TY - JOUR
T1 - C3 glomerulonephritis associated with monoclonal gammopathy
T2 - A case series
AU - Zand, Ladan
AU - Kattah, Andrea
AU - Fervenza, Fernando C.
AU - Smith, Richard J.H.
AU - Nasr, Samih H.
AU - Zhang, Yuzhou
AU - Vrana, Julie A.
AU - Leung, Nelson
AU - Cornell, Lynn D.
AU - Sethi, Sanjeev
N1 - Funding Information:
Support: This research was supported in part by National Institutes of Health grant DK074409 to Dr Smith and the Fulk Family Foundation award (Mayo Clinic) to Dr Sethi.
PY - 2013/9
Y1 - 2013/9
N2 - Background: C3 glomerulonephritis (GN) is a proliferative GN resulting from glomerular deposition of complement factors due to dysregulation of the alternative pathway of complement. Dysregulation of the alternative pathway of complement may occur as a result of mutations or functional inhibition of complement-regulating proteins. Functional inhibition of the complement-regulating proteins may result from a monoclonal gammopathy. Study Design: Case series. Setting & Participants: 32 Mayo Clinic patients with C3 GN, 10 (31%) of whom had evidence of a monoclonal immunoglobulin in serum. Outcomes: Clinical features, hematologic and bone marrow biopsy findings, kidney biopsy findings, kidney measures, complement pathway abnormalities, treatment, and follow-up of patients with C3 GN that was associated with a monoclonal gammopathy. Results: Mean age of patients with C3 GN associated with monoclonal gammopathy was 54.5 years. Bone marrow biopsy done in 9 patients revealed monoclonal gammopathy of undetermined significance in 5 patients, small lymphocytic lymphoma/chronic lymphocytic leukemia in one patient, and no abnormal clones in the other 3 patients. Kidney biopsy showed membranoproliferative GN with bright capillary wall C3 staining in all 10 patients. Evaluation of the alternative pathway of complement showed abnormalities in 7 of 9 patients tested. No mutation in complement-regulating proteins was detected in any patient. As an index case, one patient with C3 GN and chronic lymphocytic leukemia was treated with rituximab, cyclophosphamide, vincristine, and prednisone, and one patient with C3 GN and monoclonal gammopathy of undetermined significance was treated with dexamethasone and bortezomib. Both patients showed significant decreases in hematuria and proteinuria and stabilization of kidney function. Limitations: Studies to show evidence of direct activation of the alternative pathway by monoclonal immunoglobulin were not done. Conclusions: The study highlights the association of C3 GN and monoclonal gammopathy, in particular in the older population, and the importance of targeting the underlying hematologic malignancy as an approach to treating C3 GN.
AB - Background: C3 glomerulonephritis (GN) is a proliferative GN resulting from glomerular deposition of complement factors due to dysregulation of the alternative pathway of complement. Dysregulation of the alternative pathway of complement may occur as a result of mutations or functional inhibition of complement-regulating proteins. Functional inhibition of the complement-regulating proteins may result from a monoclonal gammopathy. Study Design: Case series. Setting & Participants: 32 Mayo Clinic patients with C3 GN, 10 (31%) of whom had evidence of a monoclonal immunoglobulin in serum. Outcomes: Clinical features, hematologic and bone marrow biopsy findings, kidney biopsy findings, kidney measures, complement pathway abnormalities, treatment, and follow-up of patients with C3 GN that was associated with a monoclonal gammopathy. Results: Mean age of patients with C3 GN associated with monoclonal gammopathy was 54.5 years. Bone marrow biopsy done in 9 patients revealed monoclonal gammopathy of undetermined significance in 5 patients, small lymphocytic lymphoma/chronic lymphocytic leukemia in one patient, and no abnormal clones in the other 3 patients. Kidney biopsy showed membranoproliferative GN with bright capillary wall C3 staining in all 10 patients. Evaluation of the alternative pathway of complement showed abnormalities in 7 of 9 patients tested. No mutation in complement-regulating proteins was detected in any patient. As an index case, one patient with C3 GN and chronic lymphocytic leukemia was treated with rituximab, cyclophosphamide, vincristine, and prednisone, and one patient with C3 GN and monoclonal gammopathy of undetermined significance was treated with dexamethasone and bortezomib. Both patients showed significant decreases in hematuria and proteinuria and stabilization of kidney function. Limitations: Studies to show evidence of direct activation of the alternative pathway by monoclonal immunoglobulin were not done. Conclusions: The study highlights the association of C3 GN and monoclonal gammopathy, in particular in the older population, and the importance of targeting the underlying hematologic malignancy as an approach to treating C3 GN.
KW - C3 Glomerulonephritis (C3 GN)
KW - membranoproliferative glomerulonephritis (MPGN)
KW - monoclonal gammopathy
KW - monoclonal gammopathy of undetermined significance (MGUS)
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U2 - 10.1053/j.ajkd.2013.02.370
DO - 10.1053/j.ajkd.2013.02.370
M3 - Article
C2 - 23623956
AN - SCOPUS:84883236791
SN - 0272-6386
VL - 62
SP - 506
EP - 514
JO - American Journal of Kidney Diseases
JF - American Journal of Kidney Diseases
IS - 3
ER -