In today’s time, there are various medical processes that involve taking a blood test. This allows doctors to check whether a person is healthy or not. However, there are various types of blood tests that are taken for different purposes. INR and APT are two such tests that are conducted to check the concretion of blood.
INR vs APT
The main difference between INR and APT is that INR test is done to measure the amount of time it takes for a person’s blood to clot, in order to check for blood clotting problems whereas APT test is done to distinguish a baby’s blood from the blood of his mother.
INR test is also commonly known as ‘international normalized ratio’. It is done to check whether a person’s blood is clotting properly in due time or not. Generally, a doctor may ask a patient using blood-thinning medications to take an INR test. This helps monitor the intake and effect of the medicine.
Meanwhile, an APT test is taken to distinguish the blood of mothers and babies. It is commonly known as ‘alkali denaturation test’ (A). The test is normally done for women in the ending stages of their pregnancy. Unlike INR, APT checks for haemoglobin and has nothing to do with blood clotting.
Comparison Table Between INR and APT
| Parameters of Comparison | INR | APT |
| Common Name | INR is commonly known as ‘international normalized ratio’. | APT is commonly known as ‘alkali denaturation test’ (A). |
| Purpose | It is done to check if a person is suffering from blood clotting problems. | It is done to distinguish the blood of a fetus and mother. |
| Mechanism | It measures the time taken for a person’s blood to clot. | It checks the haemoglobin of the blood. |
| Patient | It is done for people using blood-thinning medicines. | It is done for women in the ending stages of their pregnancy. |
| Method | It is done by taking a blood sample through injection. | It is done by checking the maternal vaginal blood. |
What is INR?
INR is most commonly known as ‘international normalized ratio’. As the name suggests, it checks the amount of time that is being taken by a person’s blood for the process of clotting. This helps to diagnose whether a person is suffering from blood clotting problems or not. Patients who use blood-thinning medicines are generally suggested to get this test done.
This kind of blood test is conducted by collecting a blood sample of the patient through an injection. The blood is then checked for a protein called prothrombin which is secreted by the liver. This protein is one of the many proteins that play an important role in the process of blood clotting.
The INR test is used by doctors all over the world to check for bleeding conditions, blood clotting problems, and even the health of the liver. Many doctors prefer to conduct this test before surgery.
If the results of an INR test are very high, this means that the blood is taking too long to clot. This means that there is a major risk of bleeding. In contrast, if the results are too low, then the person is prone to form a blood clot in his body.
What is APT?
APT stands for alkali denaturation test (A). It is done to distinguish the blood of a foetus and mother. The test can be done for women in their ending stages of pregnancy as well as newborn babies. Unlike INR, APT check for the haemoglobin in the blood and has nothing to do with blood clotting.
An APT test is taken by checking for maternal vaginal blood, or blood present in a newborn baby’s vomit or stool. This blood is taken and combined with sterile water. This results in the haemolysis of RBCs present in the blood. Further, the sample is centrifuged and mixed with certain chemicals. In doing so, the colour of the sample changes, indicating whose blood it is.
The APT test is very useful for checking the origins of bleeding in pregnant women. It also helps to know if a baby has somehow swallowed maternal blood.
If the blood is of the baby, it will stay pink. This means that the test would be positive. On the other hand, if the blood changes colour and becomes yellowish-brown, it means that the test is negative, and the blood is of the mother. However, it must be noted that this process is performed under a microscope.
Main Differences Between INR and APT
- INR is commonly known as ‘international normalized ratio’ whereas APT is commonly known as ‘alkali denaturation test’ (A).
- INR is done to check if a person is suffering from blood clotting problems whereas APT is done to distinguish the blood of a fetus and mother.
- INR measures the time taken for a person’s blood to clot whereas APT checks the haemoglobin of the blood.
- INR is done for people using blood-thinning medicines whereas APT is done for women in the ending stages of their pregnancy.
- INR is done by taking a blood sample through injection whereas APT is done by checking the maternal vaginal blood.
Conclusion
INR and APT are two kinds of blood tests that have quite a few similarities. Each of them is used to check the concretion of blood and furthermore determine whether a person is healthy or not. However, there are several differences between the two when it comes to their purpose, mechanism, method, and even the people that they are conducted on.
The most notable difference between the two is that INR is done to check if a person is suffering from blood clotting problems whereas APT is done to distinguish the blood of a fetus and mother. Furthermore, the INR test is done for people who use blood-thinning medicines whereas the APT test is done for pregnant women and newborn babies.
Another major difference between the two is that in an INR test, the blood sample of the patient is taken with the help of an injection. On the other hand, in the case of an APT test, maternal vaginal blood or blood from a newborn baby’s vomit and stool is used.
References
- https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1365-2141.2004.05154.x
- https://europepmc.org/article/med/7520161