Immunological changes after highly active antiretroviral therapy with lopinavir-ritonavir in heavily pretreated HIV-infected children

Characterization of age-related immune features after autologous NK cell infusion: Protocol for an open-label and randomized controlled trial

Background

Aging is usually accompanied by functional declines of the immune system, especially in T-cell responses. However, little is known about ways to alleviate this.

Methods

Here, 37 middle-aged healthy participants were recruited, among which 32 were intravenously administrated with expanded NK cells and 5 with normal saline. Then, we monitored changes of peripheral senescent and exhausted T cells within 4 weeks after infusion by flow cytometry, as well as serum levels of senescence-associated secretory phenotype (SASP)-related factors. In vitro co-culture assays were performed to study NK-mediated cytotoxic activity against senescent or exhausted T cells. Functional and phenotypic alteration of NK cells before and after expansion was finally characterized.

Results

After NK cell infusion, senescent CD28-, CD57+, CD28-CD57+, and CD28-KLRG1+ CD4+ and CD8+ T-cell populations decreased significantly, so did PD-1+ and TIM-3+ T cells. These changes were continuously observed for 4 weeks. Nevertheless, no significant changes were observed in the normal saline group. Moreover, SASP-related factors including IL-6, IL-8, IL-1α, IL-17, MIP-1α, MIP-1β, and MMP1 were significantly decreased after NK cell infusion. Further co-culture assays showed that expanded NK cells specifically and dramatically eliminated senescent CD4+ T cells other than CD28+CD4+ T cells. They also showed improved cytotoxic activity, with different expression patterns of activating and inhibitory receptors including NKG2C, NKG2A, KLRG1, LAG3, CD57, and TIM3.

Conclusion

Our findings imply that T-cell senescence and exhaustion is a reversible process in healthy individuals, and autologous NK cell administration can be introduced to alleviate the aging.

Clinical Trial Registration

ClinicalTrials.gov, ChiCTR-OOh-17011878.

Chronic immune activation and decreased CD4 cell counts associated with hepatitis C infection in HIV-1 natural viral suppressors

We have established a cohort of natural viral suppressors (NVS) who can suppress HIV-1 replication to less than 400 copies/ml in the absence of therapy (similar to Elite Controllers/Elite Suppressors). Of the 59 patients currently in the NVS cohort, 45.8% have chronic hepatitis C virus (HCV) infection, thereby presenting a unique opportunity to study immune activation and the interaction between HCV and HIV. NVS with chronic HCV infection had elevated levels of immune activation (CD38-positive HLA-DR-positive CD8 cells) compared to NVS without chronic HCV (P = 0.004). The increased levels of immune activation were not associated with sex, HLA B57 status, or injection drug use use. NVS patients with chronic HCV had lower mean CD4 cell counts, CD4 percentage, and CD4/CD8 ratios than NVS without chronic HCV infection (P = 0.038, P = 0.008, and P = 0.048, respectively). The difference in CD4 cell count appeared to occur early in HIV infection with no difference observed in CD4 slopes between groups. Among all NVS, there was a direct correlation between mean CD4 cell count, mean CD4 percentage, and mean CD4/CD8 ratio with percentage of CD38 HLA-DR CD8 cells (P = 0.0018; P = 0.0069; and P = 0.0014, respectively). This study suggests a relationship between HCV infection, immune activation, and CD4 cell counts in the NVS, with chronic HCV infection associated with lower CD4 cell counts and higher levels of immune activation. Further studies are needed to determine if successful HCV treatment lowers immune activation levels and/or increases CD4 cell counts in these patients.

Boosted protease inhibitors as a therapeutic option in the treatment of HIV-infected children

OBJECTIVE

Paediatric HIV treatment must address various special considerations. Administration of pharmacokinetically enhanced protease inhibitors (PIs) can improve paediatric therapeutic outcomes. The objective of this study was to review the use of boosted PI regimens in children.

METHODS

Systematic literature searches of published manuscripts and conference databases using generic drug names and specific keywords were performed to ensure thorough and balanced reporting of available data.

RESULTS

Boosted PI regimens offer multiple options across a range of ages and are efficacious in naïve and experienced children; safety and tolerability are similar to those observed in adults. Novel boosted PI simplification approaches may foster adherence and diminish resistance.

CONCLUSIONS

Boosted PIs are key components of first- and second-line treatments in children. Identifying factors associated with the response to highly active antiretroviral therapy in children may ultimately permit individualized therapies.

CD57+ T lymphocytes and functional immune deficiency

CD57(+) expression in T lymphocytes has been recognized for decades as a marker of in vitro replicative senescence. In recent years, accumulating evidences have pointed on the utility of this marker to measure functional immune deficiency in patients with autoimmune disease, infectious diseases, and cancers. We review here the relevant literature and implications in clinical settings.

