A reliable method for avoiding false negative results with Luminex single antigen beads; evidence of the prozone effect.
Luminex single antigen bead (SAB) assays have become an essential tool in monitoring the status of antibody to the Human Leucocyte Antigen (HLA) of patients both before and after transplantation. In addition SAB data is used to aid risk stratification to assess immunological risk of humoral rejection in solid organ transplantation (CTAG/BTAG guidelines) [1]. Increasingly laboratories are reporting false negative results at high antibody titre due to a prozone effect. Here we report a case study where the prozone effect led to a false negative antibody result that could have resulted in adverse outcome. We describe a method to reliably remove the prozone effect through heat inactivation and the addition of Ethylenediaminetetraacetic acid (EDTA) to the Luminex wash buffer.
H&I, Combined Labs, Derriford Hospital, Plymouth, United Kingdom. Electronic address: seancarey@nhs.net.
B Sean
BS
Carey
H&I, Combined Labs, Derriford Hospital, Plymouth, United Kingdom.
Kim
K
Boswijk
H&I, Combined Labs, Derriford Hospital, Plymouth, United Kingdom.
Mazen
M
Mabrok
South West Transplant Centre, Derriford Hospital, Plymouth, United Kingdom.
Peter A
PA
Rowe
South West Transplant Centre, Derriford Hospital, Plymouth, United Kingdom.
Andrew
A
Connor
South West Transplant Centre, Derriford Hospital, Plymouth, United Kingdom.
Imran
I
Saif
H&I, Combined Labs, Derriford Hospital, Plymouth, United Kingdom; NHS-BT, Filton, United Kingdom.
Anthony
A
Poles
D000328:Adult; D004492:Edetic Acid; D005188:False Negative Reactions; D005922:Glomerulonephritis, IGA / Q000175:diagnosis* / Q000628:therapy; D006084:Graft Rejection / Q000517:prevention & control*; D015789:HLA-A2 Antigen / Q000276:immunology; D006683:HLA-DQ Antigens / Q000276:immunology*; D006650:Histocompatibility Testing / Q000379:methods*; D006358:Hot Temperature; D006801:Humans; D056724:Immunity, Humoral; D007166:Immunosuppressive Agents / Q000627:therapeutic use; D007518:Isoantibodies / Q000097:blood*; D016030:Kidney Transplantation; D008297:Male; D055118:Medication Adherence; D012306:Risk; D055815:Young Adult
D015789:HLA-A2 Antigen; D006683:HLA-DQ Antigens; C069546:HLA-DQ7 antigen; D007166:Immunosuppressive Agents; D007518:Isoantibodies; D004492:Edetic Acid
Donor specific antibody; False negative; HLA antibody; Prozone; Single antigen bead assay