Norbert Gilmore

A 96-Week Comparison of Lopinavir-Ritonavir Combination Therapy Followed by Lopinavir-Ritonavir Monotherapy versus Efavirenz Combination Therapy

Antiretroviral-naive HIV-1-infected volunteers received zidovudine/lamivudine plus either lopinavir/ritonavir (n=104) or efavirenz (n=51). Lopinavir/ritonavir-treated subjects demonstrating 3 consecutive monthly HIV-1 RNA levels <50 copies/mL started lopinavir/ritonavir monotherapy. In previous-failure=failure analysis, 48% (lopinavir/ritonavir) and 61% (efavirenz) maintained HIV-1 RNA at <50 copies/mL through week 96, (P= .17; 95% confidence interval [CI] for the difference, -29% to 4%); in noncompletion=failure analysis, 60% (lopinavir/ritonavir) and 63% (efavirenz) maintained HIV-1 RNA at <50 copies/mL at week 96 (P= .73; 95% CI for the difference, -19% to 13%). Significant sparing of peripheral lipoatrophy was noted in the lopinavir/ritonavir simplification strategy. This study has provided important information for future studies using treatment simplified to lopinavir/ritonavir monotherapy.

Distinct Tryptophan Catabolism and Th17/Treg Balance in HIV Progressors and Elite Controllers

Tryptophan (Trp) catabolism into immunosuppressive kynurenine (Kyn) by indoleamine 2,3-dioxygenase (IDO) was previously linked to Th17/Treg differentiation and immune activation. Here we examined Trp catabolism and its impact on Th17/Treg balance in uninfected healthy subjects (HS) and a large cohort of HIV-infected patients with different clinical outcomes: ART-naïve, Successfully Treated (ST), and elite controllers (EC). In ART-naïve patients, increased IDO activity/expression, together with elevated levels of TNF-α and sCD40L, were associated with Treg expansion and an altered Th17/Treg balance. These alterations were normalized under ART. In contrast, Trp 2,3-dioxegenase (TDO) expression was dramatically lower in EC when compared to all other groups. Interestingly, EC displayed a distinctive Trp metabolism characterized by low Trp plasma levels similar to ART-naïve patients without accumulating immunosuppressive Kyn levels which was accompanied by a preserved Th17/Treg balance. These results suggest a distinctive Trp catabolism and Th17/Treg balance in HIV progressors and EC. Thus, IDO-induced immune-metabolism may be considered as a new inflammation-related marker for HIV-1 disease progression.

Reconsidering the lifetime deferral of blood donation by men who have sex with men

The decision by blood agencies in many developed countries to defer the donation of blood by men who have sex with men was justified when it was first implemented, in 1983, given that there was no effective mechanism to screen for HIV infection until screening for HIV antibodies became available in

Regulatory T Cells in HIV Infection: Can Immunotherapy Regulate the Regulator?

Regulatory T cells (Tregs) have a dominant role in self-tolerance and control of autoimmune diseases. These cells also play a pivotal role in chronic viral infections and cancer by limiting immune activation and specific immune response. The role of Tregs in HIV pathogenesis remains poorly understood as their function, changes according to the phases of infection. Tregs can suppress anti-HIV specific responses and conversely can have a beneficial role by reducing the deleterious impact of immune activation. We review the frequency, function and homing potential of Tregs in the blood and lymphoid tissues as well as their interaction with dendritic cells in the context of HIV infection. We also examine the new insights generated by recombinant IL-2 and IL-7 clinical trials in HIV-infected adults, including the immunomodulatory effects of Tregs. Based on their detrimental role in limiting anti-HIV responses, we propose Tregs as potential targets for immunotherapeutic strategies aimed at decreasing Tregs frequency and/or immunosuppressive function. However, such approaches require a better understanding of the time upon infection when interfering with Treg function may not cause a deleterious state of hyperimmune activation.

Platelet release of beta-thromboglobulin within the coronary circulation during cold pressor stress☆

Cold stress by increasing circulating catecholamines may sensitize blood platelets to aggregate and release their constituents. This study investigates the effect of cold stress on the release of the platelet-specific protein beta-thromboglobulin into the coronary venous blood of 12 subjects with atherosclerotic coronary artery disease (CAD) and 7 subjects with angiographically normal coronary arteries (NCA). Cold pressor stress caused a greater increase in systolic arterial pressure in patients with CAD than in subjects with NCA (p less than 0.05). There was no significant difference between the platelet counts in the arterial or coronary venous blood either before or during cold stress. Arterial beta-thromboglobulin was higher in the group with CAD (77 +/- 18 ng/ml) than in subjects with NCA (49 +/- 12 ng/ml, p less than 0.01). Although there was no arteriovenous difference of beta-thromboglobulin at rest in either group, during cold stress, coronary venous beta-thromboglobulin increased in both the NCA (53 +/- 16 to 95 +/- 26 ng/ml, p less than 0.05) and CAD groups (76 +/- 13 to 117 +/- 53 ng/ml, p less than 0.025) despite no change in arterial beta-thromboglobulin. Release of beta-thromboglobulin, although not related to the presence of angiographic arterial disease, correlated with the systolic arterial pressure during cold stress (r = 0.66) and inversely with the platelets ability to generate cyclic adenosine monophosphate (r = 0.69). The release of platelet constituents in the coronary circulation is provoked by cold stress and may play a role in stress-induced acute coronary occlusion in patients with atherosclerotic disease and in those with apparently normal vessels.

