2013 Volume 1 Issue 1 Pages 39-44
Hemolytic uremic syndrome (HUS) is characterized by the triad of microangiopathic hemolytic anemia, thrombocytopenia, and acute renal failure. Over 90％ of such cases are due to Shiga toxin-producing Escherichia coli (STEC) infection ‘typically’ presenting with a diarrheal prodrome. The remaining 10％ of childhood HUS comprises so-called, atypical HUS (aHUS) which is a heterogeneous disease associated with defective regulation of the alternative complement pathway in over 50％ of cases. In contrast to typical HUS, aHUS is associated with a poor long-term prognosis, and is characterized by frequent relapses and progression to end-stage renal disease. Furthermore, the incidence of aHUS recurrence after renal transplantation is high, and has been reported to depend on the underlying complement defect. Therefore, it is necessary to diagnose aHUS as accurately and quickly as possible. For the diagnosis of HUS/TTP, analysis of the gene mutation site through measurement of ADAMTS13 activity and protein assay including hemolytic assay and measurement of CFH autoantibodies have been performed at Nara Medical University, and the final diagnosis based on gene mutation analysis of CFH, CFI, C3, THBD, CFB, and MCP has been done at the National Cerebral and Cardiovascular Center. A diagnostic network for HUS/TTP centered on these institutions has thus been established. Through this diagnostic network, the analytical procedures from measurement of ADAMTS13 activity to genetic mutation analysis can be completed within one month.
