OAS Gene Family Expression Is Associated with HIV-Related Neurocognitive Disorders

HIV-associated neurocognitive disorders are common in HIV-infected individuals, even in the combination antiretroviral therapy (c-ART) era. Several mechanisms are involved in neuronal damage, including chronic inflammation immune activation. Mammalian 2'-5'-oligoadenylate synthetase (OAS) genes are produced in response to interferon (IFN), mainly by monocytes, and exert their antiviral functions by activation of RNase L that degrades viral and cellular RNAs. In this study, we aimed at exploring OAS gene family RNA expression in simian immunodeficiency virus encephalitis (SIVE), in HIV-associated neurocognitive disorders (HAND), and in HIV-associate dementia (HAD). We analyzed three microarray datasets obtained from the NCBI in order to assess the expression levels of OAS gene family network in brain biopsies of macaques with SIVE vs uninfected animals, as well as post-mortem brain of individuals with HAND (on or off ART) vs uninfected controls and three brain regions of HIV-infected individuals with both neurocognitive impairment (HAD) and encephalitis (HIVE). All OAS genes were upregulated both in SIVE and in HAND. OAS expression was significantly higher in high-viremic individuals; increased expression levels persisted in cART subjects when compared to healthy controls. OAS gene network analysis showed that several genes belonging to the type I IFN pathway, especially CXCL10 and IFIT3, were similarly upregulated in SIVE/HAND. Furthermore, we identified a significant upregulation of OAS gene family RNA expression in basal ganglia, white matter, and frontal cortex of HIV-1, HAD, and HAD/HIVE patients compared to healthy subjects. OAS gene family expression is increased in brain sections from individuals with HAND, HAD, and HIVE as well as macaques with SIVE. OAS family expression is likely to be induced by IFN as a consequence of viral replication in the CNS. Its long-term upregulation may contribute to the chronic inflammatory status and neurocognitive impairment we still observe in virologically suppressed individuals on c-ART

Kidney disease in HIV-infected patients

The introduction of highly active antiretroviral therapy (HAART) has reduced mortality and improved life expectancy of HIV-positive patients. However, increased survival is associated with increased prevalence of comorbidities, such as cardiovascular disease, hepatic and renal disease. Kidney disease, including HIV-associated nephropathy, acute renal failure and chronic kidney disease, represents one of the main causes of morbidity and mortality, especially if associated to other risk factors, i.e. hypertension, diabetes, older age, black race and hepatitis C coinfection. Careful evaluation of renal function may help identifying kidney disease in its early stages. In addition, proper management of hypertension and diabetes is recommended. Even if HAART has changed the natural course of HIV-associated nephropathy, reducing the risk of End-stage Renal Disease (ERDS), some antiretroviral regimens have been related with the development of acute or chronic kidney disease. Further studies are needed to optimize the management of renal disease among HIV-infected patients