title: [Renal involvement in benign monoclonal gammopathies: an underdiagnosed condition].
abstract: Renal involvement is observed frequently in association with malignant gammopathies, mainly those related to light chain deposition, although has also been described in non-malignant monoclonal gammopathy. This study reports the clinicopathological findings and outcome in 9 patients with nephropaty secondary to monoclonal immunoglobulin deposit in absence of malignancy. They were three men and six women and they were 59.2+/-12 years old. All patients presented proteinuria and different levels of renal insufficiency (mean creatinin = 315+/-187 micromol/L) at the moment of diagnostic. Two patients required dialysis at the time of renal biopsy. The pathology studies revealed a nodular sclerosing glomerulopathy in four cases, mesangiocapilary glomerulonephritis in three cases, only tubular lesions in one and mesangial lesions in the other one. The treatment applied was: Prednisone alone (two cases), with chemotherapy associated (melfalan in two, clorambucil in one and ciclophosphamide in another one). One patient received plasmapheresis and mycophenolate and another patient undergone a bone marrow authotransplant associated to mycophenolate and prednisone. One of the two patients who required dialysis at the moment of presentation was not treated. After a follow-up of more than 4 years (4.89 +/-DE: 3.69) renal function improved or remained stable in three patients and proteinuria was disappeared in more than 50% of patients. Four patients had a worsening of renal function and they required dialysis during the time of follow-up (in 2,4 years +/- DE: 4,3). In any case malignitation was observed. Chemotherapy stabilized or improved renal function in 3 of nine patients (33%) with non-malignant monoclonal gammopathy. Non-malignant monoclonal gammopathy could go unnoticed. Appearance of abnormalities in renal routine tests deserves more in-depth diagnostic procedures, including renal biopsy. Evolution to end stage renal disease could probably be avoided or reduced in severity with early detection and treatment of this entity.
authors.affiliation: Nefrología, Ciutat Sanitària i Universitària de Bellvige, L'Hospitalet del Llobregat, Barcelona, España. 30965rrs@comb.es
authors.forename: R
authors.initials: R
authors.lastname: Ramos
authors.forename: R
authors.initials: R
authors.lastname: Poveda
authors.forename: C
authors.initials: C
authors.lastname: Bernís
authors.forename: J
authors.initials: J
authors.lastname: Ara
authors.forename: M
authors.initials: M
authors.lastname: Sunyer
authors.forename: P
authors.initials: P
authors.lastname: Arrizabalaga
authors.forename: J M
authors.initials: JM
authors.lastname: Grinyó
mesh_terms: D005260:Female; D006801:Humans; D007674:Kidney Diseases / Q000175:diagnosis / Q000188:drug therapy / Q000209:etiology*; D008297:Male; D008875:Middle Aged; D008998:Monoclonal Gammopathy of Undetermined Significance / Q000150:complications*; D012189:Retrospective Studies