P41

Background

The aim of this work was to assess the potential of the optical methods for studying erythrocytes (Er) and blood serum (BS) of patients with colorectal cancer (CC).

Methods

A total of 26 persons (52 + 8 years old) with CC (histologically – adenocarcinoma) in the T1–2 stage (the 1st group consisting of 10 patients) and in the terminal stage T3–4 (the 2nd group involving 16 patients) were examined. The metastases (in the liver area) were detected in 6 patients; the remaining patients had no metastases. The degree of lymph node involvement in most patients was not determined, the ten corresponding N1. The control group consisted of 16 healthy people (50 + 6 years old). Electric and viscoelastic Er parameters were investigated by dielectrophoresis, their membrane structure – by TLC and gas chromatography. The optical properties of BS were studied by the methods of ellipsometry. The reaction of the monoclonal antibody CD 24 with BS antigens of CC patients was studied by spectroscopic ellipsometry close to the conditions of surface plasmon resonance (SPR) (ProteOn XPR36 (BioRad).

Results

We observed significant differences in Er parameters, associated with the CC stage. Given in the 2nd group (T3–4) summarized rigidity, viscosity, electrical conductivity, the relative polarizability, indexes of aggregation and destruction were significantly higher than those in the 1st (T1–2) and in the control group (p < 0.001–0.05). At the same time the patients of the 2nd group had marked disturbances of Er deformability, leading to the development of microcirculatory disorders and tissue hypoxia with the expressed deficit of intracellular macroergs. We observed high levels of cholesterol fraction, oleic, stearic acids, high index of cholesterol/phospholipids (PHL) and low levels of total lipids, easily oxidable PHL, arachidonic acid, omega-3 index in Er membranes in the 2nd group in comparison with those in the 1st group of patients (p < 0.0001–0.03). Scanning ellipsometry showed marked heterogeneity in thickness and composition, the abundance of discontinuities in thin films of BS of patients in the 2nd group compared to the 1st one (p < 0.001). Increasing the refractive index in combination with the reduction in film thickness as CC stage was weighting has been observed (p < 0.01–0,$⧹$.05). The concentration of the antigens to the CD24 in the BS of patients (obtained by SPR) in the terminal stages of CC was higher than that in the T1–2 (p < 0.001). We revealed correlations between Er parameters, BS ellipsometry characteristics and biochemical parameters, which reflected the interaction between these components depending on the CC stage.

Conclusion

Identified microcirculatory disturbances probably aggravate the course of CC and, therefore, require additional therapeutic effects. Differences in Er and BS parameters associated with the stage of CC, give hope for the development of new diagnostic methods at the early stages of the disease.