Quantitative assessment of contaminating tumor cells in autologous peripheral blood stem cells of B-cell non-Hodgkin lymphomas using immunoglobulin heavy chain gene allele-specific oligonucleotide real-time quantitative-polymerase chain reaction.

A real-time quantitative-polymerase chain reaction (RQ-PCR) targeting the immunoglobulin heavy chain (IgH) gene has been used for the quantification of minimal residual disease (MRD) in B-cell hematological malignancies. In non-Hodgkin lymphoma (NHL), experimental costs are increased, as a large number of primer-probe sets are required because of diversity, due to somatic and ongoing mutations of the IgH gene. We developed an allele-specific oligonucleotide (ASO) combined with a germline consensus probe-based RQ-PCR assay and examined MRD in peripheral blood stem cells (PBSC). The IgH consensus probes were adapted in seven (50%) of 14 amplifiable cases. Patients with heavily contaminating tumor cells in PBSC relapsed after PBSC transplantation. Our strategy will contribute to the development of a cost-efficient, precisely quantitative and systemic detection assay for MRD in NHL.

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.

[Reduced intensity stem cell transplantation for metastatic renal cell carcinoma].

PURPOSE: We reviewed reduced intensity stem cell transplantation (RIST) in metastatic renal cell cancer (RCC). PATIENTS AND METHODS: Two cases of lung metastasis of immunotherapy invalidity. Six days of fludarabine 30 mg/m2 and 2 days of busulfan 4 mg/kg were given as conditioning for mini-SCT. CyA and short-term MTX were used as immunosuppressive agents. RESULTS: Size reduction of tumor was observed with dose reduction of CyA. Following steroid therapy for the treatment of GVHD, the tumor progressed. No serious complications except for GVHD. CONCLUSION: These results suggested that RIST might be considered as salvage therapy in patients metastatic RCC.

Clonal evolution of blasts in an elderly patient with CD56(+) relapsed acute promyelocytic leukemia.

We describe an elderly patient with acute promyelocytic leukemia (APL), whose leukemic cells expressed CD56 antigen at relapse but not at diagnosis. Chromosome analysis revealed that blasts with t(8;15;17)(q24.1;q22;q11.2) increased from 4 of 20 cells (20%) at first relapse to 10 of 14 cells (71.4%) at second relapse. In addition, the positivity for CD56 expression on blasts judged by flow cytometric analysis using CD45 blast gating was also increased from 14.2% at first relapse to 75% at second relapse. Although conventional chemotherapy was performed for the initial disease and the first relapse, relapse developed again. Therefore, three courses of intensive postremission chemotherapy including concurrent administration of recombinant human granulocyte colony-stimulating factor (rhG-CSF) with cytarabine were performed after achievement of complete remission (CR) by the treatment with all-trans-retinoic acid (ATRA). Although PML-RARalpha mRNA was not detectable by reverse transcription polymerase chain reaction (RT-PCR), a third relapse occurred. This case demonstrated clonal evolution from a CD56(-) to a CD56(+) blast population and provided further support for the suggestion that CD56 expression might be an unfavorable prognostic factor in t(15;17) APL.