Anti-thymocyte globulin therapy induced a spurious increase of fibrinogen degradation products in hypoplastic myelodysplastic syndrome.

摘要

To the Editor:A 60-yr-old Japanese woman with hypoplastic myelodysplastic syndrome (MDS, refractory anemia) admitted to our hospital because of uncontrolled bleeding tendency. Physical examination showed multiple purpura on the trunk and extremities. She had no peripheral lymphade-nopathy or hepatosplenomegaly. Laboratory analysis revealed a white blood cell count of 3. x 10~9/L with 47% of neutrophils, hemoglobin 7. g/dL, platelet count ll.OxlOVL, T-Bil 1. mg/dL, lactate dehydrogenase 265 IU/L, aspartate transaminase 59 IU/L, alanine aminotransferase 68 IU/L, fibrinogen 335.0 mg/dL and fibrinogen degradation products (FDP) < 5.0 mug/mL. Although bone marrow examination showed hypocellular marrow with 2.9% of blasts and no apparent myelodysplasia, del(20) (qllql3.) was detected in 5 of 20 analyzed metaphase cells. Hypoplastic MDS was diagnosed, and she started equine anti-thymocyte globulin (ATG) and cyclosporine A. She developed watery diarrhea on day 8. High fever, abdominal pain, skin eruption and arthralgia followed, and C-reactive protein (CRP) increased to 16. mg/dL. Immune-complex level elevated to 6.6 (mu)g/dL and hemolytic complement level (CH50) was undetectable on day 11. On day 10, FDP and D-dimer levels abruptly rose to 2865 (mu)g/mL and 999.0 mug/mL, respectively, although neither deterioration of the bleeding tendency nor thrombotic events were observed. Skin biopsy revealed only perivascular dermatitis infiltrated with lymphocytes, a finding compatible with serum sickness after ATG. Methylprednisolone started on day 13 rapidly improved the serum sickness, and the FDP level gradually decreased to 184.6 by day 30.