Abstract: Objective To analyze the relationship between dynamic change of GPI-80 and disease severity and prognosis of childhood anaphylactoid purpura. Methods Patients were collected and divided into three groups according to their clinical features:purpura group (purpura only), mixed group (purpura+arthritis+gastrointestinal bleeding) and nephritis group. There were 20 patients in each group. GPI-80 expression on the neutrophils was detected by flow cytometry during acute and regressive phases of the disease. GPI-80 expression was compared among different groups and different phases. Renal biopsies were performed in 20 nephritis patients. Results GPI-80 expression was significantly increased in all patient groups compared with that in the normal control (P<0.001). Mixed and nephritis groups had higher GPI-80 expression than that of purpura group respectively (P<0.001, P<0.001). Moreover, the more the organs involved, the higher GPI-80 expressed. There was no significant difference of GPI-80 expression between mixed and nephritis groups (P>0.05). No significant difference of GPI-80 expression was found among 20 nephritis patients with different pathological patterns. Forty-two patients (10 in purpura group, 15 in mixed group, and 17 in nephritis groups) were followed up and GPI-80 expression was detected at the time of discharge and 2 weeks after discharge, the results showed that GPI-80 expression was decreased from 93.26% (±7.89%) at acute phase to 91.37% (±6.9%) at regressive phase with an average interval of 13.5 days. Most of them (35/42) further decreased to 38.44% (±7.8%) in 2 weeks after discharge. GPI-80 expression remained high in 7 patients for 2 weeks after discharge and relapsed in 5 patients within 1 month after discharge. Conclusions High GPI-80 expression is related to the severity of the disease. The decrease of GPI-80 takes place later than the improvement of clinical symptoms. Children with persistently high GPI-80 expression are likely to relapse. It seems that there is no correlation between GPI-80 expression and different pathological patterns of nephritis.

Key words: Purpura, Schoenlein-Henoch, GPI-80 expression, Nephritis