Preradial myxedema in a euthyroid male: A distinct rarity.

Localized or pretibial myxedema is one of the signs of Graves disease (along with goiter, exophthalmus, thyroid acropathy, and high circulating levels of long-acting thyroid-stimulating hormone) and usually tends to occur at a later stage of the disease or even after the patient becomes euthyroid post treatment. Very rarely has it been reported in euthyroid patients. We report a euthyroid man presenting with localized myxedema on the extensor surface of his forearm with clinical and histopathological features consistent with pretibial myxedema. He responded partially to topical clobetasol propionate cream and tacrolimus ointment 0.1 percent for about 7 months. To the best of our knowledge, this is the first case of preradial myxedema in a euthyroid patient in the English international dermatological literature.

[Treatment of pretibial myxoedema with pentoxifylline]. / Praetibialis myxoedema kezelése pentoxifillinnel.

Pretibial myxoedema is a rare symptom of Graves' disease. Histological studies detected mucopolysaccharide and glycosaminoglycan accumulation, and the role of anti-TSH receptor antibodies has been suggested. In this paper the authors present the case of a 34-year-old male patient with pretibial myxoedema treated successfully with pentoxifylline. In his case history multiple autoimmune diseases (type 1 diabetes mellitus, Graves' disease with severe ophthalmopathy) concomitantly occurred. His severe pretibial myxoedema was undiagnosed and untreated at the time of admission. Because of his diabetes, steroid was contraindicated, which made the choice of the treatment more difficult. He received first intradermal, then intravenous and, finally, oral pentoxifylline, which resulted in a regression of the dermatological symptoms. The beneficial effect of pentoxifylline might be explained by its inhibitory effect of proinflammatory cytokines and proliferation of fibroblasts, and the production of glycosaminoglycan. It was concluded that pentoxifylline can be an effective and safe treatment of pretibial myxoedema.

Thyroid hormone action on skin.

PURPOSE OF REVIEW: To review the current understanding regarding thyroid hormone action on skin. To provide a historical context for the recent findings. RECENT FINDINGS: Although direct thyroid hormone actions have been demonstrated on multiple aspects of cutaneous biology, rigorous study remains scant. Still, there is a slowly evolving literature supporting the concept that thyroid hormone can directly stimulate epidermis, dermis, and hair. That action may be accessed to treat cutaneous disease. SUMMARY: Here, we review the literature regarding thyroid hormone action on skin along with skin manifestations of thyroid disease. We provide context for more recent findings of direct thyroid hormone stimulation of cutaneous cell proliferation in vitro and in vivo which may portend the use of thyroid hormone to treat cutaneous pathologies.

[Etiology and pathogenesis of secondary edema of the lower extremities in patients with limited pretibialnoy myxedema on the background of hyperthyroidism].

UNLABELLED: Results of the examination of patients with secondary lymphedema in the period 2006-2010. Revealed that the most frequent concomitant diseases in 150 (57,6%) patients with secondary lymphostasis lower extremities is hyperthyroidism. CLINICAL MANIFESTATIONS: an increase in thyroid size, infiltrative endocrine ophthalmopathy; balanced, solid consistency swelling of the lower extremities to the level of the upper third of the leg; hyperkeratosis; paresthesias. The results of functional studies of the condition of peripheral lymph in patients with different stages of secondary lymphostasis lower extremities against a background of hyperthyroidism showed a direct relationship between the severity of the disease, the degree of decompensation of peripheral lymph and the state of thyroid function.

Histopathologic comparison of nephrogenic fibrosing dermopathy and scleromyxedema.

