Open Access

ARTICLE

Relationship between peripheral blood dendritic cells and cytokines involved in the pathogenesis of systemic lupus erythematosus

Ewa Robak¹, Piotr Smolewski², Anna Wozniacka¹, Anna Sysa-Jedrzejowska¹, Henryk Stepień³, Tadeusz Robak²

1 Department of Dermatology and Venerology, Medical University of Łódź, ul. Krzemieniecka 5, 94-017 Łódź, Poland
2 Department of Haematology, Medical University of Łódź and Copernicus Memorial Hospital, ul. Pabianicka 62, 93-513 Łódź, Poland
3 Department of Experimental Endocrinology, Medical University of Łódź, ul. Sterlinga 5, 91-423 Łódź, Poland

* Corresponding Authors: Tadeusz Robak, ;

European Cytokine Network 2004, 15(3), 222-230.

Accepted 21 April 2004;

Abstract

Recent studies indicate that dendritic cells (DC) and several cytokines are implicated in the induction of autoimmune diseases. In this study we investigated the relationship between the total number of DC (tDC), and their plasmacytoid (pDC) and myeloid (mDC) subpopulations, with serum concentrations of interferons (IFN-α and IFN-γ) and selected cytokines (TNF-α, IL-4, IL-6), in patients with systemic lupus erythematosus (SLE) and healthy persons. Subpopulations of DC were determined by the following antigen expression profiles: BDCA-1+/CD11c+/HLA-DR+ (for mDC) and BDCA-2 +/CD123+/HLA-DR+ (for pDC), using flow cytometry. Serum levels of interferons and cytokines were assessed by an enzyme – linked immunosorbent assay (ELISA). The study was performed in 36 SLE patients and 19 healthy volunteers. The mean number of tDC was lower in SLE patients (13.9 ± 6.4/µL) than in healthy persons (24.1 ± 12.6/µL) (P < 0.001). The number of pDC was also significantly lower in SLE (6.6 ± 3.6/µL) than in the control group (12.0 ± 8.3/µL) (P < 0.02). Moreover, the mean pDC count was lower in active than in inactive disease (5.5 ± 3.6/µL vs 7.6 ± 3.4/µL; P < 0.04). The mean serum levels of IFN-α and IFN-γ were significantly higher in SLE patients (63.8 pg/mL and 6.6 pg/mL, respectively) than in the control group (2.7 pg/mL and 0.5 pg/mL, respectively) (P < 0.008 and P < 0.001, respectively). Serum levels of TNF-α and IL-6 were also higher in SLE patients (mean 7.3 pg/mL and 18.4 pg/mL, respectively) than in healthy controls (4.2 pg/mL and 0.5 pg/mL, respectively) (P < 0.02 and P < 0.001, respec-tively). The mean serum IL-4 concentrations were similar in SLE and healthy persons (0.2 pg/mL and 0.31 pg/mL, respectively; P = 0.119). A negative correlation was found between pDC number and the serum level of IFN-α (q = – 0.386, P = 0.02) and between mDC and IFN-γ(q = – 0.377, P = 0.024). In conclusion, the correlation between peripheral blood DC subsets and serum levels of IFN-α and IFN-γ suggests a possible relationship between these cytokines in the pathogenesis of SLE.

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