Paroxysmal nocturnal hemoglobinuria (PNH) is a rare, acquired clonal disorder characterized by chronic
complement-mediated
hemolysis. The humanized anti-C5 antibody
eculizumab binds to the C5
protein and suppresses
hemolysis by inhibiting
C5b-9 generation. Here, we report on a 27-year-old woman who was found to have PNH in 1997 (at 13 years of age), without subsequent transfusions,
thrombosis, or renal disorder. She had been experiencing frequent malaise and
fatigue and was sometimes unable to participate in social activities. She had also experienced repeated hemolytic episodes due to
infection, and the
hemoglobin level had decreased from 7.0 to 5.0 g/dL several times since February 2010.
Red blood cell transfusion was necessary, and 6 months later, treatment with
eculizumab was started. The
hemoglobin level stabilized, and the patient became transfusion-independent. Furthermore, the patient showed significant improvements in
fatigue scale scores and quality of life. Six months after the start of
eculizumab therapy, the percentage of PNH-type red blood cells was found to have increased from 82.0% (1.95 × 10(12) cells/L) to 89.1% (2.78 × 10(12) cells/L). Furthermore, during treatment with
eculizumab,
intravascular hemolysis occurred due to a
viral infection accompanied by a high
fever. We also observed a persistent elevation in reticulocytes and total
bilirubin levels, as well as a persistent reduction in
haptoglobin levels. Extravascular hemolytic findings were also observed. Because treatment with
eculizumab was started at a young age (27 years) and will be continued for many years, careful observation of the patient is required.