ABSTRACT
We describe a quantitative, rapid, sensitive and reproducible tandem mass spectrometry (MSMS) method for the one-step detection of aminoacid (AAs) and acylcarnitine (ACs) concentrations in amniotic fluid. This technology is quicker and more sensitive than other methods used to date since it is possible to determine very low AA and AC concentrations in samples simultaneously in a single run. The high degree of automation allows a large number of pregnancies to be screened for metabolic defects in a very short time.
Subject(s)
Amino Acids/analysis , Amniotic Fluid/metabolism , Carnitine/analogs & derivatives , Carnitine/analysis , Fetal Diseases/diagnosis , Metabolic Diseases/diagnosis , Prenatal Diagnosis/standards , Female , Humans , Mass Spectrometry/methods , Mass Spectrometry/standards , Predictive Value of Tests , Pregnancy , Sensitivity and SpecificityABSTRACT
In this study we describe the application of an enzyme-linked immunosorbent assay (ELISA) for the measurement of anti-alpha-gliadin antibodies (AGA) in absolute units (microgram protein/ml). Enriched samples of IgA and IgG AGA were obtained by means of protein A chromatography after immunoaffinity purification of pooled sera from untreated celiac patients. No cross-reactivity with other food antigens (beta-lactalbumin, soya proteins, ovalbumin) was detected. The quantitative evaluation of protein content in IgA and IgG AGA samples obtained by immunoaffinity chromatography, was performed by means of ELISA sandwich method using a reference curve obtained with pure standard human immunoglobulins. Scalar concentrations of purified IgA and IgG were then used to obtain a reference standard curve by means of an ELISA method. Such standard curve was utilized for titrating AGA in 214 sample sera. The minimal detectable concentration of IgA and IgG AGA was 0.02 micrograms/ml. The reproducibility of within- and between-assay resulted very good for IgA-AGA and acceptable for IgG-AGA. The method here described seems to be satisfactory not only for quantitative diagnostic purposes in routine screenings but also in epidemiological studies. Moreover, it can constitute a suitable way to solve practical problems of quality control of AGA ELISA assay.
Subject(s)
Antibodies/analysis , Gliadin/immunology , Immunoglobulin A/analysis , Immunoglobulin G/analysis , Celiac Disease/diagnosis , Child , Child, Preschool , Chromatography, Affinity , Enzyme-Linked Immunosorbent Assay/methods , Humans , Infant , Infant, Newborn , SeasonsSubject(s)
Adenosine/analogs & derivatives , Antineoplastic Agents/pharmacology , Deoxyadenosines , Interferon Type I/pharmacology , Thionucleosides/pharmacology , Tumor Cells, Cultured/drug effects , Adenosine/pharmacology , Cell Division/drug effects , Drug Synergism , Humans , Recombinant ProteinsABSTRACT
The ability of Interferon (IFN) alpha, beta and gamma to induce IgA production from IgA deficient patients lymphocytes was tested "in vitro". In affected patients IgG and IgM production was similar to the normal cases but no effect on IgA production was observed. In normal cases variable concentration of alpha- beta- and gamma-IFN resulted in different immunoglobulin production. In IgA selective deficiency a low number of SmIgA bearing cells and defective transformation in IgA-plasma cells was noted as possible primary defect.
