Abstract
Background: The cell-surface receptor, TCblR/CD320, binds and internalizes transcobalamin-bound cobalamin. So far, no assay has been developed in order to quantify the soluble form of the receptor.
Methods: This study developed an ELISA employing a monoclonal antibody that recognized the extracellular domain of CD320 as capture antibody and a biotinylated polyclonal antibody for detection. Serum samples were analyzed from blood donors (n==153) and samples from patients referred for analysis of serum cobalamin [n=757, serum cobalamin 75–2000 pg/mL (55–1476 pmol/L)].
Results: The ELISA specifically measured soluble CD320 with a quantification limit of 1.6 arbitrary units and a total variation of 4%–8%. Size exclusion chromatography was used which showed that the immunoreactive protein observed in serum eluted in the same position as soluble CD320 in the calibrator. Male donors (n=76) showed significantly higher median concentration [18 arbitrary units (arb.u.)] than female donors (n=77, median 16 arb.u.), but the absolute difference was marginal and suggested that a common reference interval of 12–97 arb.u. can be used. A positive correlation was observed between levels of soluble CD320 and serum cobalamin with median levels increasing from 17 arb.u. [n=203, cobalamin 75–270 pg/mL (55–200 pmol/L)] to 23 arb.u. [n=350, cobalamin 814–2000 pg/mL (601–1476 pmol/L)], p<0.0001.
Conclusions: An ELISA was established for measurement of soluble CD320 and it was shown that the protein is present in human serum. The serum concentrations of soluble CD320 correlated positively with serum cobalamin levels.
©2012 by Walter de Gruyter Berlin Boston
Articles in the same Issue
- Editorials
- An appeal to medical journal editors: the need for a full description of laboratory methods and specimen handling in clinical study reports
- Cancer diagnosis: from dogs to DNA or from DNA to dogs?
- The never-ending search of an acceptable compromise for pancreatic lipase standardisation
- Review
- Hereditary breast cancer: beyond BRCA genetic analysis; PALB2 emerges
- Mini Review
- Canine olfactory detection of cancer versus laboratory testing: myth or opportunity?
- Genetics and Molecular Diagnostics
- SLCO1B1 gene variability influences lipid-lowering efficacy on simvastatin therapy in Southern Brazilians
- Elevated plasma matrix metalloproteinase-9 protein and its gene polymorphism in patients with community-acquired pneumonia
- General Clinical Chemistry and Laboratory Medicine
- Minimum analytical quality specifications of inter-laboratory comparisons: agreement among Spanish EQAP organizers
- Monitoring quality indicators in laboratory medicine does not automatically result in quality improvement
- Speed of sample transportation by a pneumatic tube system can influence the degree of hemolysis
- 1,2-Dioleoylglycerol method for pancreatic lipase catalytic activity in serum
- Serum lactate dehydrogenase levels significantly correlate with radiological extent of disease and spirometric values in patients with silicosis due to denim sandblasting
- Clinical comparison of new monoclonal antibody-based nephelometric assays for free light chain kappa and lambda to polyclonal antibody-based assays and immunofixation electrophoresis
- The relationship between antinuclear antibody data and antibodies against extractable nuclear antigens in a large laboratory cohort
- Anti-neutrophil cytoplasmic antibodies (ANCA) specific for one or several antigens: useful markers for subtypes of ulcerative colitis and associated primary sclerosing cholangitis
- Trueness in the measurement of haemoglobin: consensus or reference method?
