Background: CD4 and CD8 are determined by either a dual step assay using a calculation of absolute lymphocytes obtained from routine CBC or by a single step assay by including cytometric beads and fluorescent microspheres in the sample so that an absolute cell count can be made, simultaneously. Since thalassemia is common in Thailand, and a number of nucleated red blood cells (NRBC) are observed in peripheral blood of thalassemia patients with severe anemia, we speculated that NRBC in HIV-1 infected thalassemia patient with severe anemia might cause an error in CD4 and CD8 determinations in the dual step assay.
Objective: Comparing cytometric beads in three-color-lyse-no-wash in the single step assay in CD4 and CD8 with dual step assay by calculation using absolute lymphocytes obtained from routine CBC in HIV-1 infected thalassemia patients with severe anemia.