Abnormalities of regulatory T cells may play an important role in the loss of self-tolerance,
which is a major characteristic of lupus. The objective of this study was to determine
the ratio and the number of natural CD4+CD25highFoxp3+ and inducible CD4+IL-10+ regulatory
T cells in lupus patients and to search correlation with disease activity. Seventy-two
Hungarian lupus patients were enrolled in the study. Fourty-one age- and sex matched
healthy donors served as controls. Flow cytometry was used for the quantification
of CD4+CD25high Foxp3+ (nTreg) and CD4+IL-10+ (iTreg) cells. The ratio (3.06 +/- 1.45%)
and the number (0.019 +/- 0.012 x 10(9)/L) of nTreg cells decreased in lupus significantly
(P < 0.001 in both) as compared to normal controls (4.26 +/- 1.01% and 0.039 +/- 0.017
x 10(9)/L). The ratio of iTreg cells were significantly higher in patients than in
controls (20.92 +/- 14.02% versus 15.49 +/- 11.65%, P < 0.03), but the number of these
cell type did not differ in significant manner (0.314 +/- 0.236 x 10(9)/L versus 0.259
+/- 0.183 x 10(9)/L). The 19 active patients were characterised by significantly higher
disease activity index (SLEDAI 8.63 +/- 2.95 versus 1.74 +/- 1.68, P < 0.001) and
anti-DNA concentration (117.85 +/- 145.89 versus 37.36 +/- 68.85 IU/mL, P = 0.001)
as compered to the 52 inactive patients. Furthermore, active patients required higher
dose of methylprednisolon than inactive ones (14.8 +/- 10.6 versus 4.8 +/- 3.4 mg/day,
P < 0.001). However, we did not find statistical significant difference in the number
and ratio of the examined cell populations regarding to disease activity. Altered
ratio and number of both natural and inducible regulatory T cells may play a role
in the pathogenesis of lupus. There are small but appreciable difference in the number
of regulatory T cells between inactive patients and healthy controls. It suggests
that immunoregulatory deficiencies are present in the inactive stage of the disease
also.
