Anna Porwit

The 2008 revision of the World Health Organization (WHO) classification of myeloid neoplasms and acute leukemia: rationale and important changes

Recently the World Health Organization (WHO), in collaboration with the European Association for Haematopathology and the Society for Hematopathology, published a revised and updated edition of the WHO Classification of Tumors of the Hematopoietic and Lymphoid Tissues. The 4th edition of the WHO classification incorporates new information that has emerged from scientific and clinical studies in the interval since the publication of the 3rd edition in 2001, and includes new criteria for the recognition of some previously described neoplasms as well as clarification and refinement of the defining criteria for others. It also adds entities-some defined principally by genetic features-that have only recently been characterized. In this paper, the classification of myeloid neoplasms and acute leukemia is highlighted with the aim of familiarizing hematologists, clinical scientists, and hematopathologists not only with the major changes in the classification but also with the rationale for those changes.

Standardization of flow cytometry in myelodysplastic syndromes: a report from an international consortium and the European LeukemiaNet Working Group

Flow cytometry (FC) is increasingly recognized as an important tool in the diagnosis and prognosis of myelodysplastic syndromes (MDS). However, validation of current assays and agreement upon the techniques are prerequisites for its widespread acceptance and application in clinical practice. Therefore, a working group was initiated (Amsterdam, 2008) to discuss and propose standards for FC in MDS. In 2009 and 2010, representatives from 23, mainly European, institutes participated in the second and third European LeukemiaNet (ELN) MDS workshops. In the present report, minimal requirements to analyze dysplasia are refined. The proposed core markers should enable a categorization of FC results in cytopenic patients as ‘normal’, ‘suggestive of’, or ‘diagnostic of’ MDS. An FC report should include a description of validated FC abnormalities such as aberrant marker expression on myeloid progenitors and, furthermore, dysgranulopoiesis and/or dysmonocytopoiesis, if at least two abnormalities are evidenced. The working group is dedicated to initiate further studies to establish robust diagnostic and prognostic FC panels in MDS. An ultimate goal is to refine and improve diagnosis and prognostic scoring systems. Finally, the working group stresses that FC should be part of an integrated diagnosis rather than a separate technique.

Multicenter validation of a reproducible flow cytometric score for the diagnosis of low-grade myelodysplastic syndromes: results of a European LeukemiaNET study

Background The current World Health Organization classification of myelodysplastic syndromes is based morphological evaluation of bone marrow dysplasia. In clinical practice, the reproducibility of the recognition of dysplasia is usually poor especially in cases that lack specific markers such as ring sideroblasts and clonal cytogenetic abnormalities. Design and Methods We aimed to develop and validate a flow cytometric score for the diagnosis of myelodysplastic syndrome. Four reproducible parameters were analyzed: CD34+ myeloblast-related and B-progenitor-related cluster size (defined by CD45 expression and side scatter characteristics CD34+ marrow cells), myeloblast CD45 expression and granulocyte side scatter value. The study comprised a “learning cohort” (n=538) to define the score and a “validation cohort” (n=259) to confirm its diagnostic value. Results With respect to non-clonal cytopenias, patients with myelodysplastic syndrome had increased myeloblast-related cluster size, decreased B-progenitor-related cluster size, aberrant CD45 expression and reduced granulocyte side scatter (P<0.001). To define the flow cytometric score, these four parameters were combined in a regression model and the weight for each variable was estimated based on coefficients from that model. In the learning cohort a correct diagnosis of myelodysplastic syndrome was formulated in 198/281 cases (sensitivity 70%), while 18 false-positive results were noted among 257 controls (specificity 93%). Sixty-five percent of patients without specific markers of dysplasia (ring sideroblasts and clonal cytogenetic abnormalities) were correctly classified. A high value of the flow cytometric score was associated with multilineage dysplasia (P=0.001), transfusion dependency (P=0.02), and poor-risk cytogenetics (P=0.04). The sensitivity and specificity in the validation cohort (69% and 92%, respectively) were comparable to those in the learning cohort. The likelihood ratio of the flow cytometric score was 10. Conclusions A flow cytometric score may help to establish the diagnosis of myelodysplastic syndrome, especially when morphology and cytogenetics are indeterminate.

