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.


METHODS
A 79-year-old female diagnosed as having multiple myeloma (MM) with monoclonal IgG-λ 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+.


CONCLUSIONS
This was a case of combined group I and III ABO discrepancies mimicking blood group AB.
Department of Laboratory Medicine, College of Medicine, Catholic University of Korea, Seoul, Republic of Korea.
Joonhong
J
Park
Dong Wook
DW
Jekarl
Suk Young
SY
Park
Soyoung
S
Shin
D000017:ABO Blood-Group System / Q000097:blood* / Q000235:genetics; D000368:Aged; D003924:Diabetes Mellitus, Type 2; D004903:Erythrocyte Aggregation; D005260:Female; D005838:Genotype; D006801:Humans; D007074:Immunoglobulin G; D007146:Immunoglobulin lambda-Chains; D009101:Multiple Myeloma / Q000097:blood*; D056910:Republic of Korea
D000017:ABO Blood-Group System; D007074:Immunoglobulin G; D007146:Immunoglobulin lambda-Chains