ALC (Absolute lymphocyte count) Test

A Lymphocyte count gives an estimate of the level of lymphocytes in the blood. Your doctor may suggest this test if he/she suspects that you may be suffering from an infection or disease. Most common symptoms that prompt doctors to order this test are fever, chills, body pain, headaches, and low level of energy. However, this test is usually not performed separately, instead, it is estimated as a part of a complete blood count test. It is then known as the blood differential test as it also gives us an estimate regarding other components of the blood such as white blood cells. 

You do not need any special preparation for this test.

In order to conduct the test, only a small amount of blood is needed. A doctor or laboratory technician will collect a blood sample from a vein in your arm by the following procedure:

• An elastic band will be wrapped around your upper arm in order to slow the flow of blood. This will make the veins present below the band to swell up so that a needle can be easily inserted
• The injection site will be cleaned with alcohol 
• A sterile needle will be inserted into the vein. Sometimes, more than one needle insertion may be required to get the right vein. You may feel a quick sting or pinch as the needle goes in
• A tube will be attached to the needle in order to collect the blood sample and once enough blood has been collected, the band will be removed from the arm

Some risks associated with taking a blood sample are:

• Difficulty in obtaining the sample
• Excessive bleeding at the site from where the blood is drawn
• Fainting 
• Haematoma (accumulation of blood under the skin)
• Infection at the site where the needle is inserted

However, these risks can easily be reduced if proper precautionary measures are taken. 

In some cases, the doctor may take a bone marrow sample for this test instead of a blood sample.

Normal results:

An ALC test calculates the number of lymphocytes in the blood and can provide an estimate of the T and B cells. The normal range for lymphocytes is 0.90-2.90 x 109/L. T cells account for about 80% of lymphocytes (800-3,200 cells/µL) whereas B cells account for 10%-15% of the total lymphocyte count (100-600 cells/µL).

Abnormal results:

High lymphocyte count can be indicative of an infection, autoimmune disease or some blood cancers.

A T-cell count above the normal range could be indicative of:

• Viral infections
• Parasitic infections
• Tuberculosis
• Blood cancer
• Cancer of the white blood cells
• Lymphocytosis (a condition in which the lymphocyte count is above the normal range due to the presence of an infection or, in extreme cases, leukaemia).

A B-cell count above the normal range may be indicative of:

• Multiple myeloma
• Cancer of the bone marrow

Lower than normal lymphocyte count can be indicative of conditions such as lymphocytopenia or may also be caused by malnutrition, severe stress, infection or intense physical exercise.

A T-cell count below the normal range can indicate:

• Diseases present at birth
• Human immunodeficiency virus (HIV)
• Cancer
• Lymphocytopenia (a condition in which your lymphocyte count is lower than the normal due to infections, autoimmune disorders, cancer treatments, or nutritional causes)

A B-cell count below the normal range could indicate:

• Acute leukaemia
• HIV

Disclaimer: All results must be clinically correlated with the patient’s complaints to make a complete and accurate diagnosis. The above information is provided from a purely educational point of view and is in no way a substitute for medical advice by a qualified doctor.