Kagekatsu Kubo

Publications (2)1.17 Total impact

• Article: Persistent thrombocytosis in elderly patients with rare hyposplenias that mimic essential thrombocythemia.

  Shinsaku Imashuku, Naoko Kudo, Kagekatsu Kubo, Naoto Takahashi, Kaoru Tohyama
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  ABSTRACT: When elderly patients present with persistent thrombocytosis, myeloproliferative disease, iron-deficiency anemia or post-splenectomy status are suspected along with autoimmune diseases. Reported here are the cases of two elderly patients with persistent thrombocytosis due to hyposplenia, which is very rarely diagnosed in old age. Case 1 was a 72-year-old man whose thrombocytosis was due to non-familial type isolated congenital asplenia. Case 2 was a 74-year-old man whose thrombocytosis was caused by an atrophied spleen resulting from perforated stomach ulcer-related panperitonitis that had been treated 20 years previously. Both patients had thrombocyte counts exceeding >500,000/μl in association with small vestigial spleen tissue on a computed tomography scan and positive Howell-Jolly bodies on the blood smear. A correct diagnosis is essential for the management of persistent thrombocytosis.
  International journal of hematology 04/2012; 95(6):702-5. · 1.17 Impact Factor
• Article: Rituximab for managing acquired hemophilia A in a case of chronic neutrophilic leukemia with the JAK2 kinase V617F mutation.

  Shinsaku Imashuku, Naoko Kudo, Kagekatsu Kubo, Katsuyasu Saigo, Nanako Okuno, Kaoru Tohyama
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  ABSTRACT: Acquired hemophilia A is rarely found in association with myeloproliferative neoplasms, such as the JAK2 kinase V617F mutation-positive chronic neutrophilic leukemia (CNL). An 80-year-old Japanese male was diagnosed with acquired hemophilia A. He had compartment-like symptoms due to soft tissue hemorrhage in his left forearm and right lower extremity. A blood examination showed neutrophilia with a white blood cell count of 31,900/μL (91.9% neutrophils), an activated partial thromboplastin time of 69.0 seconds, coagulation factor VIII (FVIII) < 1.0%, and anti-FVIII inhibitor, 190 BU/mL. The bleeding episodes were controlled with intravenous activated prothrombin complex concentrate (FEIBA(®)) followed by recombinant factor VIIa (NovoSeven(®)). In addition, oral prednisolone (maximum dose, 30 mg/day) plus four doses of rituximab effectively suppressed anti-FVIII inhibitor levels while simultaneously reducing the neutrophil count. CNL with the JAK2 kinase V617F mutation was identified as the underlying disease. This report describes the effectiveness of a combination of prednisolone and rituximab in managing acquired hemophilia A in an elderly man with a rare case of JAK2 kinase V617F mutation-positive CNL.
  Hematology Research and Reviews 01/2012; 3:157-61.