Recurrence of IgM nephropathy in a renal allograft

Renal Outcome of IgM Nephropathy: A Comparative Prospective Cohort Study

Immunoglobulin M nephropathy (IgMN) is an idiopathic glomerulonephritis characterized by diffuse deposits of IgM in the glomerular mesangium. However, its renal prognosis remains unknown. We compared renal outcomes of IgMN patients with those of patients with minimal change disease (MCD), focal segmental glomerulosclerosis (FSGS), or mesangial proliferative glomerulonephritis (MsPGN) from a prospective observational cohort, with 1791 patients undergoing native kidney biopsy in eight hospitals affiliated with The Catholic University of Korea between December 2014 and October 2020. IgMN had more mesangial proliferation and matrix expansion than MsPGN and more tubular atrophy and interstitial fibrosis than MCD. IgMN patients had decreased eGFR than MCD patients in the earlier follow-up. However, there was no significant difference in urine protein or eGFR among all patients at the last follow-up. When IgMN was divided into three subtypes, patients with FSGS-like IgMN tended to have lower eGFR than those with MCD-like or MsPGN-like IgMN but higher proteinuria than MsPGN-like IgMN without showing a significant difference. The presence of hypertension at the time of kidney biopsy predicted ≥20% decline of eGFR over two years in IgMN patients. Our data indicate that IgMN would have a clinical course and renal prognosis similar to MCD, FSGS, and MsPGN.

Successful treatment of a rare variant of mesangioproliferative glomerulonephritis with IgM deposits with Cyclosporin A

We present a case with a rare variant of glomerulonephritis, IgM nephropathy, which occurs mainly with nephrotic syndrome. The clinical features of this variant of kidney damage are characterized; the pathogenetic and the transformation of this form of nephritis into focal segmental glomerulosclerosis are discussed. The development of severe nephrotic syndrome at the beginning of the disease, the formation of secondary steroid resistance have confirmed this hypothesis and have justified the treatment with cyclosporin A aimed at the recovery of the function of the podocyte with remission of nephritis.

The natural history of immunoglobulin M nephropathy in adults

Background

Immunoglobulin M (IgM) nephropathy is an idiopathic glomerulonephritis characterized by diffuse mesangial deposition of IgM. IgM nephropathy has been a controversial diagnosis since it was first reported, and there are few data identifying specific pathological features that predict the risk of progression of renal disease.

Methods

We identified 57 cases of IgM nephropathy among 3220 adults undergoing renal biopsy at our institution. Biopsies had to satisfy the following three criteria to meet the definition of IgM nephropathy in this study: (i) dominant mesangial staining for IgM, (ii) mesangial deposits on electron microscopy (EM) and (iii) exclusion of systemic disease.

Results

The median age was 42 years and 24 patients were male. Thirty-nine per cent of patients presented with the nephrotic syndrome, 49% presented with non-nephrotic proteinuria and 39% had eGFR <60 mL/min. The median post-biopsy follow-up was 40 months and serum creatinine had doubled in 31% by 5 years. Of histological parameters, glomerular sclerosis and tubular atrophy, but not mesangial proliferation, were risk factors for renal insufficiency. Thirty-nine per cent of nephrotic patients achieved complete remission, and outcome was significantly worse in those who did not respond to treatment. Focal segmental glomerulosclerosis was diagnosed in 80% of those undergoing repeat renal biopsy, despite ongoing mesangial IgM deposition.

Conclusions

We propose criteria for a consensus definition of IgM nephropathy.

Case Report: Acute Cerebellar Thrombosis in an Adult Patient with IgM Nephropathy

IgM nephropathy is a relatively rare cause of idiopathic nephrotic syndrome.1 It was initially described by van de Putte,2 then by Cohen and Bhasin in 1978, as a distinctive feature of mesangial proliferative glomerulonephritis.2 It is typically characterized by diffuse IgM deposits on the glomeruli and diffuse mesangial hypercellularity. Little is known about the pathogenesis and treatment of this disease.1,3 We describe a patient who presented with nonspecific symptoms of epigastric pain, nausea, and early satiety. Abdominal imaging and endoscopies were unremarkable. She was found to have significant proteinuria (6.4 g/24 hours), hyperlipidemia, and edema consistent with a diagnosis of nephrotic syndrome. Kidney biopsy was performed and confirmed an IgM nephropathy. Less than 2 weeks after her diagnosis of IgM nephropathy, she presented with an acute cerebellar stroke. Thrombophilia is a well-known complication of nephrotic syndrome, but a review of the literature failed to show an association between IgM nephropathy and acute central nervous system thrombosis.

