Systematic De-escalation of Successful Triple Antiretroviral Therapy to Dual Therapy with Dolutegravir plus Emtricitabine or Lamivudine in Swiss HIV-positive Persons

BACKGROUND

Studies increasingly suggest that the efficacy of certain dual antiretroviral therapy (ART) combinations is equal to triple ART. Increasing concerns among HIV-positive patients and physicians in Switzerland include ART cost and long-term ART safety and toxicity, i.e. taking only as many ART agents as necessary. The aims of this retrospective analysis are to report on the de-escalation of our entire clinic population of eligible patients with well-controlled HIV-infection to dolutegravir-containing dual ART.

METHODS

Starting in March 2015, we systematically considered the de-escalation of eligible patients to either dolutegravir/emtricitabine or dolutegravir/lamivudine, by discontinuing tenofovir disoproxil fumarate or abacavir. We report on the virological efficacy, tolerability and patient satisfaction ≥ 48 weeks after de-escalation.

FINDINGS

Of 106 HIV-positive patients followed in our clinic, 70 patients were de-escalated. Three returned to triple ART (insomnia after dolutegravir start, n = 2; new wish for single tablet regimen, n = 1). All de-escalated patients and all who continued triple ART had suppressed HIV viremia at last follow-up and were satisfied with their ART regimen, except for one patient who had virological failure after ART discontinuation in the setting of major depression. The most common reasons to not de-escalate included hepatitis B co-infection (n = 6), physician's concern about ART adherence (n = 6), patient reluctance to switch from a single tablet to a 2-tablet regimen (n = 7), patient satisfied with current ART (n = 5) and others (n = 12).

INTERPRETATION

ART de-escalation to dolutegravir/FTC or dolutegravir/3TC is possible in the majority of patients virologically suppressed on triple ART, and may effectively address patient and physician concerns about long-term safety and cost of ART.

Pathogen- and antibiotic-specific effects of prednisone in community-acquired pneumonia

In a double-blind, randomised, placebo-controlled trial of hospitalised patients with community-acquired pneumonia (CAP), we demonstrated shorter time to clinical stability (TTCS) with adjunct corticosteroid therapy compared with placebo.

We did a pre-planned, exploratory analysis of any association between microbiological diagnosis, antibiotic treatment and procalcitonin level and effect of prednisone on TTCS, mortality, and CAP complications (n=726 participants, enrolled between December 2009 and May 2014). Multiplex viral real time PCR was systematically performed in nasopharyngeal swabs beginning November 2011 (n=489). Other investigations and treatments were at the discretion of the physician. Effect modification was tested with inclusion of interaction terms in the statistical models.

Reduced TTCS with prednisone was seen in all microbiological, antibiotic, procalcitonin and afebrile patient subgroups. We found evidence for a different prednisone response in patients with pneumococcal pneumonia in whom intravenous antibiotic duration was not shorter (interaction p=0.01) with prednisone, as was observed in the remaining study population. In patients without macrolide treatment, rehospitalisations were not lower with prednisone (interaction p=0.04). After adjustment for multiple testing, these subgroup effects were no longer significant.

Prednisone was associated with shorter TTCS independent of CAP aetiology. In pneumococcal pneumonia, prednisone effects on secondary endpoints may be less favourable.

TLR2 is required for the altered transcription of p75NGF receptors in gram positive infection

Neuroimmune interactions play a decisive role in neuronal cell survival and cell death during neuronal injury, oxidative and free radical stress. In neurons, NGF occupancy of p75 neurotrophin receptor (p75(NTR)) has been shown to promote neuronal apoptosis, while occupancy of tropomyosin receptor kinase A (TrkA) promotes survival of injured neurons. In macrophages, recent results suggest that NGF via TrkA mediates resistance to cell death through the interaction with TLR2. We have investigated the transcriptional regulation of TrkA, p75(NTR) and their ligand nerve growth factor beta (NGFbeta) upon stimulation with the TLR2 ligand Staphylococcus aureus in the spleen of C57BL/6 mice, TLR2 (-/-) and p75(NTR) (-/-) mice. S. aureus challenge (i.p.) resulted in a significant increase in NGFbeta mRNA levels in C57BL/6 (100%), TLR2 (-/-) (300%) and p75(NTR) (-/-) mice (355%). TrkA mRNA levels were upregulated only in p75(NTR) (-/-) mice (87%) whereas in TLR2 (-/-) mice they remained unchanged and even decreased in C57BL/6 mice (46%). p75(NTR) mRNA was increased in spleen of C57BL/6 mice (60%) whereas the levels in TLR2 (-/-) mice remained almost unchanged. Finally, TLR2 mRNA was upregulated by 350% in C57BL/6 mice and by 283% in p75(NTR) (-/-) mice. These data suggest that in splenocytes signaling via TLR2 is required for Gram positive infection mediated alteration of neurotrophin receptor expression as observed in an in vivo infection model with transgenic mice. This observation provides a link between Gram-positive infection and neurotrophic responses, which may be important in preserving neurons at sites of the infection.

