Remission of membranoproliferative glomerulonephritis type I with the use of tacrolimus

Rituximab for Treatment of Membranoproliferative Glomerulonephritis and C3 Glomerulopathies

Membranoproliferative glomerulonephritis (MPGN) is a histological pattern of injury resulting from predominantly subendothelial and mesangial deposition of immunoglobulins or complement factors with subsequent inflammation and proliferation particularly of the glomerular basement membrane. Recent classification of MPGN is based on pathogenesis dividing MPGN into immunoglobulin-associated MPGN and complement-mediated C3 glomerulonephritis (C3GN) and dense deposit disease (DDD). Current guidelines suggest treatment with steroids, cytotoxic agents with or without plasmapheresis only for subjects with progressive disease, that is, nephrotic range proteinuria and decline of renal function. Rituximab, a chimeric B-cell depleting anti-CD20 antibody, has emerged in the last decade as a treatment option for patients with primary glomerular diseases such as minimal change disease, focal-segmental glomerulosclerosis, or idiopathic membranous nephropathy. However, data on the use of rituximab in MPGN, C3GN, and DDD are limited to case reports and retrospective case series. Patients with immunoglobulin-associated and idiopathic MPGN who were treated with rituximab showed partial and complete responses in the majorities of cases. However, rituximab was not effective in few cases of C3GN and DDD. Despite promising results in immunoglobulin-associated and idiopathic MPGN, current evidence on this treatment remains weak, and controlled and prospective data are urgently needed.

C3 Glomerulopathy

Recent advances in our understanding of the disease pathology of membranoproliferative glomerulonephritis has resulted in its re-classification as complement C3 glomerulopathy (C3G) and immune complex-mediated glomerulonephritis (IC-GN). The new consensus is based on its underlying pathomechanism, with a key pathogenetic role for the complement alternative pathway (AP), rather than on histomorphological characteristics. In C3G, loss of AP regulation leads to predominant glomerular C3 deposition, which distinguishes C3G from IC-GN with predominant immunoglobulin G staining. Electron microscopy further subdivides C3G into C3 glomerulonephritis and dense deposit disease depending on the presence and distribution pattern of electron-dense deposits within the glomerular filter. Mutations or autoantibodies affecting the function of AP activators or regulators, in particular the decay of the C3 convertase (C3 nephritic factor), have been detected in up to 80 % of C3G patients. The natural outcome of C3G is heterogeneous, but 50 % of patients progress slowly and reach end-stage renal disease within 10-15 years. The new classification not only marks significant advancement in the pathogenic understanding of this rare disease, but also opens doors towards more specific treatment with the potential for improved outcomes.

Mycophenolate mofetil or tacrolimus compared with intravenous cyclophosphamide in the induction treatment for active lupus nephritis

BACKGROUND

Although the use of aggressive immunosuppression has improved both patient and renal survival of patients with lupus nephritis (LN), the optimal treatment of LN remains challenging. The objective of this study is to assess the efficacy and safety of mycophenolate mofetil (MMF) and tacrolimus compared with intravenous cyclophosphamide (IVC) as induction therapies for active lupus nephritis (ALN).

METHODS

In this open-label, 24-week prospective study, 60 patients with biopsy-proven ALN (Classes III, IV, V or combination) were randomly assigned to receive MMF, tacrolimus or IVC in combination with corticosteroids. The remission of proteinuria, systemic lupus erythematosus disease active index and adverse events were compared.

RESULTS

The response rates at 24 weeks were 70% (14/20) in the MMF group, 75% (15/20) in the tacrolimus group and 60% (12/20) in the IVC group (P>0.05). The complete remission rates were also similar in the three groups (40, 45 and 30%, respectively; P>0.05). There were more cases of infection in the IVC group (8/20) and the MMF group (8/20) than the tacrolimus group (3/20) and more hyperglycemia in the tacrolimus group (5/20) than the other two groups (2 or 3/20), but the results were not statistically significant among the three groups. Proteinuria decreased and serum albumin increased more quickly in the patients treated with tacrolimus (P=0.0051 and P=0.048).

CONCLUSIONS

This pilot study suggests that both MMF and tacrolimus are possible alternatives to IVC as induction therapies for ALN in Chinese patients. Tacrolimus possibly results in a faster resolution of proteinuria and hypoalbuminemia. Further studies are necessary to determine the optimal dosage and duration of the therapies.

Remission of resistant MPGN type I with mycophenolate mofetil and steroids

Very few studies have been published on how to treat children with membranoproliferative glomerulonephritis type I (MPGN I), and as yet there is only one report on the use of mycophenolate mofetil (MMF) in children with MPGN I. We report a 12-year-old boy who presented with edema, hypertension, nephrotic range proteinuria, and microscopic hematuria following an upper respiratory tract infection. Laboratory tests revealed a serum creatinine of 90 micromol/l, albumin of 20 g/l, and a C3 of 0.11 g/l (normal range: 0.7-1.4). Renal biopsy showed the presence of MPGN I. Upon failure to induce remission with prednisone, we started the patient on MMF at 500 mg/day (300 mg/m(2)), increasing up to a final dose of 2 g/day (1200 mg/m(2)), with a MMF metabolite mycophenolic acid (MPA) target range of 2-5 mg/l. Prednisone was subsequently reduced to alternate day therapy and gradually weaned to 7.5 mg on alternate days over 9 months. Within 4 months of starting MMF therapy, there was significant improvement in serum creatinine (decrease from 156 to 64 micromol/l), serum albumin (increase from 23 to 40 g/l), and proteinuria (decrease from 13 g/day to 40 mg/day). Twelve months following the introduction of MMF into his therapeutic regimen, he remains in remission with no further relapses. In summary, this case suggests that there may be potential benefit for use of MMF in children with refractory MPGN I, which supports the rationale for prospectively evaluating MMF treatment in a treatment trial of refractory MPGN I.

Dense deposit disease and the factor H H402 allele

Herein, we describe the case of an 8-year-old boy who presented with a nephritic nephrotic syndrome. His laboratory investigation was significant for a persistently low serum complement 3 level. A renal biopsy was performed, based on which, he was diagnosed with dense deposit disease/membranoproliferative glomerulonephritis type II (DDD/MPGN II). He was treated with alternate-day oral corticosteroids, angiotensin-converting enzyme (ACE) inhibitors and tacrolimus. Factor H mutational analysis showed the Y402H and I62V allele polymorphisms. The purpose of our report is to discuss the association of the H402 allele variant of factor H with the DDD/MPGN II phenotype and its possible therapeutic implications.

Translational mini-review series on complement factor H: therapies of renal diseases associated with complement factor H abnormalities: atypical haemolytic uraemic syndrome and membranoproliferative glomerulonephritis

Genetic and acquired abnormalities in complement factor H (CFH) have been associated with two different human renal diseases: haemolytic uraemic syndrome and membrano proliferative glomerulonephritis. The new genetic and pathogenetic findings in these diseases and their clinical implications for the management and cure of patients are reviewed in this paper.