Independent involvement of CD8+ CD25+ cells and thyroid autoantibodies in disease severity of Hashimoto's disease

Gene polymorphisms of VEGF and VEGFR2 are associated with the severity of Hashimoto's disease and the intractability of Graves' disease, respectively

Vascular endothelial growth factor (VEGF) is one of main regulators of angiogenesis that functions by binding to its receptors, including VEGF receptor (VEGFR) 2. There are few data available regarding the association between VEGF and VEGFR polymorphisms and the susceptibility to and prognosis of autoimmune thyroid diseases (AITDs). To elucidate this association, we genotyped four functional VEGF and two VEGFR2 polymorphisms and measured serum VEGF levels. In the four functional VEGF polymorphisms, the frequencies of the I carrier and I allele of VEGF -2549 I/D, which has lower activity, were higher in patients with severe HD than in those with mild HD. In the two functional VEGFR2 polymorphisms, the frequency of the rs2071559 CC genotype, which has higher activity, was higher in patients with intractable GD than in controls, and the proportion of GD patients with larger goiters was higher in those with the CC genotype. Moreover, the frequency of the rs1870377 TT genotype with higher activity was higher in patients with intractable GD than in those with GD in remission. Combinations of VEGF and VEGFR2 polymorphisms with stronger interactions were associated with the intractability of GD. Serum VEGF levels were higher in HD and AITD patients than those in controls. In conclusion, VEGF polymorphisms with lower activity were associated with the severity of HD, while VEGFR2 polymorphisms and the combinations of VEGF and VEGFR2 polymorphisms, which have stronger interactions, were associated with the intractability of GD. VEGF and VEGFR2 polymorphisms were associated with HD severity and GD intractability, respectively.

The proportion of peripheral blood Tregs among the CD4+ T cells of autoimmune thyroid disease patients: a meta-analysis

Autoimmune thyroid disease (AITD) is characterized by a loss of self-tolerance to thyroid antigen. Tregs, whose proportions are controversial among CD4+ T cell from AITD patients (AITDs), are crucial in immune tolerance. Considering that drugs might affect Treg levels, we assumed that the differences originated from different treatment statuses. Thus, we performed a meta-analysis to explore proportions of Tregs in untreated and treated AITDs. PubMed, Embase and ISI Web of Knowledge were searched for relevant studies. Review Manager 5.3 and Stata 14.0 were used to conduct the meta-analysis. Subgroup analysis based on different diseases and cell surface markers was performed. Egger linear regression analysis was used to assess publication bias. Approximately 1,100 AITDs and healthy controls (HCs) from fourteen studies were included. Proportions of Tregs among CD4+ T cells of untreated AITDs were significantly lower than those in HCs (p = 0.002), but were not in treated patients (p = 0.40). Subgroup analysis revealed lower proportions of Tregs in untreated Graves' disease patients (GDs) (p = 0.001) but did not show obvious differences in untreated Hashimoto's thyroiditis patients (HTs) (p = 0.62). Furthermore, proportions of circulating FoxP3+ Tregs were reduced in untreated GDs (p < 0.00001) and HTs (p = 0.04). No publication bias was found. In this first meta-analysis exploring proportions of circulating Tregs among CD4+ T cells of AITDs with different treatment statuses, we found that Tregs potentially contribute to the pathogenesis of AITD but function differently in GD and HT. Remarkably, FoxP3+ Tregs, which were decreased in both diseases, might be promising targets for novel therapies.

Association of IFNG gene methylation in peripheral blood cells with the development and prognosis of autoimmune thyroid diseases

The intractability of Graves' disease (GD) and the severity of Hashimoto's disease (HD) vary among patients. Both genetic and environmental factors may be associated with their prognoses. To clarify the role of methylation of the IFNG gene in the pathogenesis and prognosis of (AITDs), we examined interferon gamma (IFNG) methylation levels at various CpG sites and genotyped IFNG +874 A/T and +2109 C/T polymorphisms. We analyzed methylation 59 patients with HD, 57 patients with GD and 26 healthy volunteers by pyrosequencing. We genotyped IFNG gene polymorphisms from 207 patients with GD, 208 patients with HD, and 102 healthy controls. The methylation levels of IFNG -54 CpG were higher in patients with intractable GD than in those with GD in remission, but there was no difference between patients with severe and mild HD. In carriers of IFNG +2109 T (CT + TT) (85.5% in controls), the -54 CpG methylation levels were significantly higher in patients with intractable GD than in those with GD in remission. On the other hand, in carriers of IFNG +2109 CC, the -4293 CpG methylation levels were higher in intractable GD patients. The methylation levels of IFNG -54 CpG and -4293 CpG were negatively correlated with the age in HD, especially severe HD, patients and GD patients, respectively. There was no circadian variation but considerable daily variation in the methylation levels of IFNG -54 CpG. In conclusion, both the methylation levels of CpG sites and the functional polymorphisms in the IFNG gene were associated with the pathogenesis and prognosis of AITD, especially with GD intractability.

Effect of emodin on T cell subsets in NOD mice with NaI‑induced experimental autoimmune thyroiditis

Chronic lymphocytic thyroiditis (CLT), also known as Hashimoto's thyroiditis, is an autoimmune disease in which the thyroid gland is gradually destroyed. To date, only a limited number of agents can effectively suppress thyroiditis development in CLT patients. The aim of the current study was to investigate the protective effect of emodin on experimental autoimmune thyroiditis (EAT) in mice, which is considered an excellent model for CLT. NaI was used to induce the EAT model in non-obese diabetic (NOD) mice. An ELISA method was employed to detect the TgAb level (thyroid inflammation) in the serum of the EAT mice. The T cell subsets in peripheral blood and spleen were detected by flow cytometry. The histopathological study revealed that the thyroid inflammatory cell infiltration was significantly reduced by emodin compared with the model group. In addition, ELISA assays indicated that the NaI-induced serum TgAb upregulation was dramatically revered by emodin. Moreover, the level of serum IFN-γ and the cell populations of CD₃⁺CD₄⁺IL-4⁺, CD₃⁺CD₄⁺ IFN-γ⁺, CD₃⁺CD₈⁺IL-4⁺, CD₃⁺CD₈⁺ IFN-γ⁺ T cells in peripheral blood monocytes and splenic lymphocytes were significantly increased by NaI in the model group compared with in the normal group. Nevertheless, this type of increase was markedly attenuated by emodin. To conclude, the EAT model was successfully established by treating NOD mice with NaI. Emodin indicated an inhibitory effect on the autoimmune response that was significantly different in EAT compared with control mice. Furthermore, the anti-inflammatory action of emodin on EAT mice may be mediated via the inhibition of the secretion of IFN-γ and the cell numbers of CD₃⁺CD₄⁺IL-4⁺, CD₃⁺CD₄⁺ IFN-γ⁺, CD₃⁺CD₈⁺IL-4⁺ and CD₃⁺CD₈⁺ IFN-γ⁺ T cells in the peripheral blood monocytes and splenic lymphocytes. Therefore, the data may offer valuable insight on the efficacy of treatment of CLT with emodin.

