Factors affecting recurrence in subacute granulomatous thyroiditis

The role of severity and duration of inflammation and hematological parameters on the outcome of subacute thyroiditis

Background: The role of severity and duration of inflammatory findings on the development of persistent hypothyroidism and anemia has not been clarified in subacute thyroiditis (SAT). Methods: Demographic data and laboratory parameters of patients with SAT were analyzed retrospectively. Results: Permanent hypothyroidism was observed in 28.1% of patients. Baseline elevated erythrocyte sedimentation rate as defined >74.5 mm/h was found to be associated with permanent hypothyroidism, but the duration of inflammation was not different between the recovered and hypothyroid patients. Baseline hemoglobin values improved without specific therapy in 3.5 months. Conclusion: The initial severity but not the duration of inflammation increases the risk for the development of permanent thyroid dysfunction, and anemia improves with the resolution of inflammation.

Comparison of treatment outcome between glucocorticoids and non-steroidal anti-inflammatory drugs in subacute thyroiditis patients-a systematic review and meta-analysis

Importance

Subacute thyroiditis (SAT) is a self-limiting and inflammatory thyroid disease. Although SAT usually improves on its own within weeks, it needs treatment when patients have pain, fever, and symptoms of thyrotoxicosis. Therapeutic drugs mainly include non-steroidal anti-inflammatory drugs (NSAIDs) and glucocorticoids. Currently, there is no systematic review or meta-analysis of the comparison of outcomes between NSAIDs and glucocorticoids for the treatment of SAT.

Objectives

To conduct a systematic review and meta-analysis on the outcomes in subacute thyroiditis patients treated with glucocorticoids or NSAIDs.

Data sources

Using the four electronic databases, including PubMed, Embase, Cochrane Library, Wanfang database and Web of Science. All publications until 21 June 2023 were searched. The reference lists of all selected articles were independently screened to identify additional studies left out in the initial search.

Study selection

The literature comparing outcomes between glucocorticoids and non-steroidal anti-inflammatory drugs for patients with subacute thyroiditis will be included.

Data extraction and synthesis

Two independent investigators (Anqi Yuan and Jialu Wu) extracted the data following Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines (PRISMA) and then evaluated the quality of the eligible studies with the Newcastle-Ottawa Scale. Fixed-effects models for the meta-analyses were applied. Heterogeneity was assessed with the chi-squared (x²) test (Cochran's Q) and inconsistency index (I²). The robustness of the results was tested with the sensitivity analyses. The bias of publication was assessed with the Harbord test.

Main outcomes and measures

The incidence of permanent hypothyroidism in SAT patients treated with corticosteroids or NSAIDs.

Results

Our study included a total of ten comparative cohort studies with 1337 participants. We found that the incidence of developing permanent hypothyroidism in the SAT patients who received glucocorticoids treatment was significantly lower than those who received NSAIDs treatment. (OR, 0.56; 95% CI, 0.36-0.88; P = 0.01). The risk of permanent hypothyroidism in patients who received prednisone at an average initial dose < 40 mg/d was significantly lower than that in patients who received NSAIDs (OR, 0.37; 95% CI, 0.14-0.94; P = 0.04). There was no significant difference in the occurrence of permanent hypothyroidism between SAT patients who received an average initial dose ≥ 40 mg/d of prednisone and those who received only NSAIDs (OR, 0.7; 95% CI, 0.14-3.53; P = 0.67). In addition, the recurrence rate was observably higher in those receiving glucocorticoids than in those receiving NSAIDs (OR, 1.98; 95% CI, 1.12-3.5; p = 0.02). The recurrence rate was significantly higher in patients with an average initial prednisone dose of < 40 mg/d than in the NSAIDs group. There was no significant difference in the recurrence rate between patients in the mean initial prednisone dose ≥ 40 mg/d group and those in the NSAIDs group.

Conclusions and relevance

In this meta-analysis, we compared the treatment outcomes of SAT patients between glucocorticoids and NSAIDs. Our results indicated that glucocorticoid treatment was associated with a lower incidence of permanent hypothyroidism than NSAID treatment. Patients treated with NSAIDs might have a lower recurrence rate. This finding might help to understand the outcome of the disease when choosing different drugs and help physicians to make appropriate decisions.

Systematic review registration

https://www.crd.york.ac.uk/prospero/, identifier CRD42023427332.

