<prompt> Normal CD4:CD8 ratio is3:012:011:021:03  <response>: Ans. b 2:1 Ref. Harrisons Principles of Internal Medicine 16th ed., 2019CD4CD8 Ratio The ratio of 2:1 found in normal tissues. In HIV infection the CD4 count is often decreased and the CD8 count increased so the ratio might invert, that is become less than 1.AIDS Diagnosis: 200 CD4 count, HIV Positive with Aids indicator conditions E.g., PCP,or CD4CD8 ratio 1.5. Lymphopenia predominantly due to selective loss of the CD4 helper-inducer T-cell subset; inversion of CD4:CD8 ratio.CD4 Cell Also known as T4 or helper T cell, the CD4 cell is the primary target of HIV. It performs critical functions such as signaling other parts of the immune system to respond to an infection. There are two main types of T-cells.- T4 cells, also called CD4, are helper cells. They lead the attack against infections.- T8 cells CD8 are suppressor cells that end the immune response. CD8 cells can also be killer cells that kill cancer cells and cells infected with a virus. Treatment decisions are often based on viral load and CD4 count. Normal counts range from 500 to 1500. 