Objective:To observe the IgA Fc receptor FcαRI expression in both serum and skin lesions of children with acute Henoch-Schonlein purpura（HSP）

and to find out the relationship between FcαRI expression and production of inflammatory cytokines interleukin-6（IL-6）

tumor necrosis factor-α（TNF-α）.Methods:Fifty children with acute HSP were included in this study

of which30 were HSP and 20 were Henoch-Schonlein purpura nephritis（HSPN）.Twenty healthy age-matched children were admitted as control.Sandwich solid-phase ELISA was applied to detect the serum soluble IgA Fc receptor（sFcαRI）.FcαRI expression and distribution in skin lesions were assayed by immunohistochemistry and Western blot in 20 patients.Direct immunofluorescence was used in locate IgA

C3

Fib deposition.Serum cytokine IL-6 and TNF-α of PBMC supernatant were also detected.Results:（1）Serum levels of IgA

C3 in acute phase of HSP and HSPN were significantly higher than those of normal controls（F=14.000

P=0.000;F=8.227

P =0.000）;serum s FcαRI-IgA levels were elevated in HSPN group only（F=2.891

P=0.022）.（2） FcαRI deposited predominantly in epidermis and dermal neutrophils

vascular endothelial cells and around appendix;both FcαRI staining intensity and protein expression were significantly increased in HSP lesion（t=8.276

P=0.000;t=3.274

P=0.004）.（3）TNF-α levels of PBMC supernatant were higher in both HSP and HSPN（F=8.309

P=0.028

P=0.000）

with more significant increase in HSPN than in HSP（P=0.030）.Conclusion:IgA Fc receptors FcαRI are involved in HSP pathogenesis and may represent an important marker for acute stage HSP.However

the underline mechanisms remain to be further elucidated.