BACKGROUND: Nephrogenic fibrosing dermopathy (NFD) clinically presents as indurated plaques and papules in patients with renal dysfunction. The differential diagnosis generally includes scleromyxedema (SMX), an idiopathic systemic disorder with cutaneous manifestations, in which patients also develop indurated papules and plaques. The two entities can be extremely difficult to distinguish microscopically. Histopathologic differences with immunophenotypic comparison, to our knowledge, have not been thoroughly studied. We compared these two entities with an emphasis on immunohistochemistry. DESIGN: Nine biopsies diagnosed as NFD and seven biopsies diagnosed as SMX were retrospectively collected from the University of Pennsylvania Medical Center's surgical pathology and dermatopathology archives. Immunohistochemical staining for CD34, factor XIIIa, CD31, smooth muscle actin, CD68, and procollagen-I, as well as colloidal iron, were performed on each biopsy. Amount of expression for each of these markers, as well as degree of inflammation, for each biopsy was evaluated using a grading system of 0--3. RESULTS: Overall, NFD and SMX showed similar expression for all markers except procollagen-I, which showed increased expression in SMX. DISCUSSION: Although some immunophenotypic differences were found, our study did not demonstrate microscopic characteristics that can be easily used diagnostically to distinguish NFD from SMX. Clinical pathologic correlation is paramount in distinguishing these two entities. Kucher C, Xu X, Pasha T, Elenitsas R. Histopathologic comparison of nephrogenic fibrosing dermopathy and scleromyxedema.

Heparan sulphate proteoglycan in scleromyxedema promotes FGF-2 activity.

The cause of progressive dermal sclerosis, proliferation of fibroblasts, and collagen deposition in scleromyxedema is unknown. We analyzed the heparan sulphate proteoglycans (HSPG) in cutaneous nodules from a patient with scleromyxedema in order to ascertain their role in the binding of fibroblast growth factor (FGF) and promoting signaling complex assembly. Total heparan sulphate (HS) was detected with a monoclonal antibody to HSPG on paraffin sections. Binding of FGF to HS was assessed using FGF-2 followed by anti-FGF-2 antibody. The formation of HS-mediated signaling complex was studied using soluble FR1-AP, which contains the extracellular domain of FGF receptor-1 linked to alkaline phosphatase (AP) and monoclonal anti-AP-antibody. Anti FGF-2 and anti-AP antibodies were visualized using the DAKO Envision Plus system. The dermal nodule of scleromyxedema contained ample HS and these bound FGF-2 and FR1-AP. Specificity was confirmed by prior incubation with heparitinase (no staining) and omission of FGF-2 (no staining). Increased amounts of HSPG were present in the dermal nodules of scleromyxedema compared to adjacent normal dermis and these bound FGF-2, immobilized the soluble receptor protein FGFR-1 and, therefore, formed a ternary complex composed of HSPG, FGF-2 and FGFR-1 in vitro. Since this complex resembles the signaling complex formed on live cells, HSPG in the nodules of scleromyxedema are in a configuration that promotes FGF activity.

Evidence for thyrotropin receptor immunoreactivity in pretibial connective tissue from patients with thyroid-associated dermopathy.

Pretibial myxedema (PTM), mainly characterized by the accumulation of glycosaminoglycans in the dermis and subcutaneous tissue, is an extrathyroidal manifestation of autoimmune Graves' disease (GD), almost always associated with Graves' ophthalmopathy (GO). The thyrotropin receptor (TSH-R) has been proposed as the common target antigen in GD, GO and PTM, with evidence for receptor transcripts and/or protein in these locations. The aim of this study has been to investigate whether receptor protein is present in the pretibial tissues. Skin biopsies were obtained from two patients with PTM and two normal subjects without thyroid disease. A portion of each sample was fixed to produce semi-thin sections for Toluidine Blue or Periodic Acid Schiff (PAS) staining. The remainder was snap frozen to generate cryostat sections for immunohistochemical analysis using three monoclonal antibodies against TSH-R. In the skin from the two patients suffering from PTM, the dermis was infiltrated by inflammatory cells (lymphocytes, B cells, macrophages, mast cells) and adipocytes. The collagen fibers were dissociated by edema and by the accumulation of a PAS-positive material. Immunodetection of TSH-R produced positive staining on cells localized in the dermis, beneath the epidermis or close to the hypodermis. These cells were elongated and resembled fibroblasts. No immunoreactivity was observed in the dermis from control patients without thyroid disease. In conclusion, we have evidence for TSH-R immunoreactivity in the pretibium of patients with GD, GO and PTM. Further studies are needed to unambiguously identify the positive cells and determine whether the reactivity is due to the receptor itself or to a cross-reacting protein.

