Reference values for B-cell surface markers and co-receptors associated with primary immune deficiencies in healthy Turkish children.

In order to evaluate B-lymphocyte subsets of patients with primary immunodeficiencies, the normal values for national healthy children have to be used as a reference. Recently, B-cell co-receptor markers (CD19, CD21, and CD81) and CD20, CD22, and CD27 deficiencies have been reported in relation with different primary immunodeficiency diseases. The objective of this study was to establish national reference values for B-lymphocyte co-receptors and some surface markers, CD20, CD22, CD27, as well as classic lymphocyte subsets in the peripheral blood of healthy children. A total of 90 healthy children were included in this study. Complete blood counts were performed and cells with CD3, CD4, CD8, CD19, CD16/56, CD20, CD21, CD22, CD27, and CD81 surface markers were simultaneously detected by flow cytometry. The children were evaluated in three age subgroups, 0-1, 1-6, and >6 years, and minimum, maximum, mean, mean minus standard deviation, and 2.5-97.5 percentile values were all determined. By establishing reliable reference ranges for these surface markers, we hoped to help identifying and classifying some primary immunodeficiency patients, especially those defined as unclassified hypogammaglobulinemia and those without definite diagnosis.