Complete Blood Count

A Complete Blood Count test CBC is a diagnostic test to measure the following in blood - the number of red blood cells, the number of white blood cells, Platelets and the total amount of hemoglobin in blood. Hematocrit (HCT) is the fraction of blood composed of red blood cells.

A Complete Blood Count normally includes the following components:

• Red Blood Cell Count (RBC) (also known as Erythrocyte Count)
  
• Red Blood Cell Indices : MCV (Mean Corpuscular Volume), MCH (Mean Corpuscular Hemoglobin) and MCHC (Mean Corpuscular Hemoglobin Concentration)
  
• Hemoglobin (Hgb)
  
• Hematocrit ( HCT)
  
• White Blood Cell count (WBC or leukocyte count)
  
• Platelet count (thrombocyte count)
  

A CBC test provides information on measurements such as average red blood cell size or MCV, Hemoglobin per blood cell or Mean Corpuscular Hemoglobin MCH, hemoglobin concentration or the amount of hemoglobin relative to the size of the cell, per red blood cell or MCHC and platelet count.

Why Complete Blood Count test?

This is a complete lab test and is used to detect or monitor different health conditions. A doctor may require this test for various reasons: As a routine check up

If the patient exhibits symptoms such as fatigue, weight loss, fever or any other signs of infection, weakness, bruising, bleeding or signs of cancer

Blood count results may change if you are receiving treatment for medicines and radiation

To monitor any chronic health problem that can change your blood count results such as chronic kidney disease.

Results of CBC

Though blood count may vary with altitude, in general the normal ranges are given below. But it should be noted that these ranges may vary slightly from one laboratory to another. Various laboratories use varied measurements or test different samples. It is best to have it interpreted by a health care provider.

Normal Values:

Red blood cell indices:

MCV (Mean Corpuscular Volume): 80 to 95 femtoliter
MCH (Mean Corpuscular Hemoglobin): 27 to 31 pg/cell
MCHC (Mean Corpuscular Hemoglobin Concentration): 32 to 36 gm/dL

RBC (erythrocyte) count:

Male: 4.7 to 6.1 million cells/mcL
Female: 4.2 to 5.4 million cells/mcL

WBC (leukocyte) count:

4,500 to 10,800 cells/mcL

Hematocrit:

Male: 40.7 to 50.3%
Female: 36.1 to 44.3%

Hemoglobin:

Male: 13.8 to 17.2 gm/dL
Female: 12.1 to 15.1 gm/dL

Platelet (thrombocyte) count:

150,000 to 450,000/dL

What abnormal results mean?

An abnormal result means elevated RBC, hemoglobin or Hematocrit. These may be due to various factors including lack of adequate water and fluids due to severe diarrhea, excessive sweating or if diuretics are used to treat hypertension.

Low RBC, hemoglobin or hematocrit is also a sign of which result due to blood loss on account of heavy menstrual periods over long periods of time, bone marrow failure from radiation, infection or tumor, Hemolysis or breakdown of red blood cells, chronic kidney disease, ulcerative colitis or rheumatoid arthritis, leukemia, multiple myeloma, long term infections such as hepatitis, poor diet and nutritional deficiencies of iron, Vitamin B6, Vitamin B12 and folate.

High levels of Hematocrit can be the result of dehydration, diarrhea, erythrocytosis or myeloproliferative disorders such as Polycythemia Vera.

Lower than normal white blood cell count, or Leukopenia (Leucopenia), can be the result of alcohol abuse and liver damage, autoimmune diseases, bone marrow failure due to infection, tumor, radiation or fibrosis, chemotherapy medicines, disease of liver or spleen, enlarged spleen, infections caused by viruses such as AIDS or medications.

High WBC count is called leukocytosis which can result from certain medicines such as corticosteroids, infections, diseases such as rheumatoid arthritis or allergy, leukemia and severe emotional and physical stress, tissue damage

High platelet count may be due to bleeding - diseases such as cancer, iron deficiency, problems with the bone marrow.

Low platelet count may be due to anemia, disorders where platelets are destroyed during pregnancy, enlarged spleen, bone marrow failure (for example, due to infection, tumor, radiation, or fibrosis), Chemotherapy medicines used to treat cancer.

