Thymic and bone marrow output in patients with common variable immunodeficiency

Abstract

Objective: The study aims to obtain more information about the immune deficit of common variable immunodeficiency (CVID) patients.

Materials and methods: A new real-time PCR assay was used to quantify T and B lymphocyte mobilization from the production and maturation sites through the detection of T cell receptor excision circles (TRECs) and kappa-deleting recombination circles (KRECs) and to allow the estimation of the average number of B cell divisions. T and B lymphocyte subsets were analyzed by flow cytometry.

Results: The number of TREC(+) lymphocytes, which depends on age and gender, was significantly reduced in CVID patients. Similarly, KREC concentration was lower than in controls. Classification of patients according to the percentage of memory switched B cells showed that patients belonging to MB2 group and therefore with conserved B cell maturation have the lowest new B cell output but increased average peripheral divisions, leading to the highest B cell number.

Conclusions: TREC and KREC quantification can be helpful for a more complete and informative understanding of a heterogeneous disease such as CVID.