Re: CD4 percentage

[Guest guest]

When your immune system is exposed to a pathogen or vaccine the recognition of this pathogen is stored by Memory Cells. Over time, Memory Cells pass on their information by cloning new Memory Cells. One particular family of Memory Cells, a clonal line, may recognize Polio, another Pneumonia, or perhaps a fragment which is common to many pathogens.

When HIV thins out the ranks of your immune cells, mathematically you can lose entire clonal families long before you lose your entire immune system.

The same thing can happen to a complex economy during a plague or war. If you lose 50% of your population, the chances become certain that these losses will included 100% of certain vital specialties. You will not lose 50% of every family or specialty - some will be wiped out completely while others remain untouched, just by random chance. The 50% population loss may include 100% of those who know how to repair elevators or 100% of all anesthesiologists. Yes new replacements can be trained from on the job experimentation or from books, but economists who specialize in this, like the late Carlo Cipolla, say a 50% population loss in our complex economy would set our economy back 120 years or so.

The difference with the economy and your immune system is that the specialists (the Memory Cells) are the books. New Naive immune cells must be re-exposed to the same pathogen or vaccine to become replacements for the entire Memory Cell families which were lost in the 50% immune fatality.

One of the original curiosities of HIV disease was the lack of a consistent pattern in the pathologies and "opportunistic infections" people with HIV would face. One person might get pneumonia repeatedly, while another would get lymphoma etc. Part could be genetics, but another cause would be which clonal T cell lines had been lost to HIV, by random chance as the number of immune cells decline.

³Below 18% to 22% entire> clonal lines of T cells are lost resulting in the loss of immune memory.²> > What are clonal lines of T cells?> > What is immune memory, and why is it important?> > > > > >>