pathophysiology

[perstarnurse2B]

Hi,

Can some one please explain to me the relationship between MHC(major histocompatibility complex) and HLA(human leukocyte antigen)? Thanks, your help will be kindly appreciated.:monkeydance:

[perstarnurse2B]

Janet has a bad flu. A week later she got a sore throat. On examination the lymph gland on her neck were swollen and the white blood cells count was 16.3. Explain the reason for her swollen glands and the increase WBC count.:angryfire

[Daytonite, BSN, RN]

i can see why this is keeping you awake! mhc (major histocompatibility complex) is the general term for all hla antigens of which there are 4 classes. so, a hla antigen would merely be a member of the mhc. at least, that's my understanding.

[Daytonite, BSN, RN]

I think you're going in the wrong direction by looking at HLA antigens. That's immunity. If you've got someone with the flu and upper respiratory infection you're looking at something that's more non-specific that the body has to deal with. So, you want to focus on the process of inflammation and infection. I think your answer is the acute inflammatory response. It starts with mast cells in the involved tissues releasing their contents. I like to think of mast cells as little hand grenades being dropped. When they open they spew out histamine, neutrophil chemotactic factor and eosinophil chemotactic factor. (This is war, baby!) They also bring prostaglandins and leukotrienes to the party.

The histamine, wonderful stuff that it is, causes the blood vessels in the affected area to dilate and increases their permeability (opens the doors). The neutrophil chemotactic factor attracts neutrophils to the site. They are the first group of soldiers in the leukocyte orificenal to get into the fracas. They are primarily involved in phagocytosis. They are followed later by the eosinophils drawn to the area by the eosinophil chemotactic factor to help clean up the mess the neutrophils leave behind. Exudate (pus) results. The lymph nodes are just doing their part of the process—removing and storing the garbage until it can be disposed of. As the infection drags on (a week in this case) the prostaglandins and leukotrienes play more of a role in attracting more WBC's to the area of infection. As neutrophils are expended, more reinforcements are needed, so this is why the white count goes up. Review the anatomy and function of the lymphatic system.

The cardinal signs of inflammation are: (1) redness due to the dilation of the blood vessels, (2) heat also due to the vasodilation and increased blood flow, (3) edema due to intravascular fluids leaking into the surrounding tissues from the increased permeability of the blood vessels, and (4) pain due to the pain receptors being stimulated by the swollen tissue and pH changes from all these chemicals excreted during the inflammatory response.

Hopes this helps.

[perstarnurse2B]

are you suggesting that the relationship betweem them is caused by acute inflammatory response.

[Daytonite, BSN, RN]

In this case, I think so, yes.

[perstarnurse2B]

could it be that HLA is only in white blood cells and MHC in all cells. Again, I want to thank you for your help your effort was truly appreciated.