The prevalence of positive thyroid autoantibodies in patients with subacute thyroiditis: a systematic review and meta-analysis

PURPOSE

Subacute thyroiditis (SAT) is a transient inflammatory disorder of the thyroid gland with a possible viral etiology. We conducted this study to estimate the pooled prevalence of thyroid autoantibodies in SAT patients. This question arose due to the varying reports on the positivity rates of thyroid autoantibodies among SAT patients.

METHODS

We searched PubMed, Embase, Scopus, and Web of Science from their inception until March 25th, 2023. Observational studies reporting the positivity rate of thyroid autoantibodies for more than ten patients were included. We used the Joanna Briggs Institute's (JBI) critical appraisal checklist to assess the quality of the included studies. Pooled prevalence estimates with 95% confidence intervals were calculated using the random effects model. Subgroup analyses were performed to find sources of heterogeneity.

RESULTS

Out of 1373 identified records, 32 studies involving 2348 SAT patients were included in our study. Thyroglobulin antibody (TgAb) and thyroid peroxidase antibody (TPOAb) were positive in 22.8% and 12.2% of patients, respectively. The Study design, mean erythrocyte sedimentation rate and mean thyroid-stimulating hormone of patients were identified as sources of heterogeneity. As our secondary objectives, we found a recurrence rate of 14.7% and permanent hypothyroidism in 11.6% of patients.

CONCLUSION

The results of our study revealed a low TPOAb positivity rate in SAT patients, consistent with its non-autoimmune etiology. The TgAb positivity rate in SAT patients was higher than that of the general population, possibly explained by the transient release of thyroglobulin into the bloodstream during the thyrotoxic phase, leading to subsequent TgAb production. Furthermore, our findings demonstrate a notable recurrence rate and permanent hypothyroidism among SAT patients, highlighting the importance of ongoing follow-up care.

The Effects of Corticosteroid and Nonsteroid Anti-Inflammatory Therapies on Permanent Hypothyroidism Occurring After the Subacute Thyroiditis

OBJECTIVE

Subacute thyroiditis(SAT) is an acute inflammatory, self-limited, and destructive disease of the thyroid gland. Although it is a temporary disease, it has permanent consequences. We aim to investigate the influences of the treatment choice on permanent hypothyroidism occurring after SAT and whether there are predictive factors for the development of permanent hypothyroidism.

METHODS

We retrospectively investigated 57 SAT patients admitted to our tertiary hospital between 2017 and 2019. After excluding 6 patients, demographic, clinical, laboratory, and imaging findings of 36 patients treated with NSAIDs and 15 patients treated with corticosteroids were compared. The median duration of follow-up was 4 (3.5-5.5) years.

RESULTS

Permanent hypothyroidism occurred in 16 patients (31.4%) of 51 patients. It developed at a significantly higher rate in NSAID users (p=0.019). There was no significant difference in the occurrence of transient hypothyroidism and recurrence (p=0.472, p=0.082). The early maximum TSH values were strongly associated with permanent hypothyroidism. The Odds Ratio (OR) value was 2.59 (95% CI = 1.26 - 5.33, p=0.009), Nagelkerke R2 = 0.821. The early maximum TSH level had a predictive value, with an AUC of 0.966 for post-SAT permanent hypothyroidism (p<0.001). The cutoff values for the early maximum TSH were 9.07uIU/ml (81.3% sensitivity, 100% specificity), and 7.05 uIU/ml (87.5% sensitivity, 94.3% specificity).

CONCLUSION

Corticosteroid therapy is significantly effective in preventing permanent hypothyroidism from developing after SAT. The early maximum TSH values are an indicator for the prediction of the development of permanent hypothyroidism.

Could the Systemic Immune Inflammation Index Predict Diagnosis, Recovery Time, Hypothyroidism, and Recurrence Rates in Subacute Thyroiditis?

Purpose

Subacute thyroiditis (SAT) is a non-infectious inflammatory disease of the thyroid. The Systemic Immune-Inflammation Index (SII), also known as an easy economical marker, correlates with the severity of inflammatory responses. We aimed to evaluate the clinical significance of the SII and to compare it to other inflammatory markers in terms of diagnosis, recovery time, and recurrence of SAT.