IgM nephropathy: is it closer to minimal change disease or to focal segmental glomerulosclerosis?

Immunoglobulin (Ig)M nephropathy (IgMN), known since 1978, is a very controversial clinicopathological entity characterized by IgM diffuse deposits in the mesangium at immunofluorescence whereas light microscop identifies minimal glomerular lesion, hypercellularity and expansion of the mesangium or sclerotic focal, segmental lesion. Clinically, it is a nephrotic syndrome, especially in pediatric patients, or asymptomatic proteinuria and/or isolated hematuria. These characteristics narrowly define IgMN between minimal change disease and focal segmental glomerulosclerosis, so it is not often recognized as a separate pathology. Homogeneous epidemiologic, pathogenetic, clinical or histological data are not available. Recent research on the pathogenetic role of mesangial IgM has, however, renewed interest in IgMN and naturally the controversies.

IgM nephropathy; time to act

Implication for health policy/practice/research/medical education: Much has been published on the epidemiology and clinicopathological characteristics of IgM nephropathy, but there is little information on the etiology,pathogenesis and specific therapy of the disease. Controversy still shrouds the definition and nosologic status of the disease. Well-coordinated and concerted international efforts and collaboration between researchers in the developing and developed countries are needed to make further progress on the above aspects of the disease.

IgM nephropathy revisited

IgM nephropathy (IgMN) is an idiopathic immune complex-mediated glomerulopathy that was first described as a distinct disease in a nephropathology literature in 1978. Here, a historical review and the current status of IgMN in the light of world literature and the current experience will be presented. The Pubmed (www.pubmed.gov) search was made for articles on IgMN as the sole subject of the study or where it constituted a significant number of cases in a biopsy series in the world literature written in English. A total of 41 articles were found. A critical review of the literature was made. Soon after 1978, a series of reports were published mostly from the western world, but the interest in the entity did not withstand the test of time. No substantial basic medical research was carried out and the disease was largely ignored by the western researchers. More recently, a flurry of articles have appeared in the literature on the topic, mostly from tropical countries, and have renewed the interest in the entity. However, most of the current literature on IgMN is based on clinical observations, and experimental models and mechanistic studies of IgMN are lacking. There is an urgent need to develop consensus based criteria for the diagnosis of the condition, as well as, to focus the research on mechanistic studies to understand the pathogenesis of the disease better.

Characteristics of immunoglobulin A nephropathy with mesangial immunoglobulin G and immunoglobulin M deposition

AIM

There are immunoglobulin (Ig)A nephropathy (IgAN) cases showing mesangial IgG and/or IgM deposition, however, their characteristics have remained unknown.

METHODS

Three hundred and eighty-four IgAN patients were divided according to the existence of mesangial IgG and/or IgM deposition: IgA deposition only (A group, n = 77); IgA and IgM deposition (AM group, n = 114); IgA and IgG deposition (AG group, n = 36); and IgA, IgG and IgM deposition (AGM group, n = 157). Clinical and histological findings, and outcomes were examined and compared among these four groups.

RESULTS

At the time of renal biopsy, serum creatinine was significantly higher in the A and AM group, however, creatinine clearance did not differ among the four groups. The ratio of glomerular obsolescence was significantly higher in the AM group than in the A and AGM group, and the ratio of glomerular tuft adhesion was significantly higher in the AM, AG and AGM group than in the A group. However, the other clinical and histological findings, electron microscopic findings and renal survivals did not differ among the four groups. Proteinuria was independently associated with an increase in risk of doubling of creatinine (P = 0.005), however, IgG and IgM depositions were not by multivariate Cox regression.

CONCLUSION

The presence of other Ig classes, besides IgA deposits, was found to be associated with glomerular obsolescence and tuft adhesions, however, without any effect on renal survival in IgAN.

