Incidence of subacute thyroiditis recurrences after a prolonged latency: 24-year survey

The Old and the New in Subacute Thyroiditis: An Integrative Review

Subacute thyroiditis (SAT) is the most common cause of neck pain and thyrotoxicosis. Although this disease was recognized already by the end of the 18th century, new concepts regarding pathogenesis have emerged in recent years. Moreover, in the last two years, literature on SAT has increased significantly due to articles describing the possible connection with coronavirus disease 2019 (COVID-19). This integrative review depicts old and new concepts of this disease, proposing a detailed overview of pathogenesis, a practical approach to diagnosis and treatment, and a thorough description of the latest discoveries regarding the association of SAT with COVID-19.

C-reactive protein and thyroid-stimulating hormone levels as risk factors for hypothyroidism in patients with subacute thyroiditis

OBJECTIVE

This study was designed to explore the relationships between the clinical characteristics and outcomes of patients with subacute thyroiditis (SAT).

DESIGN

This is a single-center retrospective study.

PATIENTS

Eighty-nine patients with SAT who were hospitalized in the Sir Run Run Shaw Hospital in Zhejiang, China, from October 2014 to September 2020 were included.

METHODS

The Mann-Whitney U-test, chi-square test, and Cox regression analysis were conducted to identify the relationships between clinical characteristics and outcomes. Receiver operating characteristic (ROC) analysis was performed to determine the optimal cutoff levels of C-reactive protein (CRP) and thyroid-stimulating hormone (TSH).

RESULTS

The hypothyroidism and recurrence rates were 15.7 and 16.9%, respectively. CRP (≥72.0 mg/L), TSH (<0.02 mIU/L), and free triiodothyronine (fT3) (≥4.10 pg/mL) were associated with hypothyroidism. The cutoff level was 97.80 mg/L for CRP (area under the curve (AUC), 0.717, P = 0.014; sensitivity, 57.1%; specificity, 84.0%) and 0.10 mIU/L for TSH (AUC, 0.752, P = 0.004; sensitivity, 100%; specificity, 46.0%) by ROC curve analysis for hypothyroidism. The factors under study were not associated with recurrence.

CONCLUSION

CRP and TSH were risk factors for hypothyroidism in SAT. Thyroid functions should be monitored closely for the early detection of hypothyroidism, especially in patients with CRP levels of more than 97.80 mg/L and TSH levels of less than 0.10 mIU/L.

Risk Factors for Subacute Thyroiditis Recurrence: A Systematic Review and Meta-Analysis of Cohort Studies

BACKGROUND

Subacute thyroiditis (SAT) is a self-limited inflammatory thyroid disease with recurring episodes. However, the results regarding the recurrence rate and risk factors for SAT are inconsistent. This meta-analysis aimed to summarize the evidence of the recurrence rate and the risk factors for SAT.

METHODS

The present study involved the performance of a systematic literature search of all English studies published in PubMed, Embase, Web of Science, and The Cochrane Library from inception to August 20, 2021. Cohort studies that reported the SAT recurrence rate and risk factors for recurrence were included. Two independent investigators extracted relevant information. Fixed- and random-effects models were used to pool effect sizes based on study heterogeneity.

RESULTS

Eighteen cohort studies were identified. The pooled findings showed that the recurrence rate was 12.0% (95% CI: 8.2%, 17.1%). The risk of recurrence in the glucocorticoids group was higher than that in the NSAIDs group (RR = 1.84, 95% CI: 1.04, 3.24). However, there was no significant difference in age or sex between the recurrence group and the non-recurrence group. Findings from one or two cohort studies also indicated that the copresence of HLA-B*18:01 and -B*35, the number of days required to taper prednisolone (PSL) to 5 mg/day, the duration of disease before treatment less than 30 days, the sialic acid level, or the TSH level at the termination of treatment and further extension of the hypoechoic area and increase in thyroid volume were related to the recurrence of SAT.

CONCLUSION

Recurrence was common in SAT patients. The present study indicated that glucocorticoid treatment was associated with a higher recurrence rate of SAT than NSAIDs treatment. The clinical implications of this association should be interpreted with caution, and further clinical trials on the long-term effects of different treatment strategies are needed.

Hemogram parameters in the patients with subacute thyroiditis

Background &Objective

Subacute Granulomatous Thyroiditis (De Quervain's Thyroiditis) is an acute painful inflammatory disease of the thyroid. We aimed to investigate easily accessible and cheap hemogram based parameters of Neutrophil to Lymphocyte Ratio (NLR), Platelet to Lymphocyte Ratio (PLR), and Mean Platelet Volume (MPV) in the follow up of inflammatory thyroid disease.

Methods

Patients admitted to Sakarya University Education and Research Hospital Endocrinology and Metabolism Outpatient Clinic and diagnosed as Subacute Granulomatous Thyroiditis between May 2017 and November 2018 were included in the study. Hemogram, thyroid function tests and acute phase values of these patients were recorded and compared with the values after treatment and disease recovery. On the sixth month, thyroid function tests were repeated and the rate of permanent hypothyroidism was screened. The relationships between initial hemogram parameters and acute phase reactants were evaluated.

