title: Loss of tubular creatinine secretion as the only sign of tubular proximal cell dysfunction in light chain proximal tubulopathy: A case report.
abstract: Light chain proximal tubulopathy (LCPT) is a rare disease, characterized by cytoplasmic inclusions of light chain (usually kappa) immunoglobulins. Clinical presentation is usually a Fanconi syndrome. The proximal tubular dysfunction can be incomplete, and exceptional cases of LCPT without any tubular dysfunction have even been described. Here, we report a case of LCPT in which the only sign of proximal tubulopathy is the absence of secretion of creatinine, as assessed by the simultaneous measurement of renal clearance of creatinine and CrEDTA. The loss of tubular creatinine secretion as a sign of tubular proximal cell dysfunction ought to be identified in patients with light chain proximal tubulopathy as it leads to a clinically relevant underestimation of GFR by the creatinine-derived equations. The prevalence and prognostic significance of this particular proximal tubular damage in LCPT remain to be determined.
authors.affiliation: aDepartment of Renal Physiology, DHU Fire, Bichat Hospital bDepartment of Clinical Immunology, Saint-Louis Hospital, Assistance Publique des Hôpitaux de Paris cParis Diderot University dINSERM 1149, Center of Research on Inflammation eDepartment of Pathology, Necker Hospital, Assistance Publique des Hôpitaux de Paris fParis Descartes University gDepartment of Pathology, Tenon Hospital, Assistance Publique des Hôpitaux de Paris, Paris, France.
authors.forename: Thomas
authors.initials: T
authors.lastname: Stehlé
authors.forename: Marguerite
authors.initials: M
authors.lastname: Vignon
authors.forename: Martin
authors.initials: M
authors.lastname: Flamant
authors.forename: Marie-Lucile
authors.initials: ML
authors.lastname: Figueres
authors.forename: Marion
authors.initials: M
authors.lastname: Rabant
authors.forename: Anita
authors.initials: A
authors.lastname: Rodenas
authors.forename: Laure-Hélène
authors.initials: LH
authors.lastname: Noël
authors.forename: Bertrand
authors.initials: B
authors.lastname: Arnulf
authors.forename: Emmanuelle
authors.initials: E
authors.lastname: Vidal-Petiot
mesh_terms: D000328:Adult; D003404:Creatinine / Q000378:metabolism*; D006801:Humans; D007147:Immunoglobulin Light Chains; D007674:Kidney Diseases / Q000378:metabolism* / Q000473:pathology*; D007687:Kidney Tubules, Proximal / Q000166:cytology* / Q000378:metabolism*; D008297:Male
chemical_list: D007147:Immunoglobulin Light Chains; D003404:Creatinine