Arthritis & Rheumatism, Volume 62,
November 2010 Abstract Supplement

Abstracts of the American College of
Rheumatology/Association of Rheumatology Health Professionals
Annual Scientific Meeting
Atlanta, Georgia November 6-11, 2010.


TNF Expression in Peripheral Blood Mononuclear Cells of Cutaneous Lupus & Dermatomyositis Patients.

Nabatian2,  Adam S., Wysocka4,  Maria, Bashir1,  Muhammad M., Werth3,  Victoria P.

Philadelphia VAMC, University of Pennsylvania
UMDNJ-Robert Wood Johnson Medical School, Philadelphia VAMC, University of Pennsylvania
University of Pennsylvania, Philadelphia, PA
University of Pennsylvania

Background:

There has been data published regarding TNFa in skin lesions and serum of patients with cutaneous lupus erythematosus (CLE) and dermatomyositis (DM). TNFa is increased in lesional skin of patients with discoid lupus erythematosus (DLE), subacute cutaneous lupus erythematosus (SCLE), and DM compared to controls. TNFa has been measured in sera from patients with systemic lupus erythematosus (SLE), DLE, SCLE, and DM and is elevated in patients with SLE, DLE, SCLE, but not DM. In vitro production of TNFa by unstimulated peripheral blood mononuclear cell (PBMCs) from juvenile DM patients was measured and it was found that PBMCs from children who had disease course >=36 months produced more TNFa compared to PBMCs from juvenile DM patients who had disease <36 months. Since there has been minimal data published on TNFa expression in PBMCs of CLE and DM patients, the purpose of our experiments was to evaluate TNFa production in PBMCs of DLE, SCLE, tumid lupus erythematosus (TLE), and DM patients.

Methods:

PBMCs were separated from heparanized venous blood of 21 DLE, 10 SCLE, 10 TLE, and 18 DM patients and 18 healthy controls. A subset of these cells were placed in culture and an ELISA was performed to measure TNFa protein levels. In another subset, Real-Time-PCR was performed to measure TNFa and ADAM17 (TACE) transcription. Lastly, flow cytometry was performed on another subset of cells to determine which cell type is secreting TNFa.

Summary of the Results:

The transcription of TNFa and ADAM17 and the TNFa protein production in DLE patients (55.9±11.1, 5.3±0.46, 31.6±8.9 pg/mL, respectively), but not SCLE (15.8±0.9, 2.4±0.3, 5.5±1.2 pg/mL), TLE (8.9±1.2, 3.7±1.0, 4.3±0.8 pg/mL), or DM, (11.6±2.7, 1.4±0.2, 2.0 ±0.2 pg/mL) was significantly greater than controls (3.2±0.7, 2.1±0.09, 1.5±0.37pg/mL, respectively) (P < 0.001). TNFa was predominately produced from monocytes and myeloid dendritic cells (mDCs). There was a significantly greater percentage of cells with TNFa intracellular staining in mDCs of DLE (28.5±7.1) (P < 0.01) and DM (21.6±4.1) (P < 0.05) patients when compared to controls (3.14±1.7). The mean fluorescence intensity of both monocytes (1569.8±485.8) and mDCs (1,044.5±185.4) from DLE patients was significantly greater (P < 0.05) when compared to healthy controls (470.9±82.6 and 293.6±138.1, respectively). Lastly, the total number of both monocytes (11.8±1.5%) (P < 0.001) and mDCs (1.14±0.4%) (P < 0.01) was significantly greater in DLE patients compared to healthy controls (5.2±1.1% and 0.37±0.09%). The total number of monocytes was also significantly greater in DLE patients (11.8±1.5%) compared to DM patients (6.5±2.8) (P < 0.01).

Conclusion:

TNFa may be critically important in the induction and development of DLE as these patients have significantly greater TNFa transcription and protein production. Myeloid DCs and monocytes may also have a greater role in the pathogenesis of DLE than was previously believed.

To cite this abstract, please use the following information:
Nabatian, Adam S., Wysocka, Maria, Bashir, Muhammad M., Werth, Victoria P.; TNF Expression in Peripheral Blood Mononuclear Cells of Cutaneous Lupus & Dermatomyositis Patients. [abstract]. Arthritis Rheum 2010;62 Suppl 10 :1198
DOI: 10.1002/art.28964

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