Renal Amyloidosis

Abstract

SummaryBackground and objectives The kidney is the organ most commonly involved in systemic amyloidosis. This study reports the largest clinicopathologic series of renal amyloidosis.

Leukocyte Cell–Derived Chemotaxin 2–Associated Amyloidosis

“…The glomerular and vascular amyloid deposits are variable, ranging from absent ( Figure 2C) to mild to marked (Figure 2, A and B) (5,12). This is different from AL amyloidosis and AA amyloidosis, in which glomeruli and vessels are the prime sites of amyloid deposition (6). Contrary to AApo AI amyloidosis and AApo AIV amyloidosis, which mainly affect the medullary interstitium, ALECT2 amyloidosis shows a predominant involvement of cortical interstitium ( Figure 2D) (5,12).…”

“…Histologically, renal ALECT2 amyloidosis shows preferential interstitial involvement, which is usually diffuse (Figure 2, A-D) (5,6,12,14,16). The glomerular and vascular amyloid deposits are variable, ranging from absent ( Figure 2C) to mild to marked (Figure 2, A and B) (5,12).…”

“…Glomerular amyloid spicules, which result from parallel arrangement of amyloid fibrils perpendicular to the glomerular basement membranes, are far less common than in AL amyloidosis (6). Immunofluorescence is usually negative, although false-positive staining for IgG with/without staining for IgM, IgA, k, and l may rarely occur (12), albeit with a lesser frequency than in AA deposits (6). A minority (9%) of patients with ALECT2 amyloidosis show false-positive staining for serum amyloid A (SAA) (12).…”

“…Kidney involvement is present in most patients with AL amyloidosis (3) and AA amyloidosis (4) and may also occur in several rare hereditary forms of amyloidosis, such as those derived from fibrinogen A, transthyretin (ATTR), gelsolin (particularly in homozygotes), lysozyme, apo AI (AApo AI), AApo AII, and AApo AIV (5)(6)(7)(8). The overall renal biopsy incidence of amyloidosis ranges from 1.3% to 4% (5)(6)(7)9).…”

“…It accounts for 2.7%-10% of patients with renal amyloidosis in the United States (5,6,14). In a recent series of 474 patients with biopsy-proven renal amyloidosis from the Mayo Clinic, 86% were Ig derived, 7% were AA derived, 3% were ALECT2 derived, and 1% were fibrinogen A derived (6).…”