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The flow cytometric detection of minimal residual disease (MRD) in precursor-B-acute lymphoblastic leukemias (precursor-B-ALL) mainly relies on the identification of minor leukemic cell populations that can be discriminated from their normal counterparts on the basis of phenotypic aberrancies observed at diagnosis. This technique is not very complex, but discordancies are frequently observed between laboratories, due to the lack of standardized methodological procedures and technical conditions. To develop standardized flow cytometric techniques for MRD detection, a European BIOMED-1 Concerted Action was initiated with the participation of laboratories from six different countries. The goal of this concerted action was to define aberrant phenotypic profiles in a series of 264 consecutive de novo precursor-B-ALL cases, systematically studied with one to five triple-labelings (TdT/CD10/CD19, CD10/CD20/CD19, CD34/CD38/CD19, CD34/CD22/CD19 and CD19/CD34/CD45) using common flow cytometric protocols in all participating laboratories. The use of four or five triple-stainings allowed the identification of aberrant phenotypes in virtually all cases tested (127 out of 130, 98%). These phenotypic aberrancies could be identified in at least two and often three triple-labelings per case. When the analysis was based on two or three triple-stainings, lower incidences of aberrancies were identified (75% and 81% of cases, respectively) that could be detected in one and sometimes two triple-stainings per case. The most informative triple staining was the TdT/CD10/CD19 combination, which enabled the identification of aberrancies in 78% of cases. The frequencies of phenotypic aberrations detected with the other four triple-stainings were 64% for CD10/CD20/CD19, 56% for CD34/CD38/CD19, 46% for CD34/CD22/CD19, and 22% for CD19/CD34/CD45. In addition, cross-lineage antigen expression was detected in 45% of cases, mainly coexpression of the myeloid antigens CD13 and/or CD33 (40%). Parallel flow cytometric studies in different laboratories finally resulted in highly concordant results (>90%) for all five antibody combinations, indicating the high reproducibility of our approach. In conclusion, the technique presented here with triple-labelings forms an excellent basis for standardized flow cytometric MRD studies in multicenter international treatment protocols for precursor-B-ALL patients. [ABSTRACT FROM AUTHOR]

Administration of stem cell factor (SCF) has been proven to enhance cytokine-induced mobilization of CD34+ hematopoietic progenitor cells (HPC) into the peripheral blood (PB). The aim of the present study was to explore in a homogeneous group of 22 uniformly treated breast cancer patients: (1) the kinetics of mobilization into PB of both CD34+ and CD34- cell subsets, including dendritic cells, in sequential samples obtained from day +7 up to day +12 after mobilization; and (2) the composition of the CD34+ and CD34- cell subsets present in the two leukapheresis products obtained for each patient. The following CD34+ and CD34- subsets were analyzed: early CD34+ HPC, erythroid-, myeloid- and B-lymphoid-committed CD34+ precursor cells, mature T, B and NK cells, monocytes, neutrophils, eosinophils, basophils, and dendritic cells (DC) including three subsets of lin-/HLADR+DC (CD16+, CD33high and CD123high). Our results show that the absolute number of PB CD34+ HPC progressively increases from day +7 onwards. As far as the CD34- PB leukocyte subsets are concerned, monocytes (CD14+) displayed the earliest recovery after mobilization predicting neutrophil recovery 1 day in advance. The number of CD34+ HPC collected in a single leukapheresis product was always > or = 1.4 x 10(6) cells/kg body weight. No significant changes were observed between the two leukapheresis sessions either as regards their composition in CD34+ HPC subsets or their CD34- leukocyte populations except for a higher ratio of both CD34+ erythroid/CD34+ myeloid HPC (0.35 +/- 0.13 vs 0.30 +/- 0.13; P = 0.04) and neutrophils/monocytes (1.58 +/- 2.1 vs 0.69 +/- 0.27; P = 0.009) found for the first leukapheresis. Interestingly, the overall number of dendritic cells (DC) was higher in the second leukapheresis (1.06 +/- 0.56 vs 1.9 +/- 0.46; P = 0.02) due to a selective increase of the CD16+ antigen-presenting cells. In summary, our results show that the combination of cyclophosphamide, G-CSF and SCF is highly effective for stem cell mobilization, with differences observed in the mobilization kinetics of the different hematopoietic cell subsets analyzed. [ABSTRACT FROM AUTHOR]

