Francesca Sabbatini

CD4+ T cell depletion, immune activation and increased production of regulatory T cells in the thymus of HIV-infected individuals.

Mechanisms by which HIV affects the thymus are multiple and only partially known, and the role of thymic dysfunction in HIV/AIDS immunopathogenesis remains poorly understood. To evaluate the effects of HIV infection on intra-thymic precursors of T cells in HIV-infected adults, we conducted a detailed immunophenotypic study of thymic tissue isolated from 7 HIV-infected and 10 HIV-negative adults who were to undergo heart surgery. We found that thymuses of HIV-infected individuals were characterized by a relative depletion of CD4+ single positive T cells and a corresponding enrichment of CD8+ single positive T cells. In addition, thymocytes derived from HIV-infected subjects showed increased levels of activated and proliferating cells. Our analysis also revealed a decreased expression of interleukin-7 receptor in early thymocytes from HIV-infected individuals, along with an increase in this same expression in mature double- and single-positive cells. Frequency of regulatory T cells (CD25+FoxP3+) was significantly increased in HIV-infected thymuses, particularly in priorly-committed CD4 single positive cells. Our data suggest that HIV infection is associated with a complex set of changes in the immunophenotype of thymocytes, including a reduction of intrathymic CD4+ T cell precursors, increased expression of activation markers, changes in the expression pattern of IL-7R and enrichment of T regulatory cells generation.

Qualitative Immune Modulation by Interleukin-2 (IL-2) Adjuvant Therapy in Immunological Non Responder HIV-Infected Patients

Background Treatment of HIV-infected patients with interleukin-2 (IL-2) produces significant increases in CD4 T cell counts; however an associated qualitative improvement in cells function has yet to be conclusively demonstrated. By measuring mycobacterial killing activity, we evaluated IL-2-mediated functional immune enhancement ex vivo in immunological non-responders (INRs). Methods and Findings PBMC from 12 immunological non-responders (INRs) (CD4+<200/µl, HIV-RNA<50 cp/ml) on combination antiretroviral treatment (cART) were collected at baseline, and after 3 IL-2 cycles. Eight INRs receiving only cART were studied as controls. After 21 days of PBMC incubation with a virulent M. avium suspension, counts of residual colony forming units (CFUs) and concentrations of TNF-α, IL-10 and IFN-γ were determined. In IL-2 treated patients, a significant reduction in mean residual CFUs of PBMC cultures was observed (p<0.01). Moreover, following IL-2 treatment, significant increases in PBMCs IFNγ production (p = 0.02) and substantial reductions in IL-10 levels were observed. Conclusions IL-2 therapy restores the ability of the lympho-monocyte system in eliciting an effective response against mycobacterial infections. Our data indicate the possibility of a clinical role held by IL-2 in enhancing the immune function of subjects unable to achieve immune competence through cART alone.

Metabolic syndrome in human immunodeficiency virus-positive subjects: prevalence, phenotype, and related alterations in arterial structure and function.

BACKGROUND Human immunodeficiency virus (HIV) infection itself and highly active antiretroviral treatment (HAART) have been proposed to be associated with a higher prevalence of metabolic syndrome, but, to date, prevalence and phenotype of metabolic syndrome among HIV subjects and the related structural and functional vascular alterations are not conclusively defined. METHODS We analyzed the data of 108 HIV-infected subjects without known cardiovascular risk factors: 72 were on HAART (group A, age 46.5±7.5 years, clinical blood pressure 125.7/74.9±11.6/7.8 mmHg) and there 36 in a naïve group (group B, age 40.7±7.9 years, blood pressure 126/75.8±9.8/7.7 mmHg). A total of 224 healthy subjects served as controls (group C, age 44.9±6.9 years, blood pressure 123.7/75.7±9.8/7.1 mmHg). Arterial stiffness was measured by aorto-femoral pulse wave velocity (PWV, sfigmocor), and carotid intima media thickness (IMT) was measured by a semiautomatic echotracking system (Esaote-WTS). RESULTS Metabolic syndrome was more frequent in HIV-positive subjects than in controls (19.4%, 13.8%, 4.5% for groups A, B, and C; P<0.001), with no significant difference between HAART and naïve. In metabolic syndrome subjects, group A displayed lipid profile alterations more frequently (91%, 50%, 57% for groups A, B, and C; P<0.05), whereas others metabolic syndrome components were equally represented in the three groups. In metabolic syndrome subjects, IMT was similar [556±108, 542±164, and 564±110.4 μm for groups A, B, and C; P=not significant (NS)], whereas PWV was significantly greater in HAART subjects when compared with controls (10.8±1.8, 9.±1.1, 9.3±1 cm/sec for groups A, B, and C; P=0.02 for A vs. C). Moreover, in this group (metabolic syndrome+HAART), PWV was higher than in subjects on HAART but without metabolic syndrome. CONCLUSIONS HIV subjects showed a higher prevalence and a different pattern of metabolic syndrome components. HAART, more than HIV infection per se, appeared to be responsible for the increased prevalence of metabolic syndrome and arterial function derangement.