Plasminogen-binding lipoprotein: Isolation and characterization of a plasma very low density lipoprotein which co-chromatographs with plasminogen on lysine-sepharose

By lysine-Sepharose chromatography, approximately 20% of normal plasma samples yield epsilon-aminocaproic acid (EACA) eluates which are opalescent, rather than clear, suggesting the presence of an additional, non-plasminogen component. This material has been isolated and characterized as a plasma lipoprotein of the very low density (VLDL) class on the basis of density ( less than 1.006 g/ml), size (greater than or equal to 5 X 10(7) daltons by gel filtration), electrophoretic mobility (pre-beta), chemical composition (mean cholesterol:triglyceride protein ratio, 1:3.4:1) and immunochemical evidence for apoproteins B, C, and E. Uniform particles, 100-200 Angstroms in diameter, were seen by electron microscopy. In contrast with VLDL in general, this lipoprotein co-chromatographed with plasminogen on lysine-Sepharose, where its binding was plasminogen-dependent, and from which it was eluted by EACA, but at lower concentrations than was plasminogen, suggesting a lysine-binding process. This plasminogen-binding lipoprotein (PBLP) was found in both male and female plasma samples, and increased post-prandially. Its properties suggest that it is a unique subclass of plasma VLDL. Although its isolation explains a laboratory phenomenon, and it exhibits interesting interactions with an important plasma zymogen, its function remains to be determined.

Human immunodeficiency virus antibody testing: Counselling guidelines from the Canadian Medical Association☆

The growing importance of and demand for human immunodeficiency virus (HIV) antibody testing [ 1 ] and the complex medical, psychological, ethical and social issues this testing raises [2] require physicians to be prepared to counsel their patients about HIV infection and antibody testing. Since medical literature contains little in the way of specific guidelines for counselling and education relating to HIV antibody testing, this book has been prepared to provide physicians and other health care professionals with this information. It discusses the serologic tests, requirements for testing, pretest and post-test procedures, and relevant Canadian Medical Association policies [ 31.

Liver fibrosis is strongly associated with an enhanced level of immunosuppressive tryptophan catabolism independently of HCV viremia in ART-treated HIV/HCV co-infected patients

Background HCV infection induces hepatic and extra-hepatic damage that includes kidney and neurocognitive dysfunction. Tryptophan (Trp) is catabolized into immunosuppressive kynurenine (Kyn) by indoleamine 2,3-dioxygenase (IDO) and tryptophan 2,3 dioxegenase (TDO). Increased Trp catabolism measured by Kyn/Trp ratio has been associated with neurocognitive impairment and immune dysfunction in HIV mono-infection. Here, we assessed the contribution of Trp catabolism in HCV/HIV co-infected patients.

IDO-induced immunosuppressive tryptophan catabolism following primary HIV infection

Methods Plasma and Peripheral blood mononuclear cells (PBMCs) were longitudinally collected in 41 PHI patients (infection <90 days), 24 remained untreated (ART-naive) and 17 were ART-treated one year later. In addition, samples from elite controllers (EC, n=12) and healthy subjects (HS, n=12) were also assessed. IDO enzymatic activity marker (Kyn/Trp ratio) was measured by isotope dilution tandem mass spectrometry. IL-6, IL-18, TNF-a and IP-10 plasma levels were assessed by Luminex. Frequency of Tregs (CD4+CD25highCD127lowFOXP3high), CD11c+ myeloid DC (mDC) and CD123+ plasmacytoid DC (pDC) as well as HLA-DR/CD38 co-expression of on T-cells were assessed.

Impact of autologous dendritic cell-based immunotherapy (AGS-004) on B- and T-cell subset changes and immune activation in HIV-infected patients receiving antiretroviral therapy.

Abstract:We previously reported that a combination of antiretroviral therapy with 4 monthly injections of each patients own autologous dendritic cells (AGS-004) electroporated with CD40 ligand and with HIV RNA antigens obtained from each patients own pre-antiretroviral therapy plasma induced HIV-specific CD8 T-cell responses in 10 patients. To assess other AGS-004–induced immune changes, we evaluated the modifications in B- and T-cell subsets and the level of immune activation in these patients. The proportion of Bm1 naive cells was increased along with an augmentation of the proliferation marker Ki67. Memory B-cell frequency, CD4 and CD8 T-cell subsets, regulatory T-cell frequency, and CD38/HLA-DR/PD-1 T-cell activation levels remained unchanged after AGS-004 dendritic cell immunotherapy.