Evaluation of CBC-derived inflammatory markers in Wistar rats exposed to high-dose whole-body X-ray irradiation

PURPOSE Radiation exposure can lead to acute radiation syndrome and systemic inflammation, highlighting the need for accessible tests to assess exposure and its biological effects. This study investigated changes in inflammatory markers derived from CBC in male Wistar rats exposed to total-body irradiation with 6 MV LINAC photons delivered at doses of 6 Gy and 8 Gy, at a dose rate of 200 cGy/min.

METHODS A total of 42 rats were randomized into eight groups: control, sham, and irradiated groups. These groups were evaluated at 0-, 24-, and 48-hours post-exposure. Blood samples were analyzed for standard CBC values and derived ratios, such as the NLR (Neutrophil-to-Lymphocyte Ratio), PLR (Platelet-to-Lymphocyte Ratio), MLR (Monocyte-to-Lymphocyte Ratio), HLR (Hemoglobin-to-Lymphocyte Ratio), PMR (Platelet-to- Monocyte Ratio), SII (Systemic Immune-Inflammation Index), and SIRI (Systemic Inflammatory Response Index).

RESULTS Two-way ANOVA revealed significant time-dependent increases in NLR, PLR, HLR, and SII (p < .001 for all), independent of the radiation dose. MLR and PMR showed significant effects related to both time and dose, with higher values observed at 24-48 hours post-exposure.

CONCLUSION Our results indicate that the duration following irradiation influences most ratio-based indices, which appear to be sensitive in detecting early responses to radiation effects. This makes them rapid and cost-effective methods for monitoring radiation injury.