Background: The incidence of CLL is not known in Senegal for several reasons, among them the difficuty to access the diagnosis since there is only clinical features and cytology without the possibility to apply the WHO classification criteria. Morever, no research in place can be set up without any precise diagnosis.
Aim: To obtain a precise diagnosis of lymphoproliferative disorders in adults in Dakar and to set up flow cytometry to develop immunophenotyping analysis of hematopoietic maligancies
Methods: From peripheral blood lymphocytes, we developed flow cytometry technique using monoclonal antobodies to detect the expression of kappa/lambda light chains, CD19, CD22, CD20, FMC7, CD5, CD10, CD23, CD38 and FISH technique to detect cytogenetic abnormalities : trisomy 12, deletion 13q14, 11q22-23, 17p. RNA was obtained to test micro-RNA mir15a, mir16-1, mir181a, mir181b, mir34a et 34b by qRTPCR.
Results: Twelve cases of CLL were identified, with advanced clincal stage and high hyperlymphocytosis (122 000 to 336 000/mm3). The immunophenotyping score was in favor of typical CLL with high expression of CD38, an unfavorable marker. Nine patients had cytogenetic abnormalities with 2 simultaneous abnormalities in 4 patients. The analysis of microRNA showed high value of mir15a, mir16-1 and low value of mir181a and 181b which were described in aggressive CLL.
Conclusions: Although the low number of cases of CLL, this study shows the aggressiveness of CLL in Senegal probably due to the delay of diagnosis. This analysis demonstrates the possibility to set up flow cytometry technique to obtain a precise diagnosis of CLL on site. Such experiment would be a model for epidemiologic, clinico-biological and translational research studies in order to set up the capacity building for diagnosis and research in the country.