Affiliation:
1. Department of Research Education and Innovation and Department of Medicine (Hematology Unit) Södra Älvsborg Hospital (SÄS) Borås Region Västra Götaland (VGR) Boras Sweden
2. Laboratory for Clinical Chemistry SÄS Borås and Department of Clinical Chemistry Sahlgrenska University Hospital Goteborg Sweden
3. Department of Haematology Sahlgrenska University Hospital Goteborg Sweden
4. Department of Hematology Norra Älvsborg Hospital (NÄL) Trollhattan Sweden
Abstract
AbstractMultiple myeloma (MM) is a disease, that at times poses diagnostic and monitoring challenges. Over the last decades laboratory methods have been expanded with serum free light chain (FLC) analysis. Alerted by two index cases with clinical impact due to failure of the FLC analysis to indicate a disease progression, we aimed to identify any clinical consequences due to known differences between FLC analysis methods. We applied two FLC analysis methods (Freelite Binding Site [FBS] and N‐Latex Siemens [NLS]) on all patients with MM and monoclonal gammopathy of uncertain significance diagnosed/followed up at Södra Älvsborg Hematology Unit, from April to December 2022. From a total of 123 patients with malignant plasma cell disorder, we identified five cases (4.1%) where solely the FBS method, as opposed to NLS, urine and serum electrophoresis, could support diagnosis or detect progression. The consequences of this discrepancy included not only change of diagnosis or delayed therapy but also change of treatment. Our findings indicate that a stronger awareness of the potential weaknesses of different FLC methods is needed, which calls for a closer collaboration between clinical chemists and hematologists.