Amyloidosis secondary to ankylosing spondylitis: case report and literature review

Three patients diagnosed as amyloidosis secondary to ankylosing spondylitis (AS) in Peking Union Medical College Hospital are reported. All 3 cases had renal abnormalities, 2 cases were complicated with cardiac abnormalities, 1 case was complicated with gastrointestinal abnormalities and 1 case was complicated with skin moss-like changes. Eleven cases of AS with amyloidosis were retrieved from Wanfang database and Pubmed database from 1997 to 2017. In total 14 cases, the male and female ratio was 5∶2, the mean age of AS onset was (29.6±10.5) years, and the mean age of amyloidosis diagnosed was (44.0±10.5) years. Eight patients presented with edema and severe proteinuria, 2 cases showed diarrhea, 2 cases showed dyspnea, while 2 cases had no obvious symptoms. Thirteen cases had renal abnormalities and 1 case had only heart involvement. Of the 13 patients with renal involvement, 2 cases were complicated with cardiac abnormalities, 2 cases complicated with gastrointestinal abnormalities, 2 cases complicated with skin abnormalities.The mean ESR was (83.7±22.6) mm/1 h,C reactive protein was (89±59) mg/L at onset. After the diagnosis of amyloidosis, 9 patients were treated with TNF-α inhibitors, 3 cases received symptomatic therapy, 1 case underwent renal transplantation and 1 case were treated with peritoneal dialysis. In 9 patients treated with TNF-α inhibitors, 8 cases were relieved and 1 case lost follow-up. Three patients who received symptomatic treatment all died, while patients receiving kidney transplantation and peritoneal dialysis were in stable condition. The study indicates that secondary amyloidosis often occurs in young male AS patients who have long course and poorly controlled disease, the kidney is the most common affected organ. TNF-α inhibitors may be effective for treatment of amyloidosis secondary to AS. Key words: Spondylitis, ankylosing; Amyloidosis