Treatment of idiopathic light chain deposition disease: complete remission with bortezomib and dexamethasone.

Light chain deposition disease (LCDD) is a rare clinical entity characterized by the deposition of light chain immunoglobulins in different tissues and primarily affects the kidneys, followed by the liver and heart. This disease often manifests as nephrotic syndrome with marked proteinuria and rapid deterioration of renal function. More than 50% of cases are secondary to multiple myeloma or other lymphoproliferative diseases, with a well-established treatment aimed at controlling the underlying disease. In rare cases, there is no detection of an associated hematological disease, referred to as idiopathic LCDD. In these cases, there is no evidence-based consensus on the therapeutic approach, and management is based on the clinical experience of reported cases. Here we report a case of idiopathic LCDD treated with bortezomib and dexamethasone with complete hematologic responses, significant reduction of proteinuria, and improved renal function.