Immunological changes of T helper cells in flow cytometer-sorted CD4+ T cells from patients with Hashimoto's thyroiditis

Recent incidence rates for Hashimoto's thyroiditis (HT) and hypothyroidism are higher than those of previous studies. Previous studies indicated that T helper cells may have a major role in the pathogenesis and development of HT, but there is no consensus in the literature. The aim of the present study was to explore the peripheral T helper cell response in the different stages of HT. In this cross-sectional study, we performed flow cytometry analysis to determine the various T cell subsets of 389 patients with HT (34 patients with HT who developed overt hypothyroidism, and 148 patients with HT who developed subclinical hypothyroidism), as well as 51 healthy controls. Anti-thyroid antibodies, and thyroid function were measured. The findings demonstrated that the proportion of peripheral Th1 cells was significantly lower in patients with HT than in healthy euthyroid controls (P<0.001), and the proportion of peripheral Th2, Treg cells was significantly higher in patients with HT than in healthy euthyroid controls (P<0.001). Therefore the Th1/Th2 ratio was significantly lower in HT patients than in healthy euthyroid controls (P<0.001). The Th17/Treg ratio in HT patients was significantly lower than that control subjects (P<0.001). Th1 proportions in patients with overt hypothyroidism HT were significantly higher than in subclinical hypothyroidism HT patients (P=0.031). In conclusion, the findings of the present study demonstrated that there is an increased immune deviation of Th1 lymphocytes and compensatory accelerating activity of Treg cells in HT, and the peripheral Th1 cells from the HT patients correlated to the developmental stage of hypothyroidism.

The polymorphisms in the thyroid peroxidase gene were associated with the development of autoimmune thyroid disease and the serum levels of anti-thyroid peroxidase antibody

Graves' disease (GD) and Hashimoto's disease (HD) are well known autoimmune thyroid diseases (AITDs), and the severity and intractability of AITDs varies among patients. Thyroid peroxidase (TPO) is a thyroid-specific antigen. The levels of anti-thyroid peroxidase antibody (TPOAb) were higher in patients with HD and may be associated with thyroid destruction. In this study, we genotyped eight single nucleotide polymorphisms (SNPs) in the TPO gene to clarify the association of TPO gene polymorphisms with the development, severity and intractability of AITD. We genotyped TPO rs2071399G/A, rs2071400C/T, rs2071402A/G, rs2071403A/G, rs1126799C/T, rs1126797T/C, rs732609A/C, and rs2048722A/G polymorphisms in 145 patients with GD, 147 patients with HD and 92 healthy controls by PCR-RFLP method. TPO rs2071400 T carriers (CT + TT genotypes) were more frequent in AITD, GD, and HD patients (p=0.0079, 0.0041, and 0.0488, respectively). The TPO rs2071403 GG genotype was more frequent in AITD, GD, and HD patients (p=0.0227, 0.0465, and 0.0305, respectively). There was no significant association between the SNPs and the prognosis of AITD. Serum levels of TPOAb were significantly higher in AITD patients with TPO rs2071400 T carriers (CT + TT genotypes) than in those with the CC genotype (p=0.0295), and were also significantly higher in AITD patients with TPO rs2048722 T carriers (CT + TT genotypes) than in those with the CC genotype (p=0.0056). In conclusion, TPO rs2071400 and rs2071403 polymorphisms were associated with the development of HD and GD, but not with the prognosis. Moreover, TPO rs2071400 and rs2048722 polymorphisms were associated with the serum levels of TPOAb.

Functional polymorphisms affecting Th1 differentiation are associated with the severity of autoimmune thyroid diseases

The prognosis for autoimmune thyroid diseases (AITDs), such as Hashimoto's disease (HD) and Graves' disease (GD), varies among patients. Interleukin (IL)-12 and IL-18 also induce Th1 differentiation, and SOCS1 (Suppressor of cytokine signaling 1) and TIM-3 (T cell immunoglobulin and mucin domain-3) are known to be negative regulators of Th1 cells. To clarify the association of functional polymorphisms in the IL12, IL12Rβ1, IL18, SOCS1 and TIM3 genes with the intractability and severity of autoimmune thyroid disease (AITD), we genotyped these polymorphisms in 151 GD patients, including 61 patients with intractable GD and 51 patients with GD in remission, in 140 HD patients, including 59 patients with severe HD and 55 patients with mild HD, and in 74 healthy controls. The frequency of the IL18 -607CC genotype which correlates with a high production of IL-18, was significantly higher in patients with GD in remission than in those with intractable GD (p=0.0178). The -607C allele was significantly higher in patients with severe HD than in those with mild HD (p=0.0050). The -607CC genotype in IL18 gene may be protective against the intractability of GD, and the -607C allele may enhance the severity of HD.

Involvement of genes encoding apoptosis regulatory factors (FAS, FASL, TRAIL, BCL2, TNFR1 and TNFR2) in the pathogenesis of autoimmune thyroid diseases

Apoptosis is necessary for the maintenance of self-tolerance by eliminating autoreactive immune cells in the periphery. To clarify the association between the pathogenesis of autoimmune thyroid disease (AITD) and genes encoding apoptosis regulatory factors, we genotyped the FAS -1377G/A, -670A/G, FASL -844C/T, TRAIL -716C/T, BCL2 -938C/A, +127G/A, TNFR1 -383A/C and TNFR2 +676T/G polymorphisms. The frequencies of the FASL -844CC and BCL2 -938AA genotypes were significantly lower in AITD patients than in control subjects (P=0.0101 and 0.0307, respectively). The frequency of the TNFR2 +676TT genotype was significantly lower in Graves' disease (GD) patients than in controls (P=0.0284). The serum sFasL level was significantly higher in GD and Hashimoto's disease (HD) patients than in control subjects (P=0.0003 and 0.0017, respectively). The serum sFasL levels in control subjects were significantly lower than those in intractable GD, GD in remission, and HD without treatment (P=0.0310, 0.0007 and 0.0002, respectively). The serum sFasL levels in HD with treatment were significantly lower than those in HD without treatment (P=0.0490). The polymorphisms in genes encoding apoptosis regulatory factors (FASL, BCL2) and serum levels of sFasL may be associated with immune dysregulation.

Association of Interleukin-1B and Interleukin-4 Gene Variants with Autoimmune Thyroid Diseases in Tunisian Population

Autoimmune thyroid diseases (AITD) including Graves' disease (GD) and Hashimoto's thyroiditis (HT) are complex genetic diseases. Cytokines IL-1B and IL-4 play a role in the pathogenesis of AITD. This study was conducted on Tunisian patients with GD or HT to investigate the association of IL-1B and IL-4 gene polymorphisms with the risk and the prognosis of AITD. A total of 358 healthy controls and 341 patients with AITDs (249 HT and 92 GD) were genotyped for IL-1B+3953C/T and IL-4 intron 3 VNTR polymorphisms. A significant association was found between IL-1B+3953C/T polymorphism and GD or HT, both in the dominant and additive models. The IL-1B+3953T allele was associated with GD (p = 0.0003, OR = 1.93, CI = 1.34-2.78) and HT (p = 0.009, OR = 1.43, CI = 1.09-1.88). The IL-4 VNTR polymorphism was associated only with HT risk both in additive (p = 0.03, OR = 0.31, CI = 0.11-0.86) and recessive (p = 0.03, OR = 3.04, CI = 1.13-8.17) models. No significant association was found between IL-1B+3953C/T polymorphism and change in the serum concentrations of TSH and FT4 in GD and HT patients. In HT patients, the IL-1B+3953T allele (p = 0.009, OR = 0.42, CI = 0.22-0.83) and the IL-1B+3953T/T genotype (p = 0.03, OR = 0.21, CI = 0.04-1.07) were more frequent in the absence than in the presence of an anti-TPO antibody. The proportion of HT patients with the P1P2 genotype of the IL-4 gene was significantly higher in the absence than in the presence of the anti-TPO antibody (p = 0.04, OR = 0.39, CI = 0.17-0.89). These preliminary results suggest that IL-1B and IL-4 gene polymorphisms may be associated with GD and HT susceptibility and may represent prognostic factors for predicting the severity of HT.

