Hematology Estimation of CD4 (T-Helper) Cell Count Using an Automated Hematology Analyzer

The number of CD4 (T4 or T-helper) lymphocytes in the peripheral blood is of prognostic significance in human immunodeficiency virus (HIV) infection. A decreased number of these lymphocytes is associated with the development of the acquired immunodeficiency syndrome (AIDS). We estimated the CD4 cell counts in the blood of 70 patients with HIV infection using the Technicon H·l® Automated Hematology Analyzer and compared the results with a Coulter EPICS® Flow Cytometer. The Technicon H·l uses an avidin-biotin immunoperoxidase method for lymphocyte typing on whole blood. Endogenous peroxidase in granulocytes and monocytes is taken into account. The results of the correlative study were as follows: correlation coefficient, r=.92; slope, 0.822; intercept, −0.762; range, 1.0×l06/L to 1.109×l09/L; and standard error of estimate, 0.081×l09/L. We conclude, therefore, that the Technicon H·l, which is increasingly used in general hematology laboratories, may be used for CD4 lymphocyte count determination with a fair degree of accuracy in the above range of values.