Aim: To clarify the role of leukocyte subsets in the development of glomeru
losclerosis (GS) and interstitial lesions which may contribute to the progn
osis of membranous nephropathy (MN), we investigated infiltrating cells in
both glomeruli and interstitium in biopsy specimens. Methods: Forty-one cas
es of MN were divided into two groups: MN with segmental GS (MN+GS; n = 21)
and MN without GS (MN-GS; n = 20). There was no significant difference bet
ween both groups regarding clinical data at the time of the renal biopsy. T
he cells were analyzed with a three-layer indirect immunoperoxidase method
using monoclonal antibodies against leukocyte common antigen, T cells, B ce
lls, and monocytes/macrophages (Mo/M phi). Results: Renal function tended t
o deteriorate during the final follow-up period in group MN+GS, but not in
group MN-GS. The number of glomerular and interstitial leukocytes in group
MN+GS were significantly higher than those in group MN-GS. Leukocytes were
mostly Mo/M phi in the glomerulus, while T cells and Mo/M phi were predomin
ant in the interstitium. in group MN+GS, there was a significant correlatio
n in number of M phi (CD68+) between glomeruli and interstitium, but not in
group MN-GS. Conclusion: The results suggest that Mo/M phi may play an imp
ortant role in the development of segmental GS and interstitial lesions in
MN which may be responsible for the incurability and poor prognosis.