Primary Antiphospholipid Syndrome and Thyroid Involvement

An update on the endocrine manifestations of antiphospholipid syndrome

Antiphospholipid Syndrome (APS), characterized by hypercoagulability and pregnancy morbidity, poses a significant clinical challenge when involving organ systems, such as the endocrine system. APS can directly and indirectly influence the anterior and posterior lobes of the pituitary gland. The thyroid gland exhibits involvement, especially in patients with positive anticardiolipin antibodies, yet the clinical significance of the relationship with APS remains elusive. The pancreas, often overlooked, manifests in diverse ways, from pancreatitis to implications in diabetes. Adrenal insufficiency emerges as a common endocrine manifestation of APS, with adrenal hemorrhage or infarction being a presenting manifestation. Adrenal gland involvement has also been reported in the context of catastrophic APS. Pregnancy complications and infertility might be effects of APS on the female ovaries, while testicular torsion and decreased sperm concentration and total sperm count have been reported as rare effects of APS on male testes.

Association between thyroid dysfunction and venous thromboembolism: A systematic review and meta-analysis

BACKGROUND

Thyroid dysfunction plays an important role in the development of cardiovascular disease. However, its relationship with venous thromboembolism (VTE) remains unclear. We performed a meta-analysis of published cohort and case-control studies to investigate the association between thyroid dysfunction and VTE comprehensively.

METHODS

Three reviewers independently searched EMbase, PubMed, China national knowledge infrastructure, and Cochrane Library databases for relevant articles from the time of database establishment to 01 October 2022 and identified all studies on thyroid dysfunction and VTE as studies of interest. Of the 2418 publications retrieved, we identified 10 articles with 15 studies that met our selection criteria. Pooled ORs and 95% confidence intervals were calculated using fixed- or random-effect models.

RESULTS

We pooled 8 studies by a fixed-effect model, which suggested an increased risk of VTE in patients with (subclinical) hyperthyroidism (OR 1.33, 95% CI: 1.29-1.38). In the other 7 studies on patients with (subclinical) hypothyroidism, the risk was similarly increased when pooled by a random-effect model (OR 1.52, 95% CI: 1.23-1.89). After sensitivity analysis and risk of bias analysis, the risk of VTE was still increased in both (subclinical) hyperthyroidism (OR 1.322, 95% CI: 1.278-1.368) and (subclinical) hypothyroidism (OR 1.74, 95% CI: 1.41-2.16).

CONCLUSION

Patients with thyroid dysfunction have an increased risk of VTE. Therefore, it is recommended to perform thyroid function screening routinely in patients at high risk of VTE.

Anti-β2-glycoprotein I autoantibodies influence thrombin generation parameters via various mechanisms

INTRODUCTION

Antiphospholipid syndrome (APS) is a systemic autoimmune disease characterised by recurrent thrombotic events, pregnancy loss and thrombocytopenia and the presence of antiphospholipid antibodies (APL). The exact pathomechanism of APS is still unknown, thus we investigated the effect of anti-β₂-glycoprotein I (anti-β₂GPI) on thrombin generation in different plasma samples.

METHODS

For the separation of anti-β₂GPI IgG, overall 12 APS patients were selected. The criteria were the existence of lupus anticoagulant, and the presence of anti-CL and anti-β₂GPI, the latter exceeding at least 25 times the upper reference limit. We purified anti-β₂GPI IgG antibodies from APS patients by affinity chromatography and added the antibodies to normal pooled, and heterozygous forms of inherited thrombophilia plasma samples (prothrombin G20210A, factor V Leiden). To further specify the mechanism of the effect, we also used factor deficient plasmas in the thrombin generation assay.

RESULTS

In normal pooled plasma, the anti-β₂GPI significantly prolonged Lag Time according to the lupus anticoagulant effect, in contrast, it also elevated Peak Thrombin significantly, which suggests a procoagulant effect. The antibody was also able to exert this multi-faceted effect both in FV_Leiden heterozygous plasma and prothrombin G20210A heterozygous polymorphism, however, the prolonging effect was more remarkable in the latter. By using factor deficient plasmas, it was found that FVII is required for the prolongation, while intrinsic factors are needed for the elevation of the Peak Thrombin.

CONCLUSION

The anti-β₂GPI autoantibodies exert their effect in both normal and thrombophilic plasmas via various mechanisms.

