Quantification of vascular endothelial growth factor, interleukin-8, and basic fibroblast growth factor in plasma of cancer patients and healthy volunteers - comparison of ELISA and microsphere-based multiplexed immunoassay

Application of cancer-associated glycoforms and glycan-binding probes to an in vitro diagnostic multivariate index assay for precise diagnoses of cancer

Personalized medicine has emerged as a widely accepted trend in medicine for the efficacious and safe treatment of various diseases. It covers every medical treatment tailored according to various properties of individuals. Cancer-associated glycosylation mirrors cancer states more precisely, and this "sweet side of cancer" is thus intended to spur the development of an advanced in vitro diagnostic system. The changes of glyco-codes are often subtle and thus not easy to trace, thereby making it difficult to discriminate changes from various compounding factors. Special glycan-binding probes, often lectins, can be paired with aglycosylated antibodies to enable quantitative and qualitative measurements of glycoforms. With the in vitro diagnosis multivariate index assay (IVDMIA) considered to be capable of yielding patient-specific results, the combinatorial use of multiple glycoproteins may be a good modality to ensure disease-specific, personalized diagnoses.

Cytokine and chemokine patterns across 100 days after hematopoietic stem cell transplantation in children

We mapped the cytokine response to hematopoietic stem cell transplantation (HSCT) by assaying 51 cytokines and chemokines each week for 100 days in 51 children receiving allogeneic (n = 44) or autologous HSCT (n = 7). Assay values were reported as mean fluorescence intensity (MFI). Log transformation converted MFI to clinically relevant measures (ie, pg/mL). We searched for potential markers of transplant complications by using mixed treatment by subject analysis of variance. Global cytokine secretion in HSCT recipients was significantly lower than in concurrent control patients (n = 11). Coincident with the nadir in WBC count, the concentration of many cytokines declined further by the second and third week. All analytes (except monokine induced by gamma interferon [MIG]) subsequently rebounded by week 4 (coincident with engraftment and recovery of WBC count) but often still remained well below control levels. Concurrent with the collective nadir of multiple cytokines, monocyte chemoattractant protein 1 (MCP-1), growth-regulated oncogene alpha (GRO-a), and leptin surged during weeks 2 to 4. High levels of leptin persisted throughout the 100 post-transplant days. Also during weeks 2 to 4, hepatocyte growth factor (HGF) and IL-6 surged in children with complications but not in those without complications. The peak in HGF was more pronounced in veno-occlusive disease (VOD). HGF and IL-6 secretion rose at least 2 weeks before the clinical diagnosis of VOD or graft-versus-host disease (GVHD). From week 4 onward in all groups, the MFI of the cytokine resistin increased to 5 to 15 times above concurrent control. HGF has now emerged in 3 or more biomarker discovery efforts for GVHD (and in our population for VOD as well). HGF (with or without IL-6) should be investigated as a potential predictive biomarker of VOD or GVHD. Alternatively, the hyperinflammatory "signature" provided by a multicytokine assay may be predictive.

Assessment of blood flow in hepatocellular carcinoma: correlations of computed tomography perfusion imaging and circulating angiogenic factors

Hepatocellular carcinoma (HCC) is a highly vascular tumor through the process of angiogenesis. To evaluate more non-invasive techniques for assessment of blood flow (BF) in HCC, this study examined the relationships between BF of HCC measured by computer tomography (CT) perfusion imaging and four circulating angiogenic factors in HCC patients. Interleukin 6 (IL-6), interleukin 8 (IL-8), vascular endothelial growth factor (VEGF), and platelet derived growth factor (PDGF) in plasma were measured using Bio-Plex multiplex immunoassay in 21 HCC patients and eight healthy controls. Circulating IL-6, IL-8 and VEGF showed higher concentrations in HCC patients than in controls (p < 0.05), and predicted HCC occurrence better than chance (p < 0.01). Twenty-one patients with HCC received 21-phase liver imaging using a 64-slice CT. Total BF, arterial BF, portal BF, arterial fraction (arterial BF/total BF) of the HCC and surrounding liver parenchyma, and HCC-parenchyma ratio were measured using a dual-vessel model. After analyzing the correlations between BF in HCC and four circulating angiogenic factors, we found that the HCC-parenchyma ratio of arterial BF showed a significantly positive correlation with the level of circulating IL-8 (p < 0.05). This circulating biomarker, IL-8, provides a non-invasive tool for assessment of BF in HCC.

Evaluation of multiplex immunoassays, used for determination of adiponectin, resistin, leptin, and ghrelin from human blood samples, in comparison to ELISA assays

BACKGROUND

Many different multiplex biomarker immunoassays based on Luminex®-technology have been developed during recent years. We have evaluated the performance of two multiplex immunoassays for determination of adiponectin, resistin, ghrelin and leptin in comparison to corresponding, conventional ELISA assays.

METHODS

Human serum or plasma samples were analysed by commercially available multiplex and ELISA immunoassays manufactured by Millipore Corp.

RESULTS

The correlation between tested multiplex and ELISA immunoassays was good, r > 0.9 for all analytes. The agreement between the methods was acceptable but there were differences in analytical levels. Intra- and inter-assay variation was comparable between both assays. The coefficient of variation for all analytes, independent of method, was ≤15% and for most of them <10%.

CONCLUSION

The performance of the tested multiplex assays was reasonable and they can be considered as valid options to the conventional ELISA assays. However, results obtained with the two different techniques are not necessarily interchangeable due to differences in the concentration levels.

Emerging miniaturized proteomic technologies to study cell signaling in clinical samples

Recording the state and dynamics of intracellular signaling networks in clinical specimens can help identify and validate biomarkers, but may also prove useful in developing and monitoring targeted therapies. Studying cell signaling on a system-wide level in solid tissue, however, is often not feasible using mass spectrometry, because this technique generally requires relatively large sample quantities. A number of promising miniaturized proteomic technologies have emerged, which circumvent these limitations and offer the ability to monitor protein abundances and posttranslational modification states in a multiplexed and quantitative fashion. These technologies have the potential to accelerate molecular diagnostics and therapeutics, and may ultimately facilitate the broad adoption of personalized approaches to patient management and treatment.