Transient suppression of high-prevalence Kell blood group antigens and concomitant development of a Kell-related antibody that appears to recognize a high-prevalence Kell antigen not previously defined

A previously healthy 32-year-old male patient was admitted to hospital with malaise, dyspnea, anemia, thrombocytopenia, and leukopenia. Anemia and thrombocytopenia worsened during the third week. Considering the possible need for transfusion, routine ABO and D typing and an antibody detection test were performed. Antibody detection test was positive, necessitating fur ther immunohematologic investigation that revealed an antibody with Kell-related specificity and suppression/alteration of several high-prevalence Kell blood group system antigens. Autocontrols and direct antiglobulin tests (DATs) were negative in several samples during the disease course. Sequencing of the patient's