A decreased frequency of regulatory T cells in patients with common variable immunodeficiency.
BACKGROUND
Common variable immunodeficiency disorder (CVID) is a heterogeneous syndrome, characterized by deficient antibody production and recurrent bacterial infections in addition abnormalities in T cells. CD4(+)CD25(high) regulatory T cells (Treg) are essential modulators of immune responses, including down-modulation of immune response to pathogens, allergens, cancer cells and self-antigens.


OBJECTIVE
In this study we set out to investigate the frequency of Treg cells in CVID patients and correlate with their immune activation status.


METHODS
Sixteen patients (6 males and 10 females) with CVID who had been treated with regular intravenous immunoglobulin and 14 controls were enrolled. Quantitative analyses of peripheral blood mononuclear cells (PBMC) were performed by multiparametric flow cytometry using the following cell markers: CD38, HLA-DR, CCR5 (immune activation); CD4, CD25, FOXP3, CD127, and OX40 (Treg cells); Ki-67 and IFN-gamma (intracellular cytokine).


RESULTS
A significantly lower proportion of CD4(+)CD25(high)FOXP3 T cells was observed in CVID patients compared with healthy controls (P<0.05). In addition to a higher proportion of CD8(+) T cells from CVID patients expressing the activation markers, CD38(+) and HLA-DR(+) (P<0.05), we observed no significant correlation between Tregs and immune activation.


CONCLUSIONS
Our results demonstrate that a reduction in Treg cells could have impaired immune function in CVID patients.
Melo
Karina M
KM
Federal University of São Paulo, São Paulo, Brazil.
Carvalho
Karina I
KI
Bruno
Fernanda R
FR
Ndhlovu
Lishomwa C
LC
Ballan
Wassim M
WM
Nixon
Douglas F
DF
Kallas
Esper G
EG
Costa-Carvalho
Beatriz T
BT
D000293:Adolescent; D000328:Adult; D016022:Case-Control Studies; D017074:Common Variable Immunodeficiency / Q000097:blood / Q000276:immunology*; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D016130:Immunophenotyping; D007371:Interferon-gamma / Q000096:biosynthesis; D019394:Ki-67 Antigen / Q000097:blood; D008213:Lymphocyte Activation; D008297:Male; D050378:T-Lymphocytes, Regulatory / Q000276:immunology*; D055815:Young Adult
D019394:Ki-67 Antigen; D007371:Interferon-gamma