Determination of lymphocyte subset reference ranges in peripheral blood of healthy adults by a dual-platform flow cytometry method.

Flow cytometry has emerged as a useful screening approach to evaluate whether specific cell populations are present or absent. Previous studies have shown different reference ranges in several countries. The aim of this study was to determine reference ranges of lymphocyte subsets in peripheral blood by flow cytometric method in Brazilian adults. In this study, relative and absolute reference ranges of lymphocyte subsets were: CD3+: 51.3-83.5%, 718-2494cells/µl; CD4+: 24.4-54.2%, 456-1492cells/µl; CD8+: 12.8-40.2%, 272-1144cells/µl; CD4+CD8+: double-positive 0.01-3.6%, 2-88cells/µl; TCR γδ: 1.0-15.9%, 19-345cells/µl; CD3+CD4-CD8-: 1.2-13.3%, 28-292cells/µl; TCR αß+: 44.3-77.0%, 855-2384cells/µl; CD4/CD8 ratio: 0.68-3.61; CD19+: 6.3-20.8%, 112-622cells/µl; mature NK cells: 3.1-27.4%, 70-745cells/µl; immature NK cells: 0.08-1.1%, 1-23cells/µl; total NK cells: 3.7-28.5%, 82-760cells/µl; and NKT cells: 0.9-21.4%, 18-488cells/µl. Comparison with other studies showed differences among some of them. This suggests that there are differences among lymphocyte subsets in the worldwide population and also it is important to determine reference ranges in different populations in order to better assess and monitor patients.

Comparison between two portable hemoglobinometers and a reference method to verify the reliability of screening in blood donors.

Portable hemoglobinometers are used to determine hemoglobin level, but there are conflicting reports regarding their accuracy. The aim of this study was to compare results from two portable hemoglobinometers (HemoCue® and Hemo-Control) with an automated hematology analyzer (Sysmex XE-2100D) to determine if the screening of blood donors is reliable. A total of 426 blood donors' samples were studied and on average the Hb content measured in capillary blood samples was higher than that found in venous blood samples. Hemoglobinometers can be employed as a method to screen blood donors, but critical values should be confirmed in an automated hematology analyzer.