Results

Total 71 patients were included in our study. 60 (84.5%) were female and 11 (15.5%) were male. The F/M ratio was found to be 6/1. Mean age was 43 ± 9.95 years. Receiver Operating Characteristics (ROC) Curve Analysis was performed and values for Area Under the Curve (AUC) for NLR and PLR, respectively, were 0.739 (95% CI 0.657-0.820 p<0.0001) and 0.772 (95% CI 0.694-0.850 p<0.0001), which are significant and associated with disease activity. However, the AUC for MPV parameter was: 0.578 (95% CI 0.484-0.672 P_: 0.10) and was not significant. The cut off values defined as 2.4 (80% sensitivity and 51% specificity) for NLR and 146.84 (83% sensitivity and 54% specificity) for PLR for the acute phase of the disease. In the Correlation Analysis, NLR and PLR values were significantly correlated with ESR and CRP parameters, which are the most commonly used acute phase reactants.

Conclusion

According to the present study, we believe that the NLR and PLR parameters will be of benefit in the follow-up the disease, accurately demonstrate the inflammatory load in the acute phase of the disease, and correlate with the common acute phase reactants.

Thyroid primary and metastatic malignant tumours of poor prognosis may mimic subacute thyroiditis - time to change the diagnostic criteria: case reports and a review of the literature

BACKGROUND

The diagnosis of subacute thyroiditis (SAT) is based mainly on the presence of painful thyroid goitre and a significant increase in erythrocyte sedimentation rate (ESR). Proceeding according to these diagnostic criteria may lead to an incorrect diagnosis and treatment. Extremely dangerous is the situation when the diagnosis of SAT is erroneously made based on criteria other than ultrasound (US) image and fine needle aspiration biopsy (FNAB), which leads to delayed diagnosis of malignant tumour with poor prognosis.

CASE PRESENTATION

Five patients with typical SAT symptoms are presented. In all of them, anaplastic thyroid cancer or metastatic thyroid tumours were finally diagnosed as the cause of the initial symptoms resembling SAT. Most of the patients were initially misdiagnosed and the proper diagnosis of malignancy was delayed.

CONCLUSIONS

The authors have proposed the new diagnostic criteria for SAT, and strongly suggest that thyroid gland US should be included in the main criteria of SAT diagnosis, together with FNAB result excluding the presence of malignant tumour.

The Risk of Recurrence of Subacute Thyroiditis Is HLA-Dependent

The frequency of recurrence of subacute thyroiditis (SAT) is rather high, reaching 20–30%. The reason for SAT relapse is still unknown. Recently, we have demonstrated the association between SAT and the presence of HLA-B*18:01, DRB1*01, and C*04:01, apart from the previously known HLA-B*35. The aim of the present study was to evaluate the correlation between SAT-associated HLA haplotypes and the risk of SAT recurrence. HLA-A, -B, -C, -DQB1 and -DRB1 were genotyped using a next-generation sequencing method in 49 SAT patients. The patients were divided into the following HLA groups: 1. HLA-B*35 and/or HLA-C*04, but without any other of the analyzed antigens; 2. HLA-DRB1*01, regardless of the co-presence of HLA-B*35 or -C*04:01, but without HLA-B*18:01; 3. HLA-B18 only, without any other antigen; 4. HLA-B*18:01 plus -B*35, regardless of the presence of any other analyzed antigens. The recurrence rate was compared between the groups. The recurrence rate was significantly increased in patients with HLA-B*18:01 plus HLA-B*35. In conclusion, the risk of SAT recurrence was HLA-dependent and the determining factor was the co-presence of HLA-B*18:01 and -B*35. In such high-risk patients, the steroid treatment regimen should be intensified with a slower dose reduction.

Thyroidectomy for Painful Thyroiditis Resistant to Steroid Treatment: Three New Cases with Review of the Literature

Thyroidal pain is usually due to subacute thyroiditis (SAT). In more severe forms prednisone doses up to 40 mg daily for 2-3 weeks are recommended. Recurrences occur rarely and restoration of steroid treatment cures the disease. Rarely, patients with Hashimoto's thyroiditis (HT) have thyroidal pain (painful HT, PHT). Differently from SAT, occasional PHT patients showed no benefit from medical treatment so that thyroidectomy was necessary. We report three patients who did not show clinical response to prolonged high dose prednisone treatment: a 50-year-old man, a 35-year-old woman, and a 33-year-old woman. Thyroidectomy was necessary, respectively, after nine-month treatment with 50 mg daily, two-month treatment with 75 mg daily, and one-month treatment with 50 mg daily. The two women were typical cases of PHT. Conversely, in the first patient, thyroid histology showed features of granulomatous thyroiditis, typical of SAT, without fibrosis or lymphocytic infiltration, typical of HT/PHT, coupled to undetectable serum anti-thyroid antibodies. Our data (1) suggest that not only PHT but also SAT may show resistance to steroid treatment and (2) confirm a previous observation in a single PHT patient that increasing prednisone doses above conventional maximal dosages may not be useful in these patients.

[Pharyngitis, massive ESR elevation and hyperthyroidism in a 71-year-old female patient]

We present a 71-year-old female patient suffering from a sore throat with unilateral neck swelling, pain on swallowing, subfebrile temperatures and general fatigue persisting for several weeks without any clinical signs of hyperthyroidism, although laboratory findings show high concentrations of T(3) and T(4) and a low TSH. A massive ESR elevation is found as well. Ultrasound reveals an inhomogeneous pattern of the thyroid gland with low echogenicity. (99m)Tc pertechnetate uptake is suppressed. The diagnosis of acute/subacute thyroiditis de Quervain is concluded. Therapeutic application of prednisone leads to a swift improvement, yet two weeks later asymptomatic hypothyroidism is diagnosed, requiring substitution of thyroxine. We discuss de Quervain's thyroiditis and the differential diagnosis of inflammatory disorders of the thyroid gland.