Progression of Renal Amyloidosis of FMF and Relation to Serum SAA Level

FMF is an inherited inflammatory disorder typically presented in most causes as recurrent episodes of fever and serositis. Phenotype II, another kind of this disorder, has atypical courses, when the inflammation proceeds without any clinical sign.

Each FMF attack is accompanied by sharp elevation of inflammatory markers in the serum, and serum amyloid A (SAA) one of them. The level of these inflammatory markers returns to normal with termination of the attack. The SAA is the main component of amyloids fibrils and constantly high level of SAA after the attack (as occurs in undiagnosed or undertreated disease) is the significant risk factor responsible for development of amyloidosis. On the other hand, in patients with phenotype II the amyloidosis occurs despite absolute absence of the attacks.

The kidney is one of the first organ suffers from amyloid deposits. The spectrum of kidney damage spread wildly from mild proteinuria to obvious nephrotic syndrome with disturbance in renal function and progression to end stage renal failure.

It is well known that deterioration of renal disease in AA amyloidosis links to level of SAA in serum. The permanently high SAA level is a major factor responsible to progression of renal disease. Occasionally, however, decline in the renal function occurred despite normal or near normal levels of SAA. Renal impairment in these cases may be explained by mechanisms existing in other kidney diseases when uncontrolled proteinuria aggravates renal dysfunction. The purpose of the study is to find whether a cohort of patients followed in our clinic and receiving colchicine for FMF- amyloidosis according to the SAA levels, monitored periodically, have better prognosis than an historical cohort receiving colchicine according to the attack status