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

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.

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.

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.

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.