Case 129

1. Prepared by Chen Lossos, MD and reviewed by Liz Crowe, MD and Lorraine N. Blagg, MA, MLS(ASCP)SBB

An elderly patient with high grade diffuse large B-cell lymphoma (DLBCL) is enrolled in a phase II trial of Rituximab and HU5F9-G4, an IgG4 antibody targeting CD47, after failing front-line rituximab, cyclophosphamide, hydroxydaunorubicin hydocholoride, oncovin, and prednisone (R-CHOP) and rituximab, ifosfamide, carboplatin, and etoposide (R-ICE) therapies. About a week after initiating treatment, they were transfused two crossmatched RBC units for a hemoglobin of 5.3 g/dl (7.1 g/dl pre-treatment). During transfusion of the second unit, the patient developed hives and urticaria, at which point the transfusion was stopped and a transfusion reaction work-up was sent. The transfusion work-up demonstrated no errors during the clerical check and there was no hemolysis in the post transfusion plasma. The ABO/Rh typing providing the following results.

A literature search reveals that reverse-type ABO discrepancies have been reported with anti-CD47 therapy.

In addition to the above, discrepancies in what other routine blood bank testing have been reported with treatment with anti-CD47 antibodies?