February 25, 2004
|Now able to provide many same-day blood test results for veterans and health care providers in Lufkin, (from left) Wanda Stephens, B.S. M.T. (A.S.C.P.), supervisory medical technologist, Thomas French, M.T. (A.M.T.) M.L.T. (A.S.C.P.), medical technologist, and Debbie Huber, P.O.L.T., medical technician demonstrate the capabilities of the new Lufkin VA Outpatient Clinic laboratory machine.|
LUFKIN, TX - In December 2003, the Lufkin VA Outpatient Clinic (LOPC) installed a new machine that enables its laboratory to perform several types of blood tests in-house. This now means same day results for veterans and health care providers at the clinic.
This article will describe the new blood tests the LOPC laboratory is now able to perform. It also gives you an idea what the tests mean and what they are used for.
PSA (Prostate-specific Antigen)
PSA levels are used as an aid in the diagnosis of prostate cancer. Long-term serial assays are used to follow response to therapy and to detect recurrent disease. PSA is also being used as a screening test for prostatic cancer in asymptomatic men.
The PSA test is one of the VA's performance measures. This means we do this test on our patients at least once a year.
One important thing to know is that although PSA is thought to be prostate specific, there are reports of non-prostatic conditions leading to an elevated PSA. These may include testosterone administration, prostatic massage, urinary retention, and prostatitis (inflammation of prostate). Other conditions may elevate this test so it requires careful interpretation by a physician or provider.
TSH (Thyroid Stimulating Hormone)
This test is ordered to help establish the diagnosis of Graves' disease, the most common cause of hyper-thyroidism (overproduction and elevated), and as a predictor of relapse after therapy. The symptoms of Graves' disease range from anxiety, heat intolerance, and restlessness to insomnia, diarrhea, and weight loss. In addition, the eyeballs may begin to protrude causing irritation and tearing.
Thyroid stimulating hormone (TSH) is elevated in about 80 percent of patients with Graves' disease (both treated and untreated). The new second-generation assays for TSH-receptor antibodies (which we perform) may be positive in up to 99 percent of patients with Graves' disease.
Thyroxine, Free T-4
Free thyroxine is elevated in hyperthyroidism and reduced in hypothyroidism. This test is used to confirm hypo- or hyperthyroidism in individuals with abnormal or equivocal screening tests of thyroid function such as the TSH test. TSH and Thyroxine Free T-4 tests are used in evaluating for hyperthyroidism and hypothyroidism.
Hyperthyroidism (elevated) is defined as a clinical state resulting from any one of several causes and is characterized by some of the following symptoms: nervousness, increased sweating, hypersensitivity to heat, palpitation, fatigue, weight loss, shortness of breath, weakness, goiter, and skin changes.
Hypothyroidism (decreased) symptoms may include fatigue, sleepiness, lethargy, decreased memory, depression, impaired cognitive functions, slow speech, lack of interest, cold intolerance, muscle weakness and cramps, and hair loss.
Ferritin is the main storage molecule for iron. Serum Ferritin level is helpful in differentiating between iron deficiency anemia and anemia of chronic inflammation, infection, or chronic disease. In iron deficiency anemia, serum ferritin is low (below 10 ng/ml); a serum ferritin level lower than 50 ng/ml in a patient with obvious inflammatory disease is a strong indicator of iron deficiency. If you have a low hemoglobin, your provider may order a ferritin to aid in diagnosis of your condition.
Patients may also have elevated ferritin levels indicating iron overload. Ferritin levels are usually elevated in patients with hemochromatosis. During the development of hemochromatosis, iron is confined mainly to liver parenchymal cells and in the absence of cellular damage, relatively little ferritin is released.
A patient may require a therapeutic phlebotomy (the regular removing of units of blood) if their hemoglobin level becomes too high and causes stress on other parts of the body such the heart and circulatory systems. In order to relieve these symptoms, a unit of blood may be drawn from the patient in order to lower the iron stores. Ferritin is the most reliable way to monitor therapeutic phlebotomy. Therapeutic phlebotomy should be done to maintain the serum ferritin at 50 ng/ml or less.
Vitamin B12 - (Cobalamin)
Vitamin B12 measurements are useful in the diagnosis and evaluation of Vitamin B12 deficiency, macrocytic anemias, megaloblastic anemias, depression, neurological diseases, folate deficiencies, malabsorption and gastrointestional disorders, rare inherited conditions, and some blood disorders.
Vitamin B12 measurements are often performed simultaneously with folate levels. Causes of decreased serum Vitamin B12 are inadequate diet, inadequate absorption, and interference with Vitamin B12 absorption due to medications.
Folate is ordered along with Vitamin B12 to evaluate dietary intake. Folate and folic acid are forms of a water-soluble B vitamin. Folate deficiency is most commonly encountered in pregnancy and alcoholism. Signs of folic acid deficiency are often subtle. Diarrhea, loss of appetite, and weight loss can occur. Additional signs are weakness, sore tongue, headaches, heart palpitations, irritability, and behavioral disorders. Folate deficiency is also seen in the elderly population. Serum folate values fluctuate significantly with diet.
Now that the LOPC laboratory can perform these additional tests, the blood specimens do not have to be sent to Michael E. DeBakey VA Medical Center in Houston to have the testing done. This means the results of the tests can be ready on the same day the blood is drawn and available to the clinical staff when they see the patient. Timing is everything!
by Wanda Stephens, M.T. (A.S.C.P.), LOPC Supervisory Medical Technologist
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Point of Contact: VHAHOU Public Affairs04/21/04 08:25