Immature granulocytes and neutrophil-to-lymphocyte ratio as markers of treatment response in subacute thyroiditis.

Objective: Subacute thyroiditis is also known as subacute granulomatous thyroiditis, giant cell thyroiditis, painful thyroiditis, and De Quervain's thyroiditis. Immature granulocytes (IG) and neutrophil-to-lymphocyte ratio (NLR) are new inflammatory markers that are easily detected in routine complete blood count (CBC) tests. The aim of this study was to investigate the role of IG and NLR as markers of treatment response in patients with subacute thyroiditis.

Subjects And Methods: The study included 41 patients with subacute thyroiditis treated and monitored in our outpatient clinic between April 2020 and April 2022. From a retrospective review of medical records, we recorded results of IG, NLR, thyroid-stimulating hormone (TSH), free thyroxine (fT4), free triiodothyronine (fT3), erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP) from blood tests obtained routinely before and after treatment.

Results: Overall, 31 (75.6%) patients were women and 10 (21.4%) were men. The median age was 41 years (range 22-68 years). The laboratory tests showed the following median (range) results: IG, 0.03 (0.01-0.08); NLR, 3.6 (1.2-5.2); TSH, 0.02 mIU/L (0.01-3.35 mIU/L); fT4, 2.3 ng/dL (1.0-7.0 ng/dL); fT3, 5.6 pmol/L (2.6-15.2 pmol/L); ESR, 49 mm/h (17.0-87 mm/h); and CRP, 73 mg/dL (3.0-188 mg/dL).

Conclusion: Early diagnosis and treatment of subacute thyroiditis is fundamental. In the present study, the new inflammatory markers IG and NLR, measured routinely on CBC tests, decreased significantly after subacute thyroiditis treatment relative to pretreatment values. After treatment, the NLR change correlated with ESR and CRP changes, while the IG change correlated only with CRP change. These findings suggest that the markers IG and NLR may be used to evaluate treatment response in patients with subacute thyroiditis.