ABSTRACT
This is the second article in this series. The first looked at some of the commonly encountered drugs of abuse; discussed the range of samples on offer; established why urine is the preferred matrix; and addressed methods of sample adulteration. Part 2 briefly discusses immunoassay technology; the means to comment on the integrity of a sample and issues regarding cut-points and interpretations. The necessity for confirmatory testing of positive test results is discussed and the use of a mass spectrometric method is recommended for this purpose
Subject(s)
Chromatography , Illicit Drugs , Immunoassay , Substance Abuse Detection/methodsABSTRACT
Introduction : Rapid testing and detection of acute HIV infection are two important arms in the prevention of HIV infection. Virologic testing for HIV remains the mainstay for early diagnosis of the infection. Nucleic acid-based testing for HIV however; requires expensive laboratory infrastructure and well-trained personnel; thereby making it not easily accessible in Low- Middle- Income Countries (LMIC). HIV DNA polymerase chain reaction is currently used by few laboratories in many LMIC to detect HIV in children born of HIV-positive mothers before 18 months. Challenges relating to timely result notification can be reduced if the Early Infant Diagnosis (EID) Programme is decentralized and with easy access to laboratory facilities using other tests with high performance characteristics. Methods: We evaluated the performance of five assays to identify HIV antibodies; p24 antigen; proviral DNA or viral RNA in 109 infants born to HIV-positive mothers in Yaounde; Cameroon. Results: The test performance (using plasma) of the HIV p24 antigen ELISA by Perkin Elmer; Roche Amplicor HIV-1 DNA PCR and the Abbott Realtime HIV-1 assay was 100 identifying 12 positive cases. A positive and significant correlation between the HIV-1 RNA viral load and HIV p24 antigen level was found (p0.05). Conclusion: Therefore; HIV p24 antigen detection by ELISA can be used for early diagnosis of HIV and thus recommended for a decentralized EID Programme in LMIC
Subject(s)
Antigens , Immunoassay , Virology/methodsABSTRACT
L'electroimmunodiffusion de Laurell est une assez bonne methode sensible et suffisamment precise pour le dosage des proteines specifiques. Les auteurs l'ont appliquee avec de bons resultats dans le cas d'anti-Albumine; d'anti-transferrine et d'anti-IgG prepare a Cotonou pour le dosage des anti-genes correspondants dans le serum et le CR. Ce travail de mise au point des conditions d'utilisation est indispensable a realiser pour chaque lot d'immuno-serums que ce soit en immunodiffusion radicale; en electro-immunodiffusion; ou en nephelometrie; afin de fournir a l'utilisateur un produit pret a l'emploi
Subject(s)
Benin , Blood Protein Electrophoresis , Cerebrospinal Fluid Proteins , Immunoassay , Immunodiffusion , ImmunoelectrophoresisABSTRACT
Les auteurs decrivent une methode simple; sensible et reproductible de determination des proteines totales dans les milieux biologiques a faibles concentrations proteiques. Il s'agit d'une methode de soustraction comme colorant le Rouge Ponceau S