Levothyroxine and subclinical hypothyroidism in patients with recurrent pregnancy loss

PROBLEM

The association between subclinical hypothyroidism (SCH) and recurrent pregnancy loss (RPL) remains unclear. We evaluated whether SCH affects subsequent live births and whether levothyroxine is effective in improving the live birth rate in patients with RPL.

METHOD OF STUDY

This observational cohort study included 1418 pregnancies of 1014 patients with a history of 2 or more pregnancy losses, who were euthyroid or had hypothyroidism, and had at least one subsequent pregnancy outcome. Some patients with SCH, as defined as a TSH >2.5 mIU/L, were treated with levothyroxine, and these comprised the levothyroxine group. The prevalence of SCH, subsequent live birth rates per patient and per pregnancy were compared among patients with SCH treated with and without levothyroxine and patients with euthyroid.

RESULTS

The prevalence of SCH was 14.4%. Subsequent live birth rates were 75.0% for the levothyroxine group, 68.6% for the untreated SCH group, and 70.1% for the euthyroid group. After excluding miscarriages with abnormal karyotypes, live birth rates were 89.2%, 90.0%, and 91.1%. The adjusted odds ratio (95%CI) was 0.95 (0.23-3.83) after controlling covariables when comparing SCH patients with and without treatment. The live birth rates per pregnancy were 93.1%, 85.7%, and 90.9%, respectively. The adjusted OR was 0.95 (0.23-3.83).

CONCLUSION

Levothyroxine has no effect on improving the live birth rate in patients with RPL associated with SCH. Treatment in patients with RPL and SCH raised TSH levels (2.5-10mIU/L) might not be beneficial in improving the live birth rate.

Genetics of Antiphospholipid Syndrome

PURPOSE OF REVIEW

Antiphospholipid syndrome (APS) is a rare heterogenous disorder associated with the presence of antiphospholipid antibodies and can present in a wide variety of clinical manifestations including thrombosis and pregnancy complications. Although the etiology of APS remains poorly understood, there is strong support for considering APS as a complex genetic disease in which multiple genetic risk factors, in conjunction with environmental factors, affect its onset, progression, and severity. Here, we provide a comprehensive review of the current knowledge of the genetic basis of APS, which remains in its infancy.

RECENT FINDINGS

Most genetic studies to date in APS were performed in small cohorts of patients. As a result, only few genetic associations reported are convincing. Several reports suggested genetic associations with HLA class II alleles in APS, and only two genetic loci outside of the HLA region (STAT4 and C1D) reached the threshold for genome-wide level of significance (P < 5 × 10^-8). In this review, we also shed light on the genetic differences among the diverse clinical subsets of APS and briefly discuss the role that DNA methylation changes might play in the pathophysiology of this disease. The genetic basis of APS remains poorly characterized. Larger collaborative multicenter studies using well-characterized patients are needed to comprehensively understand the role of genetic susceptibility in APS.

Subclinical hypothyroidism and cardiovascular risk factors

INTRODUCTION

Thyroid hormones have multiple effects on lipid metabolism as well as on the cardiovascular system function. These negative cardiovascular effects have long been recognized in overt hypothyroidism but can be reversed by treatment with levothyroxine.

EVIDENCES ACQUISITION

We performed on PubMed a literature search for the articles published until March 2019 by using the search terms "subclinical hypothyroidism," "cardiovascular disease," "cholesterol," "LDL," "HDL," "triglycerides," "coronary heart disease," "heart failure," "atherosclerosis," "all-cause mortality," "levothyroxine."

EVIDENCES SYNTHESIS

Subclinical hypothyroidism, defined as an elevated thyrotropin (TSH) with a normal free thyroxine (FT4), is frequent in the general population and increase with age. Subclinical hypothyroidism has been linked to cardiovascular risk factors, dyslipidemia and increased atherosclerosis. Although some studies have demonstrated that lipids are elevated in subclinical hypothyroidism, other studies did not confirm these data. Clinical trials have also demonstrated there is no clear evidence that levothyroxine therapy in subjects with milder form (TSH<10 mU/L) of subclinical hypothyroidism could improve lipid status and the other cardiovascular risk factors. Nevertheless, TSH level seems the best predictor of cardiovascular disease, in particular when its levels are above 10 mU/L.

