Clinico-pathological characterization of mesangial proliferative glomerulonephritis with predominant deposition of IgM

Abstract

Background. IgM nephropathy (IgMN) was first described in 1978 but whether IgMN is a distinct entity has not yet been confirmed. We tried to clarify the characteristics of IgMN on the basis of clinical and histological findings of patients who were treated and investigated by us. Methods. We evaluated 90 patients (group A) with mesangial proliferative glomerulonephritis (MesPGN) who exhibited more dominant mesangial deposits of IgM than of IgG and IgA. To clarify the significance of the IgM mesangial deposits, we divided these patients into two subgroups: group A1 comprised 30 patients with diffuse and global mesangial IgM deposits and group A2 comprised the other 60 patients, with focal segmental mesangial IgM deposits. Ninety Mes-PGN patients without predominant IgM deposits, excluding those with IgA nephropathy were studied as controls (group B). Results. Group A had significantly higher levels of serum IgM than group B (P Ͻ 0.01). The mean values for glomerular filtration rate (GFR), serum albumin, and CH50 in group A were significantly lower than those in group B (P Ͻ 0.01). Proteinuria in group A was significantly more severe than in group B (P Ͻ 0.05). Group A had a significantly higher incidence of adhesion (P Ͻ 0.01) and duplication (P Ͻ 0.05) of capillary loops than group B. They also demonstrated a significantly higher incidence of glomerular deposition of C1q and/or C4,C3, and fibrinogen than group B (P Ͻ 0.01). Conclusion. These findings suggest that the mesangial deposition of IgM is useful for assessing glomerular damage or renal dysfunction in MesPGN patients, regardless of the amount of mesangial IgM deposits. Furthermore, MesPGN with predominant IgM deposition, which includes both diffuse global and focal segmental deposition of IgM, should be referred to as IgM nephropathy.

Clinical Profile &Treatment Outcome in Children with IgM Nephropathy

“…This is not in agreement with other studies [2,20,21] . However, there are others studies which are in agreement with our study results.…”

A case of membranoproliferative glomerulonephritis developed over twenty years with three different findings of renal pathology

“…Moreover, 3 of 5 patients with FSGS developed end-stage renal failure, but none of the 5 patients with minimal lesions or 1 patient with lupus nephritis showed progressive renal dysfunction, although MPGN lesion was not detected according to the published report [12]. Kishimoto and Arakawa [13] also reported that MesPGN with mesangial IgM deposits demonstrated higher serum IgM level, lower glomerular filtration rate and serum CH50 level, higher level of proteinuria, and higher incidence of adhesion and duplication of capillary loops than MesPGN without mesangial IgM deposits, suggesting that predominant IgM deposition should be referred to as IgM nephropathy with impaired renal function and poor prognosis. In the present case, renal lesions developed and finally demonstrated pathological findings applicable to MPGN, but not FSGS or MesPGN.…”

IgM nephropathy; can we still ignore it

“…Most of the studies have reported on prevalence of IgMN as frequency/ percentage of renal biopsies with diagnosis of IgMN reported from 2 % to 18.5 % in native biopsies (3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13). Occasional cases of IgMN in transplant biopsies have also been reported (14).…”