Complete Blood Count (CBC) Test: What It Is and What to Expect

What is this test? The complete blood count (CBC) is a routine blood test that measures the cells that make up your blood, including red blood cells, white blood cells, and platelets. It gives your care team a broad picture of your overall health and can help detect a wide range of conditions.

The Aspergillus IgE Antibody test measures the level of immunoglobulin E (IgE) antibodies specific to Aspergillus fumigatus and Aspergillus niger in your blood. IgE is a type of antibody that plays a key role in allergic reactions. When your immune system detects these fungi, it may produce IgE antibodies, which can be measured through this blood test.

Why is it ordered? Your doctor may order a CBC as part of a routine checkup, to look into symptoms such as fatigue, weakness, fever, bruising, or signs of infection, or to monitor a condition you already have and to see how a treatment may be affecting your blood counts.

Your doctor may order this test if you have symptoms suggesting an allergic reaction to mold, such as wheezing, shortness of breath, coughing, or sinus problems. It is particularly useful for diagnosing allergic bronchopulmonary aspergillosis (ABPA), a condition often seen in people with asthma or cystic fibrosis. The test helps differentiate between allergic conditions and actual fungal infections.

How is the test performed? A healthcare professional will draw a small sample of blood, usually from a vein in your arm. The needle stick takes only a few moments, the sample is sent to a laboratory for analysis, and you can return to your normal activities right away after the draw.

A healthcare professional will draw a small blood sample from a vein in your arm. The sample is then sent to a laboratory where it is analyzed for the presence and quantity of IgE antibodies specific to Aspergillus species. No special fasting or preparation is typically required before this test.

Understanding your results: Your report lists the measured level of each blood cell type next to a reference range. Values that are higher or lower than normal may suggest conditions such as anemia, infection, or inflammation, but a single result rarely provides a diagnosis. Your provider will interpret the results along with your symptoms and medical history and discuss any next steps with you.

Results are typically reported as a numerical value indicating the level of IgE antibodies. A positive result suggests that your immune system has produced antibodies against Aspergillus, which may indicate an allergy or allergic disease. Your doctor will interpret these results along with your symptoms, medical history, and other test results to make an accurate diagnosis.