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Updated: Oct 13, 2026

Examination of Thymic Positive and Negative Selection by Flow Cytometry
Published on: October 8, 2012
CD4 lymphocyte subset abnormalities associated with impaired delayed cutaneous hypersensitivity reactions in patients
A D Crockard1, N A Boyd, T A McNeill
1Regional Immunology Laboratory, Royal Victoria Hospital, Queen's University of Belfast, Northern Ireland.
Abstract:
Circulating CD4 lymphocyte subset (CD45RA; CD45RO; CD29; Leu8) levels were determined in nine patients with X-linked agammaglobulinaemia (XLA), nine patients with common variable immunodeficiency (CVI) and in 18 age- and sex-matched controls. CD4CD45RO and CD4CD29 cells were significantly lower (P less than 0.01) in the XLA patient group (CD45RO, 15.7 +/- 10.2%; CD4CD29, 32.1 +/- 14.6%) compared with CVI patients (61.8 +/- 25.4%; 60.1 +/- 11.2%) and normal controls (43.7 +/- 22.3%, 54.5 +/- 22.0%). The levels of CD4CD45RA and CD4Leu8 cells were not abnormal in the XLA patient group. No selective reduction in CD4 subsets was observed in the CVI patient group. Delayed cutaneous hypersensitivity testing of five XLA and five CVI patients revealed a significantly reduced response to recall antigens in patients with XLA. This may relate to the deficiency of circulating memory T cells observed in these patients.
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