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Biomedical subjects

G Flandrin

Publications and source records attributed to G Flandrin.

At least 271 records · Page 15Linked to original sources
PubMedDate not supplied

The value of the monoclonal antibody, DBA44, in the diagnosis of B-lymphoid disorders.

The DBA44 monoclonal antibody described by Al Saati recognizes a membrane antigen expressed by a sub-population of B-lymphocytes. It was tested on paraffin-embedded tissues, and it distinguishes Hairy Cell Leukemia (HCL) from the more common B-cell Chronic Lymphocytic Leukemia (CLL). Neither Splenic Lymphoma with Villous Lymphocytes (SLVL) cases nor Prolymphocytic Leukemia (PLL) cases were tested. We have tested 87 B-lymphoproliferative disorders with DBA44 on cytocentrifuge preparations. All five HCL cases were positive (100%). Of 24 cases of SLVL, 19 were positive (79%); of 58 other B-cell malignancies, five cases were positive (8.5%), including 1/8 CD5- CLLs, 1/5 PLLs and 3/24 lymphomas. All CD5+ CLL were negative. DBA44 positivity cannot distinguish HCL from SLVL, which is the disease that may create major diagnostic problems. In contrast, when we compare SLVL to CLL (which is another diagnostic problem), significant differences were found between the incidence of DBA44 positivity in SLVL and both CD5+ B-CLL (p< 10(-5)), and CD5- B-CLL (p< 0.01). The monoclonal antibody DBA44 is positive in HCL and SLVL. It is not helpful in the differential diagnosis of HCL and SLVL. In contrast, when a diagnostic problem arises between SLVL and CLL, the reactivity of DBA44 is of great value.

Antibodies, Monoclonal↗
PubMedDate not supplied

A multicentric study of 41 cases of B-prolymphocytic leukemia: two evolutive forms.

B-prolymphocytic leukemia (B-PLL) is an infrequent disease with a poor prognosis. We present the clinical and biological features of 41 patients. Median age was 67 years [42-89] and male-female sex ratio was 2.4. The immunophenotyping revealed B-cell phenotype, with a high level expression of surface IgM and/or IgD in all cases, FMC7+ in 76 % of cases and CD5+ in 67%. Marked spontaneous in-vitro apoptosis was observed in most cases tested (n = 12). The median overall survival time was 5 years and the event-free survival time was 37 months. As detected by univariate and multivariate analysis, the only variables associated with a poor prognosis were advanced age and anemia. No significant difference was observed between de novo PLL (n = 27) and prolymphocytoid transformation of chronic lymphocytic leukemia (n = 14). Two groups of patients were individualized according to their clinical course: patients who died within one year of diagnosis (n = 14) and patients who had a prolonged survival (n = 23) without any treatment in some cases. The comparison between the 2 groups showed that they differed in age (p = 0.01) and anemia (p = 0.02). We also observed that the patients with p53 mutations had a worse clinical outcome. Taken together these data confirm that B-PLL should be regarded as a distinct form of chronic lymphoproliferative disorder and suggest the existence of two patterns of clinical evolution.

Adult↗
PubMedDate not supplied

[Persistent polyclonal B-cell lymphocytosis].

Persistent polyclonal B-cell lymphocytosis (PPBL) is a rare and recently described entity. PPBL is diagnosed predominantly but not exclusively in women, usually smokers and is characterized by a moderate, chronic and absolute lymphocytosis (> 4 x 109/L). Peripheral blood examination show in all cases atypical binucleated lymphocytes. A polyclonal serum IgM is also associated and HLA-DR7 expression is present in most cases. The B cells are polyclonal with kappa and lambda light-chain expression. No clonal rearrangement of immunoglobulin heavy chain genes is observed. Finally, +i(3q) is a recurrent chromosomal abnormality and detected in 77% of cases with premature chromosome condensation in 50% and both abnormalities in 41% of cases. The benign clinical course of PPBL and lack of biological evolution in the majority of cases suggest that recognition is so important that aggressive therapy could be avoided.

B-Lymphocytes↗
PubMedDate not supplied

[Role of the biologist in the study of schistocytes].

The appearance of schistocytes in a peripheral blood film is considered to be an important diagnostic marker for thrombotic microangiopathy. However, the morphological analysis of schistocytes remains uneasy. To determine practice patterns in the biological management of schistocytosis, the French Group of Cellular Hematology from the French Society of Hematology conducted a survey on the approach of the diagnosis of microangiopathy. A guideline is proposed in order to cancel the substantial variation among biologists.

Diagnosis, Differential↗
PubMedDate not supplied

[New diagnostic approaches in malignant B-cell lymphomas].

The new WHO classification of B-cell neoplasms published in 2001 gathers leukaemia and lymphoma. This classification highlights the stage of differentiation of the tumour cell. It groups B-cell neoplasms morphology, histology (nodular or diffuse pattern, cell morphology), immunophenotypes, cytogenetic, molecular abnormalities and clinical data. Recent advances of the normal B cell differentiation understanding and the development of new types of analysis have shown that mature B-cell neoplasms appear to recapitulate stages of normal B-cell differentiation, leading to such a new classification.

B-Lymphocytes↗
PubMedDate not supplied

[Reproductibility of the morphological identification of schisocytes and evaluation of non observer-dependent methods].

Schistocytes are red blood cell fragments observed on a blood smear. They are a mark of mechanical haemolytic anaemias whose group of the thrombotic micro-angiopathies requires an urgent treatment. The detection of the schistocytes and sometimes their quantification are thus of primary importance. To evaluate this search for schistocytes, several surveys of practice were carried out (1999-2003) including pictures of blood fields (identification of schistocytes among abnormal red blood cells) near biologists of variable level of specialization. The aim was to try to lead to a consensus, in particular for the morphological criterias of identification. Our results indicated that: 1) the biologists are badly sensitized with the importance of this research and the consequences of their response for the diagnosis; 2) the morphological identification of the schistocytes is difficult with an important variability of the criteria according to the observers. An investigation overviewed by the French Group of Cellular Hematology (Delphi method) allowed the development of a morphological consensus (fragments of triangular/crescent/helmet forms with rectilinear zone testifying to the zone of break). In order to cancel the observer-dependent identification of the schistocytes, a software of morphometric analysis (Q-WIN, Leica) was developed for sorting, starting from digitalized microscopic fields, the fragmented - among the normal - red blood cells. The results appeared encouraging, but not yet optimized. An automated analyzer (Bayer ADVIA 120) was also evaluated for the measurement of the schizocytes ("fragmented red blood cells" parameter). The moderate over-estimation of the real schizocytes (+ 0,4%) encouraged to observe the clinical value of the fragmented red blood cells detection in a group of patients that undergone a bone-marrow transplantation. The predictive value of the test (98%) was satisfactory.

Erythrocyte Count↗