Novel Use of Glacial Acetic Acid and Owren-Koller Buffer in the Laboratory Evaluation of Clotted Blood Sample Specimen from Immunoglobulin M Paraproteinemia with Hyperviscosity Syndrome

Abstract: It is not common to observe a variety of paraproteins produced in the body which are capable of leading to inaccurate values in laboratory testing. The current case report focused on an 82-year-old Malay male, initially presenting with symptoms of hyperviscosity syndrome (HVS), including unilateral weakness and reduced level of effort tolerance, who had a paraprotein in the body that interfered with the values of the complete blood count (CBC) in the laboratory. A routine sample of CBC was dispatched to the laboratory and was reported as clotted in the automated analysis. The laboratory was unable to proceed to analyze bone marrow aspirate, serum electrophoresis (ELP), and flow cytometry due to the presence of the paraprotein. To properly identify the paraprotein and to enable correct analysis of the necessary laboratory testing, a water bath of 37°C was employed with the blood tube, and glacial acetic acid, along with Owren-Koller buffer, was utilized to make the paraprotein soluble. Subsequently, the CBC and serum ELP were manually performed, demonstrating a paraprotein of immunoglobulin M (IgM) lambda. Symptoms were HVS gradually resolved with rituximab and bendamustine, with a reduction in the level of the IgM paraprotein. The current case highlights the importance of an effective, alternative method of solubilization for a paraprotein that interfered with usual laboratory practices.