of our hospital observed a progressive increase in the creatinine levels from 2.2 mg/dL to 5.2 mg/dL (creatinine clearance: from 33 mL/min to 17 mL/min) in only 10 months. a future option for these patients. Key words:light chain deposition disease, free light chain, monoclonal gammopathy, bortezomib, transplant. == Introduction == Light Chain Deposition Disease (LCDD) is a rare plasma cell dyscrasia characterized by deposition of monoclonal immunoglobulin light chains (LCs) in various organs.1LCs are physiologically filtered by glomeruli, reabsorbed in proximal tubules and degraded in tubular cells, which makes kidney a prominent target for LC deposition.2,3In this disease, monoclonal component is in virtually 100% of cases,1which contrasts with the higher lambda frequency that is RG3039 present in primary amyloidosis (AL). LCDD can be a primary disorder, although it is usually described associated to lymphoproliferative disorders or plasma cells dyscrasias (50% with concurrent multiple myeloma). From the clinical point of view, most patients with LCDD present with nephrotic range proteinuria and rapid deteriorating renal function.4Pathogenic background for nephrotic syndrome usually is predominant glomerular deposition (similar to AL amyloidosis), but some have predominant tubular deposition resulting in renal insufficiency with not very high proteinuria.4 There is no standard treatment for patients with LCDD. Traditionally, specific treatment of LCDD has been considered to be ineffective in altering the course of the severe or end-stage renal failure.1,2,5High dose therapy (HDT) and autologous peripheral blood stem cell transplantation APBSCT have been demonstrated to be efficient, even providing the possibility of renal disease reversibility in LCDD.610However, the use of this strategy in patients with end-stage renal disease is of very high risk.11Some reports have demonstrated that bortezomib and dexamethasone (BD) can be very effective in AL.12Taking into account the similarities between AL and LCDD, some experiences have also shown that BD can be an option in LCDD.13Accordingly, the combination of both strategies, BD and HDT, results very attractive, but no experience RG3039 has been reported up to now in this specific situation. Here we present a patient with an end-stage renal failure associated to LCDD in whom BD followed by HDT and APBSCT resulted in HCR and renal function recovery, allowing the patient to be treatment and dialysis independent for more than four years. == Case Report == ACF, female, was diagnosed in January 2006 at 63 of age, as having a renal impairment. The Nephrology Dept. of our hospital observed a progressive increase in the creatinine levels from 2.2 mg/dL to 5.2 mg/dL (creatinine clearance: from 33 mL/min to 17 mL/min) in only 10 months. Since RG3039 no clear explanation for the disorder was initially found, in November 2006 a renal biopsy was performed to elucidate the origin of the renal chronic failure, and a light chain deposition disease (kLCDD) diagnosed. The patient was then admitted to Hematology for refining the diagnosis and to initiate appropriate treatment. The bone marrow aspirate demonstrated 9% of Bone marrow plasma cells (BMPC). Flow cytometry demonstrated a 6% bone marrow plasmacytosis with restriction in cytoplasmic immunoglobulins, as well as an aberrant immunophenotype (CD138+, CD38+++, CD56+, CD19, CD45) and a non-hyperdiploid DNA cell content. Among the plasma cell compartment, 90% of cells were aberrant, but 10% displayed normal immunophenotype (Figure 1). Conventional karyotype and FISH analysis for IgH translocations, Rb deletion and P53 deletion were normal either. Radiologic bone survey did not show any lytic lesion and serum calcium was normal. The serum creatinine at the moment was 6.4 mg/dL. Conventional serum electrophoresis and immunofixation failed to detect any monoclonal protein (Figure 2and3). Within a high amount of urinary proteins, a minimum Rabbit polyclonal to Synaptotagmin.SYT2 May have a regulatory role in the membrane interactions during trafficking of synaptic vesicles at the active zone of the synapse. peak was observed, and the immunofixation demonstrated a very weak monoclonal-like band in the anti- line and was scored as possible positive. In addition, the serum free light chain determination was highly favorable for , rendering a / ratio of 64.4, typically monoclonal. Accordingly, she was diagnosed as suffering Primary Light Chain Deposition Disease with renal impairment. Since the serum creatinine was higher than 5.