Identification and Quantification of Anti-Gp.Mur Antibodies in Human Serum Using an Insect-Cell-Based System.

Robert John S Lamis,Sung-Chan Wei,Yu-Chan Chao,Huei-Ru Lo,Tsong-Shi Chiueh,Chih-Hsuan Tsai

doi:10.3390/diagnostics11060966

Abstract

Gp.Mur is a clinically relevant antigen of the MNS blood group system that is highly prevalent in several Asian populations. Its corresponding antibody, anti-Gp.Mur, has been implicated in hemolytic transfusion reactions and hemolytic disease of the fetus and newborn. Currently, identifying and confirming anti-Gp.Mur antibody presence in sera via agglutination of a panel of red blood cells (RBCs) is inefficient and difficult to quantify. Using a baculovirus expression system to express Gp.Mur antigen on insect cell surfaces, we have developed a quantitative cell-based system to confirm the presence of anti-Gp.Mur antibody in human serum. We obtained 10 serum samples preidentified as having anti-Gp.Mur antibody and another 4 samples containing noncorresponding antibodies from hospital patients. Insect cells displaying Gp.Mur antigen successfully adsorbed anti-Gp.Mur antibody in the sera and inhibited the RBC agglutination mediated by this antibody. By varying the concentration of Gp.Mur-displaying cells, we could grade levels of RBC agglutination by anti-Gp.Mur antibody. Densitometric analysis further enabled quantitative determinations of hemagglutination inhibition by Gp.Mur-displaying cells. We believe that this cell-based hemagglutination inhibition system greatly improves or supplements existing technology and is a convenient means for accurately identifying and quantifying anti-Gp.Mur antibody.

Highlights

Gp.Mur antigen, previously known as Miltenberger antigen subtype III (Mi.III) or Mia antigen, is one of several antigens of the MNS blood group system [1,2]
Anti-Gp.Mur antibody is one of the most commonly identified red blood cells (RBCs) antibodies in humans in Taiwan [6,10,43], and it may be highly prevalent in Southeast Asia, South Asia, and some parts of East Asia [7], detailed prevalence and incidence studies on this antibody are lacking
This antibody has been implicated in hemolytic transfusion reactions and hemolytic disease of the fetus and newborn [14,15,16]

Summary

Introduction

Gp.Mur antigen, previously known as Miltenberger antigen subtype III (Mi.III) or Mia antigen, is one of several antigens of the MNS blood group system [1,2]. Gp.Mur antigen is a variant of the red blood cell (RBC) glycophorins in the MNS system, and it most likely evolved from crossover events between glycophorin A and glycophorin B [3,4]. Anti-Gp.Mur antibody is one of the most commonly identified RBC alloantibodies among thalassemia and multitransfused patients in Taiwan [10,11]. An aboriginal group in Taiwan, the Ami tribe, presents a markedly high incidence of this antigen (up to 88.4%), which has been credited to their athleticism [9,12]. The Yami and Puyuma tribes exhibit Gp.Mur antigen frequencies of 34.3% and

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Conclusion