FMF patients with histologically proven AA amyloidosis, treated with TCZ (8 mg/kg per month) were followed monthly and the changes in creatinine, creatinine clearance, the amount of 24-hour urinary protein, erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) were noted throughout the treatment period.
Multiple regression analysis indicated that the interval from RA onset to diagnosis of AA amyloidosis is determined by age at RA onset (p < 0.001), the most recent median annual CRP concentration (p=0.006) and SAA1.3 allele (p=0.058).
On the other hand, the mean C-reactive protein (CRP) level during 2 years prior to the diagnosis of AA-amyloidosis was significantly higher in the patients with larger numbers of the gamma allele at the SAA1 locus (Spearman's correlation coefficient: 0.34, P<0.05).