title: The clinicopathologic characteristics of kidney diseases related to monotypic IgA deposits.
abstract: Monoclonal gammopathy of renal significance (MGRS) regroups renal disorders caused by a monoclonal immunoglobulin without overt hematological malignancy. MGRS includes tubular disorders, glomerular disorders with organized deposits, and glomerular disorders with non-organized deposits, such as proliferative glomerulonephritis with monoclonal IgG deposits. Since glomerular involvement related to monotypic IgA deposits is poorly described we performed retrospective analysis and defined clinico-biological characteristics, renal pathology, and outcome in 19 referred patients. This analysis allowed distinction between 2 types of glomerulopathies, α-heavy chain deposition disease (5 patients) and glomerulonephritis with monotypic IgA deposits (14 patients) suggestive of IgA-proliferative glomerulonephritis with monoclonal immunoglobulin deposits in 12 cases. Clinicopathologic characteristics of α-heavy chain deposition disease resemble those of the γ-heavy chain disease, except for a higher frequency of extra-capillary proliferation and extra-renal involvement. IgA-proliferative glomerulonephritis with monoclonal immunoglobulin deposits should be differentiated from diseases with polytypic IgA deposits, given distinct clinical, histological, and pathophysiological features. Similarly to IgG-proliferative glomerulonephritis with monoclonal immunoglobulin deposits, overt hematological malignancy was infrequent, but sensitive serum and bone marrow studies revealed a subtle plasma cell proliferation in most patients with IgA-proliferative glomerulonephritis with monoclonal immunoglobulin deposits. Anti-myeloma agents appeared to favorably influence renal prognosis. Thus, potential progression towards symptomatic IgA multiple myeloma suggests that careful hematological follow-up is mandatory. This series expands the spectrum of renal disease in MGRS.
authors.affiliation: Department of Nephrology, Hôpital Necker Enfants Malades, Université Paris Descartes, Paris, France. Electronic address: marguerite.vignon@aphp.fr.
authors.forename: Marguerite
authors.initials: M
authors.lastname: Vignon
authors.affiliation: Department of Nephrology, Hôpital Necker Enfants Malades, Université Paris Descartes, Paris, France.
authors.forename: Camille
authors.initials: C
authors.lastname: Cohen
authors.affiliation: Department of Nephrology, CHU Rangueil, Toulouse, France.
authors.forename: Stanislas
authors.initials: S
authors.lastname: Faguer
authors.affiliation: Department of Pathology, Hôpital Necker Enfants Malades, Université Paris Descartes, Paris, France.
authors.forename: Laure-Hélène
authors.initials: LH
authors.lastname: Noel
authors.affiliation: Department of Pathology, CHU Rangueil, Toulouse, France.
authors.forename: Celine
authors.initials: C
authors.lastname: Guilbeau
authors.affiliation: Department of Pathology, Hôpital Necker Enfants Malades, Université Paris Descartes, Paris, France.
authors.forename: Marion
authors.initials: M
authors.lastname: Rabant
authors.affiliation: Department of Pathology, Hôpital Necker Enfants Malades, Université Paris Descartes, Paris, France.
authors.forename: Sarah
authors.initials: S
authors.lastname: Higgins
authors.affiliation: Department of Nephrology, Hôpital Necker Enfants Malades, Université Paris Descartes, Paris, France.
authors.forename: Aurélie
authors.initials: A
authors.lastname: Hummel
authors.affiliation: Department of Nephrology, Hôpital Tenon, Université Pierre et Marie Curie, Paris, France.
authors.forename: Alexandre
authors.initials: A
authors.lastname: Hertig
authors.affiliation: Department of Nephrology, CHU de Bicêtre, Université Paris Sud, Bicêtre, France.
authors.forename: Hélène
authors.initials: H
authors.lastname: Francois
authors.affiliation: Department of Nephrology, CHU de Montpellier, Montpellier, France.
