ABSTRACT
INTRODUCTION: To investigate the role of urine immunofixation electrophoresis in detecting relapse in patients with myeloma who have undergone autologous and allogeneic hematopoietic stem cell transplantation (HSCT). METHODS: The study included a total of 78 patients, comprising 49 males and 29 females, with progressive disease or relapse after HSCT. Serum protein electrophoresis (sPE), serum immunofixation electrophoresis (sIFE) and serum free light chain κ/λ ratio in addition to urine immunofixation (uIFE) were studied. RESULTS: sPE, sIFE and κ/λ ratio demonstrated relapse in 65.3%, 88.3% and 58.9% of the cases by theirselves respectively. The combination panel of sPE and sIFE demonstrated relapse in 88.3% of patients whereas sPE, sIFE and κ/λ ratio all together demonstrated relapse in 95.8% of the patients. In relapsed patients, urine immunofixation was found to be positive in 16.2% of the patients. No patients with relapsed disease were missed by omitting uIFE from serum studies (sPE, sIFE and sFLC). CONCLUSION: For evaluation of relapse in MM patients after HSCT, uIFE had no additional diagnostic capability compared to serum studies (sPE, sIFE, and sFLC). Therefore, urine studies should be performed more selectively.