Myxedema coma of both primary and secondary origin, with non-classic presentation and extremely elevated creatine kinase.

Myxedema coma is a rare, often fatal endocrine emergency that concerns elderly patients with long-standing primary hypothyroidism; myxedema coma of central origin is exceedingly rare. Here, we report a 37-year-old woman in whom classical symptoms of hypothyroidism had been absent. Six years earlier, she had severe obstetric hemorrhage and, shortly after, two subsequent episodes of pericardial effusion. On the day of admission, pericardiocentesis was performed for the third episode of pericardial effusion. Because of the subsequent grave arrhythmias and unconsciousness, she was transferred to our ICU. Prior to the endocrine consultation, a silent myocardial infarction had been suspected, based on the extremely high serum levels of creatine kinase (CK) and isoenzyme CK-MB. However, based on thyroid sonography, pituitary computed tomography, elevated titers of antithyroid antibodies and pituitary stimulation tests, the final diagnosis was myxedema coma of dual origin: an atrophic variant of Hashimoto's thyroiditis and post-necrotic pituitary atrophy (Sheehan syndrome). Substitutive therapy caused a prompt clinical amelioration and normalization of CK levels. Our patient is the first case of myxedema coma of double etiology, and illustrates how its presentation deviates markedly from the one endocrinologists and physicians at ICU are prepared to encounter. In addition, cardiac problems as those of our patient should not discourage from substitutive treatment (using L-thyroxine and the gastrointestinal route of absorption), if the age is relatively low.

Fatal scleromyxedema: report of a case and review of the literature.

Scleromyxedema is a rare fibromucinous connective tissue that can be associated with systemic changes, such as myopathy, neurologic defects, esophageal dysmotility, paraproteinemia, and restrictive lung disease. We describe a fatal case of scleromyxedema in which neurologic, cardiac, gastrointestinal, and muscle changes were present. At autopsy, mucin was found in the papillary dermis of skin and in coronary and pulmonary vessels, but was absent from the brain, kidneys, heart, gastrointestinal tract, esophagus, liver, thyroid, lymph nodes, bone marrow, and pancreas. Because the pathogenesis of scleromyxedema may not always be attributable to mucin deposition, the role of circulating factors in the development of systemic manifestations warrants further investigation.

TSH receptor transcripts and TSH receptor-like immunoreactivity in orbital and pretibial fibroblasts of patients with Graves' ophthalmopathy and pretibial myxedema.

Several lines of experimental and clinical evidence favor a close etiologic link between Graves' disease and its associated extrathyroidal manifestations, ophthalmopathy and pretibial dermopathy. The human TSHR represents a candidate antigen shared between the thyroid gland and the involved extrathyroidal sites in Graves' disease. Here, we demonstrate that ribonucleic acid encoding exons 1-10 of human TSHR can be detected in fibroblasts derived from the affected orbital and pretibial space in patients with Graves' ophthalmopathy and pretibial dermopathy. RNA prepared from cultured fibroblasts was reverse transcribed and the resulting cDNA amplified by the polymerase chain reaction using primers spanning exons 1 through 10 of TSHR. The predicted transcripts (1890 and 2092 bp, respectively) were obtained with cDNA derived from orbital and pretibial fibroblasts of all patients with GO and PTM, and orbital fibroblasts of one healthy individual, and confirmed by southern hybridization. Sequencing of TSHR transcripts confirmed their identity with the reported nucleotide sequence of the human TSHR. Immunostaining using both monoclonal and polyclonal antibodies directed against the recombinant human TSHR revealed specific TSHR-like immunoreactivity in fibroblasts and adipose/connective tissue derived from the orbital and pretibial space of patients with GO and PTD, but not in normal individuals or control tissues. Detection, within the orbital and pretibial tissues, of RNA encoding nonvariant hTSHR and of immunoreactivity for this important autoantigen in Graves' disease suggests that the pathogenic role of the TSHR may extend beyond the thyroid gland, and may include the associated extrathyroidal manifestations.

