Caso Clínico: Síndrome nefrótico como presentación de amiloidosis AL, una asociación poco frecuente en nuestro medio

BACKGROUND: Amyloidosis is a heterogeneous group of diseases with multi-organ involvement and different clinical manifestations; one of them is nephrotic syndrome. Amyloidosis results from the extracellular deposit of fibrillar proteins that form the amyloid substance; amyloidogenic proteins resistant to proteolysis infiltrate tissues extracellularly and are capable of severely altering their structure and function. Amyloid deposits in the renal parenchyma can be observed in the mesangium, capillary wall, interstitium, and arterial vessels. Its diagnosis requires a biopsy of the comprised organs. CASE REPORT: 53-year-old male patient, presented with the incidental finding of microalbuminuria. The only clinical manifestations were mild lower limbs edema and foamy urine. Laboratory tests showed: hypoalbuminemia, hypercholesterolemia, hypertriglyceridemia and nephrotic- range proteinuria. With pure nephrotic syndrome diagnosis a renal biopsy was performed, leading to the histopathological diagnosis of amyloidosis. EVOLUTION: Nephroprotective measures were instituted and the extent of systemic involvement was studied, we diagnosed congestive heart failure and amyloid deposition in the digestive system. The patient initially received treatment based on Cyclophosphamide, Bortezomib and dexamethasone, with no renal or haematological response after four cycles of treatment, so treatment was changed to Bortezomib and Bendamustine. CONCLUSION: It is vitally important to have a high index of suspicion and to make an early diagnosis of the disease through a biopsy with Congo red staining. The treatment depends on the type of amyloidosis, its opportune start allows to increase survival rate, as well as, to avoid the deposit of amyloid in other organs.