CD4 and IgA glomerulonephritis: They also reported that CD4(+) T cells, especially CD4(+) human leukocyte antigen-DR isotype (HLA-DR)(+) cells representing activated helper T cells, in epipharyngeal abrasive cells that may originate from the surface mucosa of the epipharynx were significantly higher in patients with IgA nephropathy than in normal healthy subjects.