[Comparison of age-based clinical and abnormal immune parameters in patients with Henoch-Schönlein purpura].

Objective: To explore age-based clinical and immune parameters in Henoch-Schönlein purpura (HSP) to determine clinically useful markers reflecting disease characteristic. Methods: A cohort of 502 patients with HSP were enrolled into this retrospective study to evaluate their clinical and immune data. Results: Majority HSP cases occurred at age ≤14 years and showed significant immune imbalances of ESR, CD3(+) cells, CD4(+) cells, CD3(-)CD16(+)CD56(+) cells, CD4(+)/CD8(+) cells, IgG, IgA, IgM, IgE, complements C3/C4 and ASO in the acute phase. Compared to patients aged >14 years, symptoms of joint were more frequent at disease onset in patients aged ≤14 years (20.8% vs 7.6%, χ (2)=13.547, P <0.001) , and involvement of digestive tract and joint were also more frequent (57.4% vs 33.8%, χ (2)=24.106, P <0.001; 55.9% vs 32.5%, χ (2)=23.768, P <0.001, respectively) , but not for involvement of kidney (21.4% vs 51.3%, χ (2)=42.440, P <0.001) . The patients aged ≤14 years had distinct immune state, reductions of CD3(+) cells, CD4(+) cells and IgG were more frequent than patients aged >14 years, also increase of ASO (33.1% vs 20.0%, χ (2)=6.656, P =0.010) , but not increase of IgA (2.6% vs 39.4%, χ (2)=15.582, P <0.001) . In addition, reduction of IgG and increase of IgE were positively associated with digestive tract involvement ( P <0.001, P =0.001, respectively) , reduction of CD3(+)CD4(+) cells and normal IgM were positively associated with joint involvement ( P =0.004, P =0.003, respectively) , increase of CD3(+)CD8(+) cells and normal CD3(+) cells were positively associated with kidney involvement ( P =0.032, P =0.014, respectively) . Conclusion: HSP showed significant immune imbalance in the acute phase, patients between aged ≤14 and >14 years had distinct clinical and immune characteristic, and abnormal immune parameters were significantly associated with organ involvements.