Thymic and bone marrow output in patients with common variable immunodeficiency.

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.