- Soluble transcobalamin receptor, sCD320, is present in human serum and relates to serum cobalamin – establishment and validation of an ELISA
- An on-line solid phase extraction procedure for the routine quantification of caspofungin by liquid chromatography-tandem mass spectrometry
- Effects of subcutaneous low molecular weight heparin and intravenous unfractionated heparin on serum S100 concentrations in patients with cerebrovascular diseases
- Urinary 8-hydroxy-2′-deoxyguanosine level and plasma paraoxonase 1 activity with Alzheimer’s disease
- A HPLC-MS method to detect and quantify guanfacine in urine
- Collection and storage requirements for urinary kidney injury molecule-1 (KIM-1) measurements in humans
- Kidney stones in a Mediterranean population from the south of Spain
- Reference Values and Biological Variations
- First trimester biochemistry at different maternal ages
- Age- and gender-related alteration in plasma advanced oxidation protein products (AOPP) and glycosaminoglycan (GAG) concentrations in physiological ageing
- Cancer Diagnostics
- Direct sequencing in cytological specimens as a useful strategy for detecting EGFR mutations in non-small cell lung cancer patients
- Investigation of lung cancer biomarkers by hyphenated separation techniques and chemometrics
- Letters to the Editor
- Aberrant results observed with four immuno-assays for total and free prostate-specific antigen (PSA) determination: a case-report
- Assay-dependent abnormalities in measurements of prostate-specific antigen in serum: an occasional occurrence, but of clinical significance
- Clinical comparison of new monoclonal antibody-based nephelometric assays for free light chain κ and λ to polyclonal antibody-based assays and immunofixation electrophoresis
- Agarose-gel electrophoresis for the diagnosis of mucopolysaccharidoses
- Leptin levels in exhaled breath condensate from asthmatic children: a pilot study
- Masthead
- Masthead
Articles in the same Issue
- Editorials
- An appeal to medical journal editors: the need for a full description of laboratory methods and specimen handling in clinical study reports
- Cancer diagnosis: from dogs to DNA or from DNA to dogs?
- The never-ending search of an acceptable compromise for pancreatic lipase standardisation
- Review
- Hereditary breast cancer: beyond BRCA genetic analysis; PALB2 emerges
- Mini Review
- Canine olfactory detection of cancer versus laboratory testing: myth or opportunity?
- Genetics and Molecular Diagnostics
- SLCO1B1 gene variability influences lipid-lowering efficacy on simvastatin therapy in Southern Brazilians
- Elevated plasma matrix metalloproteinase-9 protein and its gene polymorphism in patients with community-acquired pneumonia
- General Clinical Chemistry and Laboratory Medicine
- Minimum analytical quality specifications of inter-laboratory comparisons: agreement among Spanish EQAP organizers
- Monitoring quality indicators in laboratory medicine does not automatically result in quality improvement
- Speed of sample transportation by a pneumatic tube system can influence the degree of hemolysis
- 1,2-Dioleoylglycerol method for pancreatic lipase catalytic activity in serum
- Serum lactate dehydrogenase levels significantly correlate with radiological extent of disease and spirometric values in patients with silicosis due to denim sandblasting
- Clinical comparison of new monoclonal antibody-based nephelometric assays for free light chain kappa and lambda to polyclonal antibody-based assays and immunofixation electrophoresis
- The relationship between antinuclear antibody data and antibodies against extractable nuclear antigens in a large laboratory cohort
- Anti-neutrophil cytoplasmic antibodies (ANCA) specific for one or several antigens: useful markers for subtypes of ulcerative colitis and associated primary sclerosing cholangitis
- Trueness in the measurement of haemoglobin: consensus or reference method?
- Soluble transcobalamin receptor, sCD320, is present in human serum and relates to serum cobalamin – establishment and validation of an ELISA
- An on-line solid phase extraction procedure for the routine quantification of caspofungin by liquid chromatography-tandem mass spectrometry
- Effects of subcutaneous low molecular weight heparin and intravenous unfractionated heparin on serum S100 concentrations in patients with cerebrovascular diseases
- Urinary 8-hydroxy-2′-deoxyguanosine level and plasma paraoxonase 1 activity with Alzheimer’s disease
- A HPLC-MS method to detect and quantify guanfacine in urine
- Collection and storage requirements for urinary kidney injury molecule-1 (KIM-1) measurements in humans
- Kidney stones in a Mediterranean population from the south of Spain
- Reference Values and Biological Variations
- First trimester biochemistry at different maternal ages
- Age- and gender-related alteration in plasma advanced oxidation protein products (AOPP) and glycosaminoglycan (GAG) concentrations in physiological ageing
- Cancer Diagnostics
- Direct sequencing in cytological specimens as a useful strategy for detecting EGFR mutations in non-small cell lung cancer patients
- Investigation of lung cancer biomarkers by hyphenated separation techniques and chemometrics
- Letters to the Editor
- Aberrant results observed with four immuno-assays for total and free prostate-specific antigen (PSA) determination: a case-report
- Assay-dependent abnormalities in measurements of prostate-specific antigen in serum: an occasional occurrence, but of clinical significance
- Clinical comparison of new monoclonal antibody-based nephelometric assays for free light chain κ and λ to polyclonal antibody-based assays and immunofixation electrophoresis
- Agarose-gel electrophoresis for the diagnosis of mucopolysaccharidoses
- Leptin levels in exhaled breath condensate from asthmatic children: a pilot study
- Masthead
- Masthead