Disease recurrence in paediatric renal transplantation

Renal transplantation (Tx) is the treatment of choice for end-stage renal disease. The incidence of acute rejection after renal Tx has decreased because of improving early immunosuppression, but the risk of disease recurrence (DR) is becoming relatively high, with a greater prevalence in children than in adults, thereby increasing patient morbidity, graft loss (GL) and, sometimes, mortality rate. The current overall graft loss to DR is 7-8%, mainly due to primary glomerulonephritis (70-80%) and inherited metabolic diseases. The more typical presentation is a recurrence of the full disease, either with a high risk of GL (focal and segmental glomerulosclerosis 14-50% DR, 40-60% GL; atypical haemolytic uraemic syndrome 20-80% DR, 10-83% GL; membranoproliferative glomerulonephritis 30-100% DR, 17-61% GL; membranous nephropathy approximately 30% DR, approximately 50% GL; lipoprotein glomerulopathy approximately 100% DR and GL; primary hyperoxaluria type 1 80-100% DR and GL) or with a low risk of GL [immunoglobulin (Ig)A nephropathy 36-60% DR, 7-10% GL; systemic lupus erythematosus 0-30% DR, 0-5% GL; anti-neutrophilic cytoplasmic antibody (ANCA)-associated glomerulonephritis]. Recurrence may also occur with a delayed risk of GL, such as insulin-dependent diabetes mellitus, sickle cell disease, endemic nephropathy, and sarcoidosis. In other primary diseases, the post-Tx course may be complicated by specific events that are different from overt recurrence: proteinuria or cancer in some genetic forms of nephrotic syndrome, anti-glomerular basement membrane antibodies-associated glomerulonephritis (Alport syndrome, Goodpasture syndrome), and graft involvement as a consequence of lower urinary tract abnormality or human immunodeficiency virus (HIV) nephropathy. Some other post-Tx conditions may mimic recurrence, such as de novo membranous glomerulonephritis, IgA nephropathy, microangiopathy, or isolated specific deposits (cystinosis, Fabry disease). Adequate strategies should therefore be added to kidney Tx, such as donor selection, associated liver Tx, plasmatherapy, specific immunosuppression protocols. In such conditions, very few patients may be excluded from kidney Tx only because of a major risk of DR and repeated GL. In the near future the issue of DR after kidney Tx may benefit from alternatives to organ Tx, such as recombinant proteins, specific monoclonal antibodies, cell/gene therapy, and chaperone molecules.

Early Recurrence of Nephrotic Syndrome (Immunoglobulin M Nephropathy) After Renal Transplantation Successfully Treated With Combinations of Plasma Exchanges, Immunoglobulin, and Rituximab

In contrast to focal segmental glomerulosclerosis, which is well known to recur early in a renal graft, there are only few cases described with recurrence of immunoglobulin M (IgM) nephropathy after transplantation. We herein describe a patient with early recurrence of IgM nephropathy. A 15-year-old boy with nephrotic syndrome (IgM nephropathy) proceeding to end-stage renal disease was on dialysis before living related renal transplantation. Native kidneys were not removed. Standard immunosuppression including steroids, tacrolimus, and mycophenolate mofetil yielded initially good graft function with the s-creatinine falling to 73 micromol/L. Proteinuria was present on day 1, increasing to 20 g/L after 3 days. S-creatinine increased to 158 micromol/L and urine production diminished. A graft biopsy showed no rejection or glomerulopathy but protein vacuoles were seen within tubular cells indicating massive proteinuria. Treatment with plasma exchanges, immunoglobulin, and steroids was started. Hemodialysis was necessary. Proteinuria improved to 3.5 g/L, but s-creatinine continued to rise and a second graft biopsy showed vascular rejection (Banff type IIA). The patient was treated with antithymocyte globulin and further plasma exchanges. A single dose of rituximab was given. Five months after transplantation the s-creatinine was 67 micromol/L and there was no proteinuria. In this case early recurrence of nephrotic syndrome occurred on the first posttransplant day in combination with later occurring vascular rejection. Successful treatment included a combination of plasma exchanges, rituximab, immunoglobulin, and antithymocyte globulin.