The Prognostic Impact of Abnormal Protein Bands in Multiple Myeloma: A Systematic Review and Meta-Analysis

Introduction: The detection of abnormal protein bands (APB) different from the original monoclonal protein in patients with multiple myeloma (MM) who underwent stem cell transplantation and/or chemotherapy has been reported. These atypical serum immunofixation patterns may be monoclonal (also termed secondary monoclonal gammopathy of undetermined significance) or oligoclonal bands (OB). The prognostic significance of this phenomenon remains controversial. This systematic review and meta-analysis aimed to summarize and analyze the evidence for the association between APB with survival in MM patients.