Cd71 Expression In Iga Deposited Nephritis Of Glomeruli

Objective To study expression of CD71 molecular characteristic in renal tissues and correlation between IgA deposits and CD71 expression in IgA nephropathy(IgAN) and non-IgAN IgA deposited nephritis, and investigate the role of CD71 in pathogenesis of IgAN in directing the therapeutical strategies and provide a beneficial help in improving and retarding progression of IgA nephropathy.Methods According to clinical diagnosis and pathological diagnosis,109 cases of renal biopsy were classified into the primary group (35 cases of IgA deposited patients), the secondary group (31 cases of non-IgAN IgA deposited patients) and the control group (43 cases of no IgA deposited patients). Every specimen of renal biopsy was dictomized. One section was embedded by paraffin for light microscope. The other was embedded by ornithine carbamoyltransferase compound (O.C.T) for immunofluorescene microscope. Their sections of paraffin were routinely stained by hematoxylin and eosin stain, periodic acid-Schiff stain, masson trichrome stain and a silver methenamine stain. Their cryostat sections were routinely incubated by fluorescein isothiocyanate (FITC)-conjugated anti-human IgA, IgG, IgM, C3, C4, FRA antibody (direct immunofluorescene method) (DIF) and HbsAg, HBcAg antibody (indirect immunofluorescene method) (IIF) under immunofluorescene microscope. In the meantime, their frozen sections were incubated by tetramethylrhodamine-isothyocyanate (TRITTC)-conjugated anti-CD71 antibody (indirect immunofluorescene method) respectively. When the sections that were incubated by TRITTC-conjugated anti-CD71 antibody were positive under immunofluorescene microscope, they were incubated by FITC-conjugated anti-human IgA antibody respectively (direct immunofluorescene method). Finally, confocal laser scan microscopy was used to examine CD71 and IgA configuration by dual labeled immunofluorescene antibodies.Results Under immunofluorescene microscope, CD71 was not expressed or weak in control group. However, it was expressed in the primary group and the secondary group in various degrees in mesagium and capillary walls. Moreover, the level of CD71 intensity in the primary group is higher than that in the secondary group (P<0.05). Under confocal laser scan microscopy, the deposits of IgA (green immunofluorescene) and CD71 (red immunofluorescene) were visualized in mesagium and capillary walls by a single excitation wavelength (488/476nm) respectively in different planes, and a certain positive correlation between IgA and CD71 deposits was noted(Pearson correlation r=0.992). Moreover, when two excitation wavelengths (488/476nm) of confocal laser scan microscopy scanned them by two different lasers simulantaously, moving along Z axis in every other 0.2um distance, deposits of IgA and CD71 co-localization were visualized in different planes(yellow immunofluorescene). We also observed a good correlation between IgA deposits and C3 deposits in renal tissues, and the incidence of positive immunofluorescene for C3 in the primary group was higher than that in the secondary group and the cotrolled group(P<0.05). Association between intensity of CD71 expression and clinical or biologic finding was not found.Conclusion CD71 is expressed in the primary IgA nephropathy and the non-IgAN IgA deposited nephritis, the level of CD71 intensity in the primary group than that in the secondary group. Moreover, CD71 is co-localized with IgA, therefore, it is one of IgA receptors, which can play an important role in pathogenisis of IgA nephropathy. But it is not known whether agents that can block their binding could retard or improve progression of IgA nephropathy. What is more, the reason why CD71 expression is induced is unclear, the role of its detailed immune mechanism in IgA nephropathy remains unclear and needs further study.