Abstract:

Objective To investigate the effect of immunoglobulin G （IgG） in bullous pemphigoid （BP） blister fluid on the secretion of chemokines by human keratinocytes. Methods IgG was obtained from the blister fluid of patients with bullous pemphigoid and sera of normal human controls, then purified by sequential precipitation with caprylic acid and ammonium sulfate. The immunological activity of blister fluid was tested before and after the purification by BP180 ELISA kit. Keratinocytes were isolated from the foreskin tissue of yong adults, and subjected to primary culture. After 3 passages, the primary keratinocytes were harvested and subcultured in the presence of purified IgG of 0.5, 1, 2, 4 and 8 g/L, respectively, for 24 hours, or IgG of 4 g/L for 3, 6, 12, 24 hours, respectively, followed by the detection of levels of eotaxin, monocyte chemoattractant protein （MCP）-1 and interleukin （IL）-8 in the supernate of keratinocytes by ELISA. Results The valence of IgG remained unchanged after the purification with caprylic acid and ammonium sulfate. Compared with IgG from the sera of normal controls, that from bullous pemphigoid blister fluid significantly enhanced the secretion of IL-8 by keratinocytes in a time- and dose-dependent manner （both P < 0.01）. Neither eotaxin nor MCP-1 was detected in the supernate of control IgG-treated, BP IgG-treated or untreated keratinocytes. Conclusions The IgG in BP blister fluid has been proved to stimulate the secretion of IL-8 by cultured human keratinocytes, which may be involved in the pathogenesis of BP.

Key words: Pemphigoid, bullous;Chemokines;Keratinocyte