Cloning and sequencing of complete thyrotropin receptor transcripts in pretibial fibroblast culture cells.

Pretibial fibroblasts are considered to be targets of autoimmune attack in pretibial myxedema. A possibility of the pathogenesis of pretibial myxedema is that T cells, reacting with thyrotropin (TSH) receptor, will be targeting to the pretibial fibroblasts where, in the presence of antigen (TSH receptor), they will secrete various cytokines and stimulate fibroblasts to secrete glycosaminoglycans. We have demonstrated that TSH and TSH receptor antibody can bind to fibroblasts and the presence of RNA encoding the extracellular domain of the TSH receptor in fibroblasts derived from skin lesions of two patients with pretibial myxedema. The present study was designed to determine whether there are complete TSH receptor transcripts in pretibial fibroblasts obtained from patients with pretibial myxedema. RNA was prepared from pretibial fibroblasts obtained from 11 patients with pretibial myxedema and from four normal subjects, then reverse-transcribed by polymerase chain reaction using three sets of primers (-11/+8 and +754/+773; +353/+373 and +1265/+1285; +1000/+1017 and +2284/+2301). The overlapped 2312 bp cDNA sequence was expected to contain the genetic sequences of the signal peptide (+1/+60), extracellular domain (+61/+1254), transmembrane domain (+1255/+2046), and cytoplasmic domain (+2047/ +2292) of the TSH receptor. The sequences were determined using dideoxy sequencing method. All of the 2312 nucleotide sequences in 15 samples were consistent with the reported TSH receptor sequence of transcripts in thyroid. These data suggest that the complete TSH receptor transcripts are very possible to be present in the fibroblasts derived from pretibial skin.

IgG, IgA and C3 deposits in the extra-thyroidal manifestations of autoimmune Graves' disease: their in vitro solubilization by intravenous immunoglobulin.

OBJECTIVE: To study the involvement of antibodies in the extrathyroidal manifestations of autoimmune Graves' disease, we determined the presence of IgG, IgA and IgM antibodies and C3c in connective tissue samples from patients with Graves' disease and pretibial myxedema (PTM) or thyroid associated ophthalmopathy (TAO). METHODS: Connective orbital tissue samples were obtained from 12 patients undergoing orbital decompression for TAO, and skin samples from lesions on the pretibial area were obtained in 7 patients with PTM. Sections from each tissue sample were stained with fluorescin-isothiocianate conjugated anti-human IgG, IgA, IgM and C3c and were examined by a fluorescence optical instrument. Other serial sections from each sample were incubated with human IgG solutions (concentration 6 mg/ml or 20 mg/ml), human albumin (40 mg/ml), PBS, myoglobin (40 mg/ml), or IgA (20 mg/ml), and were then processed by a standard direct immunofluorescence staining procedure. RESULTS: Among the samples from TAO patients 8/12 (67%) were positive for IgG deposition, 4/9 (44%) were positive for IgA, 1/9 (11%) was positive for IgM and 4/9 (44%) were positive for C3c deposition. Orbital connective samples from 3 non-TAO patients were all negative. Among samples from PTM patients 4/7 (57%) were positive for IgG deposition, 3/ 4 (75%) were positive for IgA, 0/4 was positive for IgM and 3/7 (43%) were positive for C3c deposition. Skin samples from 5 control patients undergoing skin biopsy for non-autoimmune diseases were all negative. Incubation with human IgG (20 mg/ml) resulted in the complete disappearance of IgG and C3c deposition in all positive patients. No significant variation in IgG fluorescent staining after incubation with either 6 mg/ml of IgG solution, human albumin, PBS, myoglobin or IgA was observed. CONCLUSION: The results of our study suggest that different classes of antibodies, mainly IgG and IgA, may be implicated in the disease process in autoimmune TAO and PTM. Activation of the complement cascade, via the classic or the alternative pathway, could take place in about 40% of these patients. IVIG in vitro may solubilize, by a specific mechanism, IgG and complement immune complex deposition in the extrathyroidal manifestations of autoimmune Grave's disease.

