title: Clinically significant autoimmune hemolytic anemia with a negative direct antiglobulin test by routine tube test and positive by column agglutination method.
abstract: In two to five percent of cases of autoimmune hemolytic anemia (AIHA),the patient's RBCs are negative in the direct antiglobulin test (DAT). We describe a patient with AIHA with a negative DAT when tested by the traditional tube test but with a strongly positive one when tested by column agglutination. When the DAT was repeated by tube test using 4 degrees Celsius saline washes, it became positive. This phenomenon has been observed when low-affinity antibodies are involved in AIHA. The patient's history and serologic findings are detailed in this report.
authors.affiliation: Transfusion Center, Catholic University of Sacred Heart, Largo Gemelli 8 00168 Rome, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Lai
authors.forename: C
authors.initials: C
authors.lastname: Rumi
authors.forename: G
authors.initials: G
authors.lastname: D'Onofrio
authors.forename: M T
authors.initials: MT
authors.lastname: Voso
authors.forename: G
authors.initials: G
authors.lastname: Leone