BAL regulatory T cells (Tregs) are decreased in common variable immunodeficiency (CVID) with ILD

Background: Common variable immunodeficiency disorder (CVID) is the most frequent symptomatic primary immunodeficiency. Previous studies indicates that a subgroup of CVID patients develop autoimmune diseases and granulomatous lesions in the lung. Circulatory Tregs (CD4+Foxp3+CD25high) are reduced in these patients. Objective: to characterise brochoalveolar lavage (BAL) cell pattern and Treg counts in CVID with ILD versus healthy donors (HD). Methods: the study included 32 CVID-patients and 31 HD. BAL differential cell counts and spontaneous TNF-alpha production by BAL cells were tested. Various Treg subpopulations were quantified by flow cytometry. Results: BAL differential cell counts revealed a significant increase in total cell count (p Conclusion: CVID-ILD is associated with a significant lower number of BAL Tregs and an increase in spontaneous TNF-alpha production. Despite a CD19+B cell deficiency in peripheral blood, there is an increase in CXCR3+CD20+B cells in BAL.