Transmission infrared spectroscopy of whole blood – complications for quantitative analysis from leucocyte adhesion during continuous monitoring

Abstract

Infrared spectroscopy has been applied to analyse glucose and cellular components in whole blood with the aim of developing an online clinical diagnostic and monitoring modality. Leucocyte adsorption onto the CaF(2) windows was observed over a period of several hours under continuous blood flow using a transmission cell of 30 mum path length. This build-up of cellular material on the windows is responsible for diminishing the sample path length under the flow conditions chosen. The adsorption dynamics have been characterised and their impact on glucose monitoring is reported. For short-term monitoring (<2 hours) a standard error of prediction of 11 mg/dL with human citrated blood samples from three different subjects was achieved. Furthermore, the leucocyte build-up was also reported for porcine EDTA blood monitoring. Consequences and testing opportunities with regard to the first stages in the immune cell reaction to the exposure of body-foreign materials to anticoagulated whole blood are discussed.

A possible Fourier transform infrared‐based plasma fingerprint of angiotensin‐converting enzyme inhibitor‐induced reversal of endothelial dysfunction in diabetic mice

“…The observed bands were labelled and presented in a band assignment table (Table ). FTIR spectroscopy was successfully employed in the quantification of glucose in various bodily fluids and we confirmed unequivocal detection of hyperglycemia by FTIR in our plasma samples. However, for further analysis we chose samples of plasma from db/db and PER‐treated animals with the similar level of HbA1c to find changes induced by PER in FTIR spectra of plasma, that are not related directly to hyperglycemia.…”

“…According to reports showing the quantification of glucose in serum, plasma and blood by means of FTIR spectroscopy , we chose the IR bands at 1033 and 1079 cm −1 as glucose markers, and an increase in their intensity in diabetes is clearly visible in the insets in Figure A,B. The spectral region of 1200 to 950 cm −1 is also specific for carbohydrates; however, absorbances of bands present in this range do not change in the way observed for 1033 and 1079 cm −1 maxima.…”

“…Both drugs are prescribed for the glycemic control and similarly to the previous report on metformin‐treated rats , the combination therapy was more effective than the treatment by gliclazide alone as regards changes in the spectral regions of proteins and glucose. In fact, a growing interest on the application of FTIR spectroscopy has been focused on the fast and reagent‐free quantification of glucose in blood, urea, serum and saliva with a special emphasis on the development of a noninvasive technique for continuous monitoring of blood glucose .…”

Vibrational spectroscopy of biofluids for disease screening or diagnosis: translation from the laboratory to a clinical setting

“…In the handling of some biofluids such as blood, there remain challenges to be overcome [98]. Whilst there is a large body of compelling evidence to support the application of vibrational spectroscopy to biofluids such as blood to triage patients for particular conditions such as myocardial infarction [99,100], the integration of these techniques into standard clinical practice remains some way off [101] and definitive clinical trials are needed to define their true diagnostic accuracy [102].…”

Assessing the challenges of Fourier transform infrared spectroscopic analysis of blood serum

“…We have not considered the use of a fluidic system for hydration studies as we are using processed blood serum; the technique is more suited to continuous monitoring for whole blood of patients, as previously assessed [23].…”