Elevated Immunoglobulin G4 Levels in Patients with Thyroid Eye Disease and Their Clinical Implications

Study on the correlation between serum IgG4/IgG levels and the development of Graves' ophthalmopathy

Graves' ophthalmopathy (GO) with elevated IgG4 levels has different characteristics from patients with GO who do not have elevated IgG4 levels, but the study findings are contradictory. The goal of this study was first to investigate the relationship between IgG4/IgG and IgG4 levels and the occurrence of GO and then to investigate the clinical and laboratory characteristics of patients with GO who had elevated IgG4 levels. This study control group consisted of 57 Graves' disease(GD)patients with no complicated ocular disease and a median followup of 54.41 months, while the experimental group included 171 GO patients. The clinical and laboratory characteristics of the GD and GO groups were compared. Using an IgG4/IgG cut-off value of 8%, the GO patients were divided into two groups: high IgG4/IgG and low IgG4/IgG, and the differences in clinical and laboratory characteristics between these two groups, as well as between the GO patients before and after 3 months of treatment, were analyzed. The study results show that serum IgG4/IgG levels were independently correlated with the occurrence of GO, but not significantly correlated with GO activity. Patients with high IgG4/IgG levels of GO exhibit distinct characteristics, which may be associated with an unstable balance of lymphocyte subsets.

IgG4 serum levels in Graves' orbitopathy

OBJECTIVE

IgG4-related disease (IgG4-RD) can involve many organs, including thyroid and orbital tissues. A link between IgG4, Graves' disease (GD) and Graves' orbitopathy (GO) has been proposed, but results are conflicting. Here we investigated the possible association between IgG4 and GO.

METHODS

Retrospective investigation in 297 patients with Graves' disease (GD), 152 with GO.

PRIMARY OUTCOME

prevalence of IgG4 ≥ 135 mg/dL (cut-off for IgG4-RD).

SECONDARY OBJECTIVES

(1) serum IgG4 concentrations; (2) IgG4/IgG ratio; (3) prevalence of IgG4/IgG ratio ≥ 8.0%; (4) relationship between IgG4 and eye features; (5) relationship between IgG4 and anti-TSH receptor antibodies (TRAbs).

RESULTS

Because GO patients had lower FT3 concentrations, we evaluated the main objectives in the second and third FT3 quartiles subpopulation, in which there were no relevant differences between patients with (n = 81) or without GO (n = 67) for baseline parameters. Within this population, the prevalence of IgG4 levels ≥ 135 mg/dL did not differ between patients without and with GO (17.9% vs 17.3%). No difference was observed concerning IgG4 concentrations, prevalence of IgG4/IgG ≥ 8.0%, and IgG4/IgG ratio. There was no relationship between IgG4 and eye features and no correlation between IgG4 levels and TRAb was found.

CONCLUSIONS

Our results suggest that, within GD, there is no relationship between serum IgG4 and GO.

Treatment outcomes and their determinants of IgG4-related ophthalmic disease: a territory-wide cohort study

BACKGROUND

Oral corticosteroid remains the first-line treatment of IgG4-related ophthalmic disease, but steroid-dependence is common and serious. Factors associated with steroid dependence and relapse have to be further explored.

STUDY POPULATION

A city-wide, biopsy-proven, Chinese cohort.

METHODS

Retrospective, masked review of medical records, orbital images and histopathology reports.

RESULTS

There were 101 patients with at least 24-month follow-up. Up to 82% (82/101) received oral corticosteroid as first-line treatments, and 7 of them received also concomitant steroid-sparing agents (SSA)/biological agents as primary treatment. There was 61% (50/82) of patients required long-term corticosteroid (alone=23, with SSA=27) after 1.9±0.7 (range 1-5) relapses. When compared with the 21% (17/82) of patients who tapered corticosteroid successfully for 24 months, steroid dependence was associated with elevated baseline serum IgG4 level (94% vs 65%, p<0.01) and Mikulicz syndrome (46% vs 18%, p<0.05). Up to 13% (11/82) of patients tolerated residual disease after tapering off corticosteroid. There was 17% (17/101) of patients did not require any medications after biopsies. They were more likely to have debulking surgeries (71% vs 40%, p<0.05), discrete orbital lesions (65% vs 26%, p<0.05), normal baseline serum IgG4 level (24% vs 6%, p<0.05) and no Mikulicz syndrome (94% vs 61%, p<0.05).

CONCLUSION

In this cohort, 60% of patients required long-term maintenance oral corticosteroid. Elevated pretreatment serum IgG4 level and Mikulicz syndrome were associated with steroid dependence. Debulking surgery is an alternative for a subgroup of patients with discrete orbital lesions, normal baseline IgG4 level and no Mikulicz syndrome.

