Clinical significance of high-Km 5'-nucleotidase (cN-II) mRNA expression in high-risk myelodysplastic syndrome.

We analyzed cytosolic high-Km 5'-nucleotidase (cN-II) and deoxycytidine kinase (dCK) mRNA expression in bone marrow mononuclear cells (BMMNC) of patients with high-risk myelodysplastic syndrome (MDS) using quantitative real-time polymerase chain reaction (rt-PCR). At diagnosis, the cN-II mRNA expression of patients was higher than that of healthy volunteers, but the dCK mRNA expression showed no significant difference. Patients with ara-C-containing chemotherapies whose BMMNC showed a high level of cN-II expression (greater than the median value) had shorter median overall survival (15 months versus 22 months, p<0.01) and shorter median post-chemotherapy survival (10 months versus 16 months, p=0.012). These data suggest that the expression level of cN-II mRNA might be a prognostic factor of high-risk MDS.

Successful treatment with cyclosporine and high-dose gamma immunoglobulin for persistent parvovirus B19 infection in a patient with refractory autoimmune hemolytic anemia.

We describe a patient with persistent pure red cell aplasia due to human parvovirus B19 (HPVB19) infection during immunosuppressive therapy for refractory autoimmune hemolytic anemia (AIHA). The patient had been given corticosteroid (CS) and/or azathioprine for AIHA. During the course of treatment, reticulocyte count and hemoglobin levels decreased suddenly. Bone marrow aspirate showed erythroid lineage-specific aplasia with a few giant proerythroblasts, suggesting the presence of HPVB19 infection. The diagnosis of aplastic crisis due to HPVB19 infection was based on positive test results by polymerase chain reaction for HPVB19 immunoglobulin M (IgM) antibody and B19 DNA. Although splenectomy followed by administration of high-dose gamma globulin (HDIG) and plasma exchange were performed, the crisis and hemolysis recurred. Aplastic crises occurred several times when the B19 IgG result became negative and the CD4+ lymphocyte count was less than 300/microL. The patient showed complete recovery from anemia after CS was switched to cyclosporin A (CsA) and intermittent administration of HDIG. The result for B19 IgG antibody was continuously positive, and the DNA result became negative after these treatments. The results in this case indicated that concomitant administration of CsA and intermittent administration of HDIG can lead to cure of chronic anemia due to HPVB19 infection in patients with refractory AIHA.

Clinical and biological significance of CD56 antigen expression in acute promyelocytic leukemia.

The biological significance of CD56 antigen expression in patients with acute promyelocytic leukemia (APL) has been under investigation. We investigated the clinical and biologic features of CD56+APL. In our series, CD56 antigen was positive in 4 of 28 (14%) APL patients. No differences were found regarding age, gender, performance status (PS), initial leukocyte and platelet counts, lactate dehydrogenase (LDH) and fibrinogen (Fbg) levels according to CD56 expression. CD34 antigen was co-expressed in 3 of the 4 patients with CD56+ APL, in contrast to 2 of the 24 patients with CD56- APL (P = .01). Extramedullary relapse occurred in 3 of the 4 patients with CD56+ APL, in contrast to none of the 24 patients with CD56- APL (P = .001). Median remission duration was 4 months in CD56+ APL and was not reached in CD56- APL. The CD56+ population had a shorter remission duration (P < .0001) and disease-free survival (P < .0001). In contrast, no difference was found in overall survival. These results suggested that CD56 expression was associated with the leukemogenetic mutation at the primitive hematopoietic progenitor cell level and extramedullary relapse in APL patients treated with ATRA and chemotherapy.