FreeStyle Mini blood glucose results are accurate and suitable for use in glycemic clamp protocols.

OBJECTIVE: We assessed the accuracy of the FreeStyle Mini (FSM) meter for use in glycemic clamp and meal protocols in comparison with the HemoCue Glucose 201 DM Analyzer (HemoCue) and the YSI 2300 STAT Glucose Oxidase Analyzer (YSI). METHODS: Seven volunteers with type 2 diabetes mellitus, 35-69 years old, underwent a frequently sampled meal test and a graded hyperglycemic test, on two separate days, with one of the volunteers undergoing each test twice. Samples for glucose measurements were obtained from arterialized venous blood. A total of 420 samples (with glucose levels ranging from 63 to 388 mg/dl) were available for comparison. On average, 10 measurements were available for every 5 mg/dl increment in glucose level in the range of 130-310 mg/dl. Blood glucose measurements were done on each sample with the FSM, HemoCue, and YSI. RESULTS: FreeStyle Mini blood glucose values correlated closely with the YSI readings. Of the FSM measurements, 99.0% were within the Clarke error grid zone A; 51.3%, 84.7%, and 96.2% of the FSM readings were within 5%, 10% and 15% of the YSI values, respectively. The FSM was significantly more accurate than the HemoCue (84.7% vs 76.6% of results within 10% of the YSI results; p = .0038). The mean average relative difference of the FSM (5.8%) was also significantly lower than that of the HemoCue (6.8%; p = .0013) CONCLUSIONS: The FSM provides accurate results and constitutes a suitable alternative for bedside blood glucose measurements in experimental procedures, helping to reduce sample size, turnaround time, and cost.

Thyroid fetal male microchimerisms in mothers with thyroid disorders: presence of Y-chromosomal immunofluorescence in thyroid-infiltrating lymphocytes is more prevalent in Hashimoto's thyroiditis and Graves' disease than in follicular adenomas.

The presence of fetal cells in a maternal compartment is defined as fetal-maternal microchimerism, which has been detected in thyroids of mothers suffering from autoimmunity. We analyzed the immunohistology of paraffin-embedded thyroid specimen taken at surgery from 49 women with Hashimoto's thyroiditis (n = 25), Graves' disease (n = 15), or nodular or diffuse follicular adenomas (n = 9), whose childbirth history was positive for sons. By fluorescence in situ hybridization we screened for X-chromosome- and Y-chromosome-specific staining and compared the finding with human leukocyte antigen (HLA) DQ types of the mothers and, where available, their offspring. In 23 thyroids we found Y-chromosome-specific staining, which was more frequent in thyroid autoimmune disease (60% Hashimoto's thyroiditis and 40% Graves' disease) than in follicular adenomas (22.2%). There was no significant difference for HLA DQ alleles among women whose thyroids showed Y-chromosome staining and those without. However, a subgroup of all investigated microchimerism-positive mother-child pairs and women with Hashimoto's thyroiditis and Graves' disease more often had the susceptibility alleles HLA DQA1*0501-DQB1*0201 or DQB1*0301. In conclusion, fetal microchimerism is observed in thyroids of mothers with sons, and this is found more frequently in thyroid autoimmune diseases.

CYP27B1 polymorphisms variants are associated with type 1 diabetes mellitus in Germans.

CYP27B1 (25-hydroxyvitamin D(3)-1alpha-hydroxylase) catalyzes the metabolization of 25-hydroxyvitamin D(3) to 1,25(OH)(2)D(3) the most active natural Vitamin D metabolite. 1,25(OH)(2)D(3) plays a role in the regulation of autoimmunity and cell proliferation and prevents the development of autoimmune diabetes mellitus in animal models besides other autoimmune disorders. One hundred and eighty-seven families with one offspring affected with type1diabetes mellitus were genotyped for the polymorphisms in the promoter region (-1260 C/A) and intron 6 (2338 T/C) of the CYP27B1 gene on chromosome 12 q13.1-13.3 and extended transmission disequilibrium tests (ETDT) were performed. The haplotype CT (-1260 A/2338 T) was significantly more often transmitted to affected offspring (96 transmitted (T) versus 63 not transmitted (NT), P = 0.0089). While the AT (-1260 C/2838 T) was significantly less often transmitted (37 T versus 60 NT, P = 0.0195). This study suggests that CYP27B1 haplotypes may confer susceptibility to type 1 diabetes mellitus in Germans.

No association of two Fas gene polymorphisms with Hashimoto's thyroiditis and Graves' disease.