Reshaping the Concept of Riedel's Thyroiditis into the Larger Frame of IgG4-Related Disease (Spectrum of IgG4-Related Thyroid Disease)

Recently, Riedel's thyroiditis (RT) was assimilated into the larger spectrum of immunoglobulin IgG4-related disease (IgG4-RD) in addition to a particular frame of IgG4-related thyroid disease (IgG4-RTD), underlying IgG4-RT, IgG4-associated Hashimoto's thyroiditis (and its fibrotic variant), and IgG4-related Graves's disease. Our objective was to overview recent data on RT, particularly IgG4-RD and IgG4-RTD. The case and study- sample analysis (2019-2023) included 293 articles and selected 18 original studies: nine single case reports (N = 9, female/male = 2/1, aged: 34-79 years, 5/9 patients with serum IgG4 available data, 2/5 with high serum IgG4) and four case series (N = 21; 4/5 series provided data on IgG4 profile, 3/21 had serum IgG4 assays, and 2/3 had abnormally high values). IgG4-RD and thyroid findings were analyzed in three cohorts (N = 25). Another two studies (N = 11) specifically addressed IgG4-RTD components. On presentation, the patients may have hypothyroidism, transitory thyrotoxicosis, goiter, long-term history of positive anti-thyroid antibodies, and hypoechoic ultrasound thyroid pattern. The 5-year analysis (N = 66) showed the rate of serum IgG4 evaluation remained low; normal values do not exclude RT. Mandatory histological and immunohistochemistry reports point out a high content of IgG4-carrying plasma cells and IgG4/IgG ratio. Unless clinically evident, histological confirmation provides a prompt indication of starting corticoid therapy since this is the first-line option. Surgery, if feasible, is selective (non-responders to medical therapy, emergency tracheal intervention, and open/core needle biopsy). Current open issues are identifying the role of serum IgG4 assays in patients with IgG4-RD, finding out if all cases of RT are IgG4-mediated, applying IgG4-RTD criteria of differentiation among four entities, and providing an RT/IgG4-RTD guideline from diagnosis to therapy. It remains that the central aim of approaching RT in daily practice is the early index of suspicion in order to select patients referred for further procedures that provide enough histological/immunohistochemistry material to confirm RT and its high IgG4 burden.

IgG4-positive Hashimoto thyroiditis and its association with IgG4-related sclerosing disease

A woman in her 50s was referred with suspected thyroid malignancy and underwent total thyroidectomy. Immunohistochemical analysis revealed IgG4-positive Hashimoto's thyroiditis. IgG4-related thyroid disease is poorly understood, and thought to encompass various entities including IgG4-positive Hashimoto's thyroiditis, Fibrosing Variant of Hashimoto's thyroiditis, Reidel's thyroiditis and Graves' disease with elevated IgG4 levels. Furthermore, it may be associated with a systemic fibrosing condition called 'IgG4-related sclerosing disease'. The clinical significance of IgG4-positive thyroid disease, however, remains unclear.

Clinical relevance of serum immunoglobulin G4 in glucocorticoid therapy of Graves' ophthalmopathy

OBJECTIVE

Previous study suggested IgG4 levels were associated with the development of Graves' ophthalmopathy (GO). The aims of the present study were to investigate the role of IgG4 levels in glucocorticoid (GC) treatment in GO patients.

DESIGN

69 GO patients were enrolled. Serum thyroid hormones, thyroid antibodies, IgG, IgG4, ophthalmological examinations and orbital MRI were performed. Furthermore, the clinical outcomes (a composite response endpoint including the clinical activity score (CAS), proptosis, vision, intraocular pressure, diplopia and lid width) after high-dose intravenous GC treatment in 32 active moderate-to-severe GO patients were compared.

PATIENTS

69 consecutive patients with GO were asked to participate in the study. 32 of 69 GO patients were treated with high-dose intravenous GCs.

MEASUREMENTS

Measurement of serum IgG and IgG4, serum thyroid hormones and thyroid autoantibodies. An overall ophthalmic assessment was performed pretherapy (week 0) and post-therapy (week 12).

RESULTS

33.3% of GO patients (23/69) had elevated IgG4 levels. IgG4 levels were positively correlated with the severity and activity of GO. After GC therapy, IgG4, IgG4/IgG, vision and CAS were significantly improved in GO patients. Patients with high IgG4 levels had a significantly reduced extraocular muscle area (EOMs) and better clinical outcomes than patients with normal IgG4 levels.

CONCLUSIONS

Our results suggest a possible subgroup of elevated IgG4 GO patients, with more severe ophthalmopathy and better response to GCs treatment compare with normal IgG4 GO patients.