RESUMO
Pulmonary embolism and deep venous thrombosis (PE/DVT) are well-known lethal complications in autoimmune hemolytic anemia (AIHA). However, the impact of their treatment is unclear. Here, we describe three elderly Japanese patients with AIHA who developed PE/DVT early after glucocorticoid administration. All patients presented with active hemolysis and high D-dimer levels upon admission. Thromboembolism was confirmed within 2 weeks after starting glucocorticoid, suggesting that both active hemolysis and glucocorticoid administration synergistically contributed to the development of PE/DVT. Clinicians should consider that such synergism may increase the risk of thromboembolism in patients with AIHA, and prophylactic anticoagulation is worth considering in patients after starting glucocorticoid.
RESUMO
We purified D-amino acid oxidase (EC 1.4.3.3, DAO) from Xenopus laevis tadpoles. The optimal temperature and pH for enzyme activity were 35-40 °C and 8.3-9.0, respectively, depending on the substrate amino acids available to the enzyme; the highest activity was observed with D-proline followed by D-phenylalanine. Activity was significantly inhibited by p-hydroxymercuribenzoate, but only moderately by p-chloromercuribenzoate or benzoate. Enzyme activity was increased until the final tadpole stage, but was reduced to one-third in the adult and was localized primarily in the kidney. The tadpoles contained high concentrations of D-proline close to the final developmental stage and nearly no D-amino acids were detected in the adult frog, indicating that D-amino acid oxidase functions in metamorphosis.