BACKGROUND: Apoptosis is a joint pathogenic process underlying autoimmune thyroid disease. Increased programmed cell death in thyrocytes causes hypothyroidism in Hashimoto's thyroiditis, whereas in Graves' disease infiltrating lymphocytes undergo apoptosis while thyrocytes appear to proliferate under protection of anti-apoptotic signals. The Fas/Fas ligand cascade represents a major pathway initiating apoptosis. Its role in autoimmunity is well studied and genetic polymorphisms in gene loci of Fas and its ligand have been shown to be associated with autoimmune diseases. OBJECTIVE: Due to the functional relevance of the Fas pathway in autoimmune thyroid disease we were interested in the possible contribution of polymorphisms in the Fas gene to the genetic risk of thyroid autoimmunity, which so far is mainly, but incompletely, attributed to the HLA DQ region and polymorphisms in the CTLA-4 gene. DESIGN: We genotyped Caucasian families with at least one offspring affected by Hashimoto's thyroiditis (n=95) and Graves' disease (n=109) for two Fas gene polymorphisms (g-670 G-->A in the promoter region, g-154 C-->T in exon 7). METHODS: Extended transmission disequilibrium and chi(2) testing were performed. RESULTS: Neither polymorphism alone (P=0.44 and P=0.70) nor the promoter/exon 7 haplotypes (P=0.86) were associated with Hashimoto's thyroiditis. No association with Graves' disease was observed for the promoter polymorphism (P=0.91) and exon 7 (P=0.65) or the promoter/exon 7 haplotypes (P=0.80). CONCLUSION: In summary, our data do not suggest any significant contribution of common genetic Fas variants to the genetic risk of developing Hashimoto's thyroiditis or Graves' disease.

Fas ligand gene polymorphisms are not associated with Hashimoto's thyroiditis and Graves' disease.

Hashimoto's thyroiditis and Graves' disease represent the two most common autoimmune thyroid disorders. Whereas in Hashimoto's thyroiditis FasL expression causes thyrocytes to undergo apoptosis, additional anti-apoptotic molecules appear to protect these cells in Graves' disease. Mutations of the FasL gene were observed in systemic lupus erythematosus. Given its functional relevance for the pathogenesis of thyroid autoimmunity we wondered whether variants of the FasL gene play a role in Hashimoto's thyroiditis and Graves' disease. We genotyped families with at least one offspring affected by Hashimoto's thyroiditis (n = 86) and Graves' disease (n = 90) for two FasL gene polymorphisms (C -843 T in the promoter, A IVS2nt-124 G in intron 2). Extended transmission disequilibrium (ETDT) and chi(2) testing were performed. Neither polymorphism alone nor the promoter/intron 2 haplotypes (p = 0.91) were associated with Hashimoto's thyroiditis. No association with Graves' disease was observed for the promoter polymorphism (p = 0.91) and the intron 2 "A" allele (57.1%; p = 0.36) or the promoter/intron 2 haplotypes (p = 0.31). Moreover, intron 2 genotyping revealed no difference between an additional 251 patients with Graves' disease and 197 healthy controls (p = 0.37). Italian and German families did not differ for the studied polymorphisms. In conclusion, our data do not suggest common genetic FasL variants to significantly contribute to the pathogenesis of either Hashimoto's thyroiditis or Graves' disease.

Vitamin D receptor genotype is associated with Addison's disease.

OBJECTIVE: Autoimmune Addison's disease is a rare disorder which results from the T cell-mediated destruction of adrenocortical cells. A number of genetic susceptibility markers are shared by Addison's disease, type 1 diabetes, Graves' disease and Hashimoto's thyroiditis. The vitamin D endocrine system has been shown to influence immune regulation. Variants of the nuclear vitamin D receptor (VDR) gene were found to be associated with type 1 diabetes and thyroid autoimmunity amongst others. We therefore investigated the role of VDR polymorphisms in Addison's disease. DESIGN AND METHODS: Patients (n=95) and controls (n=220) were genotyped for VDR polymorphisms FokI, BsmI, ApaI and TaqI. RESULTS: The 'ff' (13.7% vs 5.5%; P=0.0243; odds ratio = 2.75) and the 'tt' (28.4% vs 14.1%; P=0.0043; odds ratio = 2.42) genotypes were significantly more frequent in patients than in controls. Furthermore, the BsmI genotype distribution differed significantly between patients and controls (chi(2)=6.5016 (2 d.f.) P=0.0387). CONCLUSIONS: These data suggest that the VDR genotype is associated with Addison's disease. The mechanisms by which distinct receptor variants might confer disease susceptibility remain to be elucidated.

