Renal Amyloidosis and Clinicopathological Prognostic Factors: A Study of 196 Cases.
Kemal Kosemehmetoglu, Dilek Baydar. Hacettepe University Hospital, Ankara, Turkey
Background: In this study, we aimed to analyze our cases of renal amyloidosis diagnosed by needle biopsy and document their clinical and morphological features.
Design: Biopsy slides were retrieved from the archives and reviewed. Intensity and relative distribution of amyloid deposition in renal compartments were noted. Glomerular deposits were classified as hilar, mesangial segmental, mesangial nodular and mesangiocapillary. Chronic tubulointerstitial damage was graded from 1 to 3 according to its extent (<25%, 25-75% and >75%). Amyloid typing was performed by immunohistochemistry using anti-AA, lambda, kappa, apolipoprotein A, prealbumin (transthyretin), fibrinogen and lysosyme antibodies. Clinical information and follow-up data were gathered from hospital records and computer-based patient data system.
Results: Between years from 1981 to 2006, we found 196 needle biopsies with renal amyloidosis. Immunohistochemical studies could be achieved in 178 cases. Among them 168 were AA type, 3 were AL type and 1 was AFib, AApoA1 and ALys for each; 4 cases were unable to be categorized immunohistochemically. Within AA amyloidosis group, the most common preamyloidotic disease was Familial Mediterranean Fever (FMF) (29%), followed by chronic infectious diseases (tuberculosis-%16, bronchiectasis-%8) and chronic inflammatory conditions (rheumatoid arthritis-%9, Behcet's disease-%7). Patients almost always presented with edema due to proteinuria. 18% of patients had disturbed renal fuction at the time of diagnosis. Hypertension was recorded in 32% and hematuria in 45%. Glomerular amyloid deposition was noted to fall into 4 distinct patterns: Mesangial segmental (15.5%), mesangial nodular (11.3%), hilar (30.4%) and mesangiocapillary (42.8%). Regarding the compartment of dominant amyloid deposition, cases were further classified as glomerular-dominant (28.1%), vascular-dominant (15.8%) and co-dominant (51.5%) forms. Glomerular-dominant form closely correlated with level of proteinuria (p=0.008) and presence of hypertension (p=0.009). 5- and 10-year survivals were 37% and 30%, respectively. In multivariant analysis, the poor prognostic factors determining renal survival were low glomerular filtration rate and high 24-hr urine protein, mesangiocapillary type glomerular amyloid deposition and high renal injury score at the time of biopsy.
Conclusions: AA is the most common amiloid type seen in renal biopsies in our country in which FMF is endemic. Renal amyloidosis has a diverse pathology in terms of preferential location of amyloid deposition and its intensity. Patients follow variable clinical courses accordingly.
Category: Kidney (does not include tumors)
Wednesday, March 2, 2011 1:00 PM
Poster Session VI # 255, Wednesday Afternoon