The functional polymorphisms of VDR, GC and CYP2R1 are involved in the pathogenesis of autoimmune thyroid diseases

Vitamin D is a multi-functional immune regulator, and a low serum concentration of vitamin D promotes autoimmune inflammation. In this study, we evaluate the association between the prognosis of autoimmune thyroid disease (AITD) and the functional polymorphisms of genes that regulate vitamin D metabolism. For 139 Graves' disease (GD) patients, 116 Hashimoto's disease (HD) patients and 76 control subjects, we genotyped the following polymorphisms using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP): vitamin D receptor (VDR): rs731236, rs7975232, rs2228570 and rs1544410; group-specific component (GC): rs7041 and rs4588; and CYP2R1: rs10741657. The frequency of the TT genotype for the rs731236 polymorphism was higher in GD patients than in HD patients (P = 0·0147). The frequency of the C allele for the rs7975232 polymorphism was higher in GD patients than in control subjects (P = 0·0349). The proportion of GD patients whose anti-thyrotrophin receptor antibody (TRAb) level was >51% was higher in those with the CC genotype than in those with the CA+AA genotypes (P = 0·0065). The frequency of the CC genotype for the rs2228570 polymorphism was higher in HD patients than in control subjects (P = 0·0174) and GD patients (P = 0·0149). The frequency of the Gc1Gc1 genotype for the GC polymorphism and the AG genotype for the CYP2R1 polymorphism were lower in intractable GD than in GD in remission (P = 0·0093 and 0·0268, respectively). In conclusion, genetic differences in the VDR gene may be involved in the development of AITD and the activity of GD, whereas the genetic differences in the GC and CYP2R1 genes may be involved with the intractability of GD.

A higher frequency of circulating IL-22(+)CD4(+) T cells in Chinese patients with newly diagnosed Hashimoto's thyroiditis

BACKGROUND

IL-22 and IL-17A are implicated in the pathogenesis of autoimmune diseases. However, the role of IL-22(+) and IL-17A(+) CD4(+) T cells in the pathogenesis of Hashimoto's thyroiditis (HT) is not fully understood. This study investigates serum IL-22 and IL-17A levels and determines the frequency of circulating IL-22(+) CD4(+) T cells in HT patients to understand their roles in the pathogenesis of HT.

METHODS

The levels of serum IL-22, IL-17A and IFN-γ and the frequency of circulating IL-22(+)CD4(+) and IL-17A(+)CD4(+) T cells in 17 HT patients and 17 healthy controls (HC) were determined by enzyme-linked immunosorbent assay (ELISA) and flow cytometry. The levels of serum free triiodothyronine (FT4), free thyroxine (FT3), thyroid stimulating hormone (TSH), anti-thyroid peroxidase (TPO) and anti-thyroglobulin antibodies (TgAb) by chemiluminescent enzyme immunoassay and radioimmunoassay.

RESULTS

The percentages of circulating IL-22(+)CD4(+) and IL-17(+)CD4(+) T cells (p<0.0001, p<0.0001) and the levels of serum IL-22, IL-17A and IFN-γ (p<0.0001, p<0.0001, p = 0.0210) in the HT patients were significantly higher than that in the HC. The percentages of IL-22(+)CD4(+) T cells were positively correlated with Th17 cells (r = 0.8815, p<0.0001) and IL-17A(+)IL-22(+)CD4(+) T cells (r = 0.8914, p<0.0001), but were negatively correlated with Th1 cells (r = -0.6110, p<0.0092) in the HT patients. The percentages of Th22 cells, Th17 cells and IL-17A(+)IL-22(+)CD4(+) T cells were negatively correlated with the levels of serum TSH in the HT patients (r = -0.8402, p<0.0001; r = -0.8589, p<0.0001; r = -0.8289 p<0.0001, respectively).

CONCLUSIONS

A higher frequency of circulating IL-22(+)CD4(+) and IL-17A(+)CD4(+) T cells may be associated with the development of HT in Chinese patients.

Cytological diagnosis of thyroid nodules in Hashimoto thyroiditis in elderly patients

Background

Long standing Hashimoto Thyroiditis (HT) causes shrinking and atrophy of the thyroid, but may also lead to diffuse enlargement of the gland and/or formation of nodules. These nodules should be differentiated from papillary thyroid carcinoma (PTC) and primary thyroidal non-Hodgkin lymphoma (PTL), which are possible complications of HT, and require pre-surgical diagnoses and different treatments.

This study focuses on the role of fine-needle cytology (FNC) in the clinical surveillance and pre-surgical diagnosis of HT with diffuse and nodular enlargement of the gland in elderly patients.

Methods

Thirty-four elderly patients (≥ 65 yrs) with HT and diffuse or nodular enlargement of the thyroid underwent ultrasound (US)-guided FNC. Smears were routinely stained and evaluated; additional passes were used for flow cytometry (FC) assessment of lymphoid infiltrate in 6 cases.

Results

The cytological diagnosis was HT in 12 cases with prevalence of Hurtle cells in 2 cases, PTC in 1 case and PTL in 2 cases. FC assessed the reactive, non-lymphomatous nature of the lymphoid infiltrate in 5 cases and demonstrated light chain restriction, hence the lymphomatous nature of the lymphoid infiltrate in 2 cases of PTL.

Conclusions

FNC plays a key role in the clinical surveillance and pre-surgical diagnosis of diffuse enlargement and nodular presentation of HT in elderly patients. FNC can correctly diagnose HT, PTC and PTL indicating the need for surgery and its extension in suspicious or neoplastic cases, leaving other cases to the medical treatment and clinical surveillance.

Coexistent findings of renal glomerular disease with Hashimoto's thyroiditis

AIM AND BACKGROUND

Hashimoto's thyroiditis (HT) is a common autoimmune thyroid disease with a female preponderance. Renal involvement in HT is not uncommon. In the present study, we aimed to define the frequency and characteristics of the glomerular diseases associated with HT and further the understanding of any common pathogenesis between HT and glomerular disease.

MATERIALS AND METHODS

We reviewed retrospectively 28 patients with HT who were referred to our Department because of unexplained haematuria, proteinuria or renal impairment from 2007 to 2011. Routine laboratory investigations including blood count, serum biochemistry, urinalysis and 24-h urinary protein excretion were performed on all patients. Renal biopsy was performed in 20 patients with HT, and the specimens were examined by light microscopy and immunofluorescence staining.

RESULTS

We detected four cases of focal segmental glomerulosclerosis (FSGS), four membranous glomerulonephritis (MGN), two minimal-change disease (MCD), three immunoglobulin A nephritis (IgAN), three chronic glomerulonephritis (CGN) and one amyloidosis. In three patients, the renal biopsy findings were nonspecific. Daily urinary protein excretion and glomerular filtration rates were found to be independent of the level of thyroid hormone and thyroid-specific autoantibodies.

CONCLUSION

Glomerular pathologies associated with HT are similar to those in the general population, the most common lesions being MGN, FSGS and IgA nephritis.