Familial clustering of juvenile thyroid autoimmunity: higher risk is conferred by human leukocyte antigen DR3-DQ2 and thyroid peroxidase antibody status in fathers.

Thyroid autoimmunity is one of the most common immune disorders in females, and its polygenic background remains to be elucidated. The human leukocyte antigen (HLA) DQ region of chromosome 6 has been shown to confer susceptibility to thyroid autoimmune disease. The aim of our present investigation was to determine whether the transmission of high risk HLA DQ to patients with thyroid autoimmunity differs when transmission is from fathers as opposed to when transmission is from mothers. We studied 91 juvenile patients with chronic lymphocytic thyroiditis (68 females and 23 males; mean age, 10.5 +/- 3.9 yr), 12 patients with Graves' disease (all females; mean age, 8.8 +/- 4.0 yr), 53 healthy siblings, and their parents for thyroid function, antibodies, ultrasound, and DNA typing for HLA DQ susceptibility alleles. We observed an increased rate of transmission for the DQA1*0501-DQB1*0201 (DQ2) haplotype [35 of 53 transmitted (66%); P = 0.02]. This allele was preferentially transmitted by fathers [21 of 27 (78%); P < 0.004], whereas the maternal DQ2 haplotypes were not transmitted more often than expected. Subsequently, families were stratified as follows according to the parental thyroid peroxidase antibody (TPOAb) status: no parent, only mothers, only fathers, and both parents positive. There was no significant maternal transmission disequilibrium in any subset, but the paternal HLA DQ2 was preferentially transmitted [11 of 14 cases (79%); P = 0.03] in the group of TPOAb-positive mothers, and we observed a similar trend in the group of TPOAb- positive fathers (P = 0.08). Also, the portion of offspring affected by Graves' disease was significantly higher in TPOAb-positive than in TPOAb-negative fathers (P < 0.02). In conclusion, our findings demonstrate a significant effect of paternal HLA DQ alleles as well as antibody status on susceptibility to thyroid autoimmune disease in juvenile patients.

The variable endogenous retroviral insertion in the human complement C4 gene: a transmission study in type I diabetes mellitus.

A variable endogenous retroviral element has been identified in intron 9 of the complement C4 gene [HERV-K(C4)], which maps to the class III region of the major histocompatibility complex (MHC) on chromosome 6p21.3. Genetic susceptibility to type I diabetes is mainly conferred by the MHC locus and the complement C4 region has been implied to contribute to human leukocyte antigen DQ (HLA-DQ) mediated disease risk. As the HERV-K(C4) insertion has been suggested to modulate expression of homologous genes, we investigated its transmission in 220 families with an offspring affected by type I diabetes as a potential disease susceptibility marker. There was no preferential transmission of the HERV-K(C4) insertion to affected offspring (P(TDT) = 0.79). Although 77.7% of HLA-DQ8 carried the HERV-K(C4) insertion, only 52.9% of -DQ2 haplotypes did (P(chi(2)) < 0.01). However, its insertion or deletion did not modulate the risk conferred by HLA-DQ8 (DQA1*0301-DQB1*0302) (P(chi(2)) = 0.27) or -DQ2 (DQA1*0501-DQB1*0201) (P(chi(2)) = 0.46). Thus, the HERV-K(C4) insertion is not associated with type I diabetes in Germans.

Vitamin D 1alpha-hydroxylase (CYP1alpha) polymorphism in Graves' disease, Hashimoto's thyroiditis and type 1 diabetes mellitus.

OBJECTIVE: The vitamin D endocrine system plays a role in the regulation of (auto)immunity and cell proliferation. Vitamin D 1alpha-hydroxylase (CYP1alpha) is one of the key enzymes regulating both systemic and tissue levels of 1,25-dihyroxyvitamin D(3) (1,25(OH)(2)D(3)). Administration of 1,25(OH)(2)D(3), whose serum levels were found to be reduced in type 1 diabetes and thyroid autoimmunity, prevents these diseases in animal models. We therefore investigated a recently reported CYP1alpha polymorphism for an association with type 1 diabetes mellitus, Graves' disease and Hashimoto's thyroiditis. DESIGN AND METHODS: Four hundred and seven Caucasian pedigrees with one offspring affected by either type 1 diabetes (209 families), Graves' disease (92 families) or Hashimoto's thyroiditis (106 families) were genotyped for a C/T polymorphism in intron 6 of the CYP1alpha gene on chromosome 12q13.1-13.3 and transmission disequilibrium testing (TDT) was performed. Subsets of affected offspring stratified for HLA-DQ haplotype were compared using chi(2) testing. RESULTS: There was no deviation from the expected transmission frequency in either type 1 diabetes mellitus (P=0.825), Graves' disease (P=0.909) or Hashimoto's thyroiditis (P=0.204). However, in Hashimoto's thyroiditis the CYP1alpha C allele was significantly more often transmitted to HLA-DQ2(-) patients (27 transmitted vs 14 not transmitted; TDT: P=0.042) than expected. The C allele was less often transmitted to HLA-DQ2(+) patients (9 transmitted vs 12 not transmitted; TDT: P=0.513), although the difference was not significant (chi(2) test: P=0.143). A similar difference was observed in type 1 diabetes between offspring with high and low risk HLA-DQ haplotypes (chi(2) test: P=0.095). CONCLUSIONS: The CYP1alpha intron 6 polymorphism appears not to be associated with type 1 diabetes mellitus, Graves' disease and Hashimoto's thyroiditis. A potential association in subsets of patients with type 1 diabetes and Hashimoto's thyroiditis should be further investigated as well as its functional implications.