Hepatitis C infection and risk of malignant lymphoma

The association between hepatitis C virus (HCV) infection and risk of malignant lymphoma remains controversial, perhaps due to small‐sized studies and low prevalence of HCV in the general population. On the basis of a large Danish‐Swedish population‐based case‐control study, 2,819 lymphoma patients and 1,856 controls of second‐generation Danish‐Swedish origin were screened for HCV infection using an enzyme‐linked immunosorbent assay and a confirming recombinant immunoblot assay (RIBA) test. Positive samples were tested with real‐time PCR for the presence of HCV RNA. The association between HCV infection and risk of malignant lymphoma was assessed by logistic regression. When intermediate RIBA test results were interpreted as positive, anti‐HCV antibody positivity was associated with a nonsignificant increased risk of non‐Hodgkin lymphoma (NHL) overall (odds ratio (OR) = 2.2; 95% confidence interval (CI) 0.9–5.3; n = 20 cases), of B‐cell lymphomas combined (OR = 2.4 [1.0–5.8]; n = 20) and of lymphoplasmacytic lymphoma (OR = 5.2 [1.0–26.4]; n = 2). No patients with T‐cell or Hodgkin lymphoma were HCV‐positive. A more conservative definition of HCV positivity (disregarding intermediate RIBA results) resulted in an OR = 1.6 (0.3–8.5; n = 5) for NHL overall. When the definition was further restricted to require HCV RNA positivity, OR was 1.7 (0.2–16.2; n = 3) for NHL overall. Our findings from a population with a low prevalence of HCV suggest a positive association between HCV and risk of NHL, in particular of B‐cell origin.

Genetic variation in chromosomal translocation breakpoint and immune function genes and risk of non-Hodgkin lymphoma

BackgroundTumor necrosis factor (TNF) and interleukin 10 (IL10) are promising candidate susceptibility genes for non-Hodgkin lymphoma (NHL). Chromosomal translocation breakpoint genes are of interest, given their documented involvement in lymphoma progression.MethodsWe analyzed 11 polymorphisms in BCL2, CCND1, MYC, TNF, and IL10 in a large, population-based, Danish-Swedish case–control study including 2,449 NHL cases and 1,980 controls. Relative risk of NHL was computed as odds ratios (OR).ResultsThere was no clear evidence of associations between variants in BCL2, CCND1, and MYC and risk of NHL overall or subtypes. TNF rs1800629 was associated with risk of NHL (OR 1.53, 95% confidence interval, CI, 1.06–2.19 for minor allele homozygosity), T-cell lymphoma (OR 2.54, CI 1.27–5.09) and mantle cell lymphoma (OR 2.84, CI 1.38–5.87). IL10 rs1800890 was associated with risk of diffuse large B-cell lymphoma (OR 1.41, CI 1.08–1.85 for minor allele homozygosity) and mantle cell lymphoma (OR 1.77, CI 1.04–3.00). We did not replicate a previously reported interaction with autoimmunity.ConclusionsWe found no support for a role of the studied variants in BCL2, CCND1, or MYC in risk of NHL or subtypes, but we provide further evidence of putative susceptibility loci in TNF and IL10 for specific NHL subtypes.

