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Potent cold agglutinin in a patient with SARS-CoV-2 infection

Potent cold agglutinin in a patient with SARS-CoV-2 infection
#00063366
Author: Kristina Gvozdjan, MD; Bridgette Vission, MLS(ASCP)CM
Category: Red Cell: Hemolytic Anemia (HA) > Autoimmune Hemolytic Anemias > Cold-active antibodies > Cold agglutinin disease (CAD) > Secondary CAD > Infectious
Published Date: 12/28/2020

A 51-year-old male with SARS-CoV-2 infection and anemia (Hb=6.7 g/dL) required a red blood cell transfusion due to worsening hypoxemia.  Hematology and blood bank workup revealed presence of a cold agglutinin, as evidenced by red blood cell agglutination and platelet clumping on peripheral blood smear, and mixed-field agglutination on forward typing using the automated gel method (Image).  The typing discrepancy was resolved by manual tube testing, including repeating the forward typing after washing patient's red blood cells with warm saline, and repeating the reverse typing after prewarming the patient's plasma.  The patient's blood type was confirmed as O-positive.  Antibody screen showed panreactive cold agglutinin, and the direct antiglobulin test was significant for strong agglutination (4+) with monospecific anti-C3d reagent.  The patient's plasma was prewarmed for crossmatching and one unit of crossmatch-compatible red blood cells was successfully transfused resulting in appropriate Hb increment (Hb=8.5 g/dL).