Complete Blood Count (CBC) Test

A complete blood count (CBC) is a common blood test that measures the cells circulating in your blood, including red blood cells, white blood cells, hemoglobin, hematocrit, and platelets. It provides your doctor with a broad picture of your overall health and can help detect a wide range of conditions, such as infections, anemia, dehydration, and certain blood disorders, often before symptoms appear.

The Lyme Disease IgG Line Blot test is a laboratory blood test that detects IgG antibodies in your blood serum against three species of Borrelia bacteria (Borrelia afzelii, B. burgdorferi, and B. garinii) that cause Lyme disease. The test uses a technique called line immunoblot (line blot), which can identify specific antibodies to different bacterial proteins. This test is typically performed after an initial screening test (like ELISA) shows a positive or indeterminate result.

Your doctor may order a CBC as part of a routine checkup to monitor your general health, or to help evaluate symptoms like fatigue, weakness, fever, dizziness, easy bruising, or unexplained bleeding. It is also used to diagnose a suspected condition, monitor an existing illness such as kidney disease, or track how treatments like medications or chemotherapy are affecting your blood cells over time.

This test is ordered when a patient has signs and symptoms suggestive of Lyme disease, such as the characteristic 'bull's-eye' rash (erythema migrans), fever, headache, fatigue, or joint pain, especially if there is a known or suspected tick bite or exposure to areas where Lyme disease is common. It helps confirm whether the patient has been infected with Borrelia bacteria.

A CBC is performed through a simple blood draw. A healthcare professional will clean the skin on your arm, wrap a band around your upper arm to make the veins easier to see, and insert a small needle into a vein to collect a sample into a tube. The procedure usually takes only a few minutes, causes little more than a brief pinch, and you can return to your normal activities right afterward.

A blood sample is drawn from a vein in your arm. In the laboratory, the serum (the liquid part of your blood) is incubated with a strip that contains purified Borrelia antigens. If IgG antibodies against these antigens are present in your blood, they will bind to specific bands on the strip. The intensity and pattern of these bands are then analyzed to determine the result.

Your results show whether your blood cell counts fall within the normal reference ranges. A high white blood cell count may suggest an infection, inflammation, or stress on the body, while low red blood cells or hemoglobin can point to anemia, bleeding, or a nutritional deficiency, and abnormal platelet levels may affect clotting. Your doctor will interpret the values together with your symptoms and medical history, since an abnormal result does not always mean a serious problem.

Results are reported as either positive, negative, or indeterminate based on the presence and pattern of specific bands. Different bands correspond to antibodies against different Borrelia proteins. A positive result with multiple characteristic bands strongly suggests Lyme disease infection. However, the interpretation must consider the patient's clinical symptoms, exposure history, and timing of the test relative to the onset of symptoms, as IgG antibodies take time to develop.