Chikako Takeuchi-Baba1, Shoichi Ito2, Rie Kinjo1, Hitomi Miyagi1, Hiroyasu Yasuda3, Kenichi Ogasawara4, Hitoshi Ohto5. 1. Department of Clinical Laboratory, Tomishiro Central Hospital, Okinawa, Japan. 2. Japanese Red Cross Tohoku Block Center, Sendai, Japan. 3. Division of Medical Technology, Fukushima Prefectural Hygiene Institute, Fukushima, Japan. 4. Japanese Red Cross Central Blood Institute, Tokyo, Japan. 5. Department of Advanced Cancer Immunotherapy, Fukushima Medical University, Fukushima, Japan.
Abstract
BACKGROUND: Weak D-type RBCs have fewer D epitopes, but it remains unclear whether individuals with certain types of weak D produce alloanti-D directed at D epitopes absent from the RBCs, and whether it is an alloantibody or an autoantibody. We report the first case of a patient with a weak D Type 15 who produced autoantibodies mimicking alloanti-D. CASE REPORT: A 52-year-old Japanese male with weak D developed anti-D 3 months after transfusion of D-negative and -positive RBCs, and the antibody persisted for 24 months with a consistently negative direct antiglobulin test. Eluates from the patient's RBCs demonstrated anti-D specificity. The recipient did not exhibit any signs of delayed hemolytic transfusion reaction. As his anti-D was removed by the different adsorbing cells of weak D Type 15 and autologous as well as D positive, D negative, weak D Type 24, and partial DVa, it was thought to be an autoantibody mimicking anti-D rather than an alloantibody. The patient's RBCs reacted weakly with the 13 anti-D reagents used in the study. Polymerase chain reaction and nucleotide sequencing revealed that the patient had an RHD genotype of RHD*01N.01/RHD*15. CONCLUSION: Anti-D, produced in a patient with weak D Type 15 after transfusion, was found to be mimicking autoanti-D. Alloanti-D was excluded by an adsorption study with different RBC types.
BACKGROUND: Weak D-type RBCs have fewer D epitopes, but it remains unclear whether individuals with certain types of weak D produce alloanti-D directed at D epitopes absent from the RBCs, and whether it is an alloantibody or an autoantibody. We report the first case of a patient with a weak D Type 15 who produced autoantibodies mimicking alloanti-D. CASE REPORT: A 52-year-old Japanese male with weak D developed anti-D 3 months after transfusion of D-negative and -positive RBCs, and the antibody persisted for 24 months with a consistently negative direct antiglobulin test. Eluates from the patient's RBCs demonstrated anti-D specificity. The recipient did not exhibit any signs of delayed hemolytic transfusion reaction. As his anti-D was removed by the different adsorbing cells of weak D Type 15 and autologous as well as D positive, D negative, weak D Type 24, and partial DVa, it was thought to be an autoantibody mimicking anti-D rather than an alloantibody. The patient's RBCs reacted weakly with the 13 anti-D reagents used in the study. Polymerase chain reaction and nucleotide sequencing revealed that the patient had an RHD genotype of RHD*01N.01/RHD*15. CONCLUSION: Anti-D, produced in a patient with weak D Type 15 after transfusion, was found to be mimicking autoanti-D. Alloanti-D was excluded by an adsorption study with different RBC types.
Authors: Willy A Flegel; Gregory A Denomme; John T Queenan; Susan T Johnson; Margaret A Keller; Connie M Westhoff; Louis M Katz; Meghan Delaney; Ralph R Vassallo; Clayton D Simon; S Gerald Sandler Journal: Transfusion Date: 2020-03-12 Impact factor: 3.337