Hashimoto's Thyroiditis: From Genes to the Disease

Hashimoto's thyroiditis (HT) is the most prevalent autoimmune thyroid disorder. Intrathyroidal lymphocytic infiltration is followed by a gradual destruction of the thyroid gland which may lead to subclinical or overt hypothyroidism. Biochemical markers of the disease are thyroid peroxidase and/or thyroglobulin autoantibodies in the serum which are present with a higher prevalence in females than in males and increase with age. Although exact mechanisms of aetiology and pathogenesis of the disorder are not completely understood, a strong genetic susceptibility to the disease has been confirmed predominantly by family and twin studies. Several genes were shown to be associated with the disease occurrence, progression, and severity. Genes for human leukocyte antigen, cytotoxic T lymphocyte antigen-4, protein tyrosine phosphatase nonreceptor-type 22, thyroglobulin, vitamin D receptor, and cytokines are considered to be of utmost importance. Amongst endogenous factors for the disease development, the attention is focused predominantly on female sex, pregnancy with postpartum period and fetal microchimerism. Environmental factors influencing HT development are iodine intake, drugs, infections and different chemicals. Disturbed self-tolerance accompanied by the increased antigen presentation is a prerequisite for the HT occurrence, whereas proper interaction of thyroid cells, antigen presenting cells, and T cells are necessary for the initiation of thyroid autoimmunity. Secreted cytokines lead predominantly to T-helper type 1 (Th1) response as well as to Th 17 response which has only recently been implicated. Final outcome of HT is thyroid destruction which is mostly a consequence of the apoptotic processes combined with T-cell mediated cytotoxicity.

Association of functional GITR gene polymorphisms related to expression of glucocorticoid-induced tumour necrosis factor-receptor (GITR) molecules with prognosis of autoimmune thyroid disease

The glucocorticoid-induced tumour necrosis factor (TNF)-receptor (GITR) affects the functions of regulatory T (T(reg)) and effector T (T(eff)) cells, but the significance of this phenomenon is still unclear. To examine the association of single nucleotide polymorphisms (SNPs) in the GITR gene with the expression of GITR molecules on T cells and with the pathological conditions in patients with autoimmune thyroid disease (AITD), we examined the frequencies of four candidate SNPs in AITD patients and healthy volunteers by restriction enzyme analysis and direct sequence analyses. We also analysed the GITR expression on peripheral T(reg) and T(eff) cells in AITD patients by three-colour flow cytometry. The CC genotype in the rs3753348 C/G SNP was significantly more frequent in patients with mild Hashimoto's disease (HD) than in those with severe HD [P = 0·0117, odds ratio (OR) = 3·13]. The AA genotype in the rs2298213 A/G SNP was significantly more frequent in patients with mild HD than in patients with severe HD (P = 0·010, OR = 4·43). All patients and healthy individuals had the GG genotype in rs60038293 A/G and rs11466696 A/G SNPs. The proportions of GITR(+) cells in T(reg) and T(eff) cells were significantly higher in AITD patients with the CC genotype of the rs3753348 SNP than in those with the GG genotype (P = 0·004 and P = 0·011, respectively). In conclusion, the rs3753348 C/G SNP in the GITR is associated with HD prognosis and expression on T(reg) and T(eff) cells.

Association of functional polymorphisms in promoter regions of IL5, IL6 and IL13 genes with development and prognosis of autoimmune thyroid diseases

To clarify the association of genetic producibility of interleukin (IL)-5, IL-6 and IL-13, which are secreted by T helper type 2 (Th2), with the development and prognosis of autoimmune thyroid disease (AITD), we genotyped IL5-746C/T, IL6-572C/G and IL13-1112C/T polymorphisms, which are functional polymorphisms in the promoter regions of the genes regulating these cytokines. Fifty-seven patients with intractable Graves' disease (GD), 52 with GD in remission, 52 with severe Hashimoto's disease (HD), 56 with mild HD and 91 healthy controls were examined in this study. The IL13-1112T allele, which correlates with higher producibility of IL-13, was more frequent in patients with GD in remission than in those with intractable GD [P=0·009, odds ratio (OR)=3·52]. The IL5-746T allele, which may correlate with lower levels of IL-5, was more frequent in patients with GD in remission than controls (P=0·029, OR=2·00). The IL6-572G allele carriers (CG and GG genotypes), which have higher producibility of IL-6, were more frequent in AITD patients (P=0·033, OR=1·75), especially in GD in remission (P=0·031, OR=2·16) and severe HD (P=0·031, OR=2·16) than in controls. Interestingly, both allele and genotype frequencies of Th2 cytokine genes were similar between GD and HD patients. In conclusion, functional polymorphisms in the genes encoding Th2 cytokines are associated differently with the development and prognosis of AITD from each other.

Association of functional polymorphisms related to the transcriptional level of FOXP3 with prognosis of autoimmune thyroid diseases

The severity of Hashimoto's disease (HD) and intractability (or inducibility to remission) of Graves' disease (GD) varies among patients. Forkhead box P3 (FoxP3) is a crucial regulatory factor for the development and function of regulatory T (T(reg) ) cells, and deficiency of the FoxP3 gene (FOXP3) suppresses the regulatory function of T(reg) cells. To clarify the association of the functional polymorphisms of the FOXP3 with the prognosis of GD and HD, we genotyped -3499A/G, -3279C/A and -2383C/T polymorphisms in FOXP3 gene obtained from 38 patients with severe HD, 40 patients with mild HD, 65 patients with intractable GD, in whom remission was difficult to induce, 44 patients with GD in remission and 71 healthy volunteers. The -3279CA genotype was more frequent in patients with GD in remission than in patients with intractable GD, and the -3279AA genotype, which correlates to defective transcription of FOXP3, was absent in patients with GD in remission. The -2383CC genotype was more frequent in patients with severe HD than in those with mild HD. In conclusion, the -3279A/C polymorphism is related to the development and intractability of GD and the -2383CC genotype to the severity of HD.

Exacerbation of corneal scarring in HSV-1 gK-immunized mice correlates with elevation of CD8+CD25+ T cells in corneas of ocularly infected mice

We have shown previously that exacerbation of corneal scarring (CS) in HSV-1 glycoprotein K (gK) immunized mice was associated with CD8+ T cells. In this study, we investigated the type and the nature of the immune responses that are involved in the exacerbation of CS in gK-immunized animals. BALB/c mice were vaccinated with baculovirus expressed gK, gD, or mock-immunized. Twenty-one days after the third immunization, mice were ocularly infected with 2 x 10(5) PFU/eye of virulent HSV-1 strain McKrae. Infiltration of the cornea by CD4+, CD8+, CD25+, CD4+CD25+, CD8+CD25+, CD19+, CD40+, CD40L+, CD62L+, CD95+, B7-1+, B7-2+, MHC-I+, and MHC-II+ cells was monitored by immunohistochemistry, qRT-PCR and FACS at various times post-infection (PI). This study demonstrated for the first time that the presence of CD8+CD25+ T cells in the cornea is correlated with exacerbation of CS in the gK-immunized group.

Regulatory T cells in Graves' disease

CONTEXT

Graves' disease (GD) involves auto-immunity against thyroid cell antigens, but the reasons for induction of auto-immunity are uncertain. We wished to determine whether there was a deficiency of regulatory T cells in patients with active GD.

DESIGN

Venous blood samples were obtained from patients with GD before and after treatment, and controls, and peripheral blood mononuclear cells were prepared.

PATIENTS AND MEASUREMENTS

Regulatory T cells were enumerated by Fluorescent Activated Cell sorting (FACS) in nineteen patients with untreated GD, 9 patients 6-8 weeks post RAI therapy, and 30 control subjects. Twenty-one patients with active GD prior to control of hyperthyroidism, 23 euthyroid controls without known autoimmune thyroid disease, and 10 patients who were euthyroid 6-12 months after RAI treatment were studied for expression of genes found in regulatory T cells by real-time Polymerase Chain reaction (PCR).

