Ficin-Treated Red Cells Help Identify Clinically Significant Alloantibodies Masked as Reactions of Undetermined Specificity in Gel Microtubes

Abstract

Non-specific antibodies or antibodies of undetermined significance (AUS) often pose problems for a blood bank technologist and physician. It is well known that antibodies can weaken and evanesce over time, thus eluding detection by routine blood bank techniques. Special enhancement techniques exist (eg, ficin treatment); however, they are often underutilized due to concerns over expense. Ficin is known to enhance reactivity caused by antibodies in the ABO, Rh, Kidd, Lewis, I, and P blood group systems, while destroying reactivity of antibodies in the Duffy, and MNS blood group systems. Herein, we discuss our protocol for using ficin treatment to determine the specificity of antibodies that would otherwise be classified as AUS. Of the 97 AUS specimens that were treated with ficin, we were able to identify 25 new alloantibodies that would have otherwise been missed without ficin treatment. Thus, we believe our protocol enhances transfusion safety, while minimizing additional workload and cost.

Keywords: AUS; alloantibodies; antibodies of undetermined significance; evanesce; ficin; gel.