Abstract:

Ｏｂｊｅｃｔｉｖｅ：To characterize the clinicopathological features and prognosis of IgA nephropathy patients with endocapillary hypercellularity (IgANE) and massive glomerular macrophage infiltration, to explore their pathogenesis.
Ｍｅｔｈｏｄｏｌｏｇｙ：The 95th percentile of the glomerular CD68+ cells counts from 62 IgANE cases was defined as the threshold for massive macrophage infiltration.Patients with biopsies that met the threshold were enrolled as the study group and patients that did not meet as the control group.Clinicopathological features and followup data were evaluated.Immunohistochemical staining was performed with the cell biomarker of CD68,iNOS,CD163,CD3 and CD20.Abnormal glycosylated IgA1 (GdIgA1) was immunofluorescently stained with KM55,and overlapped with IgA.
Ｒｅｓｕｌｔｓ：The median number of glomerular CD68+ cells in 62 IgANE patients was 42 (23～61) cell/glomerulus,with 95th percentile of 14 cell/glomerulus. A total of 38 patients were enrolled in the study group,including 17 males and 21 females; the mean age was 36±17 years. Compared with 59 control group,patients in the study group showed significantly higher proteinuria,cholesterol and triglyceride,lower albumin levels,increased E lesion but decreased glomerulosclerosis,tubular atrophy and interstitial fibrosis at biopsy (all P<005); higher percentage of immunosuppressants treatment and worse renal prognosis (P=0002) during followup. The glomerular infiltrating inflammatory cells in the study group were mainly CD68+ and CD163+ cells,which both were positively correlated with E% but not with renal function. The colocalization of KM55 and IgA in the two groups confirmed that the IgA deposit in glomeruli was GdIgA1.
Ｃｏｎｃｌｕｓｉｏｎ：
IgANE with massive glomerular macrophage infiltration patients have distinctive clinicopathological features,showing a more active clinicopathological findings and worse renal prognosis.

Key words: IgA nephropathy, endocapillary hypercellularity, macrophages, galactose-deficient IgA1