Indirect Coombs Test (IAT)

Hematology

Normal Reference Ranges

Adult

Negative Titer

Pediatric

Negative Titer

Clinical Significance

Detects unbound circulating antibodies against red blood cell antigens in the serum. Used for pre-transfusion compatibility testing and prenatal screening.

Causes of High

  • Maternal-fetal Rh incompatibility
  • Prior blood transfusion sensitization
  • Autoantibodies

Causes of Low

  • Normal finding