Antiretroviral Laboratory Monitoring and Implications for HIV Clinical Care in the Era of COVID-19 and Beyond.

In the era of COVID-19, providers are delaying laboratory testing in people with HIV (PWH). The purpose of this study was to examine the clinical significance of renal, liver, and lipid testing. We reviewed the charts of 261 PWH who initiated care at an academic HIV clinic between January 1, 2016 and December 21, 2018. Analysis included one-sided binomial exact tests and multiple linear, Poisson, and Beta regression models. The most common abnormality was a glomerular filtration rate (GFR) <60 mL/min (10%). Age <40 years [estimated relative rate (rr) 0.017, 95% confidence interval (CI) 0.207 to 0.494], cobicistat (rr 0.284, 95% CI 0.128 to 0.63), and tenofovir alafenamide (rr 0.295 95% CI 0.151 to 0.573) were associated with a decreased risk of GFR <60 mL/min. An increased AST and ALT ≥2 × upper limit of normal (ULN) was found in 5% and 3%, respectively. Hepatitis C and use of darunavir and lopinavir were associated with increased AST or ALT. When a GFR was <60 mL/min or an AST or ALT was ≥2 × ULN, no action was taken in 53% of cases. In 18% of cases the only intervention was repeat testing. The most common interventions after lipid results were calculation of a 10-year cardiovascular risk score (31%) and addition of a statin (18%). Taking action after lipid results was strongly associated with age ≥40 (rr 7.37, 95% CI 3.0 to 18.3). Young PWH without hepatitis C rarely have renal, liver, or lipid test results that alter clinical care. Decreased testing should be considered.

Clinical Outcomes Following the Use of Archived Proviral HIV-1 DNA Genotype to Guide Antiretroviral Therapy Adjustment.

BACKGROUND: Evidence regarding the safety of using proviral HIV-1 DNA genotype (DNA GT) to guide antiretroviral therapy (ART) is limited. We hypothesized that HIV RNA would not increase following ART adjustment guided by DNA GT in a university HIV clinic. METHODS: Data were obtained from electronic medical records of adult persons living with HIV-1 (PWH) who underwent DNA GT testing and changed ART between October 2014 and November 2017. Logistic regression was used to evaluate the effect of ART switch on HIV RNA over time. RESULTS: Eighty-three PWH had DNA GT performed, 66 (80%) switched ART, and 59 had postswitch follow-up. Data were analyzed pre-/postswitch for these 59 PWH (median age, 54 years; 71% LWH ≥10 years; 46% ≥2 previous regimens; 36% recent low-level viremia; 34% unknown medication history). On DNA GT, 58% had ≥1-class ART resistance, 34% ≥2-class, and 10% 3-class. Median follow-up (range) was 337 (34-647) days. There was no change in probability of HIV RNA ≥50 copies/mL over time (P > .05). At baseline, 76% had HIV RNA <50 vs 88% at last postswitch follow-up (P = .092). Protease inhibitor use decreased from 58% to 24% (P < .001). Average daily pills and dosing frequency decreased from 3.48 to 2.05 (P < .001) and 1.39 to 1.09 (P < .001), respectively; ART cost did not change. CONCLUSIONS: DNA GT facilitated changes in ART in a treatment-experienced population without increases in HIV RNA. Decreased pill burden occurred without increased ART cost. Further studies to identify optimal use of DNA GT are needed.

Recurrent networks with short term synaptic depression.

Cortical circuitry shows an abundance of recurrent connections. A widely used model that relies on recurrence is the ring attractor network, which has been used to describe phenomena as diverse as working memory, visual processing and head direction cells. Commonly, the synapses in these models are static. Here, we examine the behaviour of ring attractor networks when the recurrent connections are subject to short term synaptic depression, as observed in many brain regions. We find that in the presence of a uniform background current, the network activity can be in either of three states: a stationary attractor state, a uniform state, or a rotating attractor state. The rotation speed can be adjusted over a large range by changing the background current, opening the possibility to use the network as a variable frequency oscillator or pattern generator. Finally, using simulations we extend the network to two-dimensional fields and find a rich range of possible behaviours.