[A case of Duchenne muscular dystrophy complicated by thrombotic thrombocytopenic purpura]

We experienced a patient with Duchenne muscular dystrophy (DMD) complicated by thrombotic thrombocytopenic purpura (TTP). This patient exhibited abrupt high fever, renal dysfunction and thrombocytopenia from February 2, 2002. Hemolysis was also indicated by indirect dominant hyperbilirubinemia, although hemoglobin was only slightly decreased. No central nervous system signs and symptoms were detected. TTP was suggested by these findings and confirmed by decreased activity (21%) of von Willebrand factor cleaving protease activity. Plasma exchange was performed for 4 days from February 5, and enabled recovery. Thrombosis, such as cerebral and lung infarction, has occasionally been seen in DMD. Recently, several findings associating muscle degeneration with hypercoagulation have been reported, for example, a strong correlation between serum CK level and FDP. In seven cases of DMD with pulmonary infarction, transient elevation of serum CK was detected prior to LDH elevation. However, there have been no reports of TTP in DMD patients. Since serum CK was not elevated during our patient's clinical course, it is unlikely that muscle degeneration played a role in TTP in this patient. It should be noted that endothelial abnormalities have been reported in DMD, since endothelial injury is considered a fundamental factor in TTP.