Principle

The C-reactive protein rapid latex agglutination test is based on the reaction between patient serum containing CRP as the antigen and the corresponding antihuman (CRP) antibody coated to the treated surface of latex particles. The coated particles enhance the detection of an agglutination reaction when antigen is present in the serum being tested. The clinical applications of CRP evaluation include detecting inflammatory dis eases, particularly infections. It is also a useful indicator in screening for organic disease, inflammatory and malignant dis ease, and monitoring therapy in inflammatory diseases. Because CRP is more rapidly synthesized than other acute-phase proteins, assays of CRP are the measurement of choice in suspected inflammatory conditions.

Reporting Results

 In patients who are free of inflammation and tissue necrosis, CRP is absent from the serum or present in concentrations below 0.5 mg/dL. Reference range mean values are 0.01 mg/dL in newborns and less than 0.05 mg/dL in adult men and non-pregnant women.

Positive Reaction

Agglutination of the latex suspension is a positive result. A positive reaction is reported when the undiluted specimen or the 1:5 diluted specimen demonstrates agglutination, or when both exhibit agglutination.

 Negative Reaction

 The absence of visible agglutination and the presence of opaque fluid constitute a negative reaction. A negative reaction is reported only when both the undiluted specimen and the 1:5 diluted specimen exhibit no visible agglutination.

Comments

Specimen collection and handling are important to the quality of the test. Strict adherence must be paid to technique, with a special emphasis on drop size, complete mixing, reaction time, and temperature of reagents.

The strength of a positive reaction may be graded as follows:

 1+ Very small clumping with an opaque fluid background

2+ Small clumping with a slightly opaque fluid background

 3+ Moderate clumping with a fairly clear fluid background

 4+ Large clumping with a clear fluid background

Sources of Error

False-positive results may be observed if serum specimens are lipemic, hemolyzed, or heavily contaminated with bacteria. If the reaction time is longer than 2 minutes, a false-positive result may also be produced from a drying effect.

False-negative results may be observed in undiluted serum specimens because of high levels of CRP (antigen excess). A 1:5 dilution of serum is also tested for this reason.

 Limitations

 Because the latex slide agglutination test is a qualitative and semiquantitative procedure, other methods such as nephelometry should be used for the quantitative determination of the CRP level when indicated. The strength of the agglutination reaction is not always indicative of the CRP concentration. Weak reactions may be produced in samples with elevated or low CRP values. Results may vary, depending on the patient’s condition.

This 2-minute slide latex agglutination test has a detection level of 1 mg CRP/dL; therefore, patients with CRP values less than 1 mg/dL may go undetected. The sensitivity of the procedure has been assessed at 93%.

Clinical Applications

 With the onset of a substantial inflammatory event (e.g., infection, MI, surgery), the CRP level usually increases significantly (>tenfold) above the reference range values for healthy individuals. The test is clinically useful for the early detection of inflammatory diseases (particularly infections), as an indicator in screening for organic diseases, and in monitoring patient progress.

اخر الاخبار

اخبار العتبة العباسية المقدسة

يجسد قيم النهضة الحسينية.. قسم الشؤون الفكرية يصدر العدد 120 من مجلة (حيدرة) الثقافية

ضمن حملة الكفيل العتبة العباسية المقدسة تحيي مراسم ليلة الحادي عشر من المحرم في سامراء

المجمع العلمي يحيي عاشوراء بخدمة الزائرين وإقامة مجالس العزاء ببغداد والحمزة الشرقي

المؤمنون يحيون ليلة الحادي عشر من المحرّم عند مرقدي الإمام الحسين وأخيه العباس (عليهما السلام)

المزيد

الآخبار الصحية

تناول الجبن.. مفيد للجسم أم خطر يهدد صحتك؟

طبيبة أسنان تحذر.. لا تتجاهل هذه العلامة بعد التنظيف

يجب أن تأكل المزيد من الشمام هذا الصيف.. إليك السبب ؟

تأثير صحي كبير.. كم بيضة يجب أن تتناول يوميا؟

المزيد

الآخبار التكنلوجية

أداء خلايا البيروفسكايت الشمسية تحت الماء قد يزيد كفاءة تحويل الكهرباء

مسافة الأمان: أساس القيادة الآمنة وتجنب الحوادث

هل القيادة السريعة تعني استهلاك اكثر للوقود؟

لماذا يعتبر كوكب المريخ غير صالح للحياة؟

المزيد

مواضيع ذات صلة

Hyporegenerative Macrocytic Anemias/ Megaloblastic Anemias

Unstable Hemoglobins

Glucose-6-Phosphate Dehydrogenase (G6PD) Deficiency

Hereditary Spherocytosis

Magnesium

lyme disease test

luteinizing hormone (LH assay, Lutropin) and follicle stimulating hormone (FSH) assay

liquid biopsy (Fluid biopsy, Fluid phase biopsy)

lipoproteins (High-density lipoproteins [HDLs, HDL-C], Low density lipoproteins [LDLs, LDL-C], Very-low-density lipoproteins [VLDLs], Lipoprotein electrophoresis, Lipoprotein phenotyping, Lipid fractionation, Non-HDL cholesterol, Lipid profile)

lipoprotein-associated phospholipase A2 (Lp-PLA2 PLAC test)

Hemolytic Anemias

Sickle Cell Anemia (Hemoglobinopathy S, Sickle Cell Disease)