组和LTNP组(P＜0.001).ART治疗60周后,HIV感染者mDC明显增加,与健康组、LTNP组之间差异无统计学意义.(2) ART治疗过程中浆细胞样树突状细胞(pDC)数量和血浆IFN-α水平保持相对稳定,且接近健康组、LTNP组水平.(3) ART治疗前DC亚群细胞计数与CD4+T细胞计数正相关.ART治疗12、24、60周,mDC细胞计数与CD4+T细胞计数正相关,与病毒载量负相关.ART治疗8周mDC细胞计数增加值与治疗60周CD4+T细胞计数增加值正相关,与病毒载量下降值负相关.结论 HIV感染者mDC细胞数量明显减少,ART治疗后明显上升,与CD4+T细胞计数正相关,提示mDC在控制HIV感染方面可能具有重要作用.治疗早期mDC细胞数量可能是ART治疗后免疫重建的早期预测指标.     

Reconstitution of NK cell activity in HIV-1 infected individuals receiving antiretroviral therapy

We studied natural immunity mediated by natural killer (NK) cells in 62 HIV-1 infected individuals, 54 HIV-1 infected individuals receiving highly active antiretroviral therapy (HAART) for more than one year and 8 HIV-1 infected individuals without antiretroviral therapy. 22 individuals had a complete suppression of viral replication characterized by viral load values <50 copies/ml, whereas 32 individuals presented with persistent viral replication. The 8 untreated patients had an indication to start antiretroviral treatment. Lytic activity of NK cells was measured in a 51chromium release assay. In patients with persistent viral replication under HAART NK cell activity was significantly decreased compared to patients with effective control of HIV viremia. Patients with complete suppression of HIV replication displayed a similar NK activity to healthy control persons. Differences in antibody-dependent cellular cytotoxicity (ADCC) were not observed. Further studies will investigate whether decreased NK cell activity is a reason for or the consequence of persistent viral replication.     

Efficient monitoring of HIV-1 vertically infected children in Kenya on first-line antiretroviral therapy

Background

Worldwide access to antiretroviral therapy (ART) in low- and middle-income countries has significantly increased. Although this presents better treatment options for HIV-infected individuals, the challenge of monitoring ART in these settings still remains.

Objective

To investigate efficient and cost-effective criteria for assessing ART failure among HIV-1-infected children on first-line ART in resource-limited settings.

Study design

Retrospective analysis of 75 HIV-1 vertically infected Kenyan children with a follow-up period of 24 months after initiating ART. Plasma viral load, peripheral CD4⁺T-cell counts and HIV-1 drug-resistance mutations were monitored biannually.

Results

Plasma viral load (VL) was suppressed to undetectable level or more than 1.5 log₁₀ from baseline levels in 53 (70.7%) children within 24 months. VL in the remaining 22 (29.3%) children was not suppressed significantly. Of the 22 children, 21 were infected with HIV-1 strains that developed drug-resistance mutations; 9 within 12 months and 12 between 12 and 24 months. Among the 53 who were successfully treated, VL was suppressed in 33 within 12 months and in 20 between 12 and 24 months. There was no significant difference in VL at baseline and the change of CD4⁺T-cell counts after initiating ART between those treated successfully and the failure groups.

Conclusion

After initiating ART, children may require longer times to achieve complete viral suppression. Plasma viral load testing 24 months after initiating ART could be used to differentiate ART failures among HIV-1 vertically infected children in resource-limited settings. Additionally, drug resistance testing, if affordable, would be helpful in identifying those failing therapy and in choosing second-line regimens.     

Significant differences between plasma HIV-1 RNA assays in HIV-1 subtype E infected patients treated with antiretroviral therapy

A total of 72 HIV-1 infected Thai patients treated with didanosine (ddI) or stavudine (d4T) plus ddI at the time of interim analysis were analyzed. Sixty patients (83%) carried subtype E documented by HIV-1 V3 serotyping. HIV-1 RNA levels were measured using three commercial viral load assays. At baseline (n = 57), Quantiplex 2.0 and NucliSens 2.0 showed mean log10 HIV-1 RNA of 0.7 log10 or 5 fold lower than Amplicor 1.5 (mean 4.29 versus 5.0 log10, respectively, p < 0.001). At week 20 of treatment (n = 29), HIV-1 RNA levels were detected in 55.2%, 31%, and 33.5% of subjects tested by Amplicor 1.5, Quantiplex 2.0, and NucliSens 2.0, respectively. In conclusion: plasma HIV-1 RNA analyses showed comparable values with Quantiplex 2.0 and NucliSens 2.0 assays. In contrast, Amplicor 1.5 resulted in approximately 5 folds higher HIV-1 RNA levels and a 25% higher rate of detection of plasma HIV-1 RNA as compared to the other two assays. As the current goal of therapy is to suppress plasma viral load below the detection limit of the assays, the significant differences between the assays may influence antiretroviral efficacy evaluation and management.     

Reconstitution of CD4+ T cell responses in HIV-1 infected individuals initiating highly active antiretroviral therapy (HAART) is associated with renewed interleukin-2 production and responsiveness

Reconstitution of functional CD4(+) T cell responsiveness to in vitro stimuli is associated with continuous highly active antiretroviral therapy (HAART). Thirty-six antiretroviral naive patients received HAART over 16 weeks. Antigen-specific, mitogen and interleukin (IL)-2 induced lymphocyte proliferative responses and specific IL-2 and IL-4 production were assessed at each time-point, together with quantification of HIV-1 RNA load and lymphocyte populations. Reconstitution of recall responses was limited largely to persistent antigens such as Herpes simplex virus and Candida, rather than to HIV-1 or neo-antigens. Recall antigens, mitogens and IL-2-induced renewed responses were associated with in-vitro production of IL-2, but not IL-4. Differential responsiveness to low versus high concentration IL-2 stimulus increases in a stepwise manner, suggesting normalization of IL-2 receptor expression and improved functionality. These increases in in-vitro proliferative responses thus probably reflect short lived effector clones, driven by ongoing antigenic stimulus associated with persisting long-term organisms. In this context non-responsiveness to HIV-1 antigens suggests ongoing HIV-1 specific clonal T cell anergy.     

