A CASE OF DELAYED HEMOLYTIC TRANSFUSION REACTION PROBABLY CAUSED BY A PRIMARY IMMUNE RESPONSE

We report here a rare case of delayed hemolytic transfusion reaction (DHTR) probably caused by a primary immune response. The patient was a 32-year-old Japanese female who underwent surgery for ectopic pregnancy. For treatment of intraoperative hemorrhage shock, she received 5 units of RBCs (all positive for Jka, C and e antigen) that were crossmatch-compatible by indirect antiglobulin testing using polyethylene glycol (PEG-TAT). On day 22 after transfusion, she showed symptoms of hemoglobinuria, reticulocytosis, and elevated serum levels of LDH (1,106IU/L) and total-bilirubin (5.6mg/dL). She did not receive further transfusion during this period. On irregular antibody screening of patient serum collected 24 days after transfusion, anti-Jka was detected by PEG-TAT. Her blood was typed as B, DccEE, Jk (a-b+). She then received 1 unit of RBCs (Jka-negative but C, e-positive). Her anemia improved after transfusion and no hemolytic transfusion reaction was observed. IgM type anti-C + e in the patient detected on day 24 after the first transfusion did not seem to be involved in the DHTR because transfusion of C + e + RBCs on the 24th day did not cause DHTR. Further, we demonstrated that the immunoglobulin (Ig) class of the anti-Jka switched from IgM to IgG during the clinical course. These results suggest that the DHTR was probably due to anti-Jka caused by a primary immune response.