Anti Streptolysin O

From Anvita Health Wiki

Contents 1 Reference-interval 2 Clinical-significance 3 Increases 4 Interferences 5 More General Terms 6 Additional Terms 7 References

Reference-interval

• negative is < 150 Todd units [2]

Clinical-significance

• antibody titer against streptolysin O produced by Group A beta hemolytic Streptococci
• titers rise 1 week after infection, peak in 3-5 weeks & return to baseline in 6 months to 1 year
• a rise in titer of at least 4-fold over a 1-2 week period is more useful than a single determination

Increases

• 40-50% of patients with group A beta hemolytic streptococcal pharyngitis ( culture proven)
• 80-85% of patients with rheumatic fever show a rise in ASO titer
• 25% of streptococcal pyoderma

Interferences

• serum beta lipoprotein in liver disease & some bacterial proteins may neutralize the hemolytic properties of streptolysin O thus producing a false positive titer

More General Terms

• serology

Additional Terms

• Acquired Immuno-Deficiency Syndrome (AIDS)

References

1. Clinical Guide to Laboratory Tests, 3rd ed. Teitz ed., W.B. Saunders, 1995
2. Medical Knowledge Self Assessment Program (MKSAP) 11, American College of Physicians, Philadelphia 1998

anti-streptolysin O (ASO) titer