A Case of Cerebrospinal Fluid Viral Escape on a Dual Antiretroviral Regimen: Worth the Risk?

TO THE EDITOR—Among human immunodeficiency virus (HIV)-infected patients on antiretroviral therapy (ART), incomplete viral suppression in cerebrospinal fluid (CSF) may occur even with undetectable plasma viremia [1–4]. Treatment simplification with “less-drug regimens” may favor adherence and reduce toxicity, but raises concerns on lower central nervous system (CNS) drug penetration and subsequent CNS viral escape [5, 6], as in the case we report herein. A 47-year-old HIV-infected woman, receiving different ART regimens since 2002, in 2007 withdrew emtricitabine due to lower-limb neuropathy, and maintained plasma viral control with darunavir/ritonavir 600/100 mg twice daily and tenofovir (in February 2013: HIV RNA <40 copies/mL; CD4 lymphocyte count, 508 cells/μL). InMarch 2013, shewas hospitalized after complaining of lower-limb weakness and pain, headache, dizziness, and dysarthria. Brain magnetic resonance imaging (MRI) showed extensive signal abnormalities (Figure 1A); lumbar puncture revealed CSF total protein of 76 mg/dL with oligoclonal immunoglobulin G bands, normal glycorrhachia, and cell count. CSF cultures and examinations for opportunistic infections (Cryptococcus neoformans, Epstein-Barr virus, cytomegalovirus, human herpesvirus 8, JC virus) were negative, and the CSF HIV RNA load was 2715 copies/mL. Genotypic testing showed the presence of multiple protease inhibitor (PI)–associated mutations (V32I, I54V, V82A, I84V, L10I, L33F, K20R, M36I) conferring intermediate resistance to darunavir, and nucleoside/nucleotide reverse transcriptase inhibitor–associated mutations (M41L, T215Y, V90I), conferring intermediate resistance to tenofovir. Thus, antiretroviral treatment was changed with darunavir/ritonavir 600/ 100 mg twice daily plus raltegravir 400 mg twice daily plus etravirine 200 mg twice daily. Two months later, the patient reported significant symptom improvements: the CD4 count was 759 cells/μL; both plasma and CSF HIV RNAwere undetectable. One year later, brain MRI showed clear improvements in radiological signs (Figure 1B). To our knowledge for the first time, here we describe a case of CSF viral escape in an HIV-infected patient on suppressive ART with a dual regimen. Previous cases of CSF viral escape (with or without neurological symptoms) were reported in patients with incomplete plasma HIV RNA suppression, or treated with suboptimal ART [1, 2]. Compared to others, this case clearly illustrates the improvements of neurological symptoms and radiological signs (Figure 1A and 1B) after switching ART, guided by genotypic resistance testing on CSF. Recently, a higher CNS penetration effectiveness ranking score of ART has been associated with lower levels of CSFHIVRNA, as well as improvements in neurological and cognitive functions [7, 8]. Meanwhile, new therapeutic schemes have been proposed for patients on suppressive therapy to reduce toxicity and costs, such as switching to dual regimens or to boosted PI monotherapy [5,9].These approaches may, however, be limited by lower CNS drug penetration, potentially leading to CSF viral escape (already described with boosted PI monotherapy) [5, 6]. In this report, the results of HIV genotyping in CSF suggest a CNS virus compartmentalization, with subsequent selection of

Evaluation of the Prognostic Value of Impaired Renal Function on Clinical Progression in a Large Cohort of HIV-Infected People Seen for Care in Italy