Immunological recovery and metabolic disorders in severe immunodeficiency HIV type 1-infected children on highly active antiretroviral therapy

Little is known about immunologic reconstitution in children on highly active antiretroviral treatment (HAART) during very long-term periods. A retrospective study was carried out to assess the effectiveness and development of metabolic disorders after very long-term periods on HAART in HIV-infected children with severe immunodeficiency. We included 55 children who were stratified into three groups according to %CD4(+) pre-HAART and rate of immunologic recovery: (1) S1-Rec: CD4(+) < or =5% at baseline and slow immunologic recovery; (2) S2-Rec: CD4(+) 5-15% at baseline and slow immunologic recovery; (3) R-Rec: CD4(+) < or =15% at baseline and rapid immunologic recovery (reference group). An adequate immune recovery after 8 years on HAART was achieved by only 25% of children. S1-Rec never achieved a mean of CD4(+) > or =25% after 8 years on HAART. All children had a significant increase in plasma cholesterol levels during the first 2 years. Afterward, cholesterol levels reached a plateau and remained stable until year 8 of follow-up. Higher rates of lipodystrophy were found in the R-Rec group [14 (100%)] than in the S1-Rec group [9/19 (47.4%)] or the S2-Rec group [13/20 (65%)] at the end of the study (p = 0.006). Overall, having a low nadir of CD4(+) hindered immune reconstitution; however, children with rapid immunologic recovery showed a higher prevalence of the lipodystrophy syndrome.

Current and future antiretroviral treatment options in paediatric HIV infection

Because of a lack of prevention policies or problems in implementing prevention of mother-to-child transmission (P-MTCT), most of the 1500 daily new HIV infections in children aged<15 years are caused by MTCT. Fifteen percent of all HIV-infected individuals are children, but the vast majority lack access to highly active antiretroviral therapy (HAART), which can drastically reduce morbidity and mortality. There are 22 antiretroviral drugs currently approved by the US FDA for use in the treatment of HIV-infected adults and adolescents, but only 12 of these drugs are approved for use in children. Antiretroviral drugs belong to four major classes: nucleoside and nucleotide analogue reverse transcriptase inhibitors (NRTIs), non-nucleoside reverse transcriptase inhibitors (NNRTIs), protease inhibitors and fusion inhibitors. According to international guidelines developed by organizations including WHO, the Paediatric European Network for Treatment of AIDS (PENTA) and the US National Institutes of Health (US-NIH), the treatment of choice for HIV-infected children and adults is a combination of two NRTIs (backbone treatment) plus a third potent agent from a different class, either an NNRTI or a ritonavir-boosted protease inhibitor. There are specific challenges in treating HIV-infected children, including uncertainty about the best time to start treatment, the need for more paediatric formulations, the lack of pharmacokinetic studies for new drugs, and incomplete dosing guidelines. Furthermore, the most appropriate regimen for an individual child depends on a variety of factors, including the age of the child; the availability of appropriate drug formulations; the potency, complexity and toxicity of the drug regimen; the home situation; the child and caregiver's ability to adhere to the regimen; and the child's antiretroviral treatment history. In addition, antiretroviral drugs are not licensed for all age groups and the drugs are often not affordable. This review describes NNRTI and protease inhibitors as key components of first- and second-line antiretroviral therapy (ART), focusing on the rationale for choosing an NNRTI- versus protease inhibitor-based regimen based on the results of available phase II and III studies. Some of the new agents available for children as second-line and salvage therapy both on- and off-label are also discussed. The drug regimens described in this review are relevant to clinicians in developed and developing countries. The availability of new, potent compounds with different resistance and toxicity profiles may represent an alternative option to interclass switching and could redefine ART strategy, including the option of first-line NRTI-sparing regimens.

Pharmacokinetics of high-dose lopinavir-ritonavir with and without saquinavir or nonnucleoside reverse transcriptase inhibitors in human immunodeficiency virus-infected pediatric and adolescent patients previously treated with protease inhibitors

Human immunodeficiency virus (HIV)-infected children and adolescents who are failing antiretrovirals may have a better virologic response when drug exposures are increased, using higher protease inhibitor doses or ritonavir boosting. We studied the pharmacokinetics and safety of high-dose lopinavir-ritonavir (LPV/r) in treatment-experienced patients, using an LPV/r dose of 400/100 mg/m(2) orally every 12 h (p.o. q12h) (without nonnucleoside reverse transcriptase inhibitor [NNRTI]), or 480/120 mg/m(2) p.o. q12h (with NNRTI). We calculated the LPV inhibitory quotient (IQ), and when the IQ was <15, saquinavir (SQV) 750 mg/m(2) p.o. q12h was added to the regimen. We studied 26 HIV-infected patients. The median age was 15 years (range, 7 to 17), with 11.5 prior antiretroviral medications, 197 CD4 cells/ml, viral load of 75,577 copies/ml, and a 133-fold change in LPV resistance. By treatment week 2, 14 patients had a viral-load decrease of >0.75 log(10), with a median maximal decrease in viral load of -1.57 log(10) copies/ml at week 8. At week 2, 19 subjects showed a median LPV area under the concentration-time curve (AUC) of 157.2 (range, 62.8 to 305.5) microg x h/ml and median LPV trough concentration (C(trough)) of 10.8 (range, 4.1 to 25.3) microg/ml. In 16 subjects with SQV added, the SQV median AUC was 33.7 (range, 4.4 to 76.5) microg x h/ml and the median SQV C(trough) was 2.1 (range, 0.2 to 4.1) microg/ml. At week 24, 18 of 26 (69%) subjects remained in the study. Between weeks 24 and 48, one subject withdrew for nonadherence and nine withdrew for persistently high virus load. In antiretroviral-experienced children and adolescents with HIV, high doses of LPV/r with or without SQV offer safe options for salvage therapy, but the modest virologic response and the challenge of adherence to a regimen with a high pill burden may limit the usefulness of this approach.