Three highschool students (case 1: 16-year-old schoolboy, case 2: 17-year-old schoolgirl and case 3: 15-year-old schoolboy) were admitted to our hospital with hemoglobinuria after “Kendo (a Japanese fencing)” training.
They showed no abnormality in physiological and laboratory examinations except mild neutropenia in case 1. And they were also negative in examinations for hemolytic anemia such as Coombs test, Ham's acidified serum test, sugar water test, autohemolysis test, Donath-Landsteiner test and Parpart test.
After an exertional test with 100 times of “fumikomi (a special step of kendo trainig on bare feet)” serum haptoglobin almost disappeared in 3 cases and hemoglobinemia and hemoglobinuria occured in case 1 and case 3. And these symptoms improved by putting on shoes.
The erythrocyte membrane of case 1 was studied in SDS-PAGE and it was revealed that a band of low molecular weight membrane protein decreased.