Disease of the platelets is known as Thrombocytopathy, which could be due to lower Platelet counts (a condition called as Thrombocytopenia or Thrombopenia), or due to a decrease in function (called as Thrombasthenia) or an increase in the number of platelet (addressed as Thrombocytosis). Normal platelet counts do not necessarily indicate normal functioning. In some cases the platelet counts may appear normal but the platelets themselves are dysfunctional. Aspirin inhibits cyclooxygenase-1 (COX1) which results in the disruption of platelet function affecting coagulation. Normal platelet function will be restored only when the affected platelets have been replaced which can take a week.

Precaution : At the time of drawing the blood, it is necessary to clean the venipuncture site with alcohol.

Bronchoscopy

Bronchoscopy is a diagnostic test that is used to view the airways, throat and larynx. This procedure can also facilitate removal of a growth or obstruction from the airway. Bronchoscopy is useful in diagnosing lung diseases and lung cancer. Any growth in the airways can be treated or removed. Other diagnostic tests such as CBC test, arterial blood gas test and PFT may be prescribed before embarking on bronchoscopy. The secretions in the mouth and airways are dried up with suitable medications. The vocal chords are also numbed. Fluroscope is also used to capture the images on a monitor. Avoid eating or drinking for a few hours prior to a bronchoscopy procedure. There might be blood in the sputum in case of biopsy.

Flexible bronchoscope allows a better view of the smaller airways and permits biopsy procedure too. This is called a transbronchial biopsy. Local anesthesia is often sprayed into the nose and mouth.

Rigid bronchoscope often necessitates the patient to be anesthesized and is resorted to when large samples need to be taken for biopsy and to remove pieces of food or dilating the airway. Use of laser is possible for removal for obstructions.

Abnormal results of bronchoscopy may be indicative of lung cancer, tumor, enlarged lymph nodes, ulceration or abnormality in the bronchial wall. Bronchoscopy is prescibed in cases where the patient coughs up blood or chest x-ray shows abnormal findings. If a person has inhaled a foreign body into the lung, bronchoscopy can help in removing it.

Spherocytosis

Hereditary Spherocytosis is a genetic disorder characterized by red blood cells that are fragile and spherical in shape instead of the normal flat disk shape. The abnormal shape makes it difficult for red blood cells to pass through the spleen. The spleen's function is to purify the blood and safeguard the immune function by fighting against the potentially dangerous bacteria, viruses or other microorganisms in the blood. In case of Spherocytosis, the membrane of the red blood cells is defective lending it a spherical shape. When these defective blood cells pass through the spleen, they break and destroy causing premature death of the red blood cells. The shortage of blood cells gives rise to severe anemia. It is an inherited type of Hemolytic Anemia. A parent with the disease has a 50% chance of having a child with the disease. Spherocytosis is most common in people of northern European descent.

Symptoms

The symptoms can vary from mild to severe. In severe cases, the disorder may be found in early childhood. In mild cases it may go unnoticed until adulthood. Patients with Spherocytosis exhibit all the symptoms associated with anemia such as fatigue, irritability, shortness of breath and muscle weakness. They also appear pale and weak. In addition to these symptoms, Spherocytosis also causes enlarged spleen and jaundice with yellow skin and eyes. Jaundice occurs due to the elevated levels of serum bilirubin as the red blood cells are destroyed within the body. Excess bilirubin, sometimes, also results in in the gallbladder. These stones may cause pain, infection or may block the tubes that lead out of the gallbladder.

Diagnosis

Family history is checked for hereditary factor and the abdomen has to be checked for enlarged spleen. Following blood tests may be performed to support the clinical examination:

• CBC or complete blood count test to check for anemia.
  
• The Reticulocyte Count Test is performed to measure the new and immature red blood cells produced in the bone marrow. The reticulocyte count is usually higher in cases of Spherocytosis.
  
• Osmotic Fragility Test is performed to measure the fragility of the red blood cells. This involves taking a blood sample and suspending in a salt solution and then measuring the destruction and fragility of the cells.
  
• Coombs Test to measure the antibodies in the blood.
  
• Blood test to check for bilirubin levels.

Treatment

Splenectomy is the most definitive treatment for hereditary Spherocytosis. By removing the spleen, red blood cells are prevented from damage and are allowed to stay alive for a longer duration. However, removing a spleen makes the patient susceptible to infections for a lifetime. Hence patients need to take penicillin (or another antibiotic) for the rest of their lives. Immunization against pneumococcal and meningococcal infections is also prescribed. In case of severe anemia, blood transfusion is advised.