What CD4:CD8 ratio is commonly associated with a patient diagnosed with acquired immunodeficiency syndrome (AIDS)?

In patients diagnosed with acquired immunodeficiency syndrome (AIDS), the CD4:CD8 ratio typically reflects a significant decline in CD4 T helper cells relative to CD8 T cytotoxic cells. A ratio of 1:2 indicates that for every one CD4 cell, there are two CD8 cells, which is characteristic of advanced immunodeficiency. This profound imbalance occurs because the CD4 cells are preferentially targeted and depleted by the human immunodeficiency virus (HIV), leading to an increased number of CD8 cells and a decrease in the absolute counts of CD4 cells.

The CD4:CD8 ratio in healthy adults is generally around 2:1 to 4:1, which helps to maintain effective immune responses. However, as AIDS progresses, the ratio can drop significantly, often falling to less than 1:1. A ratio of 1:2 indicates a state where the immune system is severely compromised, making it difficult for the body to mount an adequate immune response against infections and other diseases, a hallmark of AIDS.