CC BY
2DOI 10.24412/CL-37135-2023-1-16-17
REFRACTOMETRIC ANALYSIS OF BLOOD SERUM
LUDMILA PLOTNIKOVA1, OLGA VEZO1, ANDREY GARIFULLIN1,2 , ALEKSEY KUVSHINOV2 , SERGEY VOLOSHIN2,3,4 AND ALEXANDER POLYANICHKO1,5
1St. Petersburg State University, Russia
2
Russian Research Institute of Hematology and Transfusiology, Russia
o
Kirov Military Medical Academy, Russia 4Mechnikov Northwestern State Medical University, Russia 5Institute of Cytology of the Russian Academy of Sciences, Russia
ljusja@mail.ru
ABSTRACT
Refractometric analysis is based on measuring the refractive index of samples in various state. When working with biological fluids, refractometry is a fast and fairly accurate alternative to the biochemical analysis of certain parameters, in particular, the total protein of blood serum. Serum contains dissolved substances in concentrations of 80100 g/l, most of which are proteins. Serum refractometry assumes that the concentration of inorganic electrolytes and non-protein organic compounds does not change significantly from sample to sample, and differences in refractive index primarily reflect differences in protein concentrations.
The dependence of the refractive index of blood serum and its main protein components on temperature was studied using an Abbemat WR/MW refractometer (Anton Paar, Austria) in the temperature range of 15-45°C. The presence of a temperature dependence of the refractive index of both model systems and blood serum samples was shown. The paper discusses the applicability of the approach for the comparative analysis of blood serum samples from healthy donors and patients with oncohematological diseases.
Multiple myeloma (MM) is a disease of the hematopoietic system in which a monoclonal (one type) protein related to immunoglobulins (Mprotein) and (or) its light chains are synthesized, which are found in blood serum and (or) urine, rarely only in the cytoplasm clonal cells. MM is included in 1% of all malignant tumors and makes up just over 10% of all hematological malignancies; today it is considered incurable [1]. Recently, much attention has been paid to the development and use of various rapid methods for determining the protein composition of biological samples, including for the diagnosis of MM [2 - 4]. In some cases, as, for example, when determining multiple myeloma, it is necessary to obtain a reliable estimate of the amount of certain components in the composition of the biological material. Refractometric analysis in such a situation has a number of advantages, such as simplicity, short time and high accuracy of analysis.
The work studied the differences in the refractive indices of blood serum from healthy people and patients with multiple myeloma before and after a course of therapy using an Abbemat 200 refractometer (Anton Paar, Austria). We used blood serum samples from 14 patients of both sexes aged from 42 to 78 years with a diagnosis of stage II-III multiple myeloma, under the supervision of the hematology clinic of the Russian Research Institute of Hematology and Transfusiology, as well as control blood serum samples from 55 healthy blood donors. Serum samples after completion of the first course of antitumor therapy were collected from 8 of 14 patients.
Figure 1 shows the results of measuring the amount of protein in a sample depending on the refractive index of all studied samples. It can be noticed that all the points on the diagram are grouped in two areas. The area located at the bottom of the diagram contains samples from healthy donors, while the points corresponding to patients with MM before treatment are grouped at the top of the diagram. The results obtained indicate that, on average, both studied parameters, the refractive index and the amount of protein, are higher in the blood serum of patients with MM than in healthy donors. The latter is in good agreement with the data of biochemical and immunological analysis of the samples.
Figure 1. Results of measuring the amount ofprotein in a sample depending on the refractive index of all studied
samples.
rifrsicrivi ind^ii
Figure 2. Results of measuring the amount ofprotein in a sample depending on the refractive index ofpatients with MM
after the first course of antitumor therapy.
In Figure 2 there is a tendency towards a decrease in the amount of protein in the blood serum and, as a consequence, the refractive index in patients with MM who have undergone the first course of antitumor therapy, despite the persistence of significant differences between these patients and healthy donors.
Thus, we can conclude that refractometric analysis allows monitoring changes in protein concentration and refractive index of the blood serum of patients with MM, while combining simplicity, accuracy and high speed of analysis. Based on the data obtained, refractometry can be considered a promising method for studying samples of this type.
ACKNOWLEDGEMENTS
Investigations were carried out using the equipment of resource centere "Center for Diagnostics of Functional Materials for Medicine, Pharmacology and Nanoelectronics" of Scientific Park of St. Petersburg State University.
REFERENCES
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