Decrease in the rate of secondary amyloidosis in Turkish children with FMF: are we doing better?

Familial Mediterranean fever (FMF) is the most common autoinflammatory disease in the world. The most serious complication of FMF is the development of secondary amyloidosis. Besides genetic factors, environment has been implicated in the development of this complication. The main objective of this study is to analyze whether there has been a substantial decrease of secondary amyloidosis in Turkey and possible effective factors. For this purpose, clinical features of the patients diagnosed with secondary amyloidosis between the years 1978 and 1990 were compared with those diagnosed between 2000 and 2009. Severity scores were determined by the use of a scoring system modified for children. Median ages of the group diagnosed between 1978 and 1990 (n = 115; 12.1% among a total of 947 renal biopsies) and diagnosed after 2000 (n = 19; 2% among a total of 974 renal biopsies) were 12 and 13 years, respectively. There were no significant differences between the two patient groups according to gender, age, age of onset, disease duration, and disease severity. There was, however, a clear decrease in the percentage of biopsies with secondary amyloidosis from 12.1% (1978-1990) to 2% (after 2000; p < 0.001). Our results have shown that there has been a significant decrease in the rate of secondary amyloidosis in Turkey. The main reason for this decrease is better medical care with increased awareness and treatment of the disease. However, we suggest that the improvement of infectious milieu may possibly have had a positive effect on the course of this monogenic disease, since inflammatory pathways related to innate immunity are deregulated.