Homodimerization and internalization of galanin type 1 receptor in living CHO cells

Galanin is a 29- to 30-aa-long neuropeptide affecting feeding, cognitive, and sexual behavior. It exerts its effects through galanin receptors 1, 2 and 3, which are all seven transmembrane domain G-protein coupled receptors (GPCRs). The GPCRs have been shown to function as monomers, homodimers, heterodimers and oligomers. In this study, we examined the extent of galanin receptor 1 (GalR1) dimerization and internalization in living CHO cells using fluorescence resonance energy transfer (FRET) and time lapse confocal imaging. Ratio imaging analysis and emission spectral analysis revealed substantial homodimerization of GalR1. In addition, internalization of GalR1 after 1h of agonist stimulation with the GalR1 agonist galanin (1-29) was observed with time lapse fluorescence imaging, whereas stimulation with the GalR2 specific agonist galanin (2-11) did not lead to internalization. Treatment of GalR1 transfected cells with the non-selective adenylyl cyclase activator forskolin influenced the rate of internalization when administered together with galanin (1-29). These results indicate that GalR1 can act as a dimer on the cell surface and that receptor desensitization and internalization was observed after stimulation with the agonist galanin (1-29). Western blots further confirm the FRET data that GalR1-XFP dimerizes and can be detected in the cell as a monomer or dimer using antibodies to XFP. Internalization and dimerization of GalR1 is shown, contributing to the regulation of galanergic signaling.

Uncoupling protein 2 protects dopaminergic neurons from acute 1,2,3,6-methyl-phenyl-tetrahydropyridine toxicity

Oxidative stress is implicated in the death of dopaminergic neurons in sporadic forms of Parkinson's disease. Because oxidative stress can be modulated endogenously by uncoupling proteins (UCPs), we hypothesized that specific neuronal expression of UCP2, one member of the UCP family that is rapidly induced in the CNS following insults, could confer neuroprotection in a mouse model of Parkinson's disease. We generated transgenic mice overexpressing UCP2 in catecholaminergic neurons under the control of the tyrosine hydroxylase promoter (TH-UCP2). In these mice, dopaminergic neurons of the substantia nigra showed a twofold elevation in UCP2 expression, elevated uncoupling of their mitochondria, and a marked reduction in indicators of oxidative stress, an effect also observed in the striatum. Upon acute exposure to 1,2,3,6-methyl-phenyl-tetrahydropyridine, TH-UCP2 mice showed neuroprotection and retention of locomotor functions. Our data suggest that UCP2 may represent a drug target for slowing the progression of Parkinson's disease.

High frequency of TNF alleles $minus;238A and $minus;376A in individuals from northern Sardinia

The G to A single nucleotide polymorphisms (SNPs), at position -376, -308 and -238 in the promoter of the tumor necrosis factor alpha (TNF) gene, have been independently correlated with numerous diseases. Alleles TNF(-376A) and TNF(-238A) are normally found throughout the world with very low frequencies. We investigated the frequency of these SNPs in Sicilian subjects hospitalized after traumatic brain injury and in three groups of subjects from northern Sardinia: healthy subjects and individuals with multiple sclerosis or ischemic stroke. While no significant difference was found between healthy and disease subjects, the frequency of TNF(-376A) and TNF(-238A) was elevated up to 10 times in Sardinia compared to Sicily and other populations throughout the world. These elevated frequencies may be the result of genetic drift or of selective pressure on TNF itself or on neighboring genes, including the HLA. Malaria, endemic to Sardinia until the end of the 1940s, and the bubonic plague, are among the possible causes of selection. These findings indicate that Sardinia is an ideal location to further elucidate the correlation between TNF or HLA polymorphisms and diseases, including multiple sclerosis and type-I diabetes, present with an unusually high frequency and co-morbidity in Sardinia.

Interleukin-18 null mice show diminished microglial activation and reduced dopaminergic neuron loss following acute 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine treatment

Recent reports have revealed an involvement of microglial cells in dopaminergic neurodegeneration. In the present study, we tested the hypothesis that interleukin-18 (IL-18) plays a role in the microglial activation. The present study investigated microglial activation and dopaminergic neurodegeneration in substantia nigra pars compacta (SNpc) following 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) treatment in wild type (WT) and IL-18 knockout (KO) mice. The number of dopaminergic neuron loss in WT mice was significantly decreased 7 days after MPTP treatment compared with IL-18 KO mice. In WT mice microglial activation occurred in the SN at 1 day after MPTP treatment, progressively increased within the SNpc until 7 days post MPTP, and subsided by 14 days. In contrast, in IL-18 KO mice microglial activation occurred in the SN at 1 day post-MPTP, and decreased by 7 days, earlier than in WT mice. The lesser microglial activation and dopaminergic neurodegeneration in the SNpc following MPTP treatment in WT indicates the possibility that IL-18 may participate in microglial activation and dopaminergic neurodegeneration.