Immunophenotyping results of T and B cells in STK4-deficient patients. (A) Flow cytometric staining of peripheral CD3+CD4+ T cells for differentiation markers reveals relative increase of CD45RA−CD45RO+ memory T cells and decrease of CD45RA+CD45RO− naive T cells in PBMCs isolated from patients (P1, P2, and P3) compared with HD (healthy donors) and heterozygous. (B) Based on the expression of CD62L and CCR7, memory T cells were further divided into effector memory (CD45RO+CCR7−CD62L−) and central memory (CD45RO+CCR7+CD62L+) subsets. (C) The circulating B-cell pool was characterized by CD19 staining and further divided into B-cell subtypes. The immunophenotyping shows an increased fraction of transitional B cells (CD38++IgMhigh; D) and also reduction of marginal zone B cells (IgD+IgM+CD27+) and switched memory B cells (IgD−IgM−CD27+). The normal range for switched memory B cells in children 6 to 10 years of age is 5.2% to 12.1%; and for adults 19 to 25 years of age, it is 7.2% to 12.7%.34
