{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,22]],"date-time":"2026-01-22T08:27:16Z","timestamp":1769070436703,"version":"3.49.0"},"reference-count":20,"publisher":"Oxford University Press (OUP)","issue":"1","license":[{"start":{"date-parts":[[2025,10,9]],"date-time":"2025-10-09T00:00:00Z","timestamp":1759968000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2026,1,7]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:sec>\n                    <jats:title>Introduction<\/jats:title>\n                    <jats:p>Multiple myeloma (MM) is characterized by the abnormal proliferation of plasma cells, resulting in the overproduction of distinctive monoclonal proteins (M-protein). Suspected MM necessitates screening for M-protein through a combination of serum protein electrophoresis, serum immunofixation (SIFE), and serum free light chain (SFLC) determination. An M-protein appears as a relatively restricted band on agarose gel, where migration in \u0251-2 is rare.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>A 55-year-old man with pulmonary tuberculosis presented with severe lower back pain. On examination, he appeared chronically ill, with conjunctival pallor. X-rays revealed vertebral compression fractures. The full blood count confirmed anemia; however, serum calcium and creatinine levels did not meet myeloma-defining event criteria.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>The serum protein electrophoresis revealed hypogammaglobulinemia, with the SIFE demonstrating unusual unrestricted \u03ba staining in the \u0251-2 region. A markedly elevated \u03ba SFLC and \u03ba:\u03bb ratio were found. Bone marrow examination demonstrated approximately 90% plasmacytosis. Urine immunofixation revealed a small, restricted \u03ba band disproportionate to the \u03ba SFLC. Notably, matrix-assisted laser desorption\/ionization time-of-flight mass spectrometry identified only polyclonal \u03ba SFLC.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Discussion<\/jats:title>\n                    <jats:p>Given the absence of a discernible M-protein on SIFE, a small \u03ba restriction on urine immunofixation, and a polyclonal increase in \u03ba SFLCs, the patient\u2019s condition is being managed as an oligosecretory MM.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1093\/labmed\/lmaf060","type":"journal-article","created":{"date-parts":[[2025,8,31]],"date-time":"2025-08-31T11:40:53Z","timestamp":1756640453000},"source":"Crossref","is-referenced-by-count":0,"title":["An atypical finding on serum immunofixation: a case 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