Pathologic findings of initial biopsies reflect the outcomes of membranous nephropathy.
BACKGROUND
A considerable diversity of prognosis is seen with idiopathic membranous nephropathy (IMN). The initial factors affecting long-term outcome remain unclear.


METHODS
We studied retrospectively 105 patients with IMN who had been followed up for at least 5 years, or until end-stage renal failure (ESRF) (primary outcome), or death (secondary outcome). We analyzed the initial clinicopathologic factors affecting primary and secondary outcomes. We assigned the patients to two groups and one subgroup, based on the electron microscopic findings. The groupings were: homogeneous type with synchronous electron dense deposits; homogeneous type with large dense deposits (deep subgroup); and heterogeneous type with various phases of dense deposits.


RESULTS
No differences in the initial clinicopathologic states were seen between the homogeneous (N= 60) and heterogeneous types (N= 45), apart from hypertension and disease history before biopsy. In the homogeneous type, only one patient developed ESRF, which was drug-induced, and remission occurred earlier than in the heterogeneous type. With regard to secondary outcomes, increased age, male gender, heterogeneous type, and deep subgroup were independent risk factors. There were no significant differences attributable to therapeutic regime with respect to primary or secondary outcome in either group.


CONCLUSIONS
Our results indicate that an electron microscopic classification, at initial biopsy, as heterogeneous type or deep subgroup type with dense deposits are independent indicators of poor prognosis in IMN.
Yoshimoto
Keiichi
K
Department of Gastroenterology and Nephrology, and Division of Blood Purification, Kanazawa University Graduate School of Medical Science, Kanazawa, Japan.
Yokoyama
Hitoshi
H
Wada
Takashi
T
Furuichi
Kengo
K
Sakai
Norihiko
N
Iwata
Yasunori
Y
Goshima
Satoshi
S
Kida
Hiroshi
H
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001706:Biopsy; D005260:Female; D005500:Follow-Up Studies; D015433:Glomerulonephritis, Membranous / Q000473:pathology* / Q000628:therapy; D006801:Humans; D007678:Kidney Glomerulus / Q000473:pathology* / Q000648:ultrastructure; D008297:Male; D008854:Microscopy, Electron; D008875:Middle Aged; D011379:Prognosis; D012189:Retrospective Studies; D016896:Treatment Outcome