AIDS occurs when there is subesquent destruction of T-cells, which are responsible for maintaining cellular immunity. When the count of T-cells (normal= 500-1500 cells/cubic mm) decline below 200 cells/cubic mm, the patient is said to be suffering from Aids. The Aids patient has diminshed immunity and is porne to opportunistic infections (those that occur as a result other infections). The causative agents are lymphotrophics and belong to the Retrovirus family and includes;
a ) Human Immune Virus (HIV).
b ) Human T-cells Leukemia Virus (HTLV).
The incubation period of AIDS virus is 10-15 years.

Reverse Transcriptase(RT) containing HIVs and HTLVs penetrate CD-4 receptors containing cells (e.g.,T-cells, monocytes, macrophages), when RT activates and duplicates ssDNA copy of RNA. This helps ssDNA to be converted into dsDNA; which is tumorogenic. This dsDNA integrates into host cell and starts replicationg new RNA. This causes activation of POLYMERASE that lysis protein from host cell and coats it on new RNA. This results in production of new viruses on lysis of host cells. T-cells are the most affected cells and carry virus to approxiamtely all other body organs.

Aids is clinically menifested by:
* Karrosi's sarcoma.
* Pneumocystis Carinii.
* Cytomegaloviral infection (eye I.).
* Candida Albicans.
* Hodgkin's syndrome.
Initially flu like symptoms appear like sore throat, fever, swollen lumph nodes, nasal coryza plus night sweats, diarrhea and headache; lasting for 2-3 weeks. After that asymptomatic period begins and lasts for 8-10 years. Then due to decline of T-cells, anorexia, weightloss, persistent coughing, short breath, diarrhea and chronic swelling of lymph nodes occur.

CONTROL: DRUGS: AIDS therapy is directed to inhibit both the RT and Protease, which are essential for the replication of retrovirus. Highly Active Anti-Retroviral Therapy (HAART) is used, in which two "RT-Inhibitors" and one "Protease Inhibitor" are used. However rapid mutations in RT and protease inhibit / resist the inhibitor's activity.
VACCINATION: Vaccinations for retrovirus are not possible because;
a ) They cause synctium formation.
b ) They are highly mutant.
c ) Their binding site is masked with glycoprotein(a sugar unit).

BY
H/Dr. MUHAMMAD SHAFIQUE.
3rd Year B. Pharm.
shafique_tabish@hotmail.com