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ASO ( Ani Streptolysin O). Dr. M. Izad. ASO A diagnosis test for: Acute rheumatic fever (2-3% Pharyngitis-Tonsilitis) ( Antigeng M) Rheumatic heart disease Acute post streptococcal glomerulonephritis (2-5% Chronic) (Streptokinase). Streptococcal Antibody Test.
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ASO(AniStreptolysin O) Dr. M. Izad
ASO A diagnosis test for: • Acute rheumatic fever (2-3% Pharyngitis-Tonsilitis) ( Antigeng M) • Rheumatic heart disease • Acute post streptococcal glomerulonephritis (2-5% Chronic) (Streptokinase)
Streptococcal Antibody Test • Streptolysin O: An exotoxin which is sensitive to oxygen.
General pattern of antibody response to group A streptococcal extracellular antigen
Todd Unit: concentration of ASO which neutralize completely 2.5 minimum hemolytic dose of SO. minimum hemolytic dose of SO :the smallest amount of SO that produces complete lysis of 0.5 ml of 5% red blood cells at 37°c in 1h.The unit in which the results of testing for antistreptolysin O (ASO) are expressed. It denotes the reciprocal of the highest dilution of testserum at which there continues to be neutralization of a standardpreparation of the streptococcalenzymestreptolysin O.
Interpretation of the result Different factors such as age ,previous infection, immune system status & society affect the ASO interpretation Titer in adults: 250 unit 300-1500Acute rheumatic fever (85%) Todd Acute post streptococcal glomerulonephritis(ADNaseB)
VDRL(Veneral Disease Research Laboratory)& RPR(Rapid Plasma Reagin)
Syphilis (Treponema Pallidum) Primary syphilis Secondary syphilis Latent syphilis Tertiary/ late latent syphilis
Laboratory diagnosis Microscopic Tests Dark field Immunoflurescense Serologic Tests Screening non-Treponema tests (non-specific/VDRL, RPR) Confirming Treponema tests (specific/FTAabs)
Interpretation of the result Flucculation (negative/ weak positive/ positive) Titration (1/8, 1/16, 1/32) Primary syphilis: 30% Neg (repeat after 1w/ 1&3mo) Titration is used for confirming of threapy Secondary syphilis: 100% psitive &over 1/16 Late latent syphilis: 20% Neg
False positive & False negative False positive: Intravenous drug users (10% FP) Pregnancy Autoimmune disease (Rheumatoid Arthritis, lupus) Aged individuals Chronic infection (leprosy) False negative: Prozone phenomena (FN /1-2% secondary syphilis) Latent syphilis
CRPC-Reactive Protein Acute Phase Protein Passive agglutination
the increase of CRP serum concentrations observed in • Microbial infections • Acute rheumatic fever • Acute myocardial infarction • Rheumatoid Arthritis • Cancer
CRP • Severity of the disease & effectiveness of therapy • False positive: • Corticosteroids • Prozone • False positive: • Old serum