Clinical significance of anti-Jra: report of two cases and review of the literature


  • MeeAe Y. Kwon,

  • Leon Su,

  • Patricia A. Arndt,

  • George Garratty,

  • Douglas P. Blackall

  • From the Division of Transfusion Medicine, Department of Pathology and Laboratory Medicine, University of California, Los Angeles; and the American Red Cross Blood Services, Southern California Region, Los Angeles, California.

  • TRANSFUSION 2004;44:197-201.

Douglas P. Blackall, MD, Department of Pathology, Arkansas Children's Hospital, 800 Marshall Street; Slot 820, Little Rock, AR 72202; e-mail:


BACKGROUND: Jra is a high-frequency antigen seen in all populations, but the clinical significance of Jra antibodies is incompletely understood. Two cases are reported in which patients with anti-Jra received incompatible transfusions.

CASE REPORTS: A 69-year-old Japanese man had anti-K and anti-Jra. Despite multiple transfusions of Jr(a+), K– RBCs, his clinical course remained stable without evidence of hemolysis. A 45-year-old Japanese woman with anti-Jra was transfused with two units of Jr(a+) RBCs without clinical evidence of hemolysis. However, the same patient received an additional unit of Jr(a+) RBCs 1 week after the initial transfusions and, within 6 hours of transfusion, developed signs and symptoms of an acute hemolytic transfusion reaction.

STUDY DESIGN AND METHODS: Routine serologic methods were used to study the patients’ RBCs and plasma. A monocyte monolayer assay (MMA) was used to determine the potential clinical significance of the anti-Jra, where reactivity (R) greater than 5 percent indicates potential clinical significance.

RESULTS: The anti-Jra in the first case had a pretransfusion titer of 32 with a MMA result of 3.3 percent R. No clinical or laboratory evidence of hemolysis was seen after transfusion of 4 units of Jr(a+), K– RBCs. The anti-Jra in the second case had a pretransfusion titer of 32 with a MMA result of 24.5 percent R. This patient developed an acute hemolytic reaction after transfusion of Jr(a+) RBCs.

CONCLUSION: Anti-Jra can be clinically significant as demonstrated by acute hemolysis in the second case. The MMA accurately predicted the clinical outcome of each case and appears to be a useful tool in predicting the biologic behavior of anti-Jra.