Subacute Thyroiditis from COVID-19 Infection: A Case Report and Review of Literature

INTRODUCTION

The novel severe-acute-respiratory-syndrome-coronavirus-2 (SARS-CoV-2) virus has led to the ongoing Coronavirus disease 2019 (COVID-19) disease pandemic. There are increasing reports of extrapulmonary clinical features of COVID-19, either as initial presentations or sequelae of disease. We report a patient diagnosed with subacute thyroiditis precipitated by COVID-19 infection, as well as review the literature of similar cases.

CASE PRESENTATION

A 41-year-old female with no significant personal or family history of endocrinologic disorders presented with clinical features of thyroiditis that began after COVID-19 infection. Clinical, laboratory, and radiologic findings were indicative of subacute thyroiditis. Workup for potential triggers other than SARS-CoV-2 was negative.

DISCUSSION/CONCLUSION

We compared the clinical and diagnostic findings of our patient with other well-documented cases of subacute thyroiditis presumed to be triggered by SARS-CoV-2 viral infection. We also reviewed the literature related to the potential mechanisms leading to thyroiditis. Clinicians must be aware of the possibility of thyroid dysfunction after COVID-19 infection. Early recognition and timely anti-inflammatory therapy help in successful management.

High normal TSH is associated with lower mannan-binding lectin in women of childbearing age

BACKGROUND

Mannan-binding lectin (MBL) is a main component of the lectin pathway of the complement system. Lower MBL levels are associated with, among other conditions, hypothyroidism and adverse pregnancy outcomes. In turn, adverse pregnancy outcomes and infertility may result from hypothyroidism, even in patients with high normal Thyroid-stimulating hormone (TSH). The aim of this study was to determine if MBL level differs between women of reproductive age with low normal (< 2.5 mIU/l) and high normal (≥2.5 mIU/l) TSH. Associations with other parameters potentially affected by hypothyroidism were also evaluated.

METHODS

Ninety five (95) patients with normal thyroid tests (TSH 0.27-4.2 mIU/l), aged 18-48 years, were prospectively enrolled. Several laboratory parameters were measured, including MBL level, thyroid tests and lipid profile.

RESULTS

Serum MBL level was lower in women with TSH ≥ 2.5 mIU/l than with TSH < 2.5 mIU/l. This association was confirmed by univariate regression analysis. MBL level was significantly lower in patients with abnormally low HDLC/cholesterol ratio and a positive correlation was found between MBL level and HDL/cholesterol ratio.

CONCLUSION

In women of reproductive age with normal thyroid tests, lower MBL is associated with high normal TSH and with less favourable lipid profile. Therefore treatment with L-thyroxine should be considered in women of reproductive age with TSH ≥ 2.5 mIU/l.

Reference Values for TSH and Free Thyroid Hormones in Healthy Pregnant Women in Poland: A Prospective, Multicenter Study

OBJECTIVES

The diagnosis and treatment of thyroid diseases in pregnant women remains a challenge. Various medical associations recommend establishing the reference intervals for thyroid hormones by a local laboratory. Considering differences within geophysical, socioeconomic conditions, and iodine prophylaxis in various populations, it is advisable to assess reference intervals for thyroid hormones specific to a region of residence. The objective was to assess trimester-specific reference intervals for TSH, fT₃, and fT₄ for pregnant women in the Polish population.

METHODS AND RESULTS

We conducted a prospective study in 4 centers representing different regions of Poland (Krakow, Warsaw, Poznan, and Bialystok). Our study included consecutive, healthy pregnant women (172 patients), with an age range of 27-47 years. All women had a negative history for thyroid diseases, normal thyroid peroxidase antibody levels, and proper iodine prophylaxis. All newborns had TSH levels in the appropriate reference range. Serum TSH, fT₃, fT₄, and thyroid-peroxidase antibodies were measured in each trimester. The reference intervals were calculated using the percentile method, as recommended by the International Federation of Clinical Chemistry. The reference values calculated were 0.009-3.177, 0.05-3.442, and 0.11-3.53 mIU/L for TSH; 3.63-6.55, 3.29-5.45, and 3.1-5.37 pmol/L for fT₃; and 11.99-21.89, 10.46-16.67, and 8.96-17.23 pmol/L for fT₄ in consecutive trimesters of pregnancy. Reference intervals for pregnant women when compared to the general population showed a lower concentration of TSH in every trimester of pregnancy and lower fT₄ in the 2nd and 3rd trimesters.

CONCLUSIONS

Using appropriate trimester-specific reference intervals may improve care of pregnant women by preventing misdiagnosis and inadequate treatment.

