Blood Types

Over 100 years ago, it was discovered that people have different types of blood. Even though all blood consists of the same basic elements, not all blood is alike. The four main ABO blood types are O, A, B, and AB. Each is paired with a + or – Rh factor, which is determined by the presence or absence of substances that can trigger immune responses if they are foreign to the body. These substances are called antigens. Safe blood transfusions depend on careful blood typing and cross-matching. Click your type below to learn more about it.

As you can see, some types mix, while others don’t, but each type is important when it comes to saving lives. Miller-Keystone Blood Center often runs short of types O and B blood, and AB plasma. However, shortages of all types of blood occur during the summer and winter holidays. If all eligible donors gave at least twice a year, it would help prevent blood shortages.

There are more than 600 known antigens besides A and B. Certain blood types are unique to specific racial and ethnic groups. Therefore, it is essential that the donor diversity match the patient diversity. For example, U-negative and Duffy-negative blood types are unique to African-Americans. So Sickle cell patients with these blood types must rely on donors with matching blood types within their own community.

Different ethnic and racial groups also have different frequencies of the main blood types in their populations. For example, 51 percent of African-Americans and 57 percent of Hispanics are type O, but only 45 percent of Caucasians are type O. Type O is routinely in short supply and in high demand by hospitals – both because it is the most common blood type and because type O negative blood, in particular, is the universal type needed for emergency transfusions. Minority and diverse populations, therefore, play a critical role in meeting the constant need for blood.