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Monoclonal gammopathy are a heterogeneous group of disorders. They are characterized by proliferation of clonal differentiated B-cells producing the monoclonal immunoglobulin (MIG). Monoclonal immunoglobulin consists of both an intact immunoglobulin molecule or also only of its structural component, i.e. light chain kappa or lambda, rarely heavy chain. The most common monoclonal gammopathy is monoclonal gammopathy of unknown (undetermined) significance. Every patient with MGUS should be monitored regularly. In recent years, the early diagnosis of MGUS has become increasingly important due to the frequency of monoclonal gammopathy in general and especially the most serious of them - multiple myeloma. A higher incidence of monoclonal gammopathies and especially MM in Czech Republic is apparent from the available data of the National Cancer Registry. The subject of our communication is the fact, that in East Bohemia region (especially in the Trutnov and Nachod regions), according to these data, the highest frequency of malignant lymphoproliferative disorders is recorded. Therefore, we focused on diagnostics and monitoring over time in patients with MGUS, who were detected by the department of clinical biochemistry of the regional hospital in Trutnov as part of a routine examination. In a 10-year follow-up of patients with newly diagnosed monoclonal gammopathy of undetermined significance we monitored their further development over time and also on the frequency of transformation in malignant lymphoproliferative disorders, especially multiple myeloma in the district Trutnov. [ABSTRACT FROM AUTHOR]

Background: Quantification of monoclonal immunoglobulin free light chains (FLCs) in serum is used increasingly in clinical practice for the diagnosis, prognostic assessment, and treatment monitoring of monoclonal gammopathies. It is used as an adjunct to standard serum protein electrophoresis and immunofixation. However, methods for FLC quantification need further standardization and validation. Methods: The Czech Myeloma Group and the Czech Society of Clinical Biochemistry have initiated an interlaboratory study where six laboratories collaborating with the primary myeloma treatment centres measured FLC concentrations in 12 serum samples from patients with monoclonal gammopathies. Results: Repeatability of the measurements in five laboratories was calculated based on differences between the results of duplicate measurements. We found that repeatability depended more on the laboratory than on the device used for measurement. Conclusions: The study revealed several weak points in the methodology, including the need for a uniform sample dilution procedure. Interlaboratory reproducibility was comparable with values achieved in the NEQAS programme. Because the κ/λ ratio cannot be measured with high precision, κ and λ FLC concentrations should be used where possible. Due to its impact on the clinical management of patients with gammopathy, FLC quantification needs to become a part of the regular quality control cycle in myeloma centres. [ABSTRACT FROM AUTHOR]