Preliminary evidence that an endogenous retroviral long-terminal repeat (LTR13) at the HLA-DQB1 gene locus confers susceptibility to Addison's disease.

OBJECTIVE: Addison's disease is associated with particular haplotypes of the human leucocyte antigen (HLA) region [DQA1*0501-DQB1*0201 (DQ2) and DQA1*0301-DQB1*0302 (DQ8)]. This locus harbours several human endogenous retroviral (HERV) long-terminal repeats (LTR). LTRs within the HLA region have been shown to confer additional susceptibility to type 1 diabetes and rheumatoid arthritis. DESIGN: We investigated the role of LTR3 and LTR13, both of which are located adjacent to the DQB1 gene, in Addison's disease. PATIENTS: Eighty-seven patients and 160 controls were genotyped for HLA-DQA, -DQB, and the presence or absence of LTR3 and LTR13. RESULTS: Significantly more patients' HLA alleles than those of controls carried the LTR13 insertion (19.0% vs. 10.6%, P = 0.0143), whereas there was only a trend for LTR3 (allele-wise chi-squared test: P = 0.0941). Both, LTR3 and LTR13 are in strong linkage disequilibrium with DQ8, which itself was significantly more frequent in patients than in controls (29.9% vs. 15.0%, P = 0.0089). However, significantly more alleles of DQ8+ patients than of DQ8+ controls carried the LTR13 insertion (44.2% vs. 18.8%, P = 0.0119), whereas we did not observe any difference for LTR3 in the DQ8+ subset (30.5 vs. 23.1%, P = 0.9416). CONCLUSIONS: We have found preliminary evidence that the endogenous retroviral element DQ-LTR13, but not LTR3, is associated with Addison's disease. LTR13 appears to enhance HLA-DQ8 mediated disease risk. This retroviral insertion therefore might represent a novel susceptibility factor in Addison's disease, but these findings need to be confirmed in a larger data set.

A polymorphism within the vitamin D-binding protein gene is associated with Graves' disease but not with Hashimoto's thyroiditis.

Graves' disease and Hashimoto's thyroiditis are common autoimmune thyroid disorders. Experimentally, 1,25(OH)(2) D(3) prevents Hashimoto's thyroiditis. Vitamin D serum levels in Graves' disease were found to be significantly lower than in nonautoimmune hyperthyroidism. The polymorphic vitamin D-binding protein (DBP) greatly facilitates vitamin D actions, and DBP alleles differ regarding their affinity for 1,25(OH)(2) D(3). Therefore, we investigated polymorphisms of the DBP gene for an association with thyroid autoimmunity. Families with an offspring affected by Graves' disease (95 pedigrees) or by Hashimoto's thyroiditis (92 pedigrees) encompassing 561 individuals of Caucasian origin were genotyped for three DBP polymorphisms [(TAAA)(N) in intron 8; StyI; and HaeIII in exon 11]. Indirect haplotyping and (extended) transmission disequilibrium testing were performed. There was a significant transmission disequilibrium of the intron 8 polymorphism in patients with Graves' disease (P < 0.03) but not of the exon 11 polymorphism. In contrast, neither the intron 8 nor the exon 11 polymorphism was associated with Hashimoto's thyroiditis. Maternal and paternal transmission as well as allele frequencies in DQ2(+) and DQ2(-) patients did not differ in either disease. Therefore, allelic variants of the DBP gene confer susceptibility to Graves' disease but not to Hashimoto's thyroiditis in our population. These findings support a role of the vitamin D endocrine system in thyroid autoimmunity.