Evolution of basic immunologic parameters over time. (A) CD45RA⁺ T cells (upper row) and HLA-DR⁺ T cells (lower row) of P1 at the age of 5 months (uncontrolled CMV infection, beginning eczema) and 14 months (severe erythroderma) compared with T cells from the brother at the age of 15 months (uncontrolled CMV infection, no eczema). Plots from age-matched controls (HD) are shown in comparison. (B) TCRVβ usage among CD4⁺ T cells as assessed by flow cytometry using TCRVβ-specific antibodies. The percentage of CD4⁺ T cells expressing the individual TCRVβ chain is shown for P1 and P2 compared with reference values.²⁸  (C) Staining for FoxP3⁺/CD25⁺ regulatory T cells in PBMC of P2 and a healthy control. The right panel shows the fraction of regulatory T cells in the day control (open triangle), the patient (black triangle), and 4 age-matched healthy infants (open circles). Below: CD25/FoxP3 stain of a lymph node biopsy from P1 and a control (FoxP3: red; CD25: brown). (D) Serum immunoglobulin levels over time in P1 (circles) and P2 (triangles). The shaded area represents normal values. (E) CD38⁺IgM⁺ transitional B cells (left) and IgD^–CD27⁺ switched memory B cells (right) in P2 are shown compared with an age-matched healthy control.