Use of polarization-interference microscopy to determine the optical properties of fetal erythrocytes in tissues

Objective: to evaluate the possibility of using polarization interference microscopy for morphological diagnostics of fetal erythrocytes in tissues. Materials and methods. Blood smears used during the diagnostic and treatment process and histological sections prepared from autopsy material were used. During the diagnosis, a polarization-interference microscope PZO BIOLAR PI with a microphotometric nozzle UPI was used to determine the optical density and the measure of light transmission in erythrocytes. The method of polarization-interference microscopy contributed to the study of optical properties in individual erythrocytes. The optical properties of erythrocytes containing fetal-type hemoglobin and erythrocytes with adult-type hemoglobin were compared. The difference in the composition of the structure of erythrocytes determined the difference in light transmission and refraction. Based on the results of light transmission, the optical density of fetal and adult erythrocytes was calculated. In the conducted study of clinical blood smears, in neonatal patients, 60 measurements of the light transmission coefficient and 60 similar studies were performed in patients of the comparison group - persons older than 18 years. In the study of autopsy material, 120 measurements of the erythrocyte light transmission coefficient were carried out in placental tissue samples (chorionic villi and interstitial space). Results. The optical properties of erythrocytes were determined both in blood smears and in placental tissue preparations. Erythrocytes in blood smears with HbF had an increased light transmission coefficient in relation to the optical properties of erythrocytes with HbA in the control group. During the study of placental tissues, it was revealed that the indicators of the optical density of maternal erythrocytes with HbA in the erythrocytes of the interstitial space differed in higher values of indicators compared with the optical density of fetal erythrocytes with HbF in the vessels of chorionic villi. Conclusion. The determination of differences in the physico-optical properties of erythrocytes with fetal and adult hemoglobins makes it possible to determine the affiliation of erythrocytes both in blood smears and in the interstitial space of the placenta.

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