Expression Of Macrophage Migration Inhibitory Factor In Renal Tissue Of Henoch-schonlein Purpura Nephritis And Its Significance

ObjectiveTo investigate the expression of macrophage migration inhibitory factor(MIF) in renal tissue of patients with henoch-schonlein purpura nephritis(HSPN), and its correlation with clinical indexes and pathological changes, and explore its effect on the pathogenesis of HSPN.MethodsAccording to the clinical manifestation, 60 patients with henoch-schonlein purpura(HSP) were divided into mixing group(n=20), HSPN group(n=20) and only purpura group(n=20), and 20 patients with henoch-schonlein purpura nephritis were divided into mild lesions(n=7), moderate lesions(n=8), severe lesions(n=5) According to the degree of pathological changes. MIF concentration of HSP groups and normal control were detected with enzyme-labeled immunosorbent assay(ELISA) method. MIF protein expression and the marker of human macrophage(CD68) in renal tissues of HSPN were detected with immunohistochemistry method. The total urine protein for 24 hour was detected with biuret method, and urinary N-acetyl-beta-D- glucosaminidase (NAG) level was detected with colorimetric detection.ResultsMIF concentration(ng/ml) in the mixing group(87.21±8.61) and HSPN group(89.45±8.15) was significantly higher than that in the only purpura group(46.36±7.37) and normal control(15.85±4.91) (P<0.001), and MIF concentration was significantly higher in only purpura group(46.36±7.37) than in normal control(15.85±4.91) too(P<0.001), but no difference was found between mixing group(87.21±8.61) and HSPN group(89.45±8.15) (P=0.341). Weak expression of MIF and CD68 was found in normal control, while the expression of MIF and CD68 significantly increased in HSPN (P<0.05); with the pathological changes of renal tissue aggravating, the expression of MIF and CD68 in renal tissue increased(P<0.05); and positive correlation was found between the expression of MIF and CD68 as well(P<0.05). The expression of MIF in renal tissues was significantly correlated with the total urine protein for 24 hour and urinary NAG level(P<0.05), and it was significantly correlated with MIF concentration in serum too(P<0.05).Conclusions(1) CD68-positive macrophage infiltration increased significantly in areas with up-regulation of MIF expression in renal of HSPN, both were significantly correlated, it suggested that MIF and macrophages are closely related; There was a modest up-regulation in renal MIF expression in HSPN, the degree of renal pathological changes and clinical indexes of renal damage were closely related with MIF levels, It may be an important mechanism for the renal injury of HSPN that upregulation of MIF can enhance infiltration of macrophages. (2)Comparesd with serum MIF levels in three group of HSP, the level of mixing group was significantly higher than purpura group and normal control group, and was no difference with the HSPN group. And at long-term follow-up, the risk of renal damage in mixing group was higher than purpura group, so we can observe the level of serum MIF to speculate renal damage in HSP.