Effects of exposure to low-dose ionizing radiation on changing platelets: a prospective cohort study

Immuno-Biochemical Impacts of Gamma Irradiation in Male Rats: A Dose-Response Study

During radiotherapy, immune-modulatory effects of radiation doses should be taken into consideration, not only the anti-tumor radiation effects. Thus, our study aimed to study how γ-radiation modulates immune response in comparison to common immune-suppressive/stimulant agents. Animals were divided into two groups. Category A received Echinacea purpura extract (EP) or irradiated at low radiation doses 0, .25 or .5 Gray (Gy), whereas Category B received cyclophosphamide (CP) or irradiated at high radiation doses 1, 2, or 5 Gy. Serum levels of immunological mediators interleukin-10 (IL-10) and tumor necrosis factor (TNF-α), as well as redox-markers malondialdehyde (MDA) and nitric oxide (NO), hemoglobin (Hgb), white and red blood cells (WBCs, RBCs), and platelet counts were assessed following irradiation. Of the immune-stimulant category, .25 Gy dose offered EP-comparable effects in TNF-α, RBCs, Hgb, and platelet counts cases. As for the immune-suppressive category; 5 Gy irradiation dose induced inflammatory/immunosuppressive responses indicated (rise in NO, TNF-α, and IL-10), and an oxidative stress status (increase in serum MDA). However, 5 Gy γ-irradiation was not observed, herein, as a single immunosuppressive agent. To conclude, during radiotherapy, immunological impact(s) of the used radiation doses should be optimized and followed-up closely to assess the risk/benefit of their usage.

Effects of selenium supplementation on concurrent chemoradiotherapy in patients with cervical cancer: A randomized, double-blind, placebo-parallel controlled phase II clinical trial

Objective

Selenium (Se) is an essential trace element and may affect cervical cancer occurrence and progression. The association between selenium supplementation and acute toxic reactions and clinical outcomes in patients with locally advanced cervical cancer treated with concurrent chemoradiotherapy remains unclear. The aim of this study was to determine the safety profile of add-on Se yeast and assess the potential of Se to ameliorate the hematologic toxicity of concurrent chemoradiotherapy in patients with cervical cancer.

Methods

Patients with Federation International of Gynecology and Obstetrics (FIGO) stage IIB cervical cancer who met all inclusion criteria were randomly assigned to either the experimental group or the control group. The experimental group received Se yeast tablets (100 μg Se, twice daily), while the control group received placebos (twice daily) for 5 weeks in total. All patients in both groups received standard treatment, including pelvic external irradiation, concurrent five cycles of chemotherapy, and brachytherapy. Measures included the incidence of myelosuppression, impairment of liver and kidney function, objective response rate (ORR), and blood Se concentrations before, during and after the treatment of the two groups.

Results

A total of 104 eligible patients were enrolled in the experimental group (n = 50) or the control group (n = 54). The ORR in the experimental group and control group were 96 and 94%, respectively (p = 0.47). The baseline levels of blood Se before treatment in the experimental and control groups were similar (58.34 ± 17.63 μg/L and 60.21 ± 18.42 μg/L, p = 0.60), but the concentrations became significantly different after course completion between the two groups (76.16 ± 24.47 μg/L and 57.48 ± 14.92 μg/L, respectively, p < 0.01). Se dramatically decreased the incidence of grade 3 myelosuppression (48% vs. 63%, p = 0.034) compared to the control group. In the subgroup of patients with moderately well-differentiated cervical cancer, the incidence of thrombocytopenia induced by concurrent chemoradiotherapy was lower in the experimental group than in the control group (53.8% vs. 78.9%, p < 0.01). However, no difference was observed in liver and kidney injuries between the two groups.

Conclusion

Supplementation with Se effectively increased blood Se levels in Se-inadequate cervical cancer patients. As an add-on to standard treatment, Se-yeast significantly decreased the hematologic toxicity of concurrent chemoradiotherapy.

Does occupational ionizing radiation exposure in healthcare workers affect their hematological parameters?

Blood cells are used as the most sensitive marker to determine the effects and intensity of ionizing radiation. This descriptive study aimed to evaluate the effect of radiation exposure on hematological parameters in healthcare workers who were exposed to radiation in a university hospital between May and June 2021. A total of 339 participants were included, of which 169 (49.9%) were radiation workers and 170 (50.1%) were in the control group. A decrease was observed in white blood cell and neutrophil counts in those exposed to ionizing radiation for less than 10 years; however, white blood cell, neutrophil, hemoglobin levels decreased, and red cell distribution width (RDW) levels increased in those exposed to ionizing radiation for 10 years or more (p < 0.005). A statistically significant increase was observed in the RDW and lymphocyte levels as the years of work experience in the profession increase in the group exposed to IR. The findings indicate that the effect of low-dose ionizing radiation on the hematopoietic system is related to the frequency and duration of the dose. Hematological parameters can be sensitive biomarkers of low-dose ionizing radiation; possible disturbances in the hematopoietic system can be recognized before the onset of symptoms, and necessary precautions can be taken promptly.

Dose-Response Effects of Low-Dose Ionizing Radiation on Blood Parameters in Industrial Irradiation Workers

While previous studies have focused on the health effects of occupational exposure of radiations on medical radiation workers, few have analyzed the dose-response relationship between low radiation doses and changes in blood parameters. Even fewer studies have been conducted on industrial worker populations. Using a prospective cohort study design, this study collected health examination reports and personal dose monitoring data from 705 industrial irradiation workers who underwent regular physical examinations at Dongguan Sixth People’s Hospital. The dose-response effects of low-dose ionizing radiation on blood parameters were assessed using a generalized linear model and restricted cubic spline model. Red blood cell counts decreased then increased, before decreasing again with increasing ionizing radiation. This was in contrast to the curve of the total platelet count after irradiation. Additionally, a radiation dose of 2.904 mSv was the turning point for the nonlinear curve of hemoglobin count changes. In conclusion, long-term, low-dose ionizing radiation affects blood cell levels in industrial irradiation workers. There is a nonlinear dose-response relationship between red blood cell, platelet, and hemoglobin counts and the cumulative radiation dose. These findings should alert radiation workers to seek preventive medical treatment before the occurrence of any serious hematopoietic disease.

Platelets in Wound Healing: What Happens in Space?

Beyond their fundamental role in hemostasis, platelets importantly contribute to other processes aimed at maintaining homeostasis. Indeed, platelets are a natural source of growth factors and also release many other substances-such as fibronectin, vitronectin, sphingosine 1-phosphate-that are important in maintaining healthy tissues, and ensuring regeneration and repair. Despite rare thrombotic events have been documented in astronauts, some in vivo and in vitro studies demonstrate that microgravity affects platelet's number and function, thus increasing the risk of hemorrhages and contributing to retard wound healing. Here we provide an overview about events linking platelets to the impairment of wound healing in space, also considering, besides weightlessness, exposure to radiation and psychological stress. In the end we discuss the possibility of utilizing platelet rich plasma as a tool to treat skin injuries eventually occurring during space missions.