Marie Therese Daniel

Fine Structure and Peroxidase Activity of Circulating Micromegakaryoblasts and Platelets in a Case of Acute Myelofibrosis

Summary. In a case of acute myelofibrosis with thrombocytosis, electron microscopical examination of the buffy coat revealed the existence of numerous mononuclear cells with a blastic appearance. They were considered blasts because nucleoli were prominent, and ribosomes, free or linked to short saccules of rough endoplasmic reticulum (RER), were numerous. The presence of peroxidase activity in the perinuclear space and RER of these cells was identical with the occurrence and location of this enzyme reaction product in normal bone marrow megakaryocytes. The results indicated that the atypical cells were circulating micromegakaryoblasts. Highly abnormal platelets were also present in the patients peripheral blood. The peroxidase test provides a useful adjunct for distinguishing cells of the megakaryocyte line which in the past may have been mistaken for atypical lymphocytes or myeloblasts by light or electron microscopy.

Promyelocytic blast crisis of chronic myelocytic leukemia with both t(9;22) and t(15;17) in M3 cells.

A blast crisis with the features of promyelocytic leukemia (M3) occurred during the evolution of chronic myelocytic leukemia (CML) with the t(9;22) translocation. This rare form of transformation was confirmed by means of cytologic and electron microscopic examination. Cytogenetic studies showed two simultaneous translocations t(15;17) and t(9;22) in the promyelocytes. After intensive chemotherapy, a complete remission was obtained and only karyotypes with t(9;22) translocation were present. These data confirm the specificity of the t(15;17) translocation in malignant promyelocytic proliferation and provide evidence for a second genetic event in the genesis of blast crisis occurring in a committed cell belonging to the abnormal population defined by the Ph1 chromosome.

Immunological typing of acute lymphoblastic leukemia: concurrent analysis by flow cytofluorometry and immunocytology

For 60 cases of acute lymphoblastic leukemia (ALL) immunological typing was done concurrently by the avidin-biotin-peroxidase method using cytocentrifuged smears and by flow cytofluorometry for the study of surface antigens. The use of a large panel of antibodies detecting differentiation antigens allowed us to sub-classify 57/60 cases as 43 B-lineage ALLs and 14 T-lineage ALLs. The two types of ALL can be accurately distinguished by the expression of the antigens recognized by the antibodies of the clusters of differentiation CD19 (B4) and CD7 (Leu 9). Almost perfect agreement was obtained between the results of the two methods for antigens DR, CD10 (cALLA;J5) and CD7. A number of discordances were observed with other antigens [CD19 (B4), CD20 (B1), CD22 (To15), CD1 (T6), CD2 (T11), CD4 (T4), CD8 (T8), CD3 (T3), T9, T10]. In spite of these discordances, the avidin-biotin-peroxidase method can predict the lineage involved in most ALLs with a high degree of reliability. Nevertheless, for weakly expressed surface antigens (such as B4 and B1) the immunocytological method is less sensitive than flow cytofluorometry and can only approximately determine the stage of differentiation of neoplastic cells. Furthermore, the existence of cases which are at the same time negative with flow cytofluorometry and positive with immunocytology is consistent with the intracytoplasmic expression of certain differentiation antigens. Thus in the course of lymphoid differentiation, intra-cytoplasmic expression of T3, To15 and possibly J5 precedes their expression at the cell surface.

Management and treatment results in patients with acute promyelocytic leukaemia (APL) not enrolled in clinical trials

PURPOSE Acute promyelocytic leukaemia (APL) therapy with all-trans retinoic acid and chemotherapy is associated with a high cure rate in clinical trials. As some patients are not enrolled in these trials due to early severe events, these results might be overestimated. To address this issue, we reviewed all APL patients referred to the Hospital Saint-Louis within the 2000-2010 period, with a special focus on inclusion in recruiting trials. PATIENTS AND METHODS One hundred patients (including eight children) with newly diagnosed APL were admitted during this period, which covered two consecutive APL trials conducted by the French-Belgian-Swiss APL group. RESULTS The rate of patients not enrolled within recruiting trials was 29%. The main reason for non-inclusion was protocol ineligibility related to disease severity at diagnosis. Non-enrolled patients more frequently had white blood cell count (WBC) . or =50×10(9)/L (31% versus 8%; p=.01), platelet count<40×10(9)/L (97% versus 65%; p=.001) and microgranular variant APL (38% versus 11%; p=.004) and were more frequently admitted in intensive care unit during induction (41% versus 24%; p=.094). Early mortality rate was higher in non-enrolled patients (21% versus 3%; p=.007), translating into a lower complete remission rate (79% versus 96%; p=.007) and lower event-free survival (65% versus 84% at 5 years; p=.05), while disease-free survival was similar in both non-enrolled and enrolled patient groups (81% versus 88% at 5 years; p=.68). CONCLUSION Initial APL severity leads to a significant proportion of patients non-registered within clinical trials, which may underestimate the real early mortality, which remained nonetheless less than 10% in this study.

Rare diseases and disabilities: improving the information available with three Orphanet projects

There is currently very little information available about the disabilities encountered by rare disease (RD) patients. Orphanet [http://www.orpha.net], the international database and portal on RDs and orphan drugs, has developed various projects to improve the knowledge and visibility of disabilities associated with RDs, and to provide tools to help the stakeholders. First, we have added content to the texts of the Orphanet Encyclopaedia for the General Public (133 texts) about the daily difficulties associated with the disease and its management. This information is provided through three questions: “What disabilities result from the disease?”, “What resources are available to limit and prevent the disability?” and “Living with: the disability on a daily basis”. These texts are validated by medical experts, disability specialists and patient support groups. Secondly, we have created a specialised collection of texts dedicated to professionals and social service providers, the Orphanet Disability Encyclopaedia. It focuses on the disabilities associated with a specific RD. These disability factsheets provide a brief overview of the medical aspects of the disease, validated by medical experts, and include a description of the disabilities experienced by patients and their management. Fifteen texts are currently available in French. Finally, with the Orphanet Disability Project, we index the functional consequences of each RD with the Orphanet Functioning Thesaurus, adapted from the “Activities and participation” and “Environmental factors” domains of the International Classification of Functioning, Disability and Health-Children & Youth version (ICF-CY [1]), as well as additional terms to describe cognitive abilities, sleep, temperament and behaviour. Through a questionnaire sent to medical experts, disability specialists and patient organisations, we collect data for each RD: the activity limitations and participation restrictions, their temporality during the course of the disease (permanent or transient difficulty, delay, loss of abilities), their severity and respective frequency in the patient population with current standard management, and important environmental factors. The collected data is analysed and standardised to constitute the Orphanet Functioning Database. 857 RDs are already indexed and 540 more are in progress, thanks to the contribution of hundreds of people and organisations from 43 countries. These RD disability core sets, which can be integrated into information systems, will be freely available in 7 languages. In addition, we will map the “Body structures” and the “Body functions” domains of the ICF-CY to the Human Phenotype Ontology [2], enabling us to list the anatomical structures and physiological functions impaired for each RD. This information will increase knowledge and aid in better evaluating and managing the daily difficulties and needs experienced by RD patients. It can also help social agencies in distributing appropriate disability compensation measures with equity and equality. Finally, it will enable decision makers to assess the social burden of RDs and can be utilised in the set-up of measures that will allow for the better social integration of disabled people with RDs.