In the present paper, we report on the use of the heteroduplex PCR technique to detect the presence of clonally rearranged VDJ segments of the heavy chain immunoglobulin gene (VDJH) in the apheresis products of patients with multiple myeloma (MM) undergoing autologous peripheral blood stem cell (APBSC) transplantation. Twenty-three out of 31 MM patients undergoing APBSC transplantation with VDJH segments clonally rearranged detected at diagnosis were included in the study. Samples of the apheresis products were PCR amplified using JH and VH (FRIII and FRII) consensus primers and subsequently analyzed with the heteroduplex technique, and compared with those obtained at diagnosis. 52% of cases yielded positive results (presence of clonally rearranged VDJH segments in at least one apheresis). The presence of positive results in the apheresis products was not related to any pretransplant characteristics with the exception of response status at transplant. Thus, while no one patient with positive apheresis products was in complete remission (CR), negative immunofixation, before the transplant, five cases (46%) with negative apheresis were already in CR at transplant (P = 0.01). The remaining six cases with heteroduplex PCR negative apheresis were in partial remission before transplant. Patients with clonally free products were more likely to obtain CR following transplant (64% vs 17%, P= 0.02) and a longer progression-free survival, (40 months in patients transplanted with polyclonal products vs 20 with monoclonal ones, P = 0.03). These results were consistent when the overall survival was considered, since it was better in those patients with negative apheresis than it was in those with positive (83% vs 36% at 5 years from diagnosis, P= 0.01). These findings indicate that the presence of clonality rearranged VDJH segments is related to the response and outcome in MM transplanted patients. [ABSTRACT FROM AUTHOR]

The objectives of the present study were to investigate whether interferon alpha (IFN) maintenance could prolong response duration and survival in patients with multiple myeloma (MM) in objective response and to analyze the characteristics of relapse and subsequent survival. From January 1991 to November 1994, 92 patients from the Spanish Cooperative Group PETHEMA with MM in objective response after 12 courses of VCMP/VBAP chemotherapy were randomized to receive IFN maintenance vs no treatment until relapse. Prognostic factors at diagnosis were similar in both groups. IFN was administered at a starting dose of 3 mU/m2 three times per week. The IFN toxicity was moderate with granulocytopenia and fatigue being the most common adverse effects. Median duration of response from randomization until relapse was 13 months in the IFN group vs 7.7 months in the no treatment arm (P = 0.042). Median survival from randomization was 38.8 months for patients given IFN vs 32.7 months for those allocated to the no treatment arm (P = 0.12). Features at relapse were similar in patients who received IFN maintenance and in those assigned to no treatment. Finally, survival from relapse was identical in both groups. In summary, our results show a significant prolongation of response in patients maintained with IFN with no significant influence on survival. In addition, in our series features at relapse and subsequent outcome were similar in both groups. [ABSTRACT FROM AUTHOR]

In the present study we examined by Southern blot analysis the presence of deletions and rearrangements of the p16 tumor-suppressor gene in B cell non-Hodgkin's lymphomas (NHLs) in order to determine whether or not these changes can be related to a particular histological subtype and the different clinico-biological and prognostic characteristics of the disease. 103 untreated patients were enrolled in the study. Seven cases displayed alterations in the p16 gene: four cases with homozygous deletions and three with gene rearrangement. The presence of these abnormalities did not correlate with any specific histological subtype: three cases were small lymphocytic lymphomas (two of them reclassified as mantle cell lymphoma on the basis of the REAL classification), two diffuse large cell lymphomas and two small non-cleaved cell lymphomas (one of them considered to be a Burkitt-like lymphoma according to the REAL). These seven cases showed a trend towards worse prognostic indicators than the remaining patients, and this was confirmed in the survival analysis, since the presence of p16 gene abnormalities was associated with a shorter survival (10 vs 81 months, P = 0.0006). In the multivariate analysis, p16 abnormalities were selected as an independent prognostic factor together with the LDH and beta2-microglobulin. These findings support a role for the p16 gene in the pathogenesis of B cell NHLs and suggest an association of p16 abnormalities with aggressive forms of the disease that could be useful to predict the prognosis of patients. [ABSTRACT FROM AUTHOR]

Cites a study which illustrates a case displaying morphological and immunological criteria of acute nonlymphoblastic leukemia (ANLL) that showed a rearrangement of the immunoglobulin lambda locus. Details of patients analyzed in the study; Southern blot analysis of the genes of the patient; Issues related to rearrangement of the genes.