Flow cytometry for meningeal infiltration in B acute lymphoblastic leukemia in a low middle income country.

Meningeal infiltration in children with B acute lymphoblastic leukemia is one of the most serious complications. Timely diagnosis not only significantly enhances treatment efficacy but also leads to improve patient outcome and reduce risk of relapse. This is particularly crucial in low to middle income countries facing health constraints, where optimizing resources is essential. Conventional cytology (CC) study of cerebrospinal fluid (CSF) is considered in different countries to be the Gold-standard despite its low sensitivity (< 50%). The study of CSF by multiparametric flow cytometry (MFC) appears to be an alternative. The aim of our study was to assess MFC analytical performance compared with CC. Our cross sectional study was conducted over a six-month period in the biological hematology department. CSF samples underwent analysis for the presence of blasts using both CC and MFC. Cytological slides of the CSF were prepared by cytocentrifugation in a Shandon Cytospin 4™. Flow cytometric analysis was performed on the BD FACSLyric™ flow cytometer. All statistical analyses were performed using SPSS version 21.0 (SPSS Inc.). Agreement between the two methods was made using the Kappa index and χ2 test. This study was approved by the local ethics committee. Sixty CSF samples from 39 children with B acute lymphoblastic leukemia were analyzed. Meningeal infiltration was detected respectively in 20% of cases by MFC and 5% of cases by CC, with a significant difference p = 0.006. Comparing the two methods, the Kappa coefficient was 0.35, indicating weak agreement between the two methods. Moreover, MFC positivity was higher even for hypocellular samples. Of the 51 hypocellular samples, eight were positive by MFC while they were negative by CC. MFC shows better sensitivity while retaining good specificity for the detection of meningeal involvement. MFC could therefore be a complementary method to CC for detecting blast cells in the central nervous system.

Clot waveform analysis in acute promyelocytic leukemia.

The aim of this study was to evaluate the activated partial thromboplastin time (APTT) and prothrombin time (PT)-based clot waveform analysis (CWA) in patients diagnosed with acute promyelocytic leukemia (APL). APTT-based and PT-based CWA parameters of patients diagnosed with APL were analyzed and compared with healthy volunteers. Four APTT-CWA parameters were noted, maximum velocity corresponding to the first peak of the first derivative (max1), maximum acceleration corresponding to the first peak of the second derivative (max2) and the corresponding peak times of max1 and max2 (Tmax1, Tmax2). For the PT-CWA, two PT-CWA parameters were noted, maximum velocity (max1') and the corresponding timing (Tmax1'). The results were expressed in medians. Mann-Whitney U test was used to compare the CWA parameters. Correlations were examined using the Spearman correlation test. Tmax1 and Tmax2 were significantly prolonged in patients with APL in comparison with healthy volunteers. Although max1 and max2 were lower in APL patients compared with healthy volunteers, no significant difference was noted. There was a strong and significant correlation between the DIC score and the parameters max1, max2 and max1' and a very strong and significant correlation between fibrinogen levels and max1, max2 and max1'. When comparing DIC patients with hypofibrinogenemia and DIC without hypofibrinogenemia, a significant difference was noted in max1, max2, Tmax1 and Tmax2. The APTT and PT-based CWA analysis is a good tool to evaluate the bleeding tendency in APL, as it offers a novel approach for evaluating global hemostasis, predicting the bleeding risk and delivering improvements to APL patients management.

[Immunophenotyping of B chronic lymphoproliferative syndromes (CLL excluded): confrontation with the histology]. / Immunophénotypage des syndromes lymphoprolifératifs chroniques B non LLC : confrontation avec l'histologie.

Immunophenotyping is a major tool for the diagnosis of the chronic lymphoïd leukaemia (CLL). Its interest remains limited in the classification of the other B chronic lymphoproliférative syndromes (B-CLPS). We evaluate the place of the flow cytometry (CMF) in the diagnosis and classification of the non CLL B-CLPS. The cases with Matutes score of 4 or more are excluded. A confrontation of the results to the histology is made. 28 cases of non CLL B-CLPS are diagnosed. CMF shows a κ monoclonal population in 15 cases and λ in 13 cases. A co-expression CD19+CD5 + is found in 11 cases concording with an atypic CLL or a mantel cell lymphoma in 6 cases with Matutes score of 3. In 5 cases, we concluded to non CLL B-CLPS (Matutes<3). The histology retained the diagnosis of a mantel cell lymphoma (4 cases), a SLVL (1 case) and an atypical LLC (1 case). CD5 is negative in 17 cases. In 5 cases, the diagnosis of hairy cell leukemia (HCL) is retained (CD 11c+ CD103+) and confirmed by the histology. The diagnosis of a marginal zone lymphoma is retained in 2 cases, a SLVL in 2 cases, a follicular lymphoma in 3 cases and prolymphocytes leukaemia in 1 case. Nine cases of non CLL B-CLPS were difficult to classify by histology. CMF is insufficient for the classification of most of the non CLL B-CLPS. Only the phenotype of the HCL is characteristic. The confrontation of the histology results remains essential.

[Cytology and immunophenotype features of hairy cell leukemia: 6 cases]. / Caracteristiques cytologiques et immunophenotypiques des leucemies a tricholeucocytes: a propos de 6 cas.

BACKGROUND: Hairy cell leukemia is a rare lymphoproliferative disorder. AIM: with cytological and immunophenotypic features. METHODS: We report 6 cases of hairy cell leukemia diagnosed in the Biological Department of Hematology at the Aziza Othmana Hospital of Tunis. RESULTS: Hairy cells was observed in blood smears of 5 cases. Flow cytometry analysis shown monoclonal a monoclonal population B while gatinting on the expression of the CD19 and SSC signal. The positivity of the CD103 is noted in 5 cases and the CD11c signal is intense in all the cases. CONCLUSION: Immunophenotype is of great interest in the diagnosis of hairy cell leukemia.