A case of therapy-related myeloid neoplasm in a patient with Crohn's disease treated with azathioprine.

Acute leukaemia (AL) has been observed in association with Crohn's disease (CD) notably in patients treated with azathioprine (AZA), which is an immunosuppressant known for its carcinogenicity and in particular known to induce therapy-related acute myeloid leukaemia according to the 2008 WHO classification. Whereas the link between inflammatory bowel disease and AL has been well established, the exact role of AZA remains controversial. In this paper, we report the case of a 71-year-old white Caucasian male with CD treated for 7 years with AZA who developed an acute leukaemia. Chemotherapy was administered unsuccessfully and the patient died from this haematological disorder 9 months after diagnosis. We reviewed the current evidence on the interactions between CD, AL and AZA as well as the potential underlying mechanisms of leukaemia in AZA-treated patients. From this review, we concluded that AL should be questioned when facing cytopenia in a patient with CD. The nature of the association between AZA and AL in CD patients warrants further investigation.

Morphology, cytogenetics, and survival in myelodysplasia with del(20q) or ider(20q): a multicenter study.

Isochromosome of the long arm of chromosome 20 with interstitial loss of material [ider(20q)] is a rare cytogenetic abnormality reported in myelodysplastic syndrome (MDS), with neither specific morphological pattern nor clear prognostic significance. The aim of this retrospective multicentric study is to compare the peripheral blood and bone marrow morphology of MDS patients with ider(20q) (n = 13) and del(20q) (n = 21) and controls (n = 47) in order to investigate whether the ider(20q) harbors specific morphological features. The secondary objective is to compare the outcome of patients from both groups. This study performed on the largest cohort of MDS patients with ider(20q) is the first that identifies specific morphological features (hypogranulated and vacuolized neutrophils and neutrophil erythrophagocytosis) allowing the identification of this cytogenetic abnormality with high sensitivity (70%) and specificity (85.7%). Suspected ider(20q) by morphology should therefore support targeted FISH tests in case of non informative karyotype. This combined approach will allow a better estimation of the prevalence of this underdiagnozed entity. The overall survival and progression-free survival did not statistically differ in both groups. However, hypogranulated and vacuolized neutrophils were significantly associated with survival.

No effect of lysis solutions on absolute CD19+ lymphocytes count and CD45 index in chronic lymphocytic leukemia.

The absolute CD19+ lymphocytes count is essential for chronic lymphocytic leukemia (CLL) management. At the present time, no standardized flow cytometry (FCM) protocol to measure B-lymphocytes counts is established. The aims of the present study were first to evaluate the effect of different lysis solutions and of red blood cell lysis per se on CLL lymphocytes count and B-lymphocytes CD45 expression and second to compare absolute B-lymphocytes counts obtained by single (SP) and dual platforms (DP). Absolute CD19+ B-lymphocytes counts and CD45 expression in 35 whole-blood CLL samples were determined by FCM using either different lysis solutions or using a no wash no lyse (NWNL) protocol. Single platform using microbeads was also evaluated for absolute quantification. The absolute CD19+ B-lymphocytes counts using different red blood cell lysis solutions correlated with NWNL method without any effect on CD45 expression. Bland and Altman plot showed homogenous distribution of bias; mean bias was less than 1% for all lysing solutions. Moreover, no statistically significant difference between SP and DP was observed. The type of lysis solution influences neither the CD19+ B-lymphocytes count nor the CD45 expression. The two systems, SP and DP, yield comparable values with excellent agreement. However, the tendency of slightly lower results with SP showed the requirement of larger studies before standardization of B-lymphocytes count in CLL patients.

Additional erythrocytic and reticulocytic parameters helpful for diagnosis of hereditary spherocytosis: results of a multicentre study.

Hereditary spherocytosis (HS) is characterised by weakened vertical linkages between the membrane skeleton and the red blood cell's lipid bilayer, leading to the release of microparticles. All the reference tests suffer from specific limitations. The aim of this study was to develop easy to use diagnostic tool for screening of hereditary spherocytosis based on routinely acquired haematological parameters like percentage of microcytes, percentage of hypochromic cells, reticulocyte counts, and percentage of immature reticulocytes. The levels of haemoglobin, mean cell volume, mean corpuscular haemoglobin concentration, reticulocytes (Ret), immature reticulocytes fraction (IRF), hypochromic erythrocytes (Hypo-He) and microcytic erythrocytes (MicroR) were determined on EDTA samples on Sysmex instruments from a cohort of 45 confirmed SH. The HS group was then compared with haemolytical disorders, microcytic anaemia, healthy individuals and routine samples (n = 1,488). HS is characterised by a high Ret count without an equally elevated IRF. All 45 HS have Ret >80,000/µl and Ret(10(9)/L)/IRF (%) greater than 7.7 (rule 1). Trait and mild HS had a Ret/IRF ratio greater than 19. Moderate and severe HS had increased MicroR and MicroR/Hypo-He (rule 2). Combination of both rules gave predictive positive value and negative predictive value of respectively 75% and 100% (n=1,488), which is much greater than single parameters or existing rules. This simple and fast diagnostic method could be used as an excellent screening tool for HS. It is also valid for mild HS, neonates and ABO incompatibilities and overcomes the lack of sensitivity of electrophoresis in ankyrin deficiencies.

Immunophenotypic clustering of myelodysplastic syndromes.

Myelodysplastic syndromes (MDSs) are heterogeneous diseases of bone marrow (BM) cell precursors for which immunophenotypic characterization is still considered irrelevant despite the accuracy and sensitivity of flow cytometry techniques. The aim of this study was to determine whether immunophenotypic abnormalities could be defined in MDSs and could correlate with the French-American-British classification and cytogenetics. Analysis was performed on 275 BM samples (207 MDS patients, 68 controls) and 25 control blood samples. Immunophenotyping was based on a primary gating of blast cells, monocytes, and granulocytes according to CD45 antigen expression and side scatter light diffraction. Immunophenotypic hierarchical clustering was performed to analyze the results. The data obtained show that (1) immunophenotypic clustering partly discriminates patients with refractory anemia with excess blasts/refractory anemia with excess blasts in transformation (RAEB/RAEB-T), chronic myelomonocytic leukemia (CMML), and refractory anemia/refractory anemia with ring sideroblasts (RA/RARS) for CD45(lo) blast cells and patients with RA/CMML, RARS, and RAEB/RAEB-T for CD45(hi)/side scatter(hi) (SS(hi)) granulocytes; (2) the most discriminating markers were CD16, CD34, CD36, CD38, CD71, and HLA-DR for blast cells and CD11b, CD13, CD33, CD36, CD38, CD71, and HLA-DR for CD45(hi)/SS(hi) granulocytes; (3) clusters related to CD34 expression were associated with high levels of blast cells on BM smear; (4) clusters related to high levels of CD36 expression on CD45(lo) blast cells and CD45(hi)/SS(hi) granulocytes were associated with a poor International Prognosis Scoring System score; and (5) high levels of CD71 expression on CD45(hi)/SS(hi) granulocytes were associated with the RARS category. These results show a close relationship between immunophenotypic abnormalities and BM dysplasia and suggest that flow cytometry could be a future tool for the characterization of MDSs.