Plasma Levels of Free Thyroxine and Risk of Major Bleeding in Bariatric Surgery

BACKGROUND

In a recent study of patients using vitamin K antagonists, those with low free thyroxin (FT4) levels within the normal range had a 3- to 5-fold increased risk of major bleeding. We tested the hypothesis that low levels of preoperative FT4 within the reference range are associated with an increased risk of major bleeding during and after bariatric surgery.

METHODS

The charts of 2,872 consecutive patients undergoing bariatric surgery were retrospectively screened for bleeding episodes. Patients with major bleeding until 1 month after surgery were compared to randomly selected control patients without bleeding, in a ratio of 1:4. We evaluated the association between preoperative FT4 levels and the risk of major bleeding by logistic regression.

RESULTS

Seventy-two cases (2.5%) with major bleeding were identified and 288 controls were selected. The median plasma level of FT4 was 13 pmol/l (interquartile range: 12-14) in the cases as well as in the controls. No clear effect was observed of low levels of FT4 on the risk of major bleeding: odds ratio 1.48 (95% CI: 0.46-4.80) for patients with an FT4 level <11 pmol/l, 1.03 (0.49-2.18) for patients with an FT4 level <12 pmol/l, and 1.12 (0.65-1.94) for patients with an FT4 level <13 pmol/l as compared to patients with FT4 values greater than or equal to these cutoff levels.

INTERPRETATION

We did not observe an increased risk of major bleeding with low levels of FT4 in patients undergoing bariatric surgery.

Neurotoxicant exposure during pregnancy is a confounder for assessment of iodine supplementation on neurodevelopment outcome

CONTEXT

The developing brain is vulnerable to iodine deficiency (ID) and environmental neuro-toxicants.

OBJECTIVES

To assess neurocognitive development of children whose mothers have received (or not) iodine supplementation during pregnancy, in an area of borderline ID, while assessing in utero exposure to environmental neuro-toxicants.

DESIGN/PATIENTS

Among 86 children born from normal euthyroid women who participated in our prospective interventional study on iodine supplementation (150 μg/day) started early in pregnancy, 44 (19 with iodine supplementation, 25 controls) were assessed at two years using the Bayley test. Information on parents' education and habits (smoking), and on child development was recorded. Thyroid tests at each trimester of pregnancy and on cord blood (CB) were available, as well as milk concentrations of selected environmental compounds known for their neurotoxicity, including heavy metals and PCBs.

RESULTS

There was no difference in Bayley tests for children born to mothers with and without iodine supplementation, but sample size was small. Language and Social-Emotional Scales were negatively correlated with TBG at all times tested, while PCB 118 correlated negatively with all Language scales. Among maternal and CB thyroid tests, only CB thyroglobulin, the best marker of iodine status, correlated (negatively) with neurodevelopment scales (Motor and Expressive Language).

CONCLUSIONS

This pilot study suggests that PCB118 has a negative impact on neurocognitive development, possibly mitigating the benefit of iodine supplementation in an area of borderline ID. We propose that exposure to environmental neurotoxicants should be taken into account when designing studies on the benefit of iodine supplementation in pregnancy. The potential interactions between TBG, environmental neurotoxicants and brain development warrant further studies.

Relative impact of iodine supplementation and maternal smoking on cord blood thyroglobulin in pregnant women with normal thyroid function

OBJECTIVE

To assess the impact on cord blood (CB) thyroglobulin (Tg) of early iodine supplementation during pregnancy.

METHODS

A total of 111 healthy pregnant women with normal thyroid function were included in a prospective randomized study and divided into two groups with (150 μg/day) or without iodine supplementation started during the first trimester. Maternal smoking was assessed qualitatively by self-reported statements and quantitatively by cotininuria. Exhaustive thyroid tests were performed at delivery in the mother and in CB.

RESULTS

Third-trimester ioduria documented compliance with iodine supplementation (160 vs. 76 μg/l in controls). CB Tg was not different between the iodine and control groups (median 77 vs. 79.5 ng/ml, respectively) and did not correlate with maternal ioduria. CB Tg was higher in newborns from smoking mothers (114 vs. 64.7 ng/ml) and correlated with self-reported smoking status more than with maternal cotininuria. Nonsmokers had no difference in CB Tg whether they took iodine supplementation or not, as opposed to smokers, who tended to benefit from supplementation.

CONCLUSIONS

Iodine supplementation does not significantly impact CB Tg in healthy nonsmoker pregnant women selected for normal thyroid function, as opposed to maternal smoking. CB Tg appears to be a marker of in utero tobacco exposure. In areas of mild iodine deficiency, iodine supplementation could especially benefit the fetuses of smokers.