Neuropathogenesis of HIV and emerging therapeutic targets

Neurological, Behavioral, and Pathophysiological Characterization of the Co-Occurrence of Substance Use and HIV: A Narrative Review

Combined antiretroviral therapy (cART) has greatly reduced the severity of HIV-associated neurocognitive disorders in people living with HIV (PLWH); however, PLWH are more likely than the general population to use drugs and suffer from substance use disorders (SUDs) and to exhibit risky behaviors that promote HIV transmission and other infections. Dopamine-boosting psychostimulants such as cocaine and methamphetamine are some of the most widely used substances among PLWH. Chronic use of these substances disrupts brain function, structure, and cognition. PLWH with SUD have poor health outcomes driven by complex interactions between biological, neurocognitive, and social factors. Here we review the effects of comorbid HIV and psychostimulant use disorders by discussing the distinct and common effects of HIV and chronic cocaine and methamphetamine use on behavioral and neurological impairments using evidence from rodent models of HIV-associated neurocognitive impairments (Tat or gp120 protein expression) and clinical studies. We also provide a biopsychosocial perspective by discussing behavioral impairment in differentially impacted social groups and proposing interventions at both patient and population levels.

Metamodulation of presynaptic NMDA receptors: New perspectives for pharmacological interventions

Metamodulation shifted the scenario of the central neuromodulation from a simplified unimodal model to a multimodal one. It involves different receptors/membrane proteins physically associated or merely colocalized that act in concert to control the neuronal functions influencing each other. Defects or maladaptation of metamodulation would subserve neuropsychiatric disorders or even synaptic adaptations relevant to drug dependence. Therefore, this "vulnerability" represents a main issue to be deeply analyzed to predict its aetiopathogenesis, but also to propose targeted pharmaceutical interventions. The review focusses on presynaptic release-regulating NMDA receptors and on some of the mechanisms of their metamodulation described in the literature. Attention is paid to the interactors, including both ionotropic and metabotropic receptors, transporters and intracellular proteins, which metamodulate their responsiveness in physiological conditions but also undergo adaptation that are relevant to neurological dysfunctions. All these structures are attracting more and more the interest as promising druggable targets for the treatment of NMDAR-related central diseases: these substances would not exert on-off control of the colocalized NMDA receptors (as usually observed with NMDAR full agonists/antagonists), but rather modulate their functions, with the promise of limiting side effects that would favor their translation from preclinic to clinic.

Intravenous immunoglobulin therapy for HIV-associated Guillain-Barré syndrome

OBJECTIVE

To compare the efficacy of intravenous immunoglobulin (IVIG) added to antiretroviral therapy (ART) and ART alone in people living with human immunodeficiency virus-associated Guillain-Barré syndrome (HIV-associated GBS).

METHODS

The study was a retrospective analysis of clinical records of HIV-associated GBS patients from department of neurology at West China Hospital between January 2015 and October 2020. Patients treated with ART alone were compared with those treated with IVIG + ART. The primary outcome was the GBS disability score at 4 weeks, which was assessed with multivariable ordinal regression. Additional outcomes include the GBS disability scale at 1 week, improvement of ≥ 1 point on the GBS disability score at 1 and 4 weeks, median change in the MRC sum score at 1 and 4 weeks, number of patients who were able to walk independently at 4 weeks.

RESULTS

Two hundred and fifty-two (252) individuals living with HIV were recruited in the study. According to the inclusion and exclusion criteria, 21 HIV-associated GBS patients were finally included, of whom 8 were treated with IVIG + ART and 13 were treated with ART alone. At the fourth weeks after treatment, the GBS disability scale grade was significantly lower in patients treated with IVIG + ART than those with ART alone (1 vs. 2, P = 0.02). The adjusted OR for a lower GBS disability scale was 10.6 (95 % CI 1.15 to 98.05; P = 0.03) for the IVIG + ART group. Moreover, 6 of 8 (75 %) patients treated with IVIG + ART were able to walk independently at four weeks after treatment.

CONCLUSIONS

The introduction of IVIG combined with ART may be efficacious in the treatment of HIV-infected GBS and may provide better clinical outcomes.