High Prevalence of Antithyroid Antibodies in a New Zealand Cohort of Patients With Systemic Sclerosis

Characterising the autoantibody repertoire in systemic sclerosis following myeloablative haematopoietic stem cell transplantation

OBJECTIVES

Results from the SCOT (Scleroderma: Cyclophosphamide Or Transplantation) clinical trial demonstrated significant benefits of haematopoietic stem cell transplant (HSCT) versus cyclophosphamide (CTX) in patients with systemic sclerosis. The objective of this study was to test the hypothesis that transplantation stabilises the autoantibody repertoire in patients with favourable clinical outcomes.

METHODS

We used a bead-based array containing 221 protein antigens to profile serum IgG autoantibodies in participants of the SCOT trial.

RESULTS

Comparison of autoantibody profiles at month 26 (n=23 HSCT; n=22 CTX) revealed antibodies against two viral antigens and six self-proteins (SSB/La, CX3CL1, glycyl-tRNA synthetase (EJ), parietal cell antigen, bactericidal permeability-increasing protein and epidermal growth factor receptor (EGFR)) that were significantly different between treatment groups. Linear mixed model analysis identified temporal increases in antibody levels for hepatitis B surface antigen, CCL3 and EGFR in HSCT-treated patients. Eight of 32 HSCT-treated participants and one of 31 CTX-treated participants had temporally varying serum antibody profiles for one or more of 14 antigens. Baseline autoantibody levels against 20 unique antigens, including 9 secreted proteins (interleukins, IL-18, IL-22, IL-23 and IL-27), interferon-α2A, stem cell factor, transforming growth factor-β, macrophage colony-stimulating factor and macrophage migration inhibitory factor were significantly higher in patients who survived event-free to month 54.

CONCLUSIONS

Our results suggest that HSCT favourably alters the autoantibody repertoire, which remains virtually unchanged in CTX-treated patients. Although antibodies recognising secreted proteins are generally thought to be pathogenic, our results suggest a subset could potentially modulate HSCT in scleroderma.

The prevalence and clinical features associated of hypothyroidism among Thai systemic sclerosis patients

Thyroid disease, particularly hypothyroidism, has been reported in systemic sclerosis (SSc). Some clinical features of SSc can also present in hypothyroidism. Our aims were to determine the prevalence of, and describe clinical features associated with, hypothyroidism in SSc patients. We conducted a historical cohort study of adult SSc patients who underwent screening thyroid function tests at the Scleroderma Clinic, Khon Kaen University, Thailand, between 2009 and 2018. The patients who had any thyroid disorders before the onset of SSc and were diagnosed as an overlap syndrome were excluded. A total of 200 SSc were included according to sample size calculation, among whom the female to male ratio was 2:1. The majority of cases (137; 69.5%) were diffuse cutaneous SSc subset. The mean age was 55.8 ± 10.7 years and the median duration of disease 4.9 (IQR 1.6–9.9) years. Of the total, 9 had primary hypothyroidism (prevalence 4.5%; 95%CI 2.1–8.4) and 22 had subclinical hypothyroidism (prevalence 11%; 95%CI 7.0–16.2). Of the latter 22, 71% had dcSSc. Logistic regression analysis indicated that unexplained anemia was significantly associated with either subclinical hypothyroid or hypothyroidism (OR 2.74; 95% CI 1.17–6.47), whereas Raynaud’s phenomenon had a negative association (OR 0.28; 95% CI 0.11–0.66). Neither severity of skin tightness nor internal organ involvement were associated with hypothyroidism among SSc patients. Clinical-subclinical hypothyroidism is uncommon among SSc patients, it is frequently associated with anemia, and less so Raynaud’s phenomenon. Clinical-subclinical hypothyroidism should thus be considered in cases of unexplained anemia in SSc patients.

The prevalence of thyroid autoantibodies in autoimmune connective tissue diseases: a systematic review and meta-analysis

AIM

Patients with autoimmune connective tissue disease (ACTD) may have anti-thyroid peroxidase antibody (TPOAb) and anti-thyroglobulin antibody (TgAb). This study aimed to compare the prevalence of thyroid autoantibodies in ACTD patients and controls.

