HIV attacks Central Nervous System too...

We know that HIV attacks T helper cell and makes the failure of cell mediated immunity. Besides destroys immune system HIV also destroys Central Nervous System (CNS) too. This condition is called HIV-associated encephalopathy. On this condition patients can get dementia or delirium.

HIV enters the brain through HIV-infected monocytes and other infected CD4+ cells. Then it infects other cells (such as microglia, oligodendrocytes, astrocytes, and neurons). HIV enters the CNS by transcytosis of endothelial cells. In immunohistochemistry studies, HIV is located in basal ganglia, subcortical regions, and frontal cortex. This condition makes people can get cognitive impairment, motor deficiencies, behavioral disorder. Without treatment this condition may get worse progressively (mean survival rate 3-6 months).

In infants, this condition is difficult to diagnose. Physical examination findings are often normal. Manifestation of this condition may not be noticeable until age 2-3 years. At this time, children may present with cognitive impairment, masklike facies, acquired microcephaly, and pseudobulbar and corticospinal tract signs. Common findings in older children and adolescents are impaired attention, decreased linguistic and scholastic performance, psychomotor slowing, emotional lability, and social withdrawal. Examination findings are similar to those in adults with ADC.

Criteria for HIV-associated progressive encephalopathy

The American Academy of Neurology defines HPE as the presence, for at least 2 months, of at least one of the following progressive findings in a pediatric patient with no concurrent illness, other than HIV infection, that could explain the findings^[6] :

• Failure to attain, or loss of, develop­mental milestones or loss of intel­lectual ability verified by standard developmental or neuropsychologi­cal tests
• Acquired microcephaly as dem­onstrated by head circumference measurement or brain atrophy on serial computed tomography (CT) or magnetic resonance imaging (MRI) imaging in children younger than 2 years of age
• Acquired symmetrical motor deficits manifested by 2 or more of the fol­lowing: paresis, pathological reflexes, ataxia or gait disturbance

So, we must take more concern about this condition in children. Manifestation is not as clearly as adult.  

Reference:

Niranjan N Singh, MD, DNB. 2011. HIV encephalopathy and AIDS dementia complex. emedicine.medscape.com.

PROTEASE INHIBITOR… CONSIDER IT!!

Anti retroviral (ARV) is used to treat patients with HIV-infected. But, some HIV-1 resistances from ARV have been reported. Besides all these reports, guideline of treatment has been established by WHO to control HIV. There are many studies to search the most effective combination of the drugs to inhibit HIV.  Then, I read a journal that ARV (especially Protease Inhibitor/PI) impacts the risk of Myocardial Infarction (MI) in HIV-infected patients (Lang, 2010).

Based on this study, “the risk of Myocardial Infection was increased by cumulative exposure to all the studied PIs except saquinavir and particularly to amprenavir/fosamprenavir with or without ritonavir and lopinavir with ritonavir, whereas the association with abacavir cannot be considered causal (Lang, 2010).”

The other study said that PI had so many metabolic effects, peripheral fat wasting and excessive central fat deposition (lipodystrophy), overt hyperlipidemia, and insulin resistance. The HIV protease inhibitors also suppress proteasome-mediated breakdown of nascent apolipoprotein (apo) B, thus resulting in the overproduction and secretion of triglyceride-rich lipoproteins. Finally, protease inhibitor also suppresses the inhibition of the glucose transporter GLUT-4 activity in adipose and muscle. This latter effect also contributes directly to insulin resistance and diabetes (Hui, 2003).

All of these adverse effect make patients with PI regiment easily get Myocardial Infarction. Maybe PI is effective to control HIV, but we must consider about the adverse effect.

References:

Lang, Sylvie. et al. 2010. Impact of Individual Antiretroviral Drugs on the Risk of Myocardial Infarction in Human Immunodeficiency Virus–Infected Patients. ARCH INTERN MED/VOL 167 (NO. 16), SEP 10, 2007

Hui DY. 2003. Effects of HIV protease inhibitor therapy on lipid metabolism. Prog Lipid Res. 2003 Mar;42(2):81-92.

Infants of HIV-Infected Women Easily Get Infections

Infants who were born from HIV-infected women had so poor condition. They got infectious disease and sometimes killed by this infection. Why so many children who were born from HIV-infected women have poor condition?

Immunity is the most important things to answer this question. As we know HIV infects T helper cells (CD4⁺ T cell). This is very important in the human immune system. HIV infection leads to low levels of CD4⁺ T helper. As a result, cell mediated immunity is lost and it makes host more susceptible to get infections.

Pregnant women transfer their antibodies to her infant through placenta. It can give the immunity to her child for about six months. It can be very useful to protect the baby from some infections before they vaccinated. According to the study in South Africa, infected women had lower levels of specific antibody to Hib and pneumococcus than uninfected-women. Infected women also had significant reductions in placental transfer of Hib, pertussis, and tetanus – specific antibody compare with uninfected-women (Jones, 2011). So their infants will easily get infection, especially in developing country.

We should take care of this issue. Based on the study, pneumonia and pertusis vaccination during or before pregnancy of HIV-infected women may benefit both, mother and child (Jones, 2011). So, infants of HIV-infected women can be protected from this infection. 


References:

Jones, Christine E. et al. 2011. Maternal HIV Infection and Antibody Responses Against Vaccine-Preventable Diseases in Uninfected Infants. JAMA. 2011;305(6):576-584.