Expression and existence forms of mast cell activating molecules and their antibodies in systemic lupus erythematosus.

Introduction: Mast cells are regarded as a kind of classical anaphylaxis cells. However autoimmune diseases and allergic reactions have many similarities or overlaps. A large number of papers have proved that mast cells play a significant role in the pathogenesis of systemic lupus erythematosus (SLE). It is speculated that IgE, anti-IgE antibodies, FcεRI, and anti-FcεRI antibodies activate mast cells through autoimmune pathways and participate in the disease process of SLE. Naturally occurring protein molecules not only exist in monomer form, but also in polymer of protein molecules. Therefore, whether IgE, FcεRIα, anti-IgE antibodies, and anti-FcεRI antibodies also exist in polymeric forms in the natural state is worthy of further investigation.

Methods: The serum samples and clinical data of 131 patients with SLE were collected from Qilu Hospital (Qingdao). Sixty healthy individuals were collected as the control group. Serum FcεRIα, anti-IgE, and anti-FcεRI were detected by enzyme-linked immunosorbent assay. Serum IgE was detected by rate scatter nephelometry. A Chinese hamster ovarian cancer cell line CHO3D10 transfected with human FcεRIα was cultured and the cell protein extract was prepared. The existence forms of FcεRIα in the cell protein extract were detected by the native-page method.

Results: The serum FcεRIα in SLE patients was significantly higher than that in control group (3.52 [2.18, 4.71] µg/ml and 1.87 [1.52, 2.33] µg/ml, respectively; p < .05). Anti-IgE was significantly lower than that in the control group (0.85 [0.55, 1.21] µg/ml and 1.23 [0.95, 1.58] µg/ml, respectively; p < .05). The CHO3D10 cell line expressed the FcεRIα, which had one kind of monomer (mFcεRIα) and two kinds of polymers (pFcεRIα) in the degeneration conditions.

Conclusion: In patients with SLE, the expression of FcεRIα was increased and the level of anti-IgE was decreased. FcεRIα had one kind of monomer and two kinds of polymers. Mast cell-associated FcεRIα involved in the inflammatory lesion of SLE.