What are Immunodeficiency Disorders, Acquired immunodeficiency syndrome (AIDS),Severe combined immunodeficiency (SCID)


  • It is a condition in which a patient  has deficiency of lymphocyte mediated immunity.

  • Person with immunodeficiency disorders, do not have T cells or B cells since birth. That is the reason they are prominently prone to infection


Read more about the immunity : Active and Passive immunity                                      

Severe combined immunodeficiency (SCID)

  • It is an Inborn disorder in which both B and T cells are absent and such type of patient is highly susceptible to infection.

  • The children with this disorder are kept in special units that are completely germ free


DiGeorge Syndrome
  • It is an inborn disease in which thymus glands are absent in children. As a result,
  • T cells  are not produced. In patients with this disease, only B cells are found.

Agammaglobulinemia

  • It is also an immunodeficiency disorder in this disorder B cells are not produced although T cells are present in normal disorder.

Acquired immunodeficiency syndrome (AIDS)-

  • This disease originated in southern Africa but it was first reported in Los Angeles in  USA 1981.

  • In India,the first case of AIDS was reported in chennai in 1986.

  • AIDS is caused by Human deficiency virus (HIV) Robert Gallo used the term HTLV ( Human T lymphocytes virus) instead of HIV.

  • The structure of the virus is simple , a genetic material RNA is simply enclosed in a protein coat with an enzyme reverse transcriptase.

  • HIV resides in T lymphocytes and targets helper T cells that are very important to fight against infection.

  • When any person come in contact to HIV,the virus enter in macrophages and viral RNA start to produce viral DNA with the help of reverse transcriptase by the process of reverse transcription.

  • The viral DNA now is incorporated into DNA of host cell and inject the cells to produce more viral progenies.

  • Now virus enters in to helper T lymphocyte  and start to decrease the number of T lymphocytes.

  • With the decrease in number of T lymphocytes, the immunity of body is also decrease and person is not able to produce any immune response in minor infection like Mycobacterium, toxoplasma etc. 

  • The transmission of AIDS occurs through the following ways - By sexual contact with an infected person , By transfusion of contaminated blood by sharing the infected needle and from infected mother to her child through placenta.

  • There is no effective treatment of AIDS but N Butyl deoxynojorimycin, azidothymidine is used in treatment of this order.

  • WHO  has started various programs to prevent the infection of AIDS. 
  • These programs include- To ensure use of disposable syringe and needle, To make available safe blood from blood bank, To free distribution of condom, controlling drug abuse etc.









 

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