Thrombotic thrombocytopenic purpura and adult onset Still's disease

Thrombotic thrombocytopenic purpura (TTP) has a high mortality rate if undiagnosed and untreated. Although recent literature supports the role of ADAMTS13 (a disintegrin-like metalloproteinase with thrombospondin type 1 repeats), the von Willebrand factor cleaving protease, in the pathogenesis of the disease, many aspects of the disease remain a mystery. Various drugs and autoimmune conditions, such as systemic lupus erythematosus and the antiphospholipid syndrome, have been observed in association with TTP. Adult onset Still's disease (AOSD) has been reported less frequently in association with TTP.

We report the case of a 43-year-old African American man who initially presented with fever and joint pain and was later diagnosed with TTP. He responded initially to plasma exchange, but never achieved complete remission. He eventually required splenectomy for complete resolution of symptoms of TTP, but the arthritis never resolved, resulting in several admissions for joint pain. The arthritis was eventually diagnosed as AOSD.

Literature review shows that the autoimmune diseases usually associated with TTP include systemic lupus erythematosus and the antiphospholipid syndrome. Eight reports of AOSD with TTP have been reported, but our case is unique in several aspects. Previous case reports have described TTP occurring in patients with known AOSD; here, we describe TTP preceding or coinciding with the onset of AOSD. Interestingly, the patient's AOSD-associated arthritis responded to plasma exchange, but did not resolve after splenectomy. The coincident onset of AOSD and TTP in this patient lead us to suspect a common pathophysiologic pathway in the pathogenesis for both of these diseases.