Antigen receptor variable region repertoires expressed by T cells infiltrating thyroid, retroorbital, and pretibial tissue in Graves' disease

To date, it has remained unclear whether T cells infiltrating thyroid, retroorbital, and pretibial tissue of patients with Graves' ophthalmopathy and pretibial dermopathy represent a primary immune response that is directed against certain antigenic determinants shared among these involved tissues. To characterize these T cells at the molecular level, we compared the T cell antigen receptor (TcR) variable (V) region gene usage in thyroid, retroorbital, pretibial tissue, and peripheral blood mononuclear cells of two patients with Graves' disease, ophthalmopathy, and pretibial dermopathy. Ribonucleic acid was extracted, reverse transcribed, and amplified using the PCR and 22 V alpha and 23 V beta gene-specific oligonucleotide primers. The resulting TcR V alpha and V beta transcripts were verified by Southern hybridization analysis using TcR C region-specific, digoxigenin-labeled oligonucleotide probes. In addition, complementarity determining regions 3 and junctional regions of TcR V beta genes were sequenced. Marked similarities of intrathyroidal, retroorbital, and pretibial TcR V alpha and V beta gene repertoires were noted with respect to the degree of TcR V gene restriction and the patterns of individual V genes expressed. Sequence analysis of junctional domains of V beta families revealed oligoclonality of intrahyroidal, retroorbital, and pretibial T cells. In addition, certain conserved junctional motifs were shared by T cells derived the thyroid gland and the extrathyroidal sites. Our results suggest that in the two patients with Graves' disease and extrathyroidal manifestations studied, similar antigenic determinants may have contributed to the recruitment and oligoclonal expansion of T cells both within the thyroid gland and at the involved extrathyroidal sites

A Genomic Point Mutation in the Extracellular Domain of the Thyrotropin Receptor in Patients with Graves’ Ophthalmopathy

Orbital and pretibial fibroblasts are targets of autoimmune attack in Graves' ophthalmopathy (GO) and pretibial dermopathy (PTD). The fibroblast autoantigen involved in these peripheral manifestations of Graves' disease and the reason for the association of GO and PTD with hyperthyroidism are unknown. RNA encoding the full-length extracellular domain of the TSH receptor has been demonstrated in orbital and dermal fibroblasts from patients with GO and normal subjects, suggesting a possible antigenic link between fibroblasts and thyrocytes. RNA was isolated from cultured orbital, pretibial, and abdominal fibroblasts obtained from patients with severe GO (n = 22) and normal subjects (n = 5). RNA was reverse transcribed, and the resulting cDNA was amplified by the polymerase chain reaction, using primers spanning overlapping regions of the entire extracellular domain of the TSH receptor. Nucleotide sequence analysis showed an A for C substitution in the first position of codon 52 in 2 of the patients, both of whom had GO, PTD, and acropachy. Genomic DNA isolated from the 2 affected patients, and not from an additional 12 normal subjects, revealed the codon 52 mutation by direct sequencing and AciI restriction enzyme digestions. In conclusion, we have demonstrated the presence of a genomic point mutation, leading to a threonine for proline amino acid shift in the predicted peptide, in the extracellular domain of the TSH receptor in two patients with severe GO, PTD, acropachy, and high thyroid-stimulating immunoglobulin levels. RNA encoding this mutant product was demonstrated in the fibroblasts of these patients. We suggest that the TSH receptor may be an important fibroblast autoantigen in GO and PTD, and that this mutant form of the receptor may have unique immunogenic properties

Tissue eosinophilia and eosinophil degranulation in Riedel's invasive fibrous thyroiditis.

The etiology of Riedel's invasive fibrous thyroiditis (IFT) has remained obscure. This rare disorder has been confused in the past with the more common fibrous variant of Hashimoto's disease. The typical histological features of IFT, in particular the presence of an invasive fibrosclerotic process in conjunction with a prominent chronic inflammatory infiltrate, suggest that the release of fibrogenic cytokines and other factors from these cellular infiltrates may play an important role in the pathogenesis of this condition. Our observations in routinely processed tissue sections obtained from patients with documented IFT of striking tissue eosinophilia led us to hypothesize that eosinophils and their products may play a role in the evolution of this disease. Immunofluorescence staining with affinity-purified polyclonal rabbit antibody directed against human eosinophil granule major basic protein revealed marked tissue eosinophilia and abundant extracellular deposition of major basic protein in all specimens from 16 patients with IFT. By contrast, only occasional eosinophils and no extracellular major basic protein were detected in control thyroid tissues obtained from patients with multinodular goiter, Graves' disease, Hashimoto's disease, and normal thyroid tissue. The presence of marked eosinophil infiltration and extracellular major basic protein deposition in IFT and other associated fibrosclerotic conditions suggests a role for eosinophils and their products in propagating the fibrogenesis seen in IFT

Occurrence of the Acanthocephalan Leptorhynchoides thecatus in Slimy Sculpins—A New Host Record

A new host (Cottus cognatus) for adults of the acanthocephalan Leptorhynchoides thecatus (Linton) is reported. Of 176 slimy sculpins examined from eastern Lake Michigan, 93% were infected by L. thecatus. The number of L. thecatus infecting slimy sculpins was directly related to size of fish. Mean number of L. thecatus per fish was 17 for males, 10 for females, and 3 for immatures. One male was infected with 132 L. thecatus.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141417/1/tafs0142.pd

Vitamin D receptor genotype BB is associated with higher serum osteocalcin in first pregnancy

Aim: Serum osteocalcin was shown in a previous study on first trimester pregnant women to correlate with bone density and to distinguish between fast and slow bone losers. The objective of the present study is to examine whether serum osteocalcin is related to vitamin D receptor (VDR) BsmI polymorphism in pregnant women. Study design: We determined osteocalcin serum levels and VDR BsmI genotype in 97 healthy first trimester pregnant women consecutively recruited during six months. Results: BB (21%), Bb (38%) and bb (41%) genotypes showed similar osteocalcin serum levels. However, in primigravidas (n=38) the BB genotype was significantly associated with higher mean osteocalcin level (9.67 ng/mL) than the Bb (8.07ng/mL) and the bb genotype (8.14ng/mL), respectively (P<0.05). The VDR genotype was the only independent parameter to correlate with serum osteocalcin (P<0.05). Conclusion: Only primigravidas show in the first trimester a relation between the bone formation parameter serum osteocalcin and the VDR genotype BB which indicates a higher risk of fractures. For further clinical applications serum osteocalcin and VDR genotype should be tested on a cohort of primigravidas including measurements of bone densit