Skip to main content

Anti-Streptolysin O ( ASO)




 Introduction
This test detects an antibody known as ASO, or anti-streptolysin O. This antibody appears when a person has certain bacteria in the blood. The bacteria are Group A streptococcus, which make an enzyme called streptolysin O. This enzyme destroys red blood cells.
Who is a candidate for the test?
This test can be used to:
  • confirm a recent or ongoing infection with Group A streptococcus
  • help diagnose rheumatic fever or a streptococcal infection in the kidneys
  • determine whether a person has rheumatoid arthritis or rheumatic fever
    • How is the test performed?
    To do the test, a blood sample is taken from a vein on the forearm or hand. First, the skin over the vein is cleaned with an antiseptic. Next, a strong rubber tube, or tourniquet, is wrapped around the upper arm. This enlarges the veins in the lower arm by restricting blood flow through them. A fine needle is gently inserted into the vein chosen and the tourniquet is removed. Blood flows from the vein through the needle. It is collected in a syringe or vial for testing in the laboratory. After the needle is withdrawn, the puncture site is covered for a short time to prevent bleeding.

    What do the test results mean?
    Test results report the number of Todd units of antibodies per milliliter of blood. Normally, ASO antibody levels are less than 160 Todd units per milliliter.
    Higher-than-normal levels of ASO antibodies may indicate:
  • active streptococcal infection
  • bacterial endocarditis, an inflammation in the lining of the heart
  • post-streptococcal glomerulonephritis, an infection in the kidney
  • rheumatic fever, a disease that may affect the heart and kidneys
  • scarlet fever, an infection involving the throat and tongue that causes fever, rash, and rapid pulse  

    • Reference 
    Tabers Cyclopedic Medical Dictionary, F.A.Davis, 1993
    Illustrated Guide to Diagnostic Tests, Springhouse, 1998
    Mosby's Manual of Diagnostic and laboratory Tests, Kathleen Pagana and Timothy Pagana, 1998

    Comments

    Post a Comment

    Popular posts from this blog

    Sputum Cytology

    How is the test performed? This test is usually performed in the morning, right after waking up. The person is asked to rinse his or her mouth with water to avoid a poor sample. After taking several deep breaths, the person then coughs deeply. This should bring up enough of a material from deep in the lungs known as sputum. Sputum is different from spit. The sputum sample is then taken to a lab. The lab can then examine the sample with a microscope    What is involved in preparation for the test? Instructions on sample collection are provided to people having this test. No other special preparation is needed   What do the test results mean? Usually, sputum contains some normal cells. No cells that look like cancer should be in the sample. If cancer cells are seen, the person usually has lung cancer.
    Post a Comment
    Read more

    Toxic Shock Syndrome

    Introduction Toxic shock syndrome, or TSS, is a rare, potentially life-threatening disorder. It occurs when toxins made by certain types of bacteria are released into the bloodstream. What is going on in the body? Toxic shock syndrome was first described in children in 1978. Experts quickly realized it happened more often among women who used superabsorbent tampons during their periods. TSS is triggered by toxins made by Staphylococcus aureus bacteria. The toxins cause a high fever and can damage the kidneys, liver, and heart. Experts believe that tampons may block bacteria within the vagina. The moist, humid environment allows them to grow and produce high levels of toxins. Tampons can cause very small cuts in the vagina during insertion. These small cuts allow bacteria and their toxins to enter the bloodstream. About 70% of TSS cases have been related to certain brands of highly absorbent tampons that are no longer made. What are the causes and risks of the...
    Post a Comment
    Read more

    Bone Marrow Biopsy

    Who is a candidate for the procedure? A person may undergo a bone marrow biopsy in order to: diagnose different types of leukemia when a blood test shows suspicious cell changes follow the response to a leukemia treatment help in diagnosis and treatment of certain other cancers diagnose and monitor the treatment of certain noncancerous blood disorders How is the procedure performed? First, the skin over the rear of the pelvic bone is cleansed. Local anesthesia is used to numb the area. Sometimes a drug is given intravenously to help calm the person having the procedure. A hollow stainless steel needle is inserted into the back part of the pelvic bone. Once it is inside the bone, a sample of the liquid marrow is drawn into the syringe. Sometimes a larger hollow needle is used to obtain a solid core specimen of marrow from the same area. No incision or sutures are needed. The sample taken is checked under a microscope for abnormal cells.     ...
    Post a Comment
    Read more