Histochemical study of cutaneous mucins in hypothyroid dogs.

A dermal mucinosis, visualized as dermal alcianophilic material, is occasionally present in canine hypothyroidism (myxedema). Various histochemical reactions (alcian blue/periodic acid-Schiff [PAS], alcian blue at pH 2.6, alcian blue at pH 1.0, critical electrolytical concentrations with and without dimethylsulfoxide, differential hydrolysis by hyaluronidases) were performed on skin biopsies from six dogs (four females and two males ranging from 8 to 13 years) affected by hypothyroidism, all of them presenting dermal mucinosis in hematoxylin and eosin-stained sections. In these dogs, the only polysaccharidic compound involved in the dermal mucinosis was hyaluronic acid. In this study, hyaluronic acid dermal deposits of hypothyroid dogs were significantly different from those of controls in subepidermal connective tissue and loose reticular connective tissue but not in periadnexal zones. We recommend the combined alcian blue/PAS reaction as a routine technique to assess dermal mucinosis in hypothyroid dogs.

Skin fibroblast activity in pretibial myxoedema and the effect of octreotide (Sandostatin) in vitro.

The accumulation of glycosaminoglycans in the skin in pretibial myxoedema appears to be a response by local fibroblasts to a stimulating factor in the patient's serum, but the identity of the factor, its ability to stimulate skin fibroblasts as opposed to cultured thyroid cells, and the specificity of its effect to pretibial skin fibroblasts, are all controversial. We have studied fibroblasts cultured from the lesional skin of two women with pretibial myxoedema, and compared their proliferation and secretion of glycosaminoglycans with those of fibroblasts from the patients' forearms and from the forearm skin of two normal subjects. We found that in the presence of the patients' sera all six lines of fibroblasts secreted more glycosaminoglycans [205 +/- 21% (SD)] than with normal human sera (147 +/- 19%), or fetal calf serum (100%). Fibroblast proliferation showed the same pattern of differences: patients' sera 142 +/- 22%; normal human sera 116 +/- 9%, and fetal calf serum 100%. These experiments confirm the presence of a serum factor in pretibial myxoedema which is capable of stimulating the activity of skin fibroblasts in vitro, and show that its effects are not restricted to fibroblasts from pretibial skin or to those grown from the skin of the patients. Proliferation of normal fibroblasts cultured in medium supplemented with fetal calf serum was reduced by Sandostatin (octreotide), but it failed to inhibit their secretion of glycosaminoglycans. In contrast, secretion of glycosaminoglycans by a patient's pretibial skin fibroblasts was almost completely inhibited by 1 mM minoxidil. In the presence of patients' sera Sandostatin (0.1-10 micrograms/ml) reduced secretion of glycosaminoglycans by about 50%.(ABSTRACT TRUNCATED AT 250 WORDS)

Thyrotropin stimulation of the lutropin/choriogonadotropin receptor: different sites mediate agonist activity and high affinity binding.

