Combined Group I And Iii Abo Discrepancies In Multiple Myeloma With Igg-Lambda Type: A Case Report

Objective: To report a case with unusual ABO discrepancies caused by coexistence of the loss of anti-B isoagglutinin and rouleau formation. Clinical Presentation and Intervention: A 79-year-old female diagnosed as having multiple myeloma (MM) with monoclonal IgG-lambda type showed rouleau formation in peripheral blood smear. The ABO and Rh blood type before the diagnosis of MM was A+, but the following ABO grouping was interpreted as AB+. The ABO genotype revealed the subtypes A102 and O101, which confirmed her ABO phenotype as A+. Conclusion: This was a case of combined group I and III ABO discrepancies mimicking blood group AB. (C) 2016 S. Karger AG, Basel.