RESULTS

Percent distribution of CD4+, CD4+CD25+ and CD4+ CD25+(int-hi) CD127+(lo) regulatory T cells was similar in active GD patients and control subjects. The number of CD25+ and CD4+ CD25+(int-hi) CD127+(lo) cells was similar in GD patients and control subjects, but was lower in recently treated patients. Messenger RNA was prepared from PBMC, and reverse transcribed. Copy DNA abundance was evaluated by Real Time PCR using appropriate primers, for GAPDH (glyceraldehyde phosphate dehydrogenase) as a control housekeeping gene, and 5 genes related to function of regulatory T cells. Message RNA for Gadd45 alpha, Gadd45beta (growth arrest and damage inducible proteins), GITR (glucocorticoid inducible TNF receptor) and CD25 (IL-2R subunit) was more abundant in patients with active GD than in normal controls, and FoxP3 mRNA level was equal to that in controls. Message RNA levels in patients treated and euthyroid for 6 months were also greater than or equal to values in controls.

CONCLUSION

This study provides evidence that there is no deficit in T regulatory cells during active GD, or during the months post therapy.

Cytologic, flow cytometry, and molecular assessment of lymphoid infiltrate in fine-needle cytology samples of Hashimoto thyroiditis

BACKGROUND

The thyroidal lymphoid infiltrate (TLI) in Hashimoto thyroiditis (HT) represents the substrate from which thyroid lymphoma may arise. The objective of the current study was to classify the TLI in HT by comparing the cytologic features with flow cytometry (FC) data and evaluating the kappa/lambda light chain ratio and its molecular assessment.

METHODS

Fine-needle aspiration cytology (FNAC) was performed in 34 patients with HT with nodular or diffuse palpable enlargement of the gland. Two or 3 passes were performed to prepare traditional smears, FC, and immunophenotyping, and RNAlater suspensions for molecular assessment. FC was performed using the following antibodies: CD3, CD5, CD4, CD8, CD10, CD19, and kappa and lambda light chains. In 4 cases, high molecular weight DNA was extracted and used for polymerase chain reaction (PCR) to amplify the variable diversity joining region of the heavy chain immunoglobulin (Ig) genes (IgH). Statistical analysis was performed to evaluate possible associations between clinical ultrasound presentation, cytologic pattern, and TLI phenotype. Light chain expression was evaluated as the percentage of the expressing cells (</=20% and >20%) and as the kappa/lambda ratio.

RESULTS

Smears were classified as "lymphocytic," "lymph node-like," or "mixed." FC demonstrated T cells (CD3 positive [+], CD5+) in all cases, and T cells and B cell (CD19+, CD10+/-) lymphocytes in 22 cases. Light chains were expressed in 30 cases (in <20% of the gated cells in 13 cases and in >20% of the gated cells in 17 cases). Five cases demonstrated small kappa/lambda ratio imbalances and PCR analysis demonstrated diffuse bands in the gel and Gaussian curves at the heteroduplex. Statistical analysis indicated significant associations between the "lymphocytic" pattern and T-cell phenotype and between the "lymph node-like" pattern and B-cell phenotype. A significant association also was observed between light chain restriction and low light chain expression (P < .005).

CONCLUSIONS

The cytologic pattern of TLI in HT is quite representative of the clinical presentation and phenotypic cell type. Small light chain imbalances are not sustained by heavy chain Ig gene (IgH) rearrangements. FNA coupled with FC may contribute to making the distinction between florid TLI and non-Hodgkin lymphoma.

Increases of the Th1/Th2 cell ratio in severe Hashimoto's disease and in the proportion of Th17 cells in intractable Graves' disease

BACKGROUND

T helper type 1 (Th1), Th2, and Th17 cells produce interferon (IFN)-gamma, interleukin (IL)-4, and IL-17A, respectively. We reported that IFN-gamma and IL-4 gene polymorphisms, which are related to higher IFN-gamma and lower IL-4 production, respectively, are more frequent in patients with severe Hashimoto's disease (HD) than in those mild HD. We now aim to investigate the proportion of peripheral Th1, Th2, and Th17 cells in patients with autoimmune thyroid disease (AITD).

METHODS

We studied 17 patients with HD who developed hypothyroidism and were treated with l-thyroxine, referred to as severe HD; 17 untreated patients with HD who were euthyroid, referred to as mild HD; 18 euthyroid patients with Graves' disease (GD) who remained positive for anti-thyrotropin receptor antibody (TRAb) despite being treated with anti-thyroid drugs for more than 5 years, referred to as intractable GD; and 17 patients with GD who were euthyroid and negative for TRAb for more than 2 years after cessation of anti-thyroid drugs, referred to as GD in remission; and 10 control subjects without AITD. By the definitions in this study Th1 cells were CD4(+)IFN-gamma(+)IL-4(-)IL-17A(-) cells, Th2 cells were CD4(+)IFN-gamma(-)IL-4(+)IL-17A(-) cells, and CD4(+)IFN-gamma(-)IL-4(-)IL-17A(+) cells were Th17 cells.

RESULTS

The proportion of peripheral Th1 cells was higher in patients with severe HD than in patients with mild HD (p < 0.05), and the proportion of peripheral Th2 cells was lower in patients with severe HD than in patients with mild HD (p < 0.001). Therefore the Th1/Th2 ratio was higher in severe than in mild HD patients (p < 0.001). The proportion of peripheral Th17 cells in patients with AITD was higher than in control subjects and the proportion of these cells in patients with intractable GD was higher than in patients with GD in remission (p < 0.05).

CONCLUSIONS

The peripheral Th1/Th2 cell ratio is related to the severity of HD, and the proportion of Th17 cells is related to the intractability of GD. We hypothesize that these patterns of peripheral Th cell subsets may be expressed within the thyroid.

Mathematical analysis of clinical data reveals a homunculus of bacterial mimotopes protecting from autoimmunity via oral tolerance in human

Oral tolerance (OT) means systemic immunological unresponsiveness to harmless antigens present in the gastrointestinal tract. We presumed that tolerance to these antigens may also protect self-proteins that show immunological similarity to the intestinal normal flora. To investigate the existence and in vivo relevance of such a tolerogenic molecular mimicry, we focused our attention to Autoimmune Polyendocrine Syndrome type 1 (APS1) and Hemolysis, Elevated Liver Enzymes, Low Platelet count (HELLP) syndrome. APS1 is a human form of Autoimmune Regulator (AIRE) dysfunction with severely impaired central immunotolerance to a specific set of autoantigens, allowing investigation of tolerogenic mimicry by itself, without a disturbing background. HELLP syndrome is a mediocre manifestation of thrombotic microangiopathy, complicating pregnancy, with platelet-fibrin deposits in small blood vessels and transient development of autoantibodies. Impaired microcirculation in the liver is well described, while intestinal ischemia is possible but has not yet been studied. As the harmless nature of an antigen is essential for OT, ischemia-induced bacterial microinvasion represses this process. In case that oral tolerance to a bacterial homunculus is an existing way of self-protection and has an in vivo relevance when central tolerance is intact, significant intestinal ischemia--if present--is expected to promote autoimmunity in HELLP syndrome. We used an experimentally validated, highly reliable mathematical algorithm to predict the extent of immunological similarity between a certain autoantigen and intestinal bacteria. We found a strong negative correlation between the similarity of autoantigens to intestinal bacteria and the production of specific autoantibodies in APS1 (R=-0.70, P=0.002), while a positive correlation was observed in patients with predominantly the severe/moderately severe form of HELLP syndrome according to Mississippi classification (R=0.94, P=0.005). Autoantigen length inversely correlated with the production of autoantibodies in APS1 (R=-0.68, P=0.004). As a longer chain with more epitopes associates with an increased possibility of mimicry to any proteome, molecular mimicry in general--regarding at least major tissue-specific autoantigens--seems to be rather protective. Our calculations support the hypothesis that OT to an intestinal "bacterial homunculus" is an in vivo relevant mechanism of self-protection in humans, furthermore, HELLP syndrome presumably associates with significant intestinal ischemia and leak, resulting in transient autoimmunity via loss of OT.

