cold agglutinins test

test overview

a cold agglutinins blood test is done to check for conditions that cause the body to make certain types of antibodies called cold agglutinins. cold agglutinins are normally made by the immune system in response to infection. they cause red blood cells to clump together (agglutinate) at low temperatures.

healthy people generally have low levels of cold agglutinins in their blood. but lymphoma or some infections, such as mycoplasma pneumonia, can cause the level of cold agglutinins to rise.

higher-than-normal levels of cold agglutinins generally do not cause serious problems. sometimes, high levels of cold agglutinins can cause blood to clump in blood vessels under the skin when the skin is exposed to the cold. this causes pale or bluish skin and numbness in the hands and feet. the symptoms go away when the skin warms up.

sometimes high levels of cold agglutinins can destroy red blood cells throughout the body. this condition is called autoimmune hemolytic anemia.

why it is done

a cold agglutinins test may be done to see whether high cold agglutinin levels are causing autoimmune hemolytic anemia.

how to prepare

in general, there's nothing you have to do before this test, unless your doctor tells you to.

how it is done

a health professional uses a needle to take a blood sample, usually from the arm.

watch

how it feels

when a blood sample is taken, you may feel nothing at all from the needle. or you might feel a quick sting or pinch.

risks

there is very little chance of having a problem from this test. when a blood sample is taken, a small bruise may form at the site.

results

normal

each lab has a different range for what's normal. your lab report should show the range that your lab uses for each test. the normal range is just a guide. your doctor will also look at your results based on your age, health, and other factors. a value that isn't in the normal range may still be normal for you.

high values

• high cold agglutinin levels may be caused by infections, such as pneumonia caused by mycoplasma, mononucleosis, hepatitis c, or other viral infections.
• high cold agglutinin levels can cause symptoms when a person is exposed to cold temperatures. these symptoms can include numbness, burning, pain, or pale or bluish skin of the fingertips, toes, ears, or nose.