Surprisingly, thyrotropin (TSH) can increase cAMP and inositol phosphate (IP) levels in Cos-7 cells transfected with the lutropin (LH)/choriogonadotropin (CG) receptor (LH/CGR) as well as LH or CG, as evidenced by similar EC50 and maximal stimulation values. Additionally surprising, TSH activation is evident, despite markedly reduced levels of high affinity TSH binding by comparison to CG (Hidaka A, et al. 1993 Biochem Biophys Res Commun 196:187-195). In this report, we questioned whether the unusual TSH activity, as well as the discrepancy between TSH activity and binding, might reflect the existence of distinct agonist and binding sites on the LH/CGR extracellular domain and the ability of TSH to interact with the former despite a minimal interaction with the latter. We evaluated this possibility by using two chimeras spanning the extracellular domain of the TSHR and the LH/CGR:Mc1 + 2, where residues 8-165 of the TSHR are substituted, and Mc2 + 3 + 4, where residues 90-370 are replaced with the corresponding peptide segment from the LH/CGR. After transfection in Cos-7 cells, Mc2 + 3 + 4 exhibits higher affinity for CG than wild-type LH/CGR, but has no CG agonist response in assays measuring cAMP or inositol phosphate (IP) levels. Conversely, the Mc1 + 2 chimera exhibits significantly decreased affinity for CG, but CG agonist activity is comparable to wild-type LH/CGR in cAMP and IP assays. These data show that the extracellular domain of the LH/CGR does have distinct sites for CG binding and agonist activity: the C-terminus in Mc2 + 3 + 4 is important for high affinity CG binding, whereas the N-terminus in Mc1 + 2 is able to exhibit a CG agonist response, despite low affinity binding. When evaluated using TSH, Mc1 + 2, with the C-terminus of the TSHR present, exhibits high affinity TSH binding comparable to wild-type TSHR. Unexpectedly, Mc1 + 2, with the substitution of the N-terminus of the extracellular domain of the LH/CGR, exhibits even better TSH agonist activity than wild-type TSHR, not a loss of activity. Thus, the N-terminus of the extracellular domain of the LH/CGR can couple TSH binding to signal transduction events even better than the N-terminus of the TSHR. This may, in part, explain why TSH has an unusual agonist activity in cells transfected with LH/CGR, despite relatively low affinity binding. Although distinct agonist and binding sites exist in the linear sequence of the extracellular domain, the activity of the two sites is interdependent.(ABSTRACT TRUNCATED AT 400 WORDS)

Pentoxifylline inhibits the proliferation and glycosaminoglycan synthesis of cultured fibroblasts derived from patients with Graves' ophthalmopathy and pretibial myxoedema.

Excessive amounts of glycosaminoglycans accumulate in the extraocular muscles of patients with Graves' ophthalmopathy and in the affected skin of patients with pretibial myxoedema. It is widely accepted that fibroblasts are the sources of glycosaminoglycan synthesis. Pentoxifylline, an analogue of the methylxanthine theobromine, inhibits the proliferation and certain biosynthetic activities of fibroblasts derived from normal human skin and from skin of patients with some fibrotic disorders. Our objective was to determine whether pentoxifylline has similar effects on fibroblasts derived from patients with Graves' ophthalmopathy and pretibial myxoedema and could serve as a candidate for the treatment of these manifestations. Fibroblasts from the extraocular muscles of two patients with Graves' ophthalmopathy and normal extraocular muscles of two subjects with strabismus, as well as the affected skin of two patients with pretibial myxoedema were cultured in vitro in the presence and absence of pentoxifylline to assay its effect on the proliferation of fibroblasts and their production of glycosaminoglycans. In subconfluent fibroblast cultures, pentoxifylline treatment caused a dose-dependent inhibition of serum-driven fibroblast proliferation. In confluent fibroblast cultures both in the presence and absence of serum, exposure to pentoxifylline similarly resulted in a dose-dependent inhibition of glycosaminoglycan synthesis for all these different kinds of fibroblasts. These findings may form the rationale for a clinical trial using pentoxifylline for the treatment of Graves' ophthalmopathy and pretibial myxoedema.

Immunoglobulin G of patients with circumscribed pretibial myxedema of Graves' disease stimulates proteoglycan synthesis in human skin fibroblasts in culture.

Hyaluronic acid and proteoglycan accumulate in the affected skin of Graves' disease patients with pretibial myxedema (PTM). We aimed to determine whether an autoantibody IgG circulating in PTM patients stimulates proteoglycan synthesis in human skin fibroblasts, resulting in PTM. IgGs were purified from 14 normal subjects, 11 Graves' disease patients with PTM. 5 Graves' disease patients with active ophthalmopathy and 15 Graves' disease patients with neither PTM nor ophthalmopathy. Human skin fibroblasts were incubated with the IgGs and labeled with [35S]sulfate. The medium and cell layer were separated and the proteoglycan was extracted. The 35S radioactivity in the proteoglycan fraction was measured. Compared with normal IgGs or with those of Graves' disease without PTM or ophthalmopathy, PTM IgGs significantly increased the incorporation of the 35S into the proteoglycan. The effect of PTM IgG was dose-dependent. As PTM IgG did not alter degradation of the 35S labeled proteoglycan, an increase in 35S incorporation reflects increased synthesis. The effect was mediated through a mechanism other than adenylate cyclase activation. The present study demonstrates the presence of an autoantibody in PTM IgG that stimulates proteoglycan production through human skin fibroblasts. This is not correlated with the thyroid stimulating antibody activity. It is suggested that the activity of this antibody leads to the development of PTM.

