ASO (Ani Streptolysin O)

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ASO(Ani Streptolysin O)

• Dr. M. Izad

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• 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)

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Streptococcal Antibody Test
Streptolysin O An exotoxin which is sensitive to
oxygen.
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General pattern of antibody response to group A
streptococcal extracellular antigen
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ASO an enzyme inhibition test
Tube NO. Tube NO. 1 1 2 3 4 Red cells control SO control
ASO Buffer ASO Buffer 0.2 0.2 0.4 0.6 0.7 1.5 1 (ml)
Serum Serum 0.8 0.8 0.6 0.4 0.3 -- --

SO SO 0.5 0.5 0.5 0.5 0.5 -- 0.5
20 min in room temperature 20 min in room temperature 20 min in room temperature 20 min in room temperature 20 min in room temperature 20 min in room temperature 20 min in room temperature 20 min in room temperature 20 min in room temperature
Red blood cells 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5
Titer (Todd) 125 125 166 166 250 333 No lysis lysis
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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 37c 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 test serum at which
there continues to be neutralization of a
standard preparation of the streptococcal enzyme
streptolysin O.
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Interpretation of the result

• Different factors such as age ,previous
  infection, immune system status society affect
  the ASO interpretation
• Titer in adults 250 unit
• 300-1500 Acute rheumatic fever (85)
• Todd Acute post streptococcal
  glomerulonephritis (ADNaseB)

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VDRL(Veneral Disease Research Laboratory)
RPR(Rapid Plasma Reagin)
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Syphilis (Treponema Pallidum)

• Primary syphilis
• Secondary syphilis
• Latent syphilis
• Tertiary/ late latent syphilis

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Laboratory diagnosis

• Microscopic Tests
• Dark field
• Immunoflurescense
• Serologic Tests
• Screening non-Treponema tests (non-specific/VDRL,
  RPR)
• Confirming Treponema tests (specific/FTAabs)

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Interpretation of the result

• Flucculation (negative/ weak positive/ positive)
• Titration (1/8, 1/16, 1/32)
• Primary syphilis 30 Neg (repeat after 1w/
  13mo)
• Titration is used for confirming of threapy
• Secondary syphilis 100 psitive over 1/16
• Late latent syphilis 20 Neg

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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

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CRPC-Reactive Protein

• Acute Phase Protein
• Passive agglutination

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the increase of CRP serum concentrations observed
in

• Microbial infections
• Acute rheumatic fever
• Acute myocardial infarction
• Rheumatoid Arthritis
• Cancer

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CRP

• Severity of the disease effectiveness of
  therapy
• False positive
• Corticosteroids
• Prozone
• False positive
• Old serum