Whilst renal dysfunction, especially mild impairment (60<eGFR<90 ml/min), has been often described in HIV-infected population, its potential contribution to HIV evolution and risk of cerebro-cardiovascular disease (CCVD) has not been clarified. Data from HIV-1 infected patients enrolled in the Italian Cohort of Antiretroviral-Naïve (Icona) Foundation Study collected between January 2000 and February 2014 with at least two creatinine values available. eGFR (CKD-epi) and renal dysfunction defined using a priori cut-offs of 60 (severely impaired) and 90 ml/min/1.73m2 (mildly impaired). Characteristics of patients were described after stratification in these groups and compared using chi-square test (categorical variables) or Kruskal Wallis test comparing median values. Follow-up accrued from baseline up to the date of the CCVD or AIDS related events or death or last available visit. Kaplan Meier curves were used to estimate the cumulative probability of occurrence of the events over time. Adjusted analysis was performed using a proportional hazards Cox regression model. We included 7,385 patients, observed for a median follow-up of 43 months (inter-quartile range [IQR]: 21-93 months). Over this time, 130 cerebro-cardiovascular events (including 11 deaths due to CCVD) and 311 AIDS-related events (including 45 deaths) were observed. The rate of CCVD events among patients with eGFR >90, 60-89, <60 ml/min, was 2.91 (95% CI 2.30-3.67), 4.63 (95% CI 3.51-6.11) and 11.9 (95% CI 6.19-22.85) per 1,000 PYFU respectively, with an unadjusted hazard ratio (HR) of 4.14 (95%CI 2.07-8.29) for patients with eGFR <60 ml/min and 1.58 (95%CI 1.10-2.27) for eGFR 60-89 compared to those with eGFR ≥90. Of note, these estimates are adjusted for traditional cardio-vascular risk factors (e.g. smoking, diabetes, hypertension, dyslipidemia). Incidence of AIDS-related events was 9.51 (95%CI 8.35-10.83), 6.04 (95%CI 4.74-7.71) and 25.0 (95%CI 15.96-39.22) per 1,000 PYFU, among patients with eGFR >90, 60-89, <60 ml/min, respectively, with an unadjusted HR of 2.49 (95%CI 1.56-3.97) for patients with eGFR <60 ml/min and 0.68 (95%CI 0.52-0.90) for eGFR 60-89. The risk of AIDS events was significantly lower in mild renal dysfunction group even after adjustment for HIV-related characteristics. Our data confirm that impaired renal function is an important risk marker for CCVD events in the HIV-population; importantly, even those with mild renal impairment (90<eGFR<60) seem to be at increased risk of cerebro-cardiovascular morbidity and mortality.

Unmasking tuberculosis in the era of antiretroviral treatment

Tuberculosis (TB) can develop soon after antiretroviral treatment initiation, as the result of restoration of the anti-TB specific immune response. This form of the disease is often defined as “unmasked TB”, and it represents a major challenge for severely immune-suppressed HIV-infected subjects initiating treatment. Emergence of previously unrecognised TB disease occurs frequently in countries where TB/HIV co-infection is common, and where antiretroviral treatment has become increasingly accessible. The challenges posed by unmasked TB, such as its high incidence, the lack of reliable diagnostic tools and the uncertainties on its optimal management, may hamper our ability to face the TB/HIV epidemic. Therefore, unmasked TB appears a major threat to global health and poses additional barriers to successful HIV/AIDS care and treatment programmes. This review focuses on the epidemiology, immunopathogenesis and clinical manifestations of unmasked TB, and provides evidence-based recommendations for management and care of the disease.

Risk of Chronic Kidney Disease among Patients Developing Mild Renal Impairment during Tenofovir-Containing Antiretroviral Treatment

Background Tenofovir (TDF) can cause kidney injury through tubular dysfunction, with or without drop of estimated glomerular filtration rate (eGFR). Whether mild eGFR reductions during treatment should be considered a reason for prompt TDF discontinuation, however, remains unclear. Methods Patients with normal pre-TDF eGFR levels, who had developed mild renal impairment (i.e., two consecutive eGFR results between 89–60 ml/min) on TDF, were observed until onset of chronic kidney disease (CKD), defined as two eGFR<60 ml/min 3 to 6 months apart. Multivariable Poisson regression analysis was used to investigate whether outcome was associated with current and cumulative use of TDF (modeled as time-varying covariates). Results 2023 (29%) out of 6984 patients developed mild renal impairment on TDF. Among them, 191 progressed to CKD. The incidence of CKD did not significantly differ during TDF treatment (2.6 per 100 PYFU; 95%CI 2.2–3.2) or after its discontinuation (2.2 per 100 PYFU; 95%CI 1.8–2.6). However, the rate of CKD was significantly higher among patients continuing with TDF treatment compared to those who had discontinued it within 6 months of occurrence of mild renal impairment (aIRR 4, 95%CI 2.4–6.8). In contrast, among patients who had maintained TDF >6 months despite mild renal impairment, current TDF use was not associated with a significantly higher rate of CKD. Other significant predictors of CKD were older age, intravenous drug use, diabetes, hypertension, lower pre-TDF eGFR, higher eGFR drop since TDF introduction and longer exposure to TDF. Conclusions Prompt discontinuation of TDF among patients developing mild renal impairment may prevent further progression of renal damage.

