Chronic lymphocytic leukemia (CLL) is the most frequent type of adult leukemia in Western countries. Recently, new molecular prognostic markers like 17p deletion, 11q deletion, 13q deletion, trisomy 12, the mutational status of the immunoglobulin variable heavy chain genes (IGHV) genes, expression of ZAP-70 and CD38 were identified as prognostically significant. The CLL patients with mutated IGHV have a more favorable prognosis while non-mutated cases with the mutation's number less than 2% compared to the germline sequence suffer from more aggressive diseases. Here, we describe a clinical laboratory method for the detection of the mutation status of IGHV in patients with CLL using reverse transcription PCR and dideoxysequencing, and the evaluation using two immunoglobulin databases IMGT/V-QUEST and IgBLAST. We analyzed 37 different clonal rearrangements in 35 patients. Using two different databases, we identified 13 mutated and 24 non-mutated clones. The most preferred subfamilies were VH1, VH3, and VH4. The CLLs using the subfamily 1-69 were all non-mutated. Unlike previous reports, there were no significant differences between the used databases observed. The clinical trials are already incorporating new prognostic molecular markers such IGHV mutational status, so it is important to use standardized clinical laboratory methods and databases for a reliable identification of the mutation status in CLL.