Involvement of functional polymorphisms in the TNFA gene in the pathogenesis of autoimmune thyroid diseases and production of anti-thyrotropin receptor antibody

The severity of Hashimoto's disease (HD) and intractability of Graves' disease (GD) varies among patients. Severity of HD is associated with the functional +874A/T polymorphism for interferon-gamma, an inflammatory cytokine. To clarify the association between functional polymorphisms in two other inflammatory cytokine genes [tumour necrosis factor (TNF)-alpha and interleukin (IL)-2] and the severity of autoimmune thyroid disease (AITD), we examined the TNF-alpha-1031T/C, TNF-alpha-857C/T and IL-2 -330T/G polymorphisms in genomic DNA samples. We genotyped 41 patients with intractable GD, 34 patients with GD in remission, 41 patients with severe HD, 36 patients with mild HD and 70 healthy controls. The frequency of carriers of TNF-alpha-1031C (CT + CC), which correlates with higher TNF-alpha production, was significantly higher in HD and GD patients than in controls, but was not associated with the severity of HD. In GD patients, the levels of anti-thyrotropin receptor antibody (TRAb) at onset of the disease was higher in patients with the TNF-alpha-857T (CT + TT) genotype, which correlates with higher TNF-alpha production, than in those with the -857CC genotype. We found no differences in the IL-2 -330T/G polymorphism among groups of AITD patients. In conclusion, the functional -1031T/C polymorphism of the TNFA gene is associated with the development of AITD and the functional -857C/T polymorphism is associated with the levels of TRAb in active GD patients.

Autoimmune thyroid diseases in a large group of Hungarian patients with primary Sjögren's syndrome

BACKGROUND

Previous studies on relatively small populations of patients with primary Sjögren's syndrome (pSS) suggested an association between pSS and Hashimoto's thyroiditis (HT). As some findings in the literature regarding the relationship between pSS and thyroid disease are contradictory, and there is little information on the sequence of pSS and HT, we conducted a study with a population of patients with pSS that was about three times larger than previously studied populations. Our objective was to determine the prevalence of HT and Graves' disease (GD) in patients with pSS and to assess the sequence of pSS and autoimmune thyroid diseases.

METHODS

A total of 479 patients with pSS were retrospectively studied. Thyroid ultrasound and scintigraphy were performed, and serum thyrotropin, free triiodothyronine, free thyroxine, antithyroid peroxidase antibody (TPOAb), and anti-thyroglobulin autoantibody (TgAb) measurements were carried out. Solitary thyroid nodules were investigated by fine-needle aspiration biopsy.

RESULTS

Thyroid dysfunction was found in 95 patients (21.25%). Thirty of these patients had HT and 18 had GD. HT predated pSS in eight patients, developed at approximately the same time in seven patients, and followed pSS in 15 patients. Almost all (90%) patients with HT had persistently elevated serum TgAb or TPOAb titers.

CONCLUSIONS

An association between HT and pSS was found based on the fact that the frequency of HT was greater among pSS patients (6.26%) than in the general population (1-2%). In contrast, no association between GD and pSS was found. We noted that both HT and GD can appear either before or after the onset of pSS. Since most cases of pSS predate the appearance of autoimmune thyroid diseases it is important to determine if pSS is a predisposing factor for the development of autoimmune thyroiditis.

HLA-DR expressing peripheral T regulatory cells in newly diagnosed patients with different forms of autoimmune thyroid disease

BACKGROUND

Several reports have claimed a role for T regulatory cells (Tregs) in the pathogenesis of various autoimmune diseases, including autoimmune thyroid disease (AITD). The aim of the present study was to examine whether changes in the number of peripheral CD4 + CD25highHLA-DR + lymphocytes, a subpopulation of Tregs, occur in patients with AITD.

METHODS

Three-color flow cytometry was used to detect the proportion of CD4 cells expressing CD25, CD25high, and HLA-DR in 70 newly diagnosed and untreated AITD patients and 20 controls. The intensity of CD25 expression on these cells was also examined.

RESULTS

The proportion of CD4 + CD25 + cells as well as the proportion of CD4 + CD25high cells among the population of CD4 lymphocytes was not different in AITD patients relative to controls. However, a significant increase in the proportion of CD4 + CD25highHLA-DR + cells among the population of CD4 lymphocytes was found in patients with Hashimoto's thyroiditis (HT) compared to controls.

CONCLUSIONS

In HT patients there is a quantitative increase of CD4 + CD25highHLA-DR + cells that may indicate a compensatory expansion of this subpopulation of Tregs in an attempt to suppress the immune response.

The +869T/C polymorphism in the transforming growth factor-beta1 gene is associated with the severity and intractability of autoimmune thyroid disease

The severity of Hashimoto's disease (HD) and the intractability of Graves' disease (GD) vary among patients. To clarify whether the +869T/C polymorphism in the transforming growth factor-beta1 (TGF-beta1) gene, which is associated with TGF-beta1 expression, is involved in the intractability of GD and severity of HD, we genotyped the TGF-beta1 +869T/C polymorphism by polymerase chain reaction-restriction fragment length polymorphism method in genomic DNA samples from 33 patients with HD who developed hypothyroidism before they were 50 years old (severe HD) and 30 untreated, euthyroid patients with HD who were older than 50 years (mild HD). We also examined 48 euthyroid patients with GD who had been under treatment and were still positive for anti-thyrotropin receptor antibodies (intractable GD), 20 euthyroid patients with GD in remission and 45 healthy controls. The frequency of the T allele and the TT genotype were higher in patients with severe HD than in those with in mild HD. In contrast, the frequency of the CC genotype was higher in patients with intractable GD than in patients with GD in remission. In conclusion, the +869T/C polymorphism in the TGF-beta1 gene is associated with the severity and intractability of autoimmune thyroid disease.

Ratio of serum IgG3 to total IgG concentration and goiter size are independent factors in intractability of Graves' disease

Peripheral immunoglobulin (Ig) G(3)-secreting cells and serum concentrations of interleukin (IL)-10, a class-switching factor to IgG(3)-secreting cells, increase in patients with intractable Graves' disease (GD). However, they are not practical for laboratory tests. To find more stable and easily detectable markers of disease intractability or disease severity in patients with GD or Hashimoto's disease (HD), we examined the serum concentration of IgG(3) in 58 euthyroid GD patients who had been undergoing antithyroid drug treatment for more than 5 years but still must continue drug treatment to maintain a euthyroid state (intractable GD), 26 GD patients who had maintained a euthyroid state for more than 2 years without any treatment (GD in remission), 20 untreated, thyrotoxic GD patients, 40 euthyroid HD patients treated with thyroxine (5 men and 35 women), 13 untreated, euthyroid HD patients, and 39 healthy volunteers. Serum concentrations of IgG(3 )increased in euthyroid patients with intractable GD and in those with GD in remission, but serum concentrations of IgG were not altered. The ratio of serum concentrations of IgG(3) to total IgG (IgG(3)/IgG ratio) was higher in euthyroid patients with intractable GD than in those with GD in remission. Multiple logistic-regression analysis demonstrated that IgG(3)/IgG ratio and goiter size were independent factors in disease intractability of GD patients. These results suggest that IgG(3)/IgG ratio and goiter size may be used as independent markers associated with GD intractability.

