Type of test Blood, cerebrospinal fluid (CSF)

Normal findings

Antistreptolysin O titer

Adult/elderly: ≤ 160 Todd units/mL

Child:

Newborn: similar to mother’s value

6 months-2 years: ≤ 50 Todd units/mL

2-4 years: ≤ 160 Todd units/Ml

 5-12 years: 170-330 Todd units/mL

Antideoxyribonuclease-B titer

 Adult: ≤ 85 Todd units/mL or titer ≤ 1:85

Child:

 Preschool age: ≤ 60 Todd units/mL or titer ≤ 1:60

School age: ≤ 170 Todd units/mL or titer ≤ 1:170

Streptozyme

 Titer < 1:100

Streptococcus group B antigen

 None detected

Test explanation and related physiology

Infection by group A Streptococcus is unique because it can be followed by a serious nonpurulent complication (e.g., rheumatic fever, scarlet fever, glomerulonephritis). Serologic tests are used primarily to determine whether a previous group A Streptococcus infection (pharyngitis, pyodermia, pneumonia) has caused a poststreptococcal disease. These poststreptococcal diseases occur after the infection and after a period of latency during which the patient is asymptomatic.

These antibodies are directed against streptococcal extracellular products that are primarily enzymatic proteins. Serial rising titers of these antibodies over several weeks followed by a slow fall in titers are more supportive of the diagnosis of a previous streptococcal infection than is a single titer.

One such extracellular enzyme produced by streptococcus is called streptolysin O, which has the ability to destroy (lyse) RBC corpuscles. The streptolysin O is antigenic, stimulating the immunologic production of a neutralizing ASO antibody. ASO appears in the serum 1 week to 1 month after the onset of a streptococcal infection. A high ASO titer is not specific for a certain type of poststreptococcal disease (i.e., rheumatic fever versus glomerulonephritis) but merely indicates that a streptococcal infection is or has been present.

Like the ASO titer, ADB is used to detect previous streptococcal infections. Although this test may be more sensitive than the ASO titer, it is not used alone in the evaluation of streptococcal infections because its results are too variable.

The Streptozyme assay detects antibodies to multiple extracellular antigens of group A Streptococcus, including antistreptolysin O, antistreptokinase, and antihyaluronidase. Approximately 80% of specimens positive by streptozyme have antistreptolysin O, and 10% have antistreptokinase and/or antihyaluronidase. The remaining 10% of positive samples are apparently caused by ADB antibodies or other streptococcal extracellular antigens.

Streptococcus group B antigens accumulate in CSF, serum, or urine and provide a direct qualitative detection of bacterial antigens. These antigens indicate acute infection and are not related to poststreptococcal sequelae as described previously. Confirmatory diagnosis of streptococcal infection is done by cultures.

Interfering factors

• Increased beta-lipoprotein levels inhibit streptolysin O and give a falsely high ASO titer.

* Drugs that may cause decreased ASO levels include adrenocorticosteroids and antibiotics.

Procedure and patient care

 • See inside front cover for Routine Blood Testing.

 • Fasting: no

• Blood tube commonly used: red

 Abnormal findings

Increased levels

- Streptococcal infection

- Acute rheumatic fever

- Acute glomerulonephritis

- Bacterial endocarditis

- Scarlet fever

- Streptococcal pyoderma

اخر الاخبار

اخبار العتبة العباسية المقدسة

معهد القرآن الكريم النسويّ يعقد الجلسة الرابعة من مسابقة فضة القرآنية

العتبة العباسية المقدسة تهيّئ الصحن الشريف استعدادًا لمهرجان رحمة للعالمين الدولي الأوّل

بمشاركة عددٍ من الطلبة.. المجمع العلمي ينظّم دورة مختصّة بالتجويد في محافظة الديوانية

العتبة العباسية المقدسة تنشر لافتات احتفائية بذكرى المولد النبوي الشريف

المزيد

الآخبار الصحية

هل من الآمن شرب القهوة على معدة فارغة؟

تحذير: مرض السكري يسرق طاقة قلبك

حقيقة صادمة.. لماذا يجب أن تتوقف عن شراء الجزر الصغير؟

بعد عمر الستين.. توقيت وجبة الإفطار مؤشر على صحتك

المزيد

الآخبار التكنلوجية

تركيب مقعد الطفل بأمان في سيارتك: دليل كامل وسهل

مليار مليار عملية في الثانية.. ألمانيا تدشن الحاسوب الفائق

أخيرا.. إنستغرام يصل رسميا إلى آيباد

حل يثير جدلا طبيا.. حقنة قادرة على إخفاء الشيب من رأسك ؟!

المزيد

مواضيع ذات صلة

syphilis detection test (Serologic test for syphilis [STS], Venereal Disease Research Laboratory [VDRL], Rapid plasma reagin [RPR], Fluorescent treponemal antibody test [FTA])

sweat test (Sweat electrolyte test, Sweat chloride test, Sweat conductivity test, Iontophoretic sweat test)

substance abuse testing (Urine drug testing, Drug testing, Drug screening, Toxicology screening)

Galectin-3

Biomarkers of Collagen Synthesis and Degradation

Cardiac Fibrosis

stool for leukocytes (White blood cell stool test, Fecal leukocyte stain, Stool for white cells)

stool culture (Stool for culture and sensitivity [C&S], Stool for ova and parasites [O&P])

stool cancer screening (stool for occult blood, Stool for OB, Fecal occult blood test [FOBT], Fecal immunotest [FIT], DNA stool sample)

Biomarkers of Myocardial Remodeling and Fibrosis

Pathophysiological and Clinical Interpretations of Changes in circulating BNP/NTproBNP

sputum cytology