Limited clinical efficacy of azacitidine in transfusion-dependent, growth factor-resistant, low- and Int-1-risk MDS: Results from the nordic NMDSG08A phase II trial

This prospective phase II study evaluated the efficacy of azacitidine (Aza)+erythropoietin (Epo) in transfusion-dependent patients with lower-risk myelodysplastic syndrome (MDS). Patients ineligible for or refractory to full-dose Epo+granulocyte colony stimulation factors for >8 weeks and a transfusion need of ⩾4 units over 8 weeks were included. Aza 75 mg m−2 d−1, 5/28 days, was given for six cycles; non-responding patients received another three cycles combined with Epo 60 000 units per week. Primary end point was transfusion independence (TI). All patients underwent targeted mutational screen for 42 candidate genes. Thirty enrolled patients received ⩾one cycle of Aza. Ten patients discontinued the study early, 7 due to adverse events including 2 deaths. Thirty-eight serious adverse events were reported, the most common being infection. Five patients achieved TI after six cycles and one after Aza+Epo, giving a total response rate of 20%. Mutational screening revealed a high frequency of recurrent mutations. Although no single mutation predicted for response, SF3A1 (n=3) and DNMT3A (n=4) were only observed in non-responders. We conclude that Aza can induce TI in severely anemic MDS patients, but efficacy is limited, toxicity substantial and most responses of short duration. This treatment cannot be generally recommended in lower-risk MDS. Mutational screening revealed a high frequency of mutations.

B‐cell lymphoma in transplanted liver: Clinical, histological and radiological manifestations

Abstract. An isolated, centroblastic lymphoma developed in a 25‐year‐old female liver transplant recipient in her liver graft a few months after transplantation. Her immunosuppressive therapy consisted of antithymocyte globulin, cyclosporin, corticosteroids and, periodically, azathioprine. Chromosome analysis showed the tumor to be of female origin, thus excluding the possibility of transfer from the male donor. The tumor cells expressed EBV nuclear antigen (EBNA). The tumor was located in the left lobe of the liver. It was successfully removed 11 months after transplantation by a hemihepatectomy following a very brief combined chemotherapy course, and was then found to be replaced by necrotic tissue. No further treatment for lymphoma was given, and the patient is now free from lymphoma 3 years after transplantation.

B-cell lymphoma in transplanted liver

An isolated, centroblastic lymphoma developed in a 25-year-old female liver transplant recipient in her liver graft a few months after transplantation. Her immunosuppressive therapy consisted of antithymocyte globulin, cyclosporin, corticosteroids and, periodically, azathioprine. Chromosome analysis showed the tumor to be of female origin, thus excluding the possibility of transfer from the male donor. The tumor cells expressed EBV nuclear antigen (EBNA). The tumor was located in the left lobe of the liver. It was successfully removed 11 months after transplantation by a hemihepatectomy following a very brief combined chemotherapy course, and was then found to be replaced by necrotic tissue. No further treatment for lymphoma was given, and the patient is now free from lymphoma 3 years after transplantation.

Dendritic Cell Regeneration in the Bone Marrow of Children Treated for Acute Lymphoblastic Leukaemia

Dendritic cells (DC) play a pivotal role in coordinating functions of the immune system. Little is known about DC levels in the bone marrow (BM) of patients receiving cytostatic treatment. We investigated DC levels by flow cytometry in BM at diagnosis, during and post‐treatment in 76 children with acute lymphoblastic leukaemia (ALL). The levels of both plasmacytoid DC (pDC) and myeloid DC (mDC) were profoundly reduced at diagnosis. However, the levels of pDC and mDC were significantly higher in T‐precursor ALL patients when compared with B‐precursor ALL patient group (P = 0.044 and 0.041 respectively). Both subsets normalized in both standard‐risk (SR) and high‐risk patients after the end of induction at day 50. Patients with minimal residual disease (MRD) at day 50 had significantly higher pDC levels than MRD‐negative patients (P = 0.021). In B‐precursor SR ALL patients, mDC levels but not pDC levels decreased during prolonged maintenance treatment, remaining reduced at the end of treatment (P = 0.032) and at 6 months post‐treatment (P = 0.028). In conclusion, levels of DC in BM normalize quickly in children treated for ALL. Long‐term treatment may more profoundly affect mDC subset, which shows reduced levels several months after treatment.

Phase I study of lenalidomide and alemtuzumab in refractory chronic lymphocytic leukaemia: maintaining immune functions during therapy-induced immunosuppression

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