Evaluation of a complementdependent anti-Jk^a by various sensitization and detection methodologies: a case report

A 79-year-old woman with a diagnosis of lower gastrointestinal bleeding was found to have a complement dependent anti-Jk^a in her serum. The anti-Jk¹ was evaluated by the antiglobulin technique with polyspecific, anti-C3, and anti-lgG antihuman globulin (AHG). A variety of sensitization and detection methods were used, including the prewarmed saline technique, enzyme treatment of test cells, a low-ionic additive solution (LISS), 22 percent albumin, Polybrene, and an increased serum/cell ratio. The anti-Jk¹ was detected only when polyspecific AHG and anti-C3 were used compared to anti-lgG, regardless of the selected enhancement technique. Anti-C3 gave weaker reactions than polyspecific AHG. IgG subclassing was inconclusive. The anti-Jk^a was not detected when plasma was substituted for serum. The use of polyspecific versus IgG AHG in pretransfusion testing is discussed.