Patients and Methods

The current non-interventional observational prospective study was performed at Outpatient Department of Endocrinology, Erzurum Training and Research Hospital. Sixty-nine patients with SAT and fifty-nine healthy individuals in total were enrolled in our study. The follow-up period was 6-12 months for all patients regarding treatment response, recurrence, and hypothyroidism.

Results

The SII level was found to be significantly higher at the time of diagnosis in the SAT group compared to the control group (p=0.000). There was a significant positive correlation between the SII and SAT recovery time (p=0.000), particularly in patients receiving methyl prednisolone treatment (p=0.002). SII was not found to be significantly associated with hypothyroidism and recurrence in patients with SAT (p=0.261, p=0.568). However, compared to the ones without recurrence, thyroid stimulating hormone (TSH) and erythrocyte sedimentation rate levels at the time of diagnosis were found to be higher in those patients with recurrence (p=0.035, p=0.046).

Conclusion

SII is a low-cost, widely available, universal indicator of inflammatory processes in SAT. It could provide many benefits in the follow-up process and the selection of aggressive anti-inflammatory treatment by estimating recovery time. SII, as a practical biomarker, may be a new diagnostic and prognostic tool for SAT.

A Novel Finding of an HLA Allele's and a Haplotype's Relationship with SARS-CoV-2 Vaccine-Associated Subacute Thyroiditis

Subacute thyroiditis (SAT) is a thyroid disease associated with viral infections. Its relationship with major histocompatibility complex (MHC) antigens was shown before. SAT cases triggered by different types of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines have been reported. In this study, human leukocyte antigen (HLA) genotypes of 27 SAT patients (13 vaccine-associated (V-SAT) and 14 non-SARS-CoV-2-infection non-vaccine-associated (non-V-SAT)) were compared with those of 362 healthy donors. HLA analyses were performed with low-resolution DNA-based sequence-specific oligonucleotide or sequence-specific primer methods. Statistical analyses were performed using IBM SPSS Statistics 25 and Stata/MP 14.1 with the hapipf function. Allele and haplotype frequencies were estimated by PyPop and gene[RATE] tool programs. The allele frequencies of HLA-A*11, HLA-B*35, and HLA-C*04 were higher in the patient groups. Both the allele frequency of HLA-A*11 and the haplotype frequency of A*11-B*35-C*04 were higher in the V-SAT group. The A*11-B*35-C*04 haplotype, including all three loci of MHC class I genes, is shown to be associated with the disease for the first time, especially in the V-SAT group. This finding will contribute to a better understanding of the etiopathogenesis of vaccine-associated SAT and the role of HLA genotypes in the functioning mechanisms of the SARS-CoV-2 vaccines.

Management of Subacute Thyroiditis - A Systematic Review of Current Treatment Protocols

Purpose

This systematic review endeavors to find an effective treatment protocol for subacute thyroiditis (SAT) to minimize side effects, recurrence and long-term hypothyroidism.

Materials and Methods

We analyzed available original studies on treatment protocols for SAT. A thorough literature search was performed on the following online databases PubMed, Cochrane library nd Google Scholar using appropriate keywords for choosing relevant articles. Two reviewers assessed the methodological quality of selected articles independently using a critical appraisal instrument. The results were analyzed and synthesized qualitatively using the level of evidence method.

Results

The literature search retrieved a total of 460 publications after abstract screening; out of which 36 articles met the inclusion criteria. After full text screening, 23 articles were further excluded as they were focusing on aspects of SAT other than management, the remaining 15 articles were investigated for both reliability and validity. Thirteen studies provided low-quality evidence, and two randomized control trials (RCT) provided a high quality of evidence. Steroid therapy was found to be the most effective for moderate to severe SAT and provided relief from acute symptoms but was found to not be a risk factor for recurrence. Low initial doses of steroid (15 mg) were preferred over high initial dosage (30–40 mg). Furthermore, a look into the mode of steroid delivery (RCT) revealed that intrathyroidal steroid therapy can potentially become a safer and faster mode of therapy. The duration of tapering was found to be of significance as a short tapering period was linked with greater recurrence rates.

Conclusion

Low initial doses of steroid along with an extended tapering period may help lower recurrence rates; also, intrathyroidal steroid injections are potentially a better alternative to oral prednisone (PSN) with regard to safety and speed of action. However, the evidence is of moderate quality and further investigation is required.

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