Saturday, December 18, 2010

Hepatitis C: White Blood Count During Therapy

What Are The Tests Given Prior To HCV Therapy:
Thyroid function test, hemoglobin, complete and differential white blood cell counts, platelet counts and blood chemistries including liver function tests. A pregnancy test, chest roentgenogram and ECG should also be performed prior to initiating interferon therapy. Also an eye exam should be preformed.

What Are The Hematologic Side Effects Of HCV Therapy
The side effects from interferon and ribavirin therapy often lead to lowered dosages or even discontinuation of therapy. Ribavirin causes a dosage-dependent, hemolytic anemia, and interferon can suppress bone marrow production of red blood cells.

See Related Information Anemia During HCV Treatment

Interferon suppresses bone marrow production of leukocytes, which leads to a drop in the white blood count or neutropenia in approximately 20% of treated patients. A certain type of white blood cell called "neutrophils" are important in fighting bacterial infections.
What Causes A Low Neutrophil Count?
Neutrophils die continuously from age or from fighting infections, and your bone marrow must make new neutrophils to replace them. When something reduces production of neutrophils in your bone marrow, the neutrophil count will drop and may become dangerously low. Prescription medications or HCV antiviral drugs such as interferon can cause neutropenia. In almost all cases, drug-induced neutropenia (low white count) resolves after the agent is stopped or its dosage is reduced.

What Is A Normal White Count ?
Normal Adult Range: 3.8 - 10.8 thous/mcl
Optimal Adult Reading: 7.3
Higher ranges are found in children, newborns and infants.
What are neutrophils?
Neutrophils are a major part of your body’s defense against bacterial infections. When the WBC is low, there may not be enough neutrophils to defend you against bacterial infections. Neutrophils are made in the bone marrow and circulate in the bloodstream. Neutrophils move out of the blood vessels into the infected tissue to attack the bacteria. The pus in a boil (abscess) is made up mostly of neutrophils. Normally a serious bacterial infection causes the body to produce an increased number of neutrophils, resulting in a higher than normal WBC.

What Do Physicians Consider A Low Neutrophil Count Or (absolute neutrophil count = (ANC)
Neutropenia is a common reason for dose adjustment during HCV therapy, if the white count or the neutrophil count gets to be very low, typically your doctor may adjust down the interferon dose.
Physicians like to keep the neutrophil count (absolute neutrophil count = (ANC) above 750, patients do not typically develop infections. However, if neutrophil counts go below 500/µL interferon is suspended.
Physicians sometimes use a drug called GM-CSF or Neupogen to keep up the white count. Neupogen is a drug that is used primarily for cancer patients receiving chemotherapy. It is effective in getting the bone marrow to make more white cells. Like interferon, it has to be injected.
How Can I Figure Out My Absolute Neutrophil Count (ANC)?
Neutrophil% x White Blood Cell = Absolute Neutrophil Count
For example, if a person's white blood cell count were 6,000 cells, and neutrophils made up 50% of those, that person's absolute neutrophil count would be 3,000.

From The Cleveland Clinic:

Hepatitis C Management
Ask The Experts

In an HCV-infected patient with neutropenia who is receiving pegylated interferon and ribavirin, what is the recommended absolute neutrophil count (ANC) target range when treating with filgrastim (Neupogen)?
At what absolute neutrophil count =ANC value should filgrastim therapy be initiated, and what is the suggested dosage?
The clinical implication of neutropenia during HCV therapy remains controversial. In one study of 119 HCV patients who were treated with the combination therapy, bacterial infections were not associated with severe neutropenia. The current recommended dose-reduction threshold for neutropenia is an ANC of less than 750. The safety and efficacy of filgrastim for managing interferon-related neutropenia in patients with HCV has not been established, and its use in this specific situation is not FDA-approved. Small-scale studies of filgrastim 300 µg weekly to 300 µg thrice weekly have suggested efficacy with relative safety.
Clinicians who decide to use filgrastim should carefully monitor white blood cell counts after filgrastim and should use the lowest effective dose.

White Blood Cell Chases Bacteria
It's dinner time for this white blood cell. White blood cells are cells of the immune system defending the body against both infectious disease and foreign materials.

What are the most serious side effects of PEGASYS and COPEGUS?
Serious side effects are:
Mental health problems (such as depression, thoughts about suicide, suicide attempts and relapse of drug abuse or drug overdose, all of which can lead to death. Other problems include thoughts of homicide or hurting other people, irritability, anxiety, aggressiveness, bipolar disorders, mania, and hallucinations)
Blood problems (like a drop in blood cells leading to increased risk for infections, bleeding and/or heart or circulatory problems). Low levels of red blood cells can cause death in patients taking COPEGUS. Most blood counts may be reduced including white blood cell, red blood cell, platelets, hemoglobin, neutrophil, and lymphocyte counts.
Other blood disorders
Problems with pregnancy
Lung problems (like trouble breathing, pneumonia, inflammation of lung tissue, and high lung blood pressure), sometimes requiring a machine to breathe for you and/or causing death
Eye problems (blurred, loss of vision, and retinal detachment)
Autoimmune problems (sarcoidosis, rheumatoid arthritis, systemic lupus erythematosus, psoriasis, and thyroid problems, such as hyperthyroidism and hypothyroidism)
Heart problems (including high or low blood pressure, chest pain, fast heart rate, and heart attacks) which can lead to death
Stomach pain (stomach or corneal ulcers)
Rash with fever or blisters
Weakness, loss of coordination, numbness, and difficulty speaking due to stroke, including patients with no known risk for stroke
Liver problems (rarely, liver function worsens) including an increased chance of liver failure in patients with cirrhosis. Patients with both the hepatitis C virus and HIV have an increased chance of liver failure during PEGASYS treatment. Change in a blood test that measures liver inflammation occurs more often in patients with hepatitis B. If you have a rise in this blood test you may need to be watched more closely with additional blood tests. Severe liver damage can lead to death
Colitis (inflammation of the colon, which can cause abdominal pain, bloody diarrhea, and fever) which can lead to death
Inflammation of the pancreas, muscles, and bile ducts which can lead to death
Blood sugar problems such as high or low blood sugar and diabetes
Bacterial, viral, fungal infections (such as in the blood, bones, heart, kidneys and lungs) which can lead to death

What are the most common side effects of PEGASYS and COPEGUS?
The most common side effects are:
Flu-like symptoms (including fever, chills, muscle aches, joint pain, headaches, tiredness)
Upset stomach (like nausea, vomiting, taste changes, diarrhea)
Skin problems (like rash, dry or itchy skin, or redness and swelling at injection site)
Hair thinning or loss (temporary)
Mental health problems (such as depression, difficulty sleeping, irritability, and anxiety)
Anorexia or loss of appetite leading to weight loss
Tell your doctor immediately if you think you or your partner may be pregnant or if any of these symptoms occur.

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