Neuropsychiatric complications among AIDS patients are called NeuroAIDS. A combination of neurological and psychiatric disorders is considered as neuropsychiatric disorder which includes mood disorders, schizophrenia, addiction, dementia, epilepsy, etc. Neuropsychiatric disorders contribute ~15% of total burden of world’s disease.[1
] An abrupt increase in incidences of neuropsychiatric disorders has been observed among HIV seropositives as well as AIDS patients in last 10 years.
More than 25 years ago, HIV was reported as a unique infection with certainty of death. Initially, the main objective of treatment was to control HIV infections and death associated with it. Therefore, an expected attention was not paid to neurological and psychiatric complications noticed among HIV patients. Incidences of opportunistic infections along with baffling signs and symptoms of neurological disorders could be traced as even in the first known report about HIV/AIDS patients.[3
] Some of the common opportunistic infection in AIDS/HIV seropositive has been listed in . Undoubtedly, medications for HIV treatment have seen enormous improvements, which have enhanced the survival among HIV seropositives. Some HIV seropositives even survive for more than 20 years after initial exposure to HIV. The current evidences clearly suggest that variety of neurological and psychological disorders among early patients of HIV/AIDS were indicative of their late stages of HIV infections.
Commonly occurring opportunistic infections in HIV/AIDS patients
Importance of HIV infection can be gauged with the fact that ~6800 patients get infected with HIV, while ~5700 patients die with AIDS everyday.[5
] As per current estimate, >34 million people have been infected with HIV out of which ≥50% of HIV seropositives show symptoms of neurological complications. These neurological complications are associated either with central nervous system (CNS) or peripheral nervous system (PNS) or both.[6
] Generally these symptoms become more clinically evident with the progression of AIDS. AIDS can be clinically defined when (i) condition in which CD4 +
T-lymphocyte counts are <200 cells/μ
l of blood, (ii) presence of AIDS defining illnesses like HAD (HIV-associated dementia), HIV wasting syndrome, etc
Unfortunately, neuroAIDS afflicts patients at their prime age i.e., ~30–40 years, resulting in a major loss of human productivity. Neuropsychiatric disorders on the one hand lead to increase in health care cost for the patient, while on the other hand these patients become ineffective to perform any productive work either for self or for society.[8
HIV variations at molecular level are described as clades. Clades have geographical preferences, e.g
., clade B is prevalent in industrialized world while other clade types like A, C, E, etc
. are prevalent mostly in developing or underdeveloped regions. Mixing as well as evolution of these clades have also been observed.[10
] Apart from clade variation, drug resistance is also common in occurrence.[11
] Importance of evolution of drug resistant HIV cannot be denied for its impact on AIDS as well as neuroAIDS. Majority of data about neuroAIDS has come from clade B of HIV. Knowledge about the role of other clades is very limited because (i) patients infected with clades other than clade B rarely have life-long access to antiretroviral treatments (ART) and (ii) these clades are prevalent in societies lacking resources.
Improved antiretrovirals have reduced morbidity and mortality among HIV seropositives.[12
] An increase in life span possibly leads toward neuroAIDS among long-term HIV survivors. In current circumstances, a significant increase in neuroAIDS cases cannot be ignored, as it may have serious consequences in near future.
Neurotoxicity is the major reason for the onset of neurocognitive disorders among HIV seropositives. Neuropsychiatric disorders among HIV patients such as HIV-associated dementia (HAD), HIV-associated encephalopathy (HIVE), etc. are common with wide-ranging symptoms . Neurotoxicity is considered as the major contributing factor for neuroAIDS. Still it is debatable, “What are the triggers for neurotoxicity?” Some of the possibilities are under active considerations such as (i) Is HIV itself responsible for neuroAIDS? (ii) Is neuroAIDS a secondary complication evolved due to long-term ART? (iii) Are low levels of persistent and chronic HIV infections contributing toward the development of neuroAIDS? Or (iv) Is it a combined effect of all these possibilities? The present understanding of neuroAIDS and its causes are still not very clear!
Common neuropsychiatric disorders in HIV/AIDS patients
In this article we will discuss susceptibility of various cell types of CNS for HIV infection and their implications in neuropsychiatric disorder among HIV seropositives.