Heterogeneity of HPA‐3 alloantibodies: consequences for the diagnosis of alloimmune thrombocytopenic syndromes

Abstract

Anti-HPA-3 alloantibodies show considerable heterogeneity, which may hamper the serologic diagnosis of FNAIT. Preservation of the alphaIIbbeta3 integrin and protection from enzymatic degradation seem to be important during PLT storage.

Low‐avidity HPA‐1a alloantibodies in severe neonatal alloimmune thrombocytopenia are detectable with surface plasmon resonance technology

“…Second, the purity and stability of the antigen(s) used are of prime importance. The question as to whether this technique is also applicable to other human PLT antigens, especially for “labile” HPAs (HPA‐2, ‐3, and ‐15), remains 23,30 . In this respect, the use of recombinant PLT alloantigens may help in the further development of the SPR technique for the detection of PLT antibodies 11,31 …”

Human platelet antigens – 2013

“…The HPA‐3 antigens are expressed on GPIIb, but antibodies against HPA‐3a and HPA‐3b are seldom detected. One reason for this is that some HPA‐3 antibodies are difficult to detect in assays like the MACE and MAIPA, in which GPIIb/IIIa is captured from detergent lysates of platelets using specific monoclonal antibodies . It has been speculated that this treatment of GPIIb/IIIa induces conformational changes in the proteins that interfere with binding of HPA‐3 antibodies.…”

Report on the 15th International Society of Blood Transfusion platelet immunology workshop

“…In contrast to HPA‐1a alloantibody detection, the detection of HPA‐3 antibodies has proved to be particularly problematic, as anticipated from previous reports and workshops [1, 3, 4, 9]. Some HPA‐3 antibodies (‘labile’) could not be identified by several laboratories.…”