Background The most frequent underlying diseases responsible for AA amyloidosis worldwide are rheumatoid arthritis, juvenile idiopathic arthritis and ankylosing spondylitis, while familial Mediterranean fever (FMF) is responsible for almost 60% of the cases in Turkey and in countries where the FMF is prevalent. Tocilizumab (TCZ), an IL-6 antagonist, seems to be a promising agent in AA amyloidosis associated with rheumatic disorders, while there is no data regarding its use in amyloidosis due to FMF.
Objectives We herein describe the short-term results of TCZ treatment in 8 patients with amyloidosis secondary to FMF.
Methods We described a series of adult FMF patients complicated with amyloidosis and treated with TCZ (8 mg/kg once monthly) in one reference center. Diagnosis of AA amyloidosis was confirmed in the renal and/or rectal biopsy specimens in all patients with Congo red and immunohistochemical staining.
Results The longest duration on the treatment with TCZ was 16 months in one patient, while 3 months in one patients with the shortest follow-up. At the beginning of TCZ treatment all patients had proteinuria with nephrotic range except case 4. Following treatment with TCZ, proteinuria was normalized in case 1 (Case with the longest duration of treatment), and considerably decreased in 4 cases, and increased in two (case 4 and 5). Serum creatine levels also increased in case 5, and patient refused to receive treatment after 6 cycles. In case 8, TCZ treatment was switched to anakinra due to frequent FMF attacks. The renal function tests were abnormal in 4 patients, and remained almost stable throughout the follow-up (Table 1). Serum albumin levels were normalized in all patients except case 5 and 8.
Conclusions To our knowledge this is the first report showing the efficacy of TCZ on renal amyloidosis secondary to FMF. While previous reports confirm the efficacy of TCZ in amyloidosis secondary to other rheumatic diseases, our findings suggest that this effect can be extended to other diseases.
Disclosure of Interest : None declared