Frank Bridoux, Jean-Paul Fermand, Bertrand Knebelmann, Arnaud Jaccard, Bertrand Arnulf, Vincent Javaugue, Christophe Sirac, Camille Cohen, Florent Joly, Guy Touchard, Université Paris Descartes - Faculté de Médecine (UPD5 Médecine), Université Paris Descartes - Paris 5 (UPD5), Contrôle de la Réponse Immune B et des Lymphoproliférations (CRIBL), Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM)-Génomique, Environnement, Immunité, Santé, Thérapeutique (GEIST FR CNRS 3503), Département de Néphrologie [CHU Poitiers], Centre hospitalier universitaire de Poitiers (CHU Poitiers), Service d'hématologie biologique, Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Groupe Hospitalier Saint Louis - Lariboisière - Fernand Widal [Paris], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP), Service d'hématologie clinique et de thérapie cellulaire [CHU Saint-Antoine], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-CHU Saint-Antoine [AP-HP], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Sorbonne Université (SU)-Sorbonne Université (SU), Service de néphrologie pédiatrique [CHU Necker], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-CHU Necker - Enfants Malades [AP-HP], Service de Néphrologie CHU Poitiers, Département de Néphrologie, Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut Génomique, Environnement, Immunité, Santé, Thérapeutique (GEIST), Université de Limoges (UNILIM)-Université de Limoges (UNILIM), Assistance publique - Hôpitaux de Paris (AP-HP) (APHP)-Groupe Hospitalier Saint Louis - Lariboisière - Fernand Widal [Paris], Assistance publique - Hôpitaux de Paris (AP-HP) (APHP), Assistance publique - Hôpitaux de Paris (AP-HP) (APHP)-CHU Saint-Antoine [APHP], Université de Limoges (UNILIM)-Génomique, Environnement, Immunité, Santé, Thérapeutique (GEIST FR CNRS 3503)-Centre National de la Recherche Scientifique (CNRS), Physiologie Moléculaire de la Réponse Immune et des Lymphoproliférations (PMRIL), and CHU Necker - Enfants Malades [AP-HP]-Assistance publique - Hôpitaux de Paris (AP-HP) (APHP)
Monoclonal immunoglobulin (Ig) deposition disease (MIDD) is a rare complication of plasma cell disorders, defined by linear Congo red-negative deposits of monoclonal light chain (LCDD), heavy chain (HCDD) or both (LHCDD) along basement membranes. MIDD should be suspected in patients presenting with glomerular proteinuria and monoclonal gammopathy, but none of these criteria is necessary for the diagnosis although renal involvement is prominent. Since an abnormal serum κ/λ ratio is found in virtually all MIDD patients, including those with HCDD, serum free light chain assay should be included in the initial workup in patients older than 50 presenting with kidney disease. Bortezomib-based regimens are efficient and well tolerated, resulting in improvement in both renal and global survival, comparatively to historical series. High dose melphalan with autologous stem cell transplantation may be proposed as second line therapy in selected patients. The achievement of hematological response, based on the difference between involved and uninvolved serum free light chains (dFLC), is mandatory. In a recent series, post-treatment dFLC