(P-HC-11) Cryofibrinogenemia As the Cause of an ABO Forward/Reverse Typing Discrepancy and Positive Antibody Screen

Cryofibrinogenemia is a rare blood disorder in which precipitates of fibrinogen, immunoglobulins, and other plasma proteins can form upon cooling and cause impaired wound healing. Pre-transfusion compatibility testing is required before all blood transfusions. A patient with a history of marginal zone lymphoma with plasmacytic differentiation and IgM monoclonal gammopathy underwent a laminectomy for lumbar spinal stenosis, which was complicated by wound dehiscence and non-healing wounds. This case is the first described case of blood bank pre-transfusion testing leading to a diagnosis of cryofibrinogenemia.


Study

Design/Methods:

Pre-transfusion ABO typing and antibody screen testing was performed with an automated instrument gel agglutination assay (IH-500 Bio-Rad Laboratories, Inc.) and manual tube methodology on an EDTA sample. Repeat EDTA blood samples were obtained. The specimen was refrigerated and visually examined later. A chart review was performed. A peripheral smear was examined. Serum protein and urine protein electrophoresis, as well as serum cryoglobulin testing was performed using standard clinical laboratory methods. A histological wound debridement specimen was examined with light microscopy. The instrument manufacturer (Bio-Rad Laboratories) independently tested three EDTA samples to troubleshoot the discrepant results. 


Results/Findings:

The automated assay revealed a forward-group A and reverse-group O discrepant result as well as a positive antibody screen result. (Figure A). A manual tube test had a non-discrepant group A result and a negative antibody screen result. Repeat automated gel agglutination assay yielded the same result with a repeat sample. A grossly visible precipitate/gel-like layer was seen in the refrigerated sample. A peripheral blood smear was negative for Rouleaux. Serum electrophoresis demonstrated an IgM monoclonal spike of 2.7 g/dL. Serum cryoglobulin studies were negative. A previous tissue debridement specimen stained with Periodic acid-Schiff (PAS) showed intraluminal deposits within the vascular endothelium. The instrument manufacturer (Bio-Rad Laboratories) confirmed the presence of cryofibrinogen.


Conclusions: The patient had cryofibrinogenemia explaining the discrepant ABO results and impaired wound healing. This case shows how immunohematology methods in the blood bank can provide diagnostic information, beyond pre-transfusion compatibility, if investigated in the correct clinical context. Some hospital systems outsource blood bank testing to outside laboratories for cost efficiency. Outsourcing not only delays providing patients with compatible blood products, but can also result in lost opportunities to obtain worthwhile clinical information.