OBJECTIVETo explore possible correlations between renal Th1/Th2 ratio and renal microvascular injury in children with Henoch-Sch-nlein purpura nephritis (HSPN).

METHODSThirty-two children with HSPN were enrolled. They were classified into four groups by renal pathology: HSPN class II (n=8), HSPN class IIIa (n=7), HSPN class IIIb (n=10) and HSPN class IV/V (n=7). Five patients undergoing nephrectomy due to trauma were used as the controls. INFγ, IL-4 and CD34 in the renal tissues were measured by immunohistochemical analysis. INFγ was used as a marker of Th1, IL-4 was used as a marker of Th2 and CD34 was used as a marker of microvessel. The renal microvessel density was evaluated according to the Weidner standard. The relationships among the local Th1/Th2 ratio, renal pathological grade, microvessel score and microvessel density were studied.

RESULTSImmunohistochemical analysis showed a lower expression of INFγ and a higher expression of IL-4 in the HSPN groups than in the control group. The local Th1/Th2 ratio in the HSPN groups decreased and correlated significantly with the renal pathological grade. There were significant differences among four HSPN subgroups (P<0.05). Compared with the control group, the renal microvessel density in the HSPN class II and class IIIa groups increased significantly (P<0.05), but it decreased in the HSPN class IV/V group (P<0.05). The renal microvessel scores in the HSPN class IIIa, class IIIb and class IV/V groups increased significantly compared with those in the control and the HSPN classⅡ. The increased renal microvessel scores were associated with more severe renal pathological changes. A negative correlation was found between the local Th1/Th2 ratio and the microvessel density in kidneys (r=-0.921, P<0.01).

CONCLUSIONSThe decrease of Th1/Th2 ratio in kidneys might be responsible for renal microvascular injury in children with HSPN.