I posted this question before, but the person who answered it did a terrible job
ID: 134991 • Letter: I
Question
I posted this question before, but the person who answered it did a terrible job and did not provide me enough information to atually produce a good answer. Please give as much detail as possible. Thank you
The Central Nervous System is considered “immunologically privileged.” What does this mean?What are the features of the anatomical structures that that enable this status. What are the factors that can cause a breach into the status of this system?
How do these characteristics play a role in the efficacy of treating infections in the Nervous System,and can they contribute to the occurrence of latent infections within this system?
Explanation / Answer
Immune-privileged sites are the ones which is isolated from the immune system. There are different cells which prevent the body from any foreign particles. When there is potential threat from a harmful particle, there is immediate immune response in the body which is sometimes accompanied by collateral damage to the own body. And there are even instances, immune system acts on the own ‘body cell’ due to few reactions going wrong, the protection from this damage to certain part can be referred as the immune-privilege sites. The body’s normal inflammatory response is absent in these sites. This is basically to protect the special sites to be prevented from any harm as these are most of the time non-renewable.
Central nervous system (CNS) is considered as one of these sites. CNS includes the brain and the spinal cord. One of the reason for CNS privilege is the Blood brain barrier. CNS also possess autoimmunity. It is one of the most essential organs and needs protection. To understand how this privilege works, we need to understand the anatomy of the CNS. The cerebrospinal fluid which covers the brain is separated from the CNS through 3 layers- dura matter, arachnoid and the inner most pia matter. All these 3 layers prevents arteries, veins and lymphatics enter the CNS. It was believed for the longest of time that CNS is immunologically privileged, recent studies shows that only certain parts of the CNS is a protected site like the parenchyma cells.
When the dye molecules were not absorbed by the brain, Blood brain barrier was discovered. This barrier allows certain cells to pass through it one of them is the T-cells which is the part of the immune system, but it takes several hours for that to happen. However, WBC could not just penetrate the CNS. And myeloid cells can also enter only when they are young whereas the activated macrophages could not enter the CNS.
It gets difficult to treat any infection caused in the CNS. One of the most common is cerebral malaria. Any infection from bacteria, fungi or virus is rare but it occurs and can be treated by antibiotics, intravenous fluids, anticonvulsants for seizures and steroids for brain swelling. These infections can cause long lasting impact even if treated. It is important to remember that it is life threatening and treating them is extremely difficult.