Possible causes of ABO discrepancy in 238 cases
| Category | Possible causes | % (N) | ||
|---|---|---|---|---|
| RBC | Extra reactivity (N=9) | Auto-agglutinins | 1.5 (5/339) | |
| BMT | 0.6 (2/339) | |||
| Paraproteinemia | 0.3 (1/339) | |||
| Unknown | 0.3 (1/339) | |||
| Weak or missing reactivity (N=175) | ABO subgroup | 30.1 (102/339) | ||
| Unknown | 18.3 (62/339) | |||
| Hematologic malignancy | 3.2 (11/339) | |||
| Serum | Extra reactivity (N=121) | ABO subgroup | 26.8 (91/339) | |
| Unexpected antibody† | 6.2 (21/339) | |||
| Unknown | 2.7 (9/339) | |||
| Weak or missing reactivity (N=34) | Unknown | 8.6 (29/339) | ||
| BMT | 0.9 (3/339) | |||
| Age-related (young age) | 0.6 (2/339) | |||
| Total | 339* | |||
*Some cases revealed multiple causes of ABO discrepancy. Hence, a total of 339 causes were found in 238 ABO discrepant cases.
†ABO discrepancy due to unexpected antibodies comprised 5 cases with autoantibodies, 5 cases with anti-M, 4 cases with anti-P1, 4 cases with unidentified alloantibodies, 1 case with a cold autoantibody, 1 case with an anti-N, and 1 case with a coexisting anti-P1 and cold autoantibody.
Abbreviations: BMT, bone marrow transplantation; RBC, red blood cell.