Deletions in env gene of HIV-1 in AIDS patients treated with highly active antiretroviral therapy (HAART)

Many AIDS patients retain high CD4+ T-cell counts despite a significant increase in PCR viral load after varied periods of treatment on drug combination with Highly Active Antiretroviral Therapy (HAART). In order to investigate this contradictory phenomenon, we assayed for infectious HIV-1 from the plasma of such patients. Since the biological assays failed to reveal any infectious virus, we undertook molecular characterization of the plasma HIV-1 genes. These studies revealed large deletions in the env gene of the free virus, while there were no deletions in the proviral DNA obtained from the infected cells of the patients' blood. This suggests that the viral particles produced and released by the infected cells during the HAART treatment have deletions in the env gene. The deletions were large enough to produce an envelop-deficient virus, which can readily explain why it is not infectious. Such a defective virus is the most likely explanation for its failure to infect the T-cells, which in turn lead to the discordance between the high PCR viral load and stable CD4+ T cell counts.     

CD4+ T-lymphocyte nadir and the effect of highly active antiretroviral therapy on phenotypic and functional immune restoration in HIV-1 infection

To evaluate the effects of the timing of highly active antiretroviral therapy (HAART) on immune reconstitution, we compared lymphocyte subpopulations and lymphocyte proliferation (LP) in response to Candida albicans, cytomegalovirus, HIV p24, Mycobacterium avium complex, pokeweed mitogen, streptokinase, and tetanus toxoid in 43 patients with pretherapy advanced, moderately advanced, and early chronic HIV-1 infection. All patients had recent CD4⁺ T-cell counts >450/μl and HIV RNA <400 copies/ml for >12 months. CD4⁺ nadirs were positively correlated with recent numbers of CD4⁺ T-cells (P < 0.001), memory cells (P < 0.001), and na??ve CD4⁺ T-cells (P < 0.05) and CD4⁺ CD28⁺ T-lymphocytes (P < 0.05) and were negatively correlated with recent CD8⁺ T-lymphocyte counts (P < 0.05). Only CD4⁺ na??ve T-cells normalized when HAART was initiated at lower CD4⁺ T-cell levels. Fifty-three percent of patients had LP responses to HIV p24 antigen. While LP responses to prevalent antigens were usually present, responses to tetanus toxoid were more common with higher CD4⁺ T-lymphocyte nadirs (P < 0.05). Delaying HAART may limit phenotypic and functional immune restoration in HIV-1 infection.     

T cell proliferation and apoptosis in HIV-1-infected lymphoid tissue: impact of highly active antiretroviral therapy.

T cell turnover was studied in situ in tonsillar lymphoid tissue (LT) from HIV-1-infected individuals during 48 weeks of highly active antiretroviral therapy (HAART) and compared to that of HIV-1-negative controls. Prior to therapy, CD4 cell proliferation (%CD4+ Ki67+) and apoptosis (%CD4+ TUNEL+) were increased in HIV-1-infected LT and both parameters correlated with tonsillar viral load. CD8 cell proliferation (%CD8+ Ki67+) was increased 4- to 10-fold, mainly in the germinal centers. Apoptotic CD8+ T cell levels (%CD8+ TUNEL+) were raised preferentially in the tonsillar T cell zone. The frequency of CD8+ Ki67+ and CD8+ TUNEL+ T cells correlated with tonsillar viral load and with the fraction of CD8(+) T cells expressing activation markers. During HAART, CD4 cell turnover normalized while CD8 cell turnover was dramatically reduced. However, low level viral replication concomitant with slightly elevated levels of CD8 cell turnover indicated a persistent cellular immune response in LT. In conclusion, enhanced T cell turnover may reflect effector cells related to HIV-1 infection.     

Effects of combined antiretroviral therapy on B- and T-cell release from production sites in long-term treated HIV-1+ patients

ABSTRACT: BACKGROUND: The immune system reconstitution in HIV-1- infected patients undergoing combined antiretroviral therapy is routinely evaluated by T-cell phenotyping, even though the infection also impairs the B-cell mediated immunity. To find new laboratory markers of therapy effectiveness, both B- and T- immune recovery were evaluated by means of a follow-up study of long-term treated HIV-1- infected patients, with a special focus on the measure of new B- and T-lymphocyte production. METHODS: A longitudinal analysis was performed in samples obtained from HIV-1-infected patients before therapy beginning and after 6, 12, and 72 months with a duplex real-time PCR allowing the detection of K-deleting recombination excision circles (KRECs) and T-cell receptor excision circles (TRECs), as measures of bone-marrow and thymic output, respectively. A cross sectional analysis was performed to detect B- and T-cell subsets by flow cytometry in samples obtained at the end of the follow-up, which were compared to those of untreated HIV-1-infected patients and uninfected controls. RESULTS: The kinetics and the timings of B- and T-cell release from the bone marrow and thymus during antiretroviral therapy were substantially different, with a decreased B-cell release and an increased thymic output after the prolonged therapy. The multivariable regression analysis showed that a longer pre-therapy infection duration predicts a minor TREC increase and a major KREC reduction. CONCLUSIONS: The quantification of KRECs and TRECs represent an improved method to monitor the effects of therapies capable of influencing the immune cell pool composition in HIV-1-infected patients.