Flow cytometry to detect bone marrow involvement by follicular lymphoma.

BACKGROUND: High-quality data on bone marrow involvement (BMI) assessed by flow cytometry (FC) in follicular lymphoma (FL) is lacking. AIMS: We set up a prospective protocol with a 10-color tube and acquisition of 500.000 leukocytes on a Nav flow cytometer for evaluation of BMI in FL by FC. MATERIALS AND METHODS: FC was compared with a combination of histopathology and IGH gene rearrangement, which were considered the gold standard. We also compared BMI by FC with PET. RESULTS: Fifty-two patients were included (median 67 years, 54% female). BMI by FC was seen in 35 (67%), with a median involvement of 1.2% (interquartile range: 0.3%-7%) of leukocytes. Comparison with the gold standard revealed two false negatives and two false positives (potentially true involvement undetected by the gold standard). BMI by PET was seen in 14/46 (30%). Immunophenotype of FL in the bone marrow was highly heterogeneous. The most common phenotypic abnormality was dim expression of CD19 (>0.5 log loss in 30% of patients). CD10 was negative in 13 (37%) and incompletely positive (overlap with the negative population) in a further 8 (28%) while entirely positive only in 14 (48%). Other abnormalities (loss of CD20, gain or loss of CD79b, expression of CD43, and substantial loss of CD45) were rare. Computational analysis by means of FlowSOM confirmed the heterogeneous phenotype, with FL from different patients clustering in unrelated metaclusters. CONCLUSION: BMI by FL was frequent and immunophenotype was heterogeneous. However, this protocol enabled detection of FL in bone marrow in the vast majority of patients with bone marrow involvement by the gold standard.

Impact of induction treatment before autologous stem cell transplantation on long-term outcome in patients with newly diagnosed multiple myeloma.

OBJECTIVE: Clinical trials for patients with multiple myeloma (MM) using novel agent (NA)-based regimens before autologous stem cell transplantation (SCT) have shown improvement in response rates and progression-free survival (PFS); however they have failed to identify a significant overall survival (OS) benefit. The aim of this study was to analyze the potential impact of initial induction on the feasibility and outcome of subsequent treatment lines in a real clinical practice setting. METHODS: Patients with consecutive MM <70 years of age diagnosed between 1999 and 2009 were prospectively registered and classified as having received conventional chemotherapy induction regimens with new agents available at relapse (CC cohort, 89 patients) or as treated with NAs upfront (NA cohort, 65 patients). RESULTS: Patients in the NA cohort demonstrated a superior median PFS (2.8 years vs 1.6 years, P=.03) and also a median PFS from diagnosis to second progression (5.2 years vs 2.7 years, P=.003). After a median follow-up of 7 years, clear differences in OS were observed (7.97 years in NA cohort compared to 3.35 years in CC cohort, P<.001). CONCLUSIONS: New agent-based first-line induction treatments provide benefits in both PFS and beyond that point, contributing to a significant improvement in OS.

CD34 expression and the outcome of nucleophosmin 1-mutated acute myeloid leukemia.

CD34 positivity has been considered as an adverse prognostic factor in acute myeloid leukemia (AML). Although nucleophosmin 1-mutated (NPM1m) AML is usually CD34 negative, this marker may be expressed at diagnosis or acquired at relapse in a variable number of cases. Our objective was to ascertain if CD34 expression has any influence on the general outcome of this form of acute leukemia. Analysis of clinical outcome (complete remissions, relapses, disease-free survival, and overall survival) was performed depending on the degree of expression of CD34 determined by flow cytometry, in 67 adult patients with NPM1m AML. CD34 expression did not have any influence on the variables analyzed whatever the percentage of blasts expressing this marker. In contrast to other forms of AML, CD34 expression is not an unfavorable prognostic factor in NPM1m AML, neither at diagnosis nor at relapse.

Correlation of CD11b and CD56 expression in adult acute myeloid leukemia with cytogenetic risk groups and prognosis.

Among other phenotypic markers, CD11b expression has been considered as an unfavorable prognostic factor, both in terms of overall survival (OS), disease-free survival (DFS), and attainment and duration of complete remissions (CRs) in adult patients with acute myeloid leukemia (AML). Recently, some groups have restricted its prognostic impact to poor prognostic karyotypic risk groups. The aim of this study was to retrospectively analyze the prevalence of CD11b and of CD56 expression in blast cells of 158 AML patients [excluding those with t(15;17)] stratified according to their cytogenetic risk and to correlate these phenotypic characteristics with OS, DFS, and CR. CD11b was more frequently expressed in intermediate and unfavorable cytogenetic prognostic groups (38.9 and 35.5 %, respectively) than in the favorable group (9.5 %). No differences were observed in CD56 expression according to the cytogenetic risk groups. When OS, DFS, and CR were analyzed according to these two markers, no statistical differences were recorded in any cytogenetic risk group. In conclusion, although CD11b was more frequently expressed in blast cells of patients with intermediate and unfavorable cytogenetic risk groups, this feature did not translate into different clinical outcome. Similarly, CD56 positivity did not have any influence on the prognosis of these patients.