Clinical significance of an alloantibody against the Kell blood group glycoprotein

MATTALONI SM.; CLAUDIA NONAKA; ANDREA TREJO; ROSARIO CÉSPEDES; LILIAN CASTILHO; MELINA ELIANA LUJÁN BRAJOVICH; CLAUDIA SILVIA BIONDI; CARINE ARNONI; CAROLINA TRUCCO BOGGIONE; NÉSTOR ZANI; COTORRUELO, CARLOS

TRANSFUSION MEDICINE AND HEMOTHERAPY

KARGER

Lugar: Basel; Año: 2016 vol. 43 p. 53 - 57

1660-3796

Kell null (K0) individuals can produce anti-Ku,an antibody against many epitopes in the Kell glycoprotein,after transfusion and/or pregnancy. Since sensitizedK0 patients are rare, little is known about anti-Ku clinicalrelevance and in particular about its association to hemolyticdisease of the fetus and newborn. Case Report: Thiswork describes a case of neonatal hyperbilirubinemia dueto immune-mediated erythrocyte destruction by an alloantibodydirected against the Kell glycoprotein. Serologicand molecular approaches identified an anti-Ku alloantibodyin maternal serum. A homozygous IVS3 + 1g>a pointmutation (KEL*02N.06 allele) was found to be responsiblefor the lack of Kell antigen expression in the mother?s redblood cell and subsequent alloimmunization after a previouspregnancy. Even though in most cases Kell antibodiesare clinically severe and may cause suppression of erythropoiesis,in our case the newborn had a moderate anemiaand hyperbilirubinemia that was successfully treated withphototherapy without requiring exchange transfusion.Serological and molecular studies performed in theproband?s family members allowed us to provide themwith proper counseling regarding alloimmunization aftertransfusion and/or pregnancy. Conclusions: This case enlargesthe understanding of the clinical significance ofalloantibodies against Kell blood group antigens.