Waldenström macroglobulinemia; hematology; neoplasms; lymphoma; mutation; MYD88; CXCR4

Waldenström?s macroglobulinemia (WM) is a B-cell malignancy characterized by high levelof monoclonal immunoglobulin M (IgM) paraprotein in blood serum and associated with thebone marrow infi ltration by malignant cells with lymphoplasmacytic diff erentiation. WM remainsincurable advances in therapy. Most of WM cases are associated with a somatic pointmutation L265P in MYD88. Signifi cantly higher risk of progression from the IgM monoclonalgammopathy of undetermined signifi cance (IgM MGUS) to WM for patients with mutatedMYD88 gene suggests that this mutation is an early oncogenic event and plays a central role indevelopment of malignant clones. The second, most prevalent mutation in WM is found in theCXCR4 gene and is often associated with drug resistance and aggressive disease presentation.Therefore, detection of these mutations (MYD88L265P and CXCR4S338X) could be useful dia gnosticand prognostic tool for the patients with WM. While detection of these mutations in bonemarrow sample is common, the aim of our study was to compare sensitivity of detection ofmutation from diff erent cell fraction from peripheral blood and bone marrow. The results showpossibility to describe MYD88 and CXCR4 mutation status even from peripheral blood sample(sensitivity for MYD88L265P was 100%, for CXCR4S338X 91%), which signifi cantly facilitate materialcollection. Moreover, comparable detection sensitivity of these mutations in bone marrow andperipheral blood samples examined before and during the therapy off ers a promising tool formore routine dia gnostic and monitoring of disease progression.