Ultrasonographic backscatter of the carotid artery wall in patients with HIV infection: a pilot study

Abstract Aims. The aim of our study was to measure carotid intima-media thickness (cIMT) and risk factors associated with its development and progression, and to evaluate arterial wall characteristics through integrated backscatter analysis (IBS) in HIV patients. Methods. Perspective cohort study enrolling 44 HIV patients treated with antiretroviral drugs who underwent standard B Mode cIMT measurement and tissue characterization of carotid wall by means of dedicated software by acoustic densitometry, at time 0 and 2 years later. Major findings. Cross-sectional evaluation performed at baseline found that cIMT value correlated significantly with age (r = 0.42, p = 0.005) and systolic blood pressure (r = 0.31, p = 0.04). No correlation was found between cIMT and CD4, HIV-RNA, triglycerides or total cholesterol. There was no difference between the group with versus the group with no protease inhibitors treatment. cIMT progression during 2 years of observation was statistically significant (median, interquartile range [IQR]: 0.005, 0–0.031). No correlation was found between IBS and duration of disease and kind of therapy, whereas a significant association was found between cIMT and IBS (r = 0.33, p = 0.03). No noticeable changes of IBS were observed during 2 years observation. Conclusions. Classic risk factors greatly affect cIMT than time of HIV infection, duration of antiretroviral therapy exposure and use of protease inhibitors. IBS is a promising technique for the evaluation of arterial wall composition in HIV patients.

Evaluation of adhesion molecules and immune parameters in HIV-infected patients treated with an atazanavir/ritonavir- compared with a lopinavir/ritonavir-based regimen

Objectives To evaluate changes in pro-atherosclerotic biomarkers and endothelial function in patients initiating two different PI-based regimens as part of ART. Design Prospective randomized 24 week study. Treatment-naive HIV-infected patients with CD4+ T cell count >250 cells/mm3 started PI-based regimens including atazanavir/ritonavir (Group A) or lopinavir/ritonavir (Group B) and were followed up in an observational follow-up study until week 96. Methods The expression of immune activation and adhesion molecules on CD4+ and CD8+ cells and plasma cytokine levels were assessed at weeks 0, 4, 12, 24, 48, 72 and 96. Flow-mediated dilation (FMD), pulse-wave velocity (PWV) and intima-media thickness (IMT) were measured at weeks 0 and 24. Median changes within (signed rank test) and between (Wilcoxon test) arms were calculated. Results Twenty-seven patients were enrolled, of whom 15 were treated with atazanavir/ritonavir and 12 with lopinavir/ritonavir. After 96 weeks of ART, CD25+/CD8+ T cells and plasma concentration of MCP-1/CCL-2 rose whereas CD44+/CD8+ T cells decreased significantly in both groups. Differences between treatments were noted for HLA-DRII+/CD8+, CD44+/CD4+ and CD11a+/CD4+, with significant increases in Group B versus Group A. No differences between groups regarding IMT, PWV and FMD were found at baseline and week 24. Conclusions ART initiation with PI-based regimens led to a decrease in pro-atherosclerotic biomarkers at week 24, which then rebounded at week 96. Lopinavir/ritonavir treatment resulted in an unfavourable modulation of such markers compared with atazanavir/ritonavir treatment.

Acute Human Immunodeficiency Virus (HIV) Infection Presenting With Bilateral Interstitial Pneumonia: Case Report and Discussion of Potential HIV-Induced Interstitial Pneumonia

Abstract A 50-year-old man was admitted to intensive care unit because of acute respiratory failure due interstitial pneumonia; after admission, a diagnosis of acute human immunodeficiency virus (HIV)-1 infection was made. Clinical and radiological improvement was observed only after introduction of antiretroviral treatment. We discuss the hypothesis of interstitial pneumonia induced by the acute HIV-1 infection.