Detection, cellular localization, and modulation of heat shock proteins in cultured fibroblasts from patients with extrathyroidal manifestations of Graves' disease.

We hypothesize that fibroblasts obtained from the retroocular space and the pretibial skin, sites affected by the peripheral manifestations of Graves' disease, share unique characteristics that may in part explain the site specificity of Graves' ophthalmopathy (GO) and pretibial myxedema (PTM). Heat shock proteins (HSPs), synthesized by cells undergoing stress, function to maintain cellular homeostasis and are probably involved in the intracellular processing and cell surface presentation of antigens. We investigated possible differences in the expression of 70-kDa HSPs between cultured fibroblasts obtained from patients with severe GO and normal individuals. In addition, we compared HSP expression in fibroblasts derived from tissues involved in the extrathyroidal manifestation of Graves' disease (GO and PTM) with that in fibroblasts from uninvolved tissues. HSPs were detected by both immunoblotting and indirect immunofluorescence, using monoclonal antibodies that are directed against HSP72, HSP72/73 (termed HSP70), and HSP90. HSP expression at baseline and after treatment with various cytokines and heat stress was examined. At baseline, HSP72 reactivity was exclusively detected in retroocular and pretibial fibroblasts from patients with severe GO and PTM, but was not observed in abdominal fibroblasts from these patients and was not detectable in fibroblasts from any anatomical site of normal individuals. The abundance of HSP70 expression at baseline and after treatment with certain cytokines was significantly greater in retroocular and pretibial fibroblasts from patients with GO than in normal individuals. In addition, characteristic changes in the cellular localization of HSPs before and after exposure to heat stress and cytokines were observed; cell surface expression of HSP70 was detected at baseline in fibroblasts from patients, but not in normal fibroblasts. These data provide the first evidence that HSPs are differentially expressed by fibroblasts derived from tissues affected by the extrathyroidal manifestations of GD. These proteins may have a role in localized immune processes, leading to the development of GO and PTM.

Responses of glucose and glucoregulatory hormones to exercise in thyrotoxic and myxoedematous patients before and after 3 months of treatment.

1. The effect of moderate endurance exercise on blood glucose concentration and on glucoregulatory hormones was studied in nine thyrotoxic and five myxoedematous humans before and 3 months after anti-thyroid and substitution therapy, respectively. 2. At rest, the fasting concentrations of insulin and pro-insulin correlated positively with the prevailing total tri-iodothyronine concentration, whereas the concentrations of noradrenaline and cortisol correlated inversely with the tri-iodothyronine concentration. 3. During exercise the plasma insulin, pro-insulin and C-peptide concentrations decreased. The plasma glucagon concentration increased slightly in thyrotoxic patients before and after treatment and was largely unchanged in myxoedematous patients in either state. 4. The plasma noradrenaline concentration increased before and after treatment in both groups, with concentrations two times higher in the myxoedematous than in the thyrotoxic patients. Treatment for 3 months did not change this pattern. The plasma adrenaline concentration increased in both groups, but in the untreated thyrotoxic patients the increase was two to three times greater than that after treatment or that in the myxoedematous group. 5. The blood glucose concentration decreased in eight of nine untreated thyrotoxic patients, but was largely unchanged after treatment or in the myxoedematous patients. A strong negative correlation was found between the decline in blood glucose concentration and the increase in plasma adrenaline concentration in the thyrotoxic group. 6. Thus, during exercise untreated thyrotoxic patients are prone to hypoglycaemia, show an inadequate glucagon response, and exhibit a large counter-regulatory increase in plasma adrenaline concentration.