Effects of angiotensin II blockade on the development of autoimmune thyroiditis in nonobese diabetic mice

We evaluated the effects of angiotensin II (Ang II) blockers, losartan, an Ang II receptor blocker, and enalapril, an angiotensin converting enzyme inhibitor, on the development of autoimmune thyroiditis in nonobese diabetic (NOD) mice, an animal model of Hashimoto's thyroiditis (HT). Mice were assigned into three groups, untreated, losartan-treated (30 mg/kg/day), and enalapril-treated (10 mg/kg/day) groups. Thyroiditis was induced by iodide ingestion (experiment 1) or mouse thyroglobulin (Tg) immunization (experiment 2). Both procedures effectively induced thyroiditis. While iodide ingestion failed to induce anti-mouse Tg antibody (TgAb) production, Tg immunization resulted in a significant increase in serum TgAb levels. In both experiments, neither losartan nor enalapril interfered with the development of thyroiditis and TgAb production. These results suggest that Ang II may not be associated with the development of autoimmune thyroiditis in NOD mice. Thus, the Ang II blockade may not have therapeutic potential in HT.

Regulatory T cells in human autoimmune thyroid disease

CONTEXT

T regulatory cells have a key role in the pathogenesis of autoimmune diseases in different animal models. However, less information is available regarding these cells in human autoimmune thyroid diseases (AITD).

OBJECTIVE

The objective of the study was to analyze different regulatory T cell subsets in patients with AITD.

DESIGN

We studied by flow cytometry and immunohistochemistry different T regulatory cell subsets in peripheral blood mononuclear cells (PBMCs) and thyroid cell infiltrates from 20 patients with AITD. In addition, the function of T(REG) lymphocytes was assessed by cell proliferation assays. Finally, TGF-beta mRNA in thyroid tissue and its in vitro synthesis by thyroid mononuclear cells (TMCs) was determined by RNase protection assay and quantitative PCR.

RESULTS

PBMCs from AITD patients showed an increased percent of CD4+ lymphocytes expressing glucocorticoid-induced TNF receptor (GITR), Foxp3, IL-10, TGF-beta, and CD69 as well as CD69+CD25(bright), CD69+TGF-beta, and CD69+IL-10+ cells, compared with controls. TMCs from these patients showed an increased proportion of CD4+GITR+, CD4+CD69+, and CD69+ cells expressing CD25(bright), GITR, and Foxp3, compared with autologous PBMCs. Furthermore, a prominent infiltration of thyroid tissue by CD69+, CD25+, and GITR+ cells, with moderate levels of Foxp3+ lymphocytes, was observed. The suppressive function of peripheral blood T(REG) cells was defective in AITD patients. Finally, increased levels of TGF-beta mRNA were found in thyroid tissue, and thyroid cell infiltrates synthesized in vitro significant levels of TGF-beta upon stimulation through CD69.

CONCLUSIONS

Although T regulatory cells are abundant in inflamed thyroid tissue, they are apparently unable, in most cases, to downmodulate the autoimmune response and the tissue damage seen in AITD.

Association between the severity of Hashimoto's disease and the functional +874A/T polymorphism in the interferon-gamma gene

CD8+ CD25+-activated cytotoxic T cells and anti-thyroglobulin antibodies (TgAb) are independently involved in the severity of Hashimoto's disease (HD). Interferon gamma (IFN-gamma) activates cytotoxic T cells. To evaluate the hypothesis that the functional +874A/T polymorphism in the gene encoding IFN-gamma is associated with the severity of HD, we examined the frequencies of this polymorphism in 34 HD patients who developed hypothyroidism (severe HD); 22 untreated, euthyroid HD patients (mild HD); 49 patients with intractable Graves' disease (GD); 16 GD patients in remission; and 57 healthy volunteers. Frequency of the +874T allele, which is associated with high IFN-gamma production, was higher in patients with severe HD than in those with mild HD (odds ratio [OR], 3.5; 95% confidence interval [CI], 1.0-12.4; p = 0.047), but there was no difference in the frequency between GD patients. The difference in the frequency of +874T was observed in the subset of patients with HD negative for TgAb (OR, 8.4; 95% CI, 1.2-57.3; p = 0.029) but not in the subset of patients with HD positive for TgAb. Our data indicate that the +874A/T polymorphism in the IFN-gamma gene is associated with severity of HD.

CD8+ T cells in autoimmunity

Mounting evidence shows that CD8(+) T cells contribute to the initiation, progression and regulation of several pathogenic autoimmune responses in which these cells were not previously thought to play a major role. CD8(+) T cells can kill target cells directly, by recognizing peptide-MHC complexes on target cells, or indirectly, by secreting cytokines capable of signaling through death receptors expressed on the target cell surface. Autoreactive CD8(+) T cells can also contribute to autoimmunity by releasing cytokines capable of increasing the susceptibility of target cells to cytotoxicity, or by secreting chemokines that attract other immune cells to the site of autoimmunity. Autoreactive CD8(+) T cells can also downregulate autoimmune responses. Recent important advances include a mechanistic understanding of events leading to the activation and recruitment of autoreactive CD8(+) T cells in certain autoimmune responses and a greater appreciation of the diverse roles that these T cells play in autoimmunity.

In vivo and in vitro effects of statins on lymphocytes in patients with Hashimoto's thyroiditis

BACKGROUND

Statins have apoptotic effects on many cell types. Hashimoto's thyroiditis (HT) is an autoimmune disease in which cell-mediated autoimmune mechanisms are pathogenetically involved.

OBJECTIVE

The aim of this study was to evaluate the in vivo effects of Simvastatin on thyroid function, lymphocyte subtypes and also to investigate the apoptotic effects of Simvastatin, Mevastatin, Pravastatin and Cerivastatin on lymphocytes from patients with HT.

METHODS

In the first part of the study, 11 patients with HT and subclinical hypothyroidism (SH) were given Simvastatin (20 mg/day) for 8 weeks. Ten patients with SH and HT served as the control group. No treatment was given to controls. Thyroid function, C-reactive protein (CRP) levels and lymphocyte subtypes of both groups were determined before the study and after 8 weeks. In the second part of the study, the apoptotic effects of statins on lymphocytes were evaluated in patients with HT (n = 10) and normal subjects (n = 10) in vitro. Apoptosis was investigated by using Annexin-V and propidium iodide. Lymphocytes from patients and controls were incubated with different concentrations of Simvastatin, Cerivastatin, Mevastatin and Pravastatin.

RESULTS

An increase in serum free tri-iodothyronine and free thyroxine levels and a decrease in TSH levels were observed (P < 0.05) with Simvastatin treatment. CD4+ cells and B lymphocytes increased whilst CD8+ cells, natural killer cells and activated T lymphocytes decreased significantly in the treatment group (P < 0.05). The CRP level of the group also decreased with Simvastatin but it did not reach significance (P = 0.057). None of parameters was found to be different from the baseline in the control group. In in vitro experiments, apoptosis was observed in CD3 + (both in CD8+ and CD4+ cells) with all statins in both patient and control samples. Mevalonate, which was used in experiments, reversed apoptosis in some but not all samples.

CONCLUSIONS

The results of this study suggested that Simvastatin is an immune modulatory agent and improves thyroid function in patients with HT. This effect is probably mediated via lymphocyte apoptosis as demonstrated with in vitro experiments and is not confined to Simvastatin since Mevastatin, Pravastatin and Cerivastatin also induced apoptosis in lymphocytes.