authors.forename: Moglie
authors.initials: M
authors.lastname: Lequintrec
authors.affiliation: Department of Nephrology, CHU Ambroise Paré, Université de Versailles Saint-Quentin-en-Yvelines, Boulogne, France.
authors.forename: Eve
authors.initials: E
authors.lastname: Vilaine
authors.affiliation: Department of Nephrology, Hôpital Necker Enfants Malades, Université Paris Descartes, Paris, France.
authors.forename: Bertrand
authors.initials: B
authors.lastname: Knebelmann
authors.affiliation: Department of Nephrology, CHU Rangueil, Toulouse, France.
authors.forename: Jacques
authors.initials: J
authors.lastname: Pourrat
authors.affiliation: Department of Nephrology, CHU Rangueil, Toulouse, France.
authors.forename: Dominique
authors.initials: D
authors.lastname: Chauveau
authors.affiliation: Departments of Pathology and Ultrastructural Pathology, CHU Poitiers, Centre de référence maladies rares amylose AL et autres maladies par dépôts d'immunoglobulines monoclonales, Poitiers, France.
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Goujon
authors.affiliation: Department of Nephrology, CHU Poitiers, Centre de référence maladies rares amylose AL et autres maladies par dépôts d'immunoglobulines monoclonales, Poitiers, France.
authors.forename: Vincent
authors.initials: V
authors.lastname: Javaugue
authors.affiliation: Departments of Pathology and Ultrastructural Pathology, CHU Poitiers, Centre de référence maladies rares amylose AL et autres maladies par dépôts d'immunoglobulines monoclonales, Poitiers, France; Department of Nephrology, CHU Poitiers, Centre de référence maladies rares amylose AL et autres maladies par dépôts d'immunoglobulines monoclonales, Poitiers, France.
authors.forename: Guy
authors.initials: G
authors.lastname: Touchard
authors.affiliation: Department of Nephrology, Hôpital Henri Mondor, Université Paris Est, Créteil, France.
authors.forename: Khalil
authors.initials: K
authors.lastname: El Karoui
authors.affiliation: Department of Nephrology, CHU Poitiers, Centre de référence maladies rares amylose AL et autres maladies par dépôts d'immunoglobulines monoclonales, Poitiers, France; Department of Immunology, National Center for Scientific Research, Joint Research Unit 7276, University of Limoges, Centre de référence maladies rares amylose AL et autres maladies par dépôts d'immunoglobulines monoclonales, Limoges, France.
authors.forename: Frank
authors.initials: F
authors.lastname: Bridoux
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000032:analysis; D001706:Biopsy; D049109:Cell Proliferation; D003937:Diagnosis, Differential; D018450:Disease Progression; D005260:Female; D005455:Fluorescent Antibody Technique; D005602:France; D005921:Glomerulonephritis / Q000188:drug therapy / Q000276:immunology* / Q000473:pathology; D005922:Glomerulonephritis, IGA / Q000188:drug therapy / Q000276:immunology* / Q000473:pathology; D006362:Heavy Chain Disease / Q000188:drug therapy / Q000276:immunology* / Q000473:pathology; D006801:Humans; D007070:Immunoglobulin A / Q000032:analysis*; D007137:Immunoglobulin alpha-Chains / Q000032:analysis; D007142:Immunoglobulin gamma-Chains / Q000032:analysis; D007668:Kidney / Q000187:drug effects / Q000276:immunology* / Q000648:ultrastructure; D008297:Male; D008875:Middle Aged; D009101:Multiple Myeloma / Q000188:drug therapy / Q000276:immunology* / Q000473:pathology; D011237:Predictive Value of Tests; D011379:Prognosis; D012189:Retrospective Studies; D013997:Time Factors
chemical_list: D015415:Biomarkers; D007070:Immunoglobulin A; D007137:Immunoglobulin alpha-Chains; D007142:Immunoglobulin gamma-Chains; C032598:heavy chain disease proteins, human
keywords: glomerular disease; monoclonal IgA deposits; monoclonal gammopathy of renal significance