Endocrine Abstracts

Background: Subacute thyroiditis is considered a rare form of inflammatory thyroid disease, triggered by a viral infection. The prevalence is higher in women and in the middle-aged groups. The rate of subacute thyroiditis recurrence is between 1.4% and 20%, with wide discrepancies between different studies; the relapse may occur soon after de treatment or even years after, and recent studies show an HLA-dependence.

Methods: We present a case report of recurrent subacute thyroiditis in a patient with co-presence of 2 high-risk HLA haplotypes.

Case report: The patient, a Caucasian 70-year-old woman, presented in the clinic with symptoms consistent with subacute thyroiditis - neck pain, shivers, mild fever, fatigue, malaise, and insomnia – which occurred 2 weeks after a viral throat infection. She also had gastrointestinal (gastroesophageal reflux disease, gastritis with recurrent helicobacter infection) and cardiovascular complications (high blood pressure, dyslipidemia) that needed to be considered. The thyroid ultrasound sustained the diagnosis: painful goiter with ill-defined heterogeneously hypoechoic areas and diminished vascularity. The lab confirmed the subacute thyroiditis with mild elevated inflammatory markers (ESR, CRP) and subclinical hyperthyroidism with negative autoimmune profile. Considering the mild form of the disease and the associated personal risk factors, the treatment was started with 25 mg oral prednisolone, with gastric protection, tapering the dose to 5 mg every week. The patient had a complete resolution of the thyroiditis after 6 weeks of treatment, however, she had elevated blood pressure requiring higher doses of her antihypertensive drugs, and the gastroesophageal reflux worsened, causing gastric discomfort. Unfortunately, our lady came back with milder symptoms after 2 months, with a similar ultrasound and lab profile. After the steroid treatment with the same doses, she had a recurring complete resolution. The disease relapsed once again after one month. Other immunosuppressive diseases were excluded and a genetic test was performed. The PCR test revealed the presence of HLA-DRB1×01, 14 and HLA-B×35:01. Higher doses of prednisolone and pantoprazole were needed.

Conclusion: The presence of HLA-B*35 is a well-known risk factor for recurrent subacute thyroiditis. Recently it has been demonstrated that other haplotypes (HLA-DRB1*01, HLA-B*18:01, HLA-C*04:01) are independent risk factors. A short period of steroid therapy may result in the recurrence of the disease, but known high-risk HLA haplotypes, as an initial diagnostic tool, could lead to a more effective approach to the case. However, its widespread implementation is limited by its costs. Further research is needed to explore more cost-effective strategies.