Methods: This study observed the immune indexes of 51 children patients including the serum sIgE and sIgG4 to five periods of pre SIT（Pre）and after SIT (half of year (0.5Y),1 year,2 year(2Y) and 3 year(3Y)). 20 patients by conventional drug treatment were collected as control group.
Results: After half of year of SIT, the levels of serum sIgE to Der p, Der p1 and Der p2 increased continuously, however,by then began to decline, after three years treatment,the levels of sIgE to Der p1 and Der p2 were reduced step by step, particularly, sIgE to Der p1 were significantly lower than Pre treatment. The levels of sIgG4 to Der p, Der p1 and Der p2 increased significantly along with the process of SIT.The increasing range of Der p sIgG4 reached to the maximum, followed by Der p1 and then Der p2. The sIgE/sIgG4 ratio of three allergens were decreased after SIT, and the biggest dropped degree was the sIgE/sIgG4 ratio to Der p1. The low age group of children (5 to 8 y) response to immune higher and faster than the high age group of children (9-16 y) after SIT, and the levels of components sIgG4 to Der p1 and Der p2 elevated faster than sIgG4 to Der p.
Conclusions: In the early stage of treatment, the levels of Der p, Der p1 and Der p2 to sIgE and sIgG4 in serum by the body in a state of immune stimulating were significantly increased. As the SIT, the levels of sIgE gradually decreased, and the levels to sIgG4 increased, namely the sIgE/sIgG4 ratio reduced gradually, and the biggest declined of sIgE/ sIgG4 ratio was Der p1. the fastest degree to SIT reaction was the low age children with allergies.