IgG4-related disease (IgG4-RD) is fibro-inflammatory, immune-mediated, systemic disease recognized as a defined clinical condition only in 2001. The prevalence of IgG4-RD is 6/100 000, but it is likely to be underestimated due to insufficient awareness of the disease. The diagnostic approach is complex because of the heterogeneity of clinical presentation and because of rather variable diagnostic criteria. Indeed, high concentrations of IgG4 in tissue and serum are not a reliable diagnostic marker. The spectrum of IgG4-RD also includes well-known thyroid diseases including Riedel’s thyroiditis, Hashimoto’s thyroiditis and its fibrotic variant, Graves’ disease and Graves’ orbitopathy. Results from clinical studies indicate that a small subset of patients with the above-mentioned thyroid conditions present some features suggestive for IgG4-RD. However, according to more recent views, the use of the term thyroid disease with an elevation of IgG4 rather than IgG4-related thyroid diseases would appear more appropriate. Nevertheless, the occurrence of high IgG4 levels in patients with thyroid disease is relevant due to peculiarities of their clinical course.
Mario Rotondi, Andrea Carbone, Francesca Coperchini, Rodolfo Fonte and Luca Chiovato
Mario Rotondi, Valentina Capelli, Francesca Coperchini, Sara Pinto, Laura Croce, Massimo Tonacchera and Luca Chiovato
Graves’ disease (GD) patients in remission after a full course of methimazole (MMI) therapy are at risk for a relapse of hyperthyroidism during the post-partum (PP) period, but whether this relapse may display any peculiarity is still unknown. Aim of this study was to compare GD patients undergoing a relapse of hyperthyroidism either in the PP period or not.
We retrospectively evaluated forty-three GD female patients in their childbearing age who experienced a relapse of hyperthyroidism. Eighteen of them relapsed in the PP period (i.e. within 12 months after delivery, PP group); the remaining 25 relapsed elsewhere during life (NPP group).
Age at relapse, thyroid volume, thyroid function tests, TRAb titers, smoking habit, presence and degree of orbitopathy and duration of methimazole (MMI) treatment did not differ in the two groups. However, the remission rate was much greater (79%) in the PP as compared with the NPP (32%) group (P = 0.002). A significant reduction in TRAb levels occurred at 12-month MMI treatment in the PP (F = 9.016; P = 0.001), but not in the NPP group (F = 2.433; NS). At 12 months, the PP group had significantly lower mean TRAb levels (0.6 ± 1.1 U/L and 4.5 ± 4.7 U/L in the PP and the NPP group, respectively; P = 0.029).
Relapsing Graves’ hyperthyroidism in the PP period is more prone to undergo a remission after a second course of MMI treatment. In these patients, a conservative therapeutic approach is more appropriate.
Mario Rotondi, Luca de Martinis, Francesca Coperchini, Patrizia Pignatti, Barbara Pirali, Stefania Ghilotti, Rodolfo Fonte, Flavia Magri and Luca Chiovato
Despite high sensitivity of current assays for autoantibodies to thyroperoxidase (TPO) and to thyroglobulin (Tg), some hypothyroid patients still present with negative tests for circulating anti-thyroid Abs. These patients usually referred to as having seronegative autoimmune thyroiditis (seronegative CAT) have not been characterized, and definite proof that their clinical phenotype is similar to that of patients with classic chronic autoimmune thyroiditis (CAT) is lacking.
To compare the clinical phenotype of seronegative CAT (SN-CAT) and CAT as diagnosed according to a raised serum level of TSH with negative and positive tests for anti-thyroid Abs respectively.
A case–control retrospective study enrolling 55 patients with SN-CAT and 110 patients with CAT was performed. Serum free triiodothyronine (FT3), free thyroxine (FT4), TSH, Tg Abs, and TPO Abs were measured in all patients.
Patients with SN-CAT displayed significantly lower mean levels of TSH (6.6±3.4 vs 10.2±9.8 μU/ml; P=0.009), higher mean FT4 levels (1.1±0.2 vs 0.9±0.2 ng/dl; P=0.0002), and similar FT3 levels when compared with CAT patients. Mean thyroid volume was significantly greater in patients with CAT when compared with SN-CAT patients (11.2±6.5 vs 8.1±3.7 ml; P=0.001). Logistic regression demonstrated that FT4 (0.123 (0.019–0.775); (P=0.026)) and thyroid volume (1.243 (1.108–1.394); (P=0.0002)) were significantly and independently related to the diagnosis (CAT/SN-CAT). Patients with SN-CAT had a similar prevalence of thyroid nodules and female gender but a lower prevalence of overt hypothyroidism (5.4 vs 20.9%; P=0.012) as opposed to patients with CAT.
These results suggest an autoimmune etiology of SN-CAT, which, however, seems to have a milder clinical course when compared with CAT.
Mario Rotondi, Gloria Groppelli, Laura Croce, Francesco Latrofa, Giuseppe Ancona, Francesca Coperchini, Daniela Pasquali, Carlo Cappelli, Alessandro Fugazza, Valeria Guazzoni, Giorgio Radetti and Luca Chiovato
The association between chronic autoimmune thyroiditis (CAT) and differentiated thyroid cancer (DTC) remains controversial. The incidence of DTC increases when screening procedures are implemented, as typically occurs in CAT patients being routinely submitted to thyroid ultrasound (US). The aim of this study was to longitudinally evaluate the long-term development of DTC in patients with CAT.
Design and methods:
A retrospective longitudinal cohort study was designed. For the study, 510 patients with chronic autoimmune thyroiditis (CAT) with a 10-year follow-up were enrolled. Patients were divided in two groups according to the presence (CAT+ NOD+; n = 115) or absence (CAT+ NOD−; n = 395) of co-existent nodules at diagnosis. The main outcome measures were appearance of new thyroid-nodules and development of DTC during follow-up.
During a 10-year median follow-up period, new thyroid-nodules were detected in 34/115 (29.5%) patients in the CAT+ NOD+ group and in 41/395 (10.3%) in the CAT+ NOD− group (P < 0.001). Logistic regression analysis showed that thyroid-volume at diagnosis and belonging to the CAT+ NOD+ group significantly predicted the appearance of a new thyroid nodule during follow-up, independently of baseline age and sex. Among the 75 patients experiencing the appearance of a new nodule, 27 (39%) met the criteria for fine-needle-aspiration-cytology (FNAC). A benign cytological diagnosis was rendered in all cases.
In our series of CAT patients, the appearance of new thyroid-nodules was frequent, but none of them were found to be malignant. The presence of CAT appears to be associated with a negligible risk of developing clinically overt DTC.