Measurement of C-reactive protein in dried blood sports on filter paper

What a drop can do: dried blood spots as a minimally invasive method for integrating biomarkers into population-based research

Logistical constraints associated with the collection and analysis of biological samples in community-based settings have been a significant impediment to integrative, multilevel bio-demographic and biobehavioral research. However recent methodological developments have overcome many of these constraints and have also expanded the options for incorporating biomarkers into population-based health research in international as well as domestic contexts. In particular using dried blood spot (DBS) samples-drops of whole blood collected on filter paper from a simple finger prick-provides a minimally invasive method for collecting blood samples in nonclinical settings. After a brief discussion of biomarkers more generally, we review procedures for collecting, handling, and analyzing DBS samples. Advantages of using DBS samples-compared with venipuncture include the relative ease and low cost of sample collection, transport, and storage. Disadvantages include requirements for assay development and validation as well as the relatively small volumes of sample. We present the results of a comprehensive literature review of published protocols for analysis of DBS samples, and we provide more detailed analysis of protocols for 45 analytes likely to be of particular relevance to population-level health research. Our objective is to provide investigators with the information they need to make informed decisions regarding the appropriateness of blood spot methods for their research interests.

Cardiometabolic risk factors assessed by a finger stick dried blood spot method

BACKGROUND

Cardiovascular and metabolic risk factors are gaining attention as potential indicators for intervention in the prevention and treatment of cardiovascular disease (CVD) and type 2 diabetes mellitus (T2DM). Blood spot technology offers an efficient, convenient method to measure these risk factors in an at-risk population. Simple and convenient methods to assess cardiometabolic risk factors will allow clinicians to formulate treatment strategies for effective prevention and management of these conditions.

METHOD

Insulin and high sensitivity C-reactive protein (hs-CRP) were measured in dried blood spot and corresponding serum samples using conventional commercial serum kits based on a direct sandwich ELISA technique. The triglyceride assay involved enzymatic hydrolysis of triglycerides by lipase to glycerol and free fatty acids. The glycerol produced was then measured by coupled enzyme reactions. Blood spot assays were modified from previously published methods to give improved accuracy and turnaround time.

RESULTS

Blood spot levels correlated well with serum levels of hs-CRP (r = 0.99), triglycerides (fasting, r = 0.95; nonfasting, r = 0.94), and insulin (fasting, r = 0.93; nonfasting, r = 0.97).

CONCLUSION

Blood spot testing for insulin, hs-CRP, and triglycerides may be helpful in the cardiometabolic screening or monitoring of patients at risk of developing CVD, T2DM, or metabolic syndrome.