CONCLUSIONS

Prospective studies are necessary to clarify the cardiovascular risk in patients with mild subclinical hypothyroidism and to assess the importance of treating elderly people in order to improve or counteract the correlated risks. However, until clinical recommendations will be updated, the decision to treat or not treat patients with subclinical hypothyroidism will still base on clinical judgment, clinical practice guidelines, and expert opinion.

ANMCO Position Paper: long-term follow-up of patients with pulmonary thromboembolism

Venous thromboembolism (VTE), including pulmonary embolism and deep venous thrombosis, is the third most common cause of cardiovascular death. The management of the acute phase of VTE has already been described in several guidelines. However, the management of the follow-up (FU) of these patients has been poorly defined. This consensus document, created by the Italian cardiologists, wants to clarify this issue using the currently available evidence in VTE. Clinical and instrumental data acquired during the acute phase of the disease are the cornerstone for planning the FU. Acquired or congenital thrombophilic disorders could be identified in apparently unprovoked VTE during the FU. In other cases, an occult cancer could be discovered after a VTE. The main targets of the post-acute management are to prevent recurrence of VTE and to identify the patients who can develop a chronic thromboembolic pulmonary hypertension. Knowledge of pathophysiology and therapeutic approaches is fundamental to decide the most appropriate long-term treatment. Moreover, prognostic stratification during the FU should be constantly updated on the basis of the new evidence acquired. Currently, the cornerstone of VTE treatment is represented by both the oral and the parenteral anticoagulation. Novel oral anticoagulants should be an interesting alternative in the long-term treatment.

Progesterone luteal support after ovulation induction and intrauterine insemination: an updated systematic review and meta-analysis

OBJECTIVE

To evaluate the effect of progesterone (P) for luteal phase support after ovulation induction (OI) and intrauterine insemination (IUI).

DESIGN

An updated systematic review and meta-analysis.

SETTING

Not applicable.

PATIENT(S)

Patients undergoing OI-IUI for infertility.

INTERVENTION(S)

Exogenous P luteal support after OI-IUI.

MAIN OUTCOME MEASURE(S)

Live birth.

RESULT(S)

Eleven trials were identified that met inclusion criteria and constituted 2,842 patients undergoing 4,065 cycles, more than doubling the sample size from the previous meta-analysis. In patients receiving gonadotropins for OI, clinical pregnancy (relative risk [RR] 1.56, 95% confidence interval [CI] 1.21-2.02) and live birth (RR 1.77, 95% CI 1.30-2.42) were more likely in P supplemented patients. These findings persisted in analysis of live birth per IUI cycle (RR 1.59, 95% CI 1.24-2.04). There were no data on live birth in clomiphene citrate or clomiphene plus gonadotropin cycles. There was no benefit on clinical pregnancy with P support for patients who underwent OI with clomiphene (RR 0.85, 95% CI 0.52-1.41) or clomiphene plus gonadotropins (RR 1.26, 95% CI 0.90-1.76).

CONCLUSION(S)

Progesterone luteal phase support is beneficial to patients undergoing ovulation induction with gonadotropins in IUI cycles. The number needed to treat is 11 patients to have one additional live birth. Progesterone support did not benefit patients undergoing ovulation induction with clomiphene citrate or clomiphene plus gonadotropins.

Thyroid Autoimmunity and Antiphospholipid Syndrome: Not Such a Trivial Association

Antiphospholipid syndrome (APS) is an autoimmune disease that manifests as recurrent venous or arterial thrombosis and/or pregnancy-related complications in the presence of persistent antiphospholipid (aPL) antibodies measured at least 3 months apart. APS occurs either as a primary condition or as a part of an underlying disorder, usually systemic lupus erythematosus (SLE). Otherwise, APS may be frequently associated with autoimmune disorders. Little is known about the association of APS and aPL antibodies with thyroid autoimmune diseases or thyroid autoantibodies. This is even more interesting that thyroid autoantibodies and aPL are both recognized causes of repeated miscarriages. Therefore, their combination is of particular importance in women of childbearing age. Several studies have pointed out an association between APS and thyroid autoimmunity, some of them suggesting common pathophysiologic processes and genetic background. A literature review was conducted on existing data on aPL/APS and thyroid autoimmune disorders, paying particular attention to the possible role of this association in obstetrical complications.