[Systemic AA amyloidosis induced by benign neoplasms]. / Amiloidosis secundaria (AA) asociada a tumoraciones benignas.

Amyloidosis is a systemic disorder characterized by the extracellular tissue deposition of insoluble, toxic aggregates in bundles of beta-sheet fibrillar proteins. These deposits are typically identified on the bases of their apple-green birrefringence under a polarized light microscope after staining with Congo red, and by the presence of rigid, nonbranching fibrils 8 to 10 nm in diameter on electron microscopy. The type of amyloid fibril unit can be further defined by immunohistology or by immunoelectron microscopy. It has been described at least 25 different human protein precursors of amyloid fibrils, which will describe its corresponding amyloid disease. The most common types of amyloidosis are AL (primary) and AA (secondary) types; the former, is the most frequent and is due to deposition of proteins derived from immunoglobulin light chain fragments, occurring alone or in association with multiple myeloma. The later (AA), is caused by deposition of fibrils composed of fragments of the acute phase reactant serum amyloid A (SAA) and complicates chronic diseases with ongoing or recurring inflammation, namely; rheumatoid arthritis (RA), juvenile chronic polyarthritis, ankylosing spondylitis, familial periodic fever syndromes (Familial Mediterranean Fever), chronic infections and furthermore, some neoplasms (mainly renal cell carcinoma and Hodgkin's disease). Despite its less frequent association, some benign neoplasms can subsequently complicate to AA amyloidosis, therefore, an early diagnose and successful treatment may lead indeed, to regression of the amyloid disease. Herein, we present two cases of AA amyloidosis, both of them caused by 2 different benign neoplasms: 1. A 34 year-old woman, after chronic oral contraceptive use, developed an hepatic adenoma (fig. 1) which finally lead to AA amyloidosis with primary kidney presentation (pure nephrotic syndrome) (table 1). Post-surgical complications yield to acute renal failure from which unfortunately could not be recovered. After being on hemodialysis therapy during 10 months she received a first renal allograft without any complication. 2. A 20 year old woman, was diagnosed of AA amyloidosis after a renal biopsy (fig. 2) because of nephrotic syndrome (table 1). Further investigation lead to the finding of a hialyne-vascular type Castleman's disease located in the retroperitoneum (fig. 2). Despite surgical resection and medical treatment (colchicine) she developed progressive renal failure requiring initialization of hemodialysis therapy. After 6 years being on hemodialysis, she received a first renal allograft which is currently functioning after one year of follow- up. Although other chronic inflammatory diseases complicate more frequently to AA amyloidosis, benign tumors have to be taken into account as a potential ethiological cause for secondary amyloidosis.

[Preservation by pulsatile perfusion machine: the initial experience]. / Preservación mediante maquina de perfusión pulsátil: experiencia inicial.

The increasing numbers of patients in a waiting list for a renal transplantation together with the epidemiological changes in donor's characteristics have given rise to a growing interest in preservation with pulsatile perfusion machines. The availability of objective predictive parameters of renal functioning after transplantation as well as of improving preservation to reduce the incidence of acute tubular necrosis (ATN) are the major features of this preservation technique. This paper presents our experience in preservation with pulsatile perfusion machines which have allowed us to have objective parameters to assess an organ's future functioning and to improve, as far as possible, the quality of treated kidneys preservation.