Secondary Amyloidosis Treated with Tocilizumab as a Complication of Temporal Arteritis

Background: Temporal arteritis is a large-vessel vasculitis mostly seen in the elderly. Amyloidosis may be secondary to a chronic inflammation of body organs. Here, we present the second case report of temporal arteritis complicated by amyloidosis that was successfully treated by tocilizumab.

Case presentation: A 64-year-old female presented complaining of fatigue, fever, and diarrhea accompanied by abdominal pain. One year before presentation, she was diagnosed with temporal arteritis. She was treated with 15 mg/day oral prednisone for the last 6 months, with partial remission, but persistence of the fatigue and an elevated erythrocyte sedimentation rate (ESR, 56 mm/h). Physical examination showed tenderness of both temporal arteries and a soft abdomen. Colon tissue biopsy showed amyloid depositions in the vessels and stroma that were positive for Congo red staining. Tocilizumab was started with 8 mg/kg intravenous, the diarrhea resolved, and the arthralgia improved within 1 month, with a decrease in the ESR to 8 mm/h, and a C-reactive protein (CRP) level of 0.98 mg/dl. Monthly tocilizumab therapy remains efficacious 12 months later and was stopped due to lack of tocilizumab from the hospital. No side effects of tocilizumab were registered.

Conclusion: Chronic inflammation may be complicated by amyloidosis in patients with rheumatic diseases and genetic predisposition. Therefore, it is important to screen for intestinal Amyloid A (AA) amyloidosis in individuals with gastrointestinal disorders complicated by rheumatic disorders. AA amyloidosis may be complicated by temporal arteritis and presented with gastrointestinal symptoms such as diarrhea.

Learning points: Amyloidosis is manifested by the deposition of insoluble protein aggregates in organs.Amyloid A (AA) amyloidosis occurs as a complication of chronic inflammation in patients with a genetic predisposition to rheumatic diseases.Temporal arteritis complicated with AA amyloidosis is extremely rare.