Novel immunoinflammatory blood markers in Graves' orbitopathy: insights into activity and severity.

Objective: This prospective case-control study examined the novel immunoinflammatory markers obtained from blood counts of patients with Graves' orbitopathy (GO), Graves' disease (GD) and healthy subjects.

Methods: Demographic data, white cell count parameters, neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), mean platelet volume (MPV), platelet-to-neutrophil ratio (PNR), red cell distribution width (RDW), RDW-to-platelet ratio (RDW/PLT), MPV-to-lymphocyte ratio (MPV/ALC), eosinophil-to-lymphocyte ratio (ELR) and systemic immune-inflammatory index (SII) were evaluated. The European Group on Graves Orbitopathy scale and Clinical Activity Score were used for clinical activity and severity assessment.

Results: The GO group showed significantly higher mean MPV (p˂0.001) and MPV/ALC (p=0.03) than the GD group. The PLR (p=0.02), MPV/ALC (p=0.04) and SII (p=0.04) were significantly higher in the GO than healthy group. A significantly higher absolute neutrophil count (p=0.005), NLR (p=0.001), MPV (p=0.001), MPV/ALC (p=0.003), MPV/PLT (p=0.04), RDW (p˂0.001), RDW/PLT (p=0.02) and SII (p=0.01) as well as lower ALC (p=0.01) and PNR (p˂0.001) was observed in the active than inactive GO. Moderate to severe GO group had a significantly higher NLR (p=0.006), PLR (p=0.04), ELR (p=0.006), MPV (p=0.03), MPV/ALC (p=0.002), RDW (p˂0.001), RDW/PLT (p=0.02) and SII (p=0.03) as well as a lower ALC (p=0.01) and PNR (p=0.01) than mild GO.

Conclusions: The MPV/ALC ratio and MPV levels may identify GD patients at risk of GO. The MPV, MPV/ALC, ALC, NLR, PLR, PNR, RDW, RDW/PLT, MPV/PLT and SII may help distinguish the GO activity and severity. However, the study's small sample size and single-centre design may limit the generalisability of the results. Furthermore, the lack of longitudinal follow-up precludes assessing marker evolution over time.