Helper/suppressor ratio

The T-Lymphocyte Helper/Suppressor Profile (Helper/Suppressor ratio, T4:T8 ratio, CD4:CD8 ratio) is a basic laboratory test in which the percentage of CD3-positive lymphocytes in the blood positive for CD4 (T helper cells) and CD8 (a class of regulatory T cells) are counted and compared. Normal values (95% confidence intervals) are approximately 30-60% CD4 and 10-30% CD8 depending on age (ratio 0.9 to 3.7 in adults). One reason for abnormal results is the loss of CD4-positive cells to HIV infection.