METHODS

All case-control studies published between 1980 and 2019 in English were searched from Medline, Embase, Web of Science, PubMed databases for meta-analysis and subgroup analyses.

RESULTS

Total 10,321 ACTD cases and 12,949 healthy controls were included, and the prevalence of thyroid autoantibody positivity was higher in ACTD patients than in controls. Subgroup analysis revealed positive association between TgAb and ACTD in populations from all continents including European, Asian, African, and American. In addition, we found positive association between TgAb positivity and most ACTD cases including RA, SLE, pSS, and UCTD, positive association between TPOAb positivity and all ACTD cases including RA, SLE, pSS, SSc, and UCTD, and positive association between TPOAb positivity and ACTD in European, Asian, and African but not in American populations.

CONCLUSION

Thyroid autoantibodies are more prevalent in ACTD patients than in healthy controls. It is important to screen patients with ACTD for the presence of thyroid autoimmunity, and perform thyroid function tests in clinical evaluation of ACTD patients.

The aggregation between AITD with rheumatologic, or dermatologic, autoimmune diseases

Autoimmune thyroid diseases (AITD) are organ-specific autoimmune disorders mediated by Th1 lymphocytes, whose main clinical presentations are Hashimoto's thyroiditis (HT), or Graves' disease (GD). HT, GD, thyroid autoantibodies and thyroid dysfunctions have been shown in systemic rheumatologic diseases (as Sjögren's syndrome, systemic lupus erythematosus, rheumatoid arthritis, systemic sclerosis, or cryoglobulinemia). New associations of AITD with other autoimmune diseases are being discovered, for example with psoriatic arthritis and dermatological diseases. Several investigations suggest the importance of a shared genetic susceptibility and of environmental factors in patients with AITD and associated systemic autoimmunity. A major Th1 autoimmune response occurs in the initial, and/or active phases of organ-specific autoimmune disorders and/or systemic rheumatologic diseases with increased serum, or tissue, expressions of the Th1 chemokine CXCL10. Thyroid dysfunctions might have an important clinical impact, so a periodic thyroid screening in women with systemic or dermatological autoimmunity, overall in presence of thyroid autoantibodies is suggested.

Systemic sclerosis patients are at higher risk of hyperthyroidism and have a worse survival than those without hyperthyroidism: A nationwide population-based cohort study

BACKGROUND

A high prevalence of thyroid disorders has been reported in patients with autoimmune diseases. The link between hyperthyroidism and systemic sclerosis (SSc) has been relatively overlooked, and only a few studies utilizing small samples or case reports have been reported so far.

OBJECTIVES

To investigate the association between SSc and hyperthyroidism.

METHODS

We designed a case-control study utilizing the medical database of the Clalit Health Services. Chi-square and t tests were used for univariate analysis, and a logistic regression model was used for multivariate analysis.

RESULTS

The study included 2,431 SSc patients and 12,710 age- and sex-matched controls. The mean age of the study population was 63.32 ± 18.06 years (median 66 years), and female-to-male ratio was 4.5:1. Age (P < .0001, OR 1.03 [95% CI 1.02-1.04]), female sex (P = .0015, OR 1.86 [95% CI 1.27- 2.74]) and diagnosis of SSc (P = .0011, OR 1.81[95% CI 1.27-2.58]) were all independently associated with hyperthyroidism. Patients with SSc and hyperthyroidism had 1.54-fold increase of mortality rates during a mean follow-up of 17 years than SSc patients without hyperthyroidism, even though at the Cox multivariate survival analysis, only age (HR 1.06 [95% CI 1.06-1.07], P < .0001) and diagnosis of SSc (HR 2.35 [CI 2.06 to 2.69], P < .0001) resulted associated with a higher risk of mortality.

CONCLUSIONS

Hyperthyroidism is highly prevalent among SSc patients and can negatively impact on their survival rates. Therefore, a pre-emptive screening may be warranted in all SSc patients. Further studies are needed to evaluate whether tight control and optimal treatment for hyperthyroidism may lead to a reduction of all-cause mortality in patients with SSc.