Reduced circulating natural killer T cells and gamma/delta T cells in patients with systemic sclerosis.
OBJECTIVE
To evaluate peripheral blood mononuclear cells (PBMC) expressing natural killer (NK) cell surface markers (CD16 and CD56, in both CD3- and CD3+ cells) and g/d T cell receptors (TCR) involved in non-MHC-restricted cytotoxicity, assessing their possible relationship with clinical and laboratory variables in patients with systemic sclerosis (SSc).


METHODS
We submitted 50 patients with SSc to detailed clinical and laboratory assessment, and also performed PBMC subset analyses by direct dual immunofluorescence and flow cytometry.


RESULTS
No statistically significant differences were found in the percentages or the absolute numbers of total lymphocytes, of B cells, and of CD4+ T cells. The absolute number of CD8+ cells was lower (p < 0.03), while HLA-DR+ elements were higher in frequency (p < 0.03) in SSc patients than in healthy controls. SSc patients had lower values (both percentage and absolute number) of NK-T cells (p < 0.01 and p < 0.003, respectively) and of T cells expressing g/d TCR (p < 0.01 and p < 0.005, respectively); whereas NK cells were marginally but not significantly decreased. The absolute number of NK-T cells showed an inverse correlation to erythrocyte sedimentation rate values (p < 0.03; rs = -0.306), percentage of g-globulins (p < 0.01; rs = -0.353), and serum concentrations of IgG (p < 0.02; rs = -0.334).


CONCLUSIONS
Impairment of NK-T cells and of T cells expressing g/d TCR may lead to downregulation of normal immune response, and seems to be important for immunological and inflammatory aspects of SSc.
Riccieri
Valeria
V
Dipartimento di Clinica e Terapia Medica Applicata, Cattedra di Reumatologia, Università degli Studi di Roma La Sapienza, Rome, Italy. valeria.riccieri@uniroma.it
Parisi
Gilberto
G
Spadaro
Antonio
A
Scrivo
Rossana
R
Barone
Francesca
F
Moretti
Tiziana
T
Bernardini
Graziella
G
Strom
Roberto
R
Taccari
Egisto
E
Valesini
Guido
G
D000328:Adult; D000368:Aged; D015536:Down-Regulation; D005260:Female; D005434:Flow Cytometry; D005455:Fluorescent Antibody Technique; D006801:Humans; D007694:Killer Cells, Natural / Q000276:immunology*; D018655:Lymphocyte Count; D008297:Male; D008875:Middle Aged; D016692:Receptors, Antigen, T-Cell, gamma-delta / Q000276:immunology*; D012595:Scleroderma, Systemic / Q000276:immunology*; D016176:T-Lymphocyte Subsets / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology*
D016692:Receptors, Antigen, T-Cell, gamma-delta