Tn Red cell polyagglutination in a healthy blood donor: A case report

Polyagglutination is a rare entity in immunohematology and unusually presents in a healthy blood donor. The general presentation was described in the literature in association with bacterial infections, which result in the exposure of crypt antigens. Nowadays, polyagglutination is rarely detected due to the use of monoclonal antisera. Our case report describes the presence of Tn polyagglutination in a healthy adult blood donor with no prior history of any infection in the recent past.

Immunohematology work-up for incompatible cross-match was done in the serology lab using commercially procured antisera and column agglutination gel card (Tulip Diagnostics India Pvt. Ltd, Goa, India). The three cell-screening panel was procured commercially (ID Dia cell I, II, III; Bio-Rad, Switzerland), and in-house lectin was prepared as per the standard method.

We have come across a case of incompatible cross-match with negative antibody screen, auto-control, and Negative direct coombs test. Cross-match with multiple adult serum and cord serum gives us a clue towards polyagglutination. Further, Polyagglutination was confirmed serologically using anti-A1 lectin and later concludes of Tn type by lectin prepared in-house from Salvia Sclarea.

Resolution of incompatible cross-match in a case of polyagglutination needs a skilled workforce and rare reagents. Identification of reason for incompatibility helps in an early issue of blood units.