Highly sensitive and accurate detection of C-reactive protein by CdSe/ZnS quantum dot-based fluorescence-linked immunosorbent assay.

BACKGROUND: The conventional and widely used enzyme-linked immunosorbent assays (ELISA), due to specificity and high-sensitivity, were suitable in vitro diagnosis. But enzymes are vulnerable to the external conditions, and the complex operation steps limit its application. Semiconductor quantum dots have been successfully used in biological and medical research due to the high photoluminescence and high resistance to photobleaching. In this study, we have developed a novel quantum dot-labeled immunosorbent assay for rapid disease detection of C-reactive protein (CRP). RESULTS: The assay for the detection of CRP can provide a wide analytical range of 1.56-400 ng/mL with the limit of detection (LOD) = 0.46 ng/mL and the limit of quantification = 1.53 ng/mL. The precision of the assay has been confirmed for low coefficient of variation, less than 10% (intra-assay) and less than 15% (inter-assay). The accuracy of assay meets the requirements with the recoveries of 95.4-105.7%. Furthermore, clinical samples have been collected and used for correlation analysis between this FLISA and gold standard Roche immunoturbidimetry. It shows excellent accurate concordance and the correlation coefficient value (R) is as high as 0.989 (n = 34). CONCLUSIONS: This in vitro quantum dot-based detection method offers a lower LOD and a wide liner detection range than ELISA. The total reaction time is only 50 min, which is much shorter than the commercialization ELISA (about 120 min). All of the results show that a convenient, sensitive, and accurate fluorescence-linked immunosorbent assay method has been well established for the detection of CRP samples. Therefore, this method has immense potential for the development of rapid and cost-effective in vitro diagnostic kits.

Assessment of the impact of introducing fetal fibronectin assay in the management of preterm labour at Middlemore Hospital, New Zealand.

UNLABELLED: Elevated levels of fetal fibronectin (fFN) in cervicovaginal secretions beyond 20-22 weeks of gestation are used as a predictor of preterm birth in patients with corroborative symptoms and signs. AIM: To assess the impact of introducing the fFN assay on the diagnosis, length of hospital stay and cost of managing patients presenting with symptoms of premature labour in our hospital. METHODS: The first 30 fFN-tested patients (fFN group) were prospectively recruited and followed up until delivery. Hospital stay and management costs (costs of individual tests and treatment administered) and neonatal outcomes were compared with 30 matching historical controls. RESULTS: Overall management costs of the fFN-group were comparable with controls (NZ dollar 918 versus NZ dollar 943 per patient, p = 0.44). The fFN-group had a trend towards reduced length of hospital stay (p = 0.082), less tocolysis (p = 0.002) and use of steroids (p < 0.001). The cost of managing an fFN-positive patient was more than an fFN-negative patient, but not statistically significant (NZ dollar 1117 versus NZ dollar 846, respectively, p = 0.11). CONCLUSION: Despite a trend towards reduced hospital stay and less use of obstetric intervention, total expenditure in patient management has not reduced with the availability of the fFN assay in our hospital. This may only reflect the slow introduction of a new policy that with time may be implemented to full effect.

Immunoadsorption may provide a cost-effective approach to management of patients with inhibitors to FVIII.

BACKGROUND: Immunoadsorption of plasma with Staphylococcal protein A removes immunoglobulins and immune complexes; hence, it should effectively remove inhibitors to FVIII in acquired or congenital hemophilia. The procedure may be cost effective, given the expense of therapies used to treat patients with inhibitors, particularly in an acute setting. STUDY DESIGN AND METHODS: Three patients with inhibitors to FVIII were treated with the Excorim Immunosorba system (two columns used in tandem). Costs for immunoadsorption and for other therapeutic products administered to the patients were calculated. RESULTS: Two patients had acquired hemophilia and severe bleeding associated with low levels of circulating FVIII and high levels of inhibitors to FVIII. They failed to achieve a satisfactory response to management with immunosuppression, pFVIII, recombinant FVIIa or IVIG but responded rapidly, with long-term benefit, to immunoadsorption therapy. The third patient had congenital hemophilia and immunoadsorption was effective in reducing his inhibitor level, allowing him to undergo immune tolerance therapy. Costs of treatment before immunoadsorption were markedly higher than those associated with the immunoadsorption procedures (i.e., >Can 350,000 dollars and >Can 1,000,000 dollars vs. < 20,000 dollars). CONCLUSION: Immunoadsorption appears to be an effective and cost-effective alternative in the management of patients with inhibitors to FVIII.

Cost-effectiveness of Prosorba column therapy for rheumatoid arthritis: a framework for analysis.

Apheresis with the Prosorba column is safe and effective for treating refractory rheumatoid arthritis. It also is resource intensive. Economic evaluation of Prosorba column therapy could help promote efficient use of this technology. This article describes a framework and the data requirements for analyzing the cost-effectiveness of Prosorba column therapy. Several factors are considered in developing the framework including the target patient population, treatment alternatives, and clinical, economic, and quality of life outcomes of alternative treatments. We propose decision modeling as the appropriate study design because it provides a flexible framework for combining and analyzing data from different sources including experimental and nonexperimental studies. The cost-effectiveness of Prosorba column therapy will depend on the patient population in which it is used and the other treatment options still available to these patients. Offsets to the costs of providing Prosorba column therapy are likely to be largest in treatment-refractory patients and when this therapy is compared to other expensive new agents such as etanercept.

Protein A immunoadsorption column versus splenectomy in the treatment of steroid-resistant immune thrombocytopenic purpura. A cost-effectiveness analysis.

The protein A immunoadsorption column is a new treatment for immune thrombocytopenic purpura (ITP). We used a decision-analytic approach with a Markov process to model the cost effectiveness of this treatment compared with splenectomy for steroid-resistant ITP patients. Data informing the model were obtained from published literature, a panel of physicians, and public databases. We found initial treatment with the protein A immunoadsorption column to be less expensive and more effective than initial treatment with splenectomy.