Distinct leucocyte redistribution after glucocorticoid treatment among difficult-to-treat asthmatic patients

Difficult-to-treat asthma (DTA) represents a heterogeneous subgroup of asthma. Up to now, the lack of specific diagnosis not only complicates appropriate specification and control of asthma, but also makes targeted research difficult. The aim of this study is to categorize this heterogeneous group of DTA patients (n=27; referring to the GINA guidelines) based on the distinct leucocyte redistribution (LR) after glucocorticoid (GC) treatment. Furthermore, the effect of adjuvant therapies was investigated for its impact on LR. The frequency of CD3+, CD4+, CD8+, CD14+, CD19+ and NK cells was analysed in peripheral blood before and 3 h after systemic GC treatment, along with the markers of activation HLA-DR and CD25. Within 3 h of GC administration, a significant average decrease of 16% in CD3+CD4+ (P < or = 0.001) and a 12% increase in NK-cell frequency (P < or = 0.001) clearly distinguished two groups of patients: LR-responsive and LR-unresponsive patients. The CD3+CD8+ T-cell number and activation marker remained unchanged. Patients who received adjuvant therapy, such as methotrexate or interferon-alpha, because of poor clinical response to GC showed an LR similar to that showed by responsive patients. DTA patients comprise at least two immunologically distinct groups: patients showing an immediate decrease in CD3+CD4+ T cells and an increase in NK cells following GC administration and patients lacking an immediate change. Analysis of LR not only may allow the identification of immunologic steroid resistance, but also may be of value for immunologic determination of effective steroid doses.

Lower concentration of serum soluble CD8 in severe Hashimoto's disease

To investigate the roles of soluble CD4 (sCD4) and CD8 (sCD8) in the severity of autoimmune thyroid diseases, we examined serum concentrations of sCD4 and sCD8 in various degrees of severity of Hashimoto's disease (HD) and Graves' disease (GD) by enzyme immunoassay. The serum concentration of sCD8 was lower in euthyroid patients with HD undergoing treatment for hypothyroidism (severe HD) than in untreated, euthyroid patients with HD (mild HD), but the sCD4 concentration did not differ between patients with severe and mild HD. The serum sCD8 concentration was negatively correlated with the proportion of CD25(+) cells in CD8(+) cells in patients with severe HD. Serum sCD4 and sCD8 concentrations did not differ between euthyroid patients with GD in remission and those with intractable GD. These results indicate that serum sCD8 is involved in the severity of HD, possibly by down-regulating the function of cytotoxic T cells.

Cellular immune responses in autoimmune thyroid disease

Recent research in autoimmune thyroid disease (AITD) has largely focused on delineation of the autoantigens and their epitopes, but there is now renewed interest in the immunoregulatory properties of T cells, an understanding of which may explain the emergence of AITD in experimental settings. T cell recognition of autoantigens has shown considerable intra- and interindividual heterogeneity, and a mixed pattern of cytokine production indicates that both the Th1 and Th2 limbs of the helper T cell response are involved in all types of AITD. It is now clear that secretion of chemokines and cytokines within the thyroid accounts for the accumulation and expansion of the intrathyroidal lymphocyte pool, and that the thyroid cells themselves contribute to this secretion. The thyroid cells also produce a number of proinflammatory molecules which will tend to exacerbate the autoimmune process. Thyroid cell destruction in autoimmune hypothyroidism is dependent on T cell-mediated cytotoxicity with the likely additional effect of death receptor-mediated apoptosis.

Decrease of CD154 intensity on peripheral CD4+ T cells in autoimmune thyroid disease

To clarify immunological differences among patients with Graves' disease (GD) and Hashimoto's disease (HD) at various levels of severity, we examined the expression of the CD154 molecules on peripheral T cells, which regulate B cell activation, B cell differentiation, and T-cell survival. We found decreases in the intensities of CD154 on peripheral CD4(+) cells from euthyroid patients with GD and HD, but we did not find any differences between patients with different disease severities. CD8(+) cells did not express CD154 molecules. Thus, CD154 expression on CD4(+) cells may be related to the pathogenesis of the autoimmune thyroid diseases, not to the disease severity.

Increased intensities of fas expression on peripheral T-cell subsets in severe autoimmune thyroid disease

Fas (CD95)-Fas ligand (FasL; CD178)-induced apoptosis is necessary for the maintenance of self-tolerance. To clarify whether or not any abnormalities in the Fas-FasL system exist in patients with autoimmune thyroid disease (AITD), we examined the expression of Fas and FasL on peripheral T lymphocytes by three-color flow cytometry in 113 patients with AITD and 49 healthy controls. The intensities of Fas expression in both CD4(+) and CD8(+) T cells decreased in thyrotoxic patients with Graves' disease (GD), but increased in both patients with severe Hashimoto's disease (HD) undergoing treatment and seriously intractable patients with GD continuously positive for thyrotropin (TSH) receptor antibody despite treatment with antithyroid drugs for more than 5 years. The proportion of Fas expression was increased in CD4(+) T cells from patients with untreated GD, and in CD8(+) T cells from patients with severe HD. The proportion of CD8(+) T cells decreased in patients with severe HD. FasL were not expressed on T cells in controls and patients with AITD. These results indicate that (1). the intensities of Fas expression on peripheral T cells increase in severe autoimmune thyroid diseases and (2). both the intensity and the proportion of Fas expression may be important for the induction of apoptosis.

Increase of serum interleukin-10 in intractable Graves' disease

The intractability of Graves' disease (GD) and the severity of Hashimoto's disease (HD) vary among patients. We previously reported that peripheral immunoglobulin (Ig) G3-secreting cells were increased in patients with intractable GD (i.e., requiring continuous antithyroid drug therapy). Isotype switching to IgG3 is induced by interleukin (IL)-4 and IL-10. To clarify which of these cytokines is related to the intractability or severity of autoimmune thyroid disease (AITD), we examined the serum concentrations of IL-10 and IL-4 by enzyme immunoassay in 166 patients with AITD and in 53 healthy controls. The serum IL-10 concentration was significantly higher in patients with GD and continuously positive for thyrotropin (TSH) receptor antibody (TRAb) despite more than 5 years of antithyroid drugs treatment than in patients with GD in remission. The serum IL-4 concentration did not differ between these two groups of patients. However, the serum IL-10 concentration was not related to the severity of HD. These results indicate that IL-10, but not IL-4, is related to the intractability of GD, but not to the severity of HD.

Relation of CD30 molecules on T-cell subsets to the severity of autoimmune thyroid disease

The prognosis of patients with autoimmune thyroid disease (AITD) varies. To clarify the immunologic differences among patients with various severities of AITD, we examined two types of molecules on peripheral T lymphocytes: CD195 (CCR5), which express dominantly on CD4(+) type 1 helper T (T(H)1) cells, and CD30, which is known as a marker of CD4(+) type 2 helper T (T(H)2) cells and a regulatory molecule of CD8(+) autoreactive cytotoxic T cells. We found presence of patients with high proportion (> 9%) of CD30 expression in CD4(+) cells in a group of patients with Graves' disease (GD) in remission compared to the patients with intractable GD and a decrease in the intensity of CD30 expression on CD8(+) cells from patients with severe Hashimoto's disease (HD) treated for hypothyroidism compared to patients with untreated and euthyroid HD. There was no difference in CD195 expression between these patients with GD or HD with different severities, but there was a decreased intensity of CD195(+) cells in thyrotoxic patients with GD. These results indicate that CD30 molecules on CD4(+) and CD8(+) cells may be related to the severities of GD and HD, respectively.