RT Journal Article
SR Electronic
T1 Familial Mediterranean Fever (FMF) with Proteinuria: Clinical Features, Histology, Predictors, and Prognosis in a Cohort of 25 Patients
JF The Journal of Rheumatology
JO J Rheumatol
FD The Journal of Rheumatology
SP 2083
OP 2087
DO 10.3899/jrheum.130520
VO 40
IS 12
A1 Olga Kukuy
A1 Avi Livneh
A1 Aharon Ben-David
A1 Juri Kopolovic
A1 Alexander Volkov
A1 Yael Shinar
A1 Eliezer Holtzman
A1 Dganit Dinour
A1 Ilan Ben-Zvi
YR 2013
UL http://www.jrheum.org/content/40/12/2083.abstract
AB Objective. Reactive (AA) amyloidosis may complicate familial Mediterranean fever (FMF), the prototype of autoinflammatory diseases. Thus, proteinuria in FMF is commonly viewed as resulting from amyloidosis, and kidney biopsy is deemed superfluous. However, nephropathy other than amyloidosis has been described in FMF, but its rate and distinctive characteristics are unknown. Our aim was to determine the rate and underlying pathology of FMF-related nonamyloidotic proteinuria and compare its clinical course, demographic, and genetic features to those of FMF-amyloid nephropathy. Methods. This study is a retrospective analysis of data from patients with FMF undergoing kidney biopsy for proteinuria above 0.5 g/24 h, over 10 years (2001–2011). Clinical, laboratory, genetic, and pathology data were abstracted from patient files. Biopsies were viewed by an experienced pathologist, as necessary. Results. Of the 25 patients referred for kidney biopsy, only 15 (60%) were diagnosed with amyloid kidney disease (AKD), and 10 were diagnosed with another nephropathy. The AKD and nonamyloid kidney disease (NAKD) groups were comparable on most variables, but showed distinct characteristics with regard to the degree of proteinuria (6.45 ± 4.3 g vs 2.14 ± 1.6 g, p = 0.006), rate of severe FMF (14 vs 5 patients, p = 0.022), and rate of development of end stage renal disease (73.3% vs 20%, p = 0.015), respectively. Conclusion. NAKD is common in FMF and, compared to amyloidosis, it is featured with milder course and better prognosis. Contrary to common practice, it is highly recommended to obtain a kidney biopsy from patients with FMF and proteinuria more than 0.5 g/24 h.