Indirect Antiglobulin Test
(IAT)

Sample type

For (IAT) Serum

Use

It is used to detect very low concentrations of antibodies present in a patient’s plasma/serum prior to a blood transfusion.

The utility of the IAT in blood banking stems from its great sensitivity in detecting various IgG antibodies in the recipient’s serum prior to transfusions. It is part of the antibody screening test. It is used to detect the presence of alloantibodies directed against non-ABO blood group antigens.

Precautions

The IAT is positive in the presence of serum alloantibodies in patients previously transfused and immunized against non-self red cell antigens.

This should be done on fresh serum. Some of the drugs that give false-positive results are cephalosporin, antiarrhythmic, insulin, methyldopa, Dilantin, sulphonamides, and tetracycline. The false-positive or negative results are seen due to: Clerical mistakes.

Interfering factors

A positive IAT requires further investigation to identify more precisely the offending antigen(s).

Pre analytical errors

1- Incorrect Analysis ordered

2- patients identification error

3- sample collection errors

Corrective action

1- Using appropriate technology.

2- Monitoring quality indicators in the lab.

3- Choosing appropriate products.

Post analytical errors

1- Report delayed

2- Not all requested tests done

3- Sharing the results of patients or writing the result incorrectly.

Corrective action

1- Done Accurate Reports after doing tests

2- Assure that the prescribed preventive maintenance for the instruments is performed

3- Attention when delivered the results of patient and write them in the reports

Reference Range

Normal findings: Negative; no agglutination