Fibrinography: A Multiwavelength Light‐Scattering Assay of Fibrin Structure

Abstract

We have previously developed a fibrin structural assay dedicated to purified fibrinogen-thrombin system. Here, we extend the pertinence of this test, called Fibrinography, to tissue factor-triggered plasma coagulation. We show that Fibrinography determines quantitatively the structure of fibrin fibers in plasma with an excellent reproducibility. We compare this assay with the commonly used single wavelength turbidity method, showing that the latter is not a proper structural assay, but determines essentially the fibrinogen content in plasma. In addition, we also show, in model plasmas, that Fibrinography is able to discriminate normal and hypocoagulant plasmas, and even between hypercoagulant plasmas. Therefore, Fibrinography, by measuring the final step of the coagulation cascade, may be used to evaluate patients’ plasma in hypo- or hypercoagulant diseases.

The Applicability of Current Turbidimetric Approaches for Analyzing Fibrin Fibers and Other Filamentous Networks

“…Although Yeromonahos later wrote a Letter to the Editor attempting to correct this equation [ 30 ], we will still evaluate Equation (18) because it is still commonly used within the fibrinogen community [ 20 , 27 , 28 , 29 ]. This equation will be referred to as the “original Yeromonahos” approach, and the corrected version will be referred to as the “corrected Yeromonahos” approach.…”

“…Turbidity is commonly used to study the kinetics of fibrin gel formation [ 19 ], where an increase in turbidity is interpreted as being caused by the bundling of protofibrils into fibers [ 20 ], and thus, increased light scattering is due to increased particle size. Turbidimetry, turbidity measurements at various wavelengths, is a commonly utilized approach in studying blood clot structure and function.…”

Automated Fiber Diameter and Porosity Measurements of Plasma Clots in Scanning Electron Microscopy Images

“…The manually measured diameter and diameters determined by T6, T5, S7, and M7 all correlated moderately with maximum absorbance. A correlation would be expected since according to light scattering theory, maximum absorbance increases with increasing diameter [53][54][55][56][57]. Fiber diameter did not correlate with clot permeability, G', G", or G"/G' for any of the other measurements, likely because these properties are related in a complex manner to other aspects of fibrin network structure, such as branching, in addition to diameter.…”

Why fibrin biomechanical properties matter for hemostasis and thrombosis

“…However, only a shortrange and weak lateral (or radial) order of around 13 nm 39 and 18 nm 40 was found, indicating that fibrin fibers have less ordered packing laterally than axially. Turbidimetry and fibrinography are multiwavelength scattering methods optimized to reveal detail about the protein density and protofibril content of fibrin fibers 37,41,42 . Different parameters may impact on protein density of the fibers: increasing thrombin concentrations decrease protein density, and clots of the γA/γ’ splice variant of fibrinogen also result in less dense fibers 43 .…”

“…Turbidimetry and fibrinography are multiwavelength scattering methods optimized to reveal detail about the protein density and protofibril content of fibrin fibers. 37,41,42 Different parameters may impact on protein density of the fibers: increasing thrombin concentrations decrease protein density, and clots of the γA/γ' splice variant of fibrinogen also result in less dense fibers. 43 Functionally, reduced protofibril packing in fibers results in a decreased clot stiffness.…”