Biomarkers in Immunoglobulin Light Chain Amyloidosis.

Immunoglobulin light chain amyloidosis (AL amyloidosis - ALA) is a monoclonal gammopathy characterized by presence of aberrant plasma cells producing amyloidogenic immunoglobulin light chains. This leads to formation of amyloid fibrils in various organs and tissues, mainly in heart and kidney, and causes their dysfunction. As amyloid depositing in target organs is irreversible, there is a big effort to identify biomarker that could help to distinguish ALA from other monoclonal gammopathies in the early stages of disease, when amyloid deposits are not fatal yet. High throughput technologies bring new opportunities to modern cancer research as they enable to study disease within its complexity. Sophisticated methods such as next generation sequencing, gene expression profiling and circulating microRNA profiling are new approaches to study aberrant plasma cells from patients with light chain amyloidosis and related diseases. While generally known mutation in multiple myeloma patients (KRAS, NRAS, MYC, TP53) were not found in ALA, number of mutated genes is comparable. Transcriptome of ALA patients proves to be more similar to monoclonal gammopathy of undetermined significance patients, moreover level of circulating microRNA, that are known to correlate with heart damage, is increased in ALA patients, where heart damage in ALA typical symptom.Key words: amyloidosis - plasma cell - genome - transcriptome - microRNA.

Diagnostic Tools of Waldenströms Macroglobulinemia - Best Possibilities for Non-invasive and Long-term Disease Monitoring.

Waldenströms macroglobulinemia (WM) is a B-cell malignancy characterized by high level of monoclonal immunoglobulin M (IgM) paraprotein in blood serum and associated with the bone marrow infiltration by malignant cells with lymphoplasmacytic differentiation. WM remains incurable advances in therapy. Most of WM cases are associated with a somatic point mutation L265P in MYD88. Significantly higher risk of progression from the IgM monoclonal gammopathy of undetermined significance (IgM MGUS) to WM for patients with mutated MYD88 gene suggests that this mutation is an early oncogenic event and plays a central role in development of malignant clones. The second, most prevalent mutation in WM is found in the CXCR4 gene and is often associated with drug resistance and aggressive disease presentation. Therefore, detection of these mutations (MYD88L265P and CXCR4S338X) could be useful diagnostic and prognostic tool for the patients with WM. While detection of these mutations in bone marrow sample is common, the aim of our study was to compare sensitivity of detection of mutation from different cell fraction from peripheral blood and bone marrow. The results show possibility to describe MYD88 and CXCR4 mutation status even from peripheral blood sample (sensitivity for MYD88L265P was 100%, for CXCR4S338X 91%), which significantly facilitate material collection. Moreover, comparable detection sensitivity of these mutations in bone marrow and peripheral blood samples examined before and during the therapy offers a promising tool for more routine diagnostic and monitoring of disease progression.Key words: Waldenström macroglobulinemia - hematology - neoplasms - lymphoma - mutation - MYD88 - CXCR4.