[Adult lymphocytosis etiology by flow cytometry]. / Classification par cryométrie en flux de 104 cas d'hyperlymphocytose de l'adulte.

BACKGROUND: Positive and differential diagnosis of chronic lymphocytic leukemia (CLL) is based on immunophenotyping analysis. CLL is searched whenever a persistent lymphocytosis is found. AIM: To evaluate the performance of flow cytometry in etiologic diagnosis of lymphocytosis. Could it allow us to distinguish CLL from other causes of lymphocytosis? METHODS: Blood samples from 104 adult patients having a rate of lymphocytes> 5000 élé/mm3 persisting more than three months were analyzed using a large panel of monoclonal antibodies in three colors and Cell Quest software. results: Lymphoproliferative B disorder was retained in 83 cases, including 50 cases of typical CLL with Matutes score≥ 4 and 12 cases of atypical CLL with Matutes score = 3 . Diagnosis of hairy cell leukemia and follicular lymphoma were guided by the respective specific antigen expression CD103 and CD10. Large granular T lymphoma (LGL-T) was the most common etiology of lymphoid T proliferation. Unusual cases of Natural Killer (NK) and NK/T proliferations were found. CONCLUSION: The Flow cytometry is a powerful tool to establish lymphocytosis etiological diagnosis; it avoids invasive investigations in a large number of cases.

[Does multiple myeloma response to induction therapy depend on plasma cell IL6 receptor gene expression?]. / L'expression de l'IL6-r par les plasmocytes influe-t-elle la réponse au traitement d'induction au cours du myélome multiple ?

BACKGROUND: Interleukine 6 (IL-6) is the most important cytokine involved in malignant plasma cells growth and survival. AIM: To analyse bone marrow plasma cells IL6 receptor gene expression in both multiple myeloma patients at diagnosis and healthy bone marrow donors. METHODS: Clinical and biological patients' features and responses to Dexamethasone-Thalidomide induction therapy were gathered. 47 patients and 16 case controls were analyzed: Bone marrow plasma cells were isolated; and IL6 receptor gene expression was quantified using Taqman quantitative PCr technology and 2-ΔCT formula. RESULTS: Quantitative and qualitative IL6 receptor gene expression were negatively correlated with the degree of response to therapy (p= 0.02). In this study, plasma cells IL6 receptor gene expression seems to be decisive in predicting the response to treatment. CONCLUSION: Understanding the mechanisms involved in plasma cells IL6 receptor gene expression may offer a better appreciation of the physiopathologic and anti-oncogenic ways of drug resistance in multiple myeloma and consequently the discovery of new specific drugs.