Objective: This study aimed to evaluate the factors affecting recurrence in subacute granulomatous thyroiditis (SAT). Materials and methods: A total of 137 patients with SAT were enrolled in the study; 98 (71.5%) were women and 39 (28.5%) were men. The patients received either steroid or nonsteroidal anti-inflammatory drug (NSAID) for eight weeks. Erythrocyte sedimentation rate (ESR), C-reactive protein, serum thyroid-stimulating hormone (TSH), free triiodothyronine, free thyroxine (FT4), anti-thyroid peroxidase antibodies and thyroglobulin antibodies, neutrophil, lymphocyte, platelet, neutrophil to lymphocyte ratio, and platelet to lymphocyte ratio levels were evaluated. In addition, recurrence rates were compared between patients who received NSAID treatment and those who received steroid therapy. Results: Treatment modality and pretreatment TSH, FT4, and ESR were significantly different between patients with and without recurrence (p = 0.011, 0.001, 0.004, and 0.026, respectively). Compared with patients without recurrence, those with recurrence had higher pretreatment TSH levels, but lower FT4 and ESR levels. On logistic regression analysis, treatment modality was found to be an independent risk factor for recurrence. The risk of recurrence was higher in those taking steroids than in those taking NSAIDs (p = 0.015). The optimal TSH cutoff value for recurrence was 0.045 µIU/mL, with a sensitivity of 83.3% and specificity of 76% (AUC 0.794, 95% CI 0.639-0.949). Conclusions: The risk of SAT recurrence was higher with steroid therapy than with NSAIDs. Patients who had mild thyrotoxicosis had relatively high recurrence rate and may need a relatively longer duration of treatment.

Background/Aim The aims of the study are to compare characteristics of subacute thyroiditis (SAT) related to different aetiologies, and to identify predictors of recurrence of SAT and incident hypothyroidism. Methods This nationwide multicenter retrospective cohort study included 53 endocrinology centers in Turkey. The study participants were divided into either coronavirus disease-2019 (COVID-19)-related SAT (Cov-SAT), severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine-related SAT (Vac-SAT), or control SAT (Cont-SAT). Results Of the 811 patients, 258 (31·8%) were included in the Vac-SAT group, 98 (12·1%) in the Cov-SAT group, and 455 (56·1%) in the Cont-SAT group. No difference was found between the groups with regard to laboratory and imaging findings. The aetiology of SAT was not an independent predictor of recurrence or hypothyroidism. In the entire cohort, steroid therapy requirement and younger age were statistically significant predictors for SAT recurrence. C-reactive protein (CRP) measured during SAT onset, female gender, absence of anti-thyroid peroxidase (TPO) positivity, and absence of steroid therapy were statistically significant predictors of incident (early) hypothyroidism, irrespective of SAT aetiology. On the other hand, probable predictors of established hypothyroidism differed from that of incident hypothyroidism. Conclusion Since there is no difference in terms of follow-up parameters and outcomes, COVID-19- and SARS-CoV-2- vaccine related SATs can be treated and followed up like classical SATs. The recurrence was determined by the younger age and steroid therapy requirement. Steroid therapy independently predict incident hypothyroidism that may sometimes be transient in overall SATs and is also associated with lower risk of established hypothyroidism.

Purpose: Patients with subacute thyroiditis (SAT) usually apply to clinics with thyrotoxicosis and neck pain. Hemogram is frequently applied tests in primary health care services, and it can warn physicians for SAT in a thyrotoxic patient. In our study, the role and usability of neutrophil to lymphocyte ratio (NLR) and platelet to lymphocyte ratio (PLR) in the diagnosis of SAT were evaluated. Material and Methods: Between January 2015 and January 2020, 192 SAT patients who applied to endocrinology clinics and 85 healthy control were included in the study. Neutrophil (Neu), lymphocyte (Lym), platelet (PLT) leves were recorded. Results: The median NLR and PLR values of SAT patients before treatment were 2.78 (0.91-11.33) and 168.3 (25.7-818.3), respectively, and were significantly higher than the control group (p<0.001). The optimum cut-off values for NLR and PLR for SAT were 1.84 (specificity 85.9% and sensitivity 90.1%; p<0.001; AUC=0.934; 95% CI: 0.905-0.964 ) and 140.2 (specificity 83.5% and sensitivity 77.1%, p<0.001, AUC=0.821 95% CI: 0.767-0.874), respectively. Pretreatment NLR, PLR, CRP, and ESR levels were significantly higher than the posttreatment levels (all p<0.001). Correlation analysis revealed positive linear relations between pretreatment PLR and CRP (p=0.002, r=0.220), pretreatment PLR and ESR (p=0.018, r=0.171), pretreatment NLR and CRP (p<0.001, r=0.330), and pretreatment NLR and ESR (p=0.001, r=0.242). Multiple linear regression analysis revealed a 0.008 unit of increment of NLR per 1 unit increase in CRP levels (B=0.008; p<0.001; %95 CI=0.004-0.012). Conclusion: High NLR and PLR values accompanying thyrotoxicosis are both warning and helpful parameters for the diagnosis of SAT.