Antistreptolysic (ASO)
From Health Facts
Latest Edit: Hector 2014-03-21 (EDT)
See Also | Lab Tests |
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This test is used mainly to determine whether a previous streptococcus infection has caused a poststreptococcal disease, such as glomerulonephritis, rheumatic fever, bacterial endocarditis, and scarlet fever.[1]
Discussion
- ASO, or antistreptolysic O titer is a seroligic procedure that shows the body's reaction to infection caused by group A beta-hemolytic streptococci.
- Streptococcus organisms produce an enzyme called streptolysin O, which can destroy red blood cells.
- Therefore, the body reacts to the antigenic streptolysin O by producing ASO, a neutralizing antibody.
- ASO can appear in the serum 1 week to a month after the onset of a streptococcal infection, levels appearing higher in glomerulonephritis and rheumatic fever.
Patient Preparation
- No fasting required.
- Factors which can cause increased levels
- Increased beta-lipoprotein levels can neutralize streptolysic O and appear as increased ASO levels
- Factors which can cause decreased levels
- Drugs: antibiotics and adrenocorticosteroids
Clinical Implications
High levels indicate:
- Acute streptococcal infection
- Acute rheumatic fever
- Bacterial endocarditis
- Acute glomerulonephritis
- Scarlet fever
- Streptococcal pyoderma
Associated Tests
- Antideoxyribonuclease-B Titer
References
- ↑ Pagana Kathleen D, Pagana Timothy J (2006) Mosby's Manual of Diagnostic and Laboratory Tests, Mosby.