Ultrastructural and immunological findings in Graves' disease with pretibial myxedema

Thyroid dermopathy and acropachy

Graves' disease is an autoimmune condition commonly associated with thyroid dysfunction and with anti-thyroid antibodies, usually TSH receptor stimulating antibodies. Thyroid autoimmunity also may be associated with extra thyroidal manifestations. Most common extra thyroidal manifestation is ophthalmopathy. Less common is thyroid dermopathy, usually occurring in pretibial area. Dermopathy is almost always associated with ophthalmopathy and in severe cases with acropachy. A common antigen with thyroid in tissues of the skin and the eyes, most likely TSH receptor, is involved in pathogenesis of extra thyroidal manifestations. Presence of dermopathy and acropachy are predictors of severity of autoimmune process. Local corticosteroid application is the standard therapy for dermopathy. Response to therapy is good in mild cases and poor in severe cases. Immune modulators and biotherapies are undergoing randomized trials for ophthalmopathy component of Graves' disease. Any therapy proven to be effective for ophthalmopathy can be utilized in future for management of dermopathy.

Multipoint subcutaneous injection of long-acting glucocorticid as a cure for pretibial myxedema

BACKGROUND

Pretibial myxedema (PM) is an uncommon and characteristic manifestation of Graves' disease (GD), with local autoimmune reaction in cutaneous tissue. The treatment of PM is a clinical challenge. We herein report a patient with PM who achieved complete remission by multipoint subcutaneous injection of long-acting glucocorticid.

SUMMARY

A 38-year-old man presented with an 18-month history of GD and a 1-year history of PM. Physical examination revealed mildly prominent eyes, diffuse enlargement of the thyroid gland, and PM of both lower extremities. The patient was treated with triamcinolone acetonide by multipoint subcutaneous injections in a combined dose of 20 mg in each lower extremity administered every 25-28 days. The injection was started from the borderline of the lesions and normal skin by selecting 4 to 5 points per leg for each course and then moving to other parts in subsequent courses of treatment. The depth of needle insertion was 0.5-1.0 cm. The patient's PM achieved complete remission in both lower extremities after an approximately 6-month period that included seven courses of treatment with a total dosage of 280 mg triamcinolone acetonide.

CONCLUSIONS

Our experience with this patient suggests that multipoint subcutaneous injection of long-acting glucocorticid is a safe, effective, and convenient treatment of PM in patients with GD.

Type I and type III collagens in cutaneous mucinosis

Cutaneous mucinoses are a heterogeneous group of diseases characterized by the focal or diffuse dermal deposition of glycosaminoglycans. The histopathologic examination of many cutaneous mucinoses reveals that the collagen fibers are fragmented. We wanted to characterize the type I (COL1) and type III (COL3) collagen distribution in skin biopsy specimens of patients with cutaneous mucinosis. The diagnosis of mucinosis was based on a modification of the classification by Rongioletti and Rebora: four patients had familial papulonodular mucinosis: four had papular mucinosis, one of which was associated with myxedema and one had scleromyxedema; and one had focal mucinosis. We performed anti-type I and type III collagens immunolabeling on frozen sections. Immunofluorescence for COL1 was increased in the superficial dermis of 2/4 familial papulonodular mucinosis, in 5/5 of papular mucinosis, and in scleromyxedema and focal mucinosis cases. The mid-dermis showed intense staining for COL1 at the periphery of collagen bundles and, in three cases of familial papulonodular mucinosis and two cases of papular mucinosis, a lacy appearance. The superficial dermis of familial papulonodular mucinosis specimens and of papular mucinosis + myxedema, scleromyxedema, and focal mucinosis specimens had decreased COL3 staining. The mid-dermis showed a more prominent fibrillar staining at the periphery of the collagen bundles, and two cases of papular mucinosis showed intense labeling for COL3. Both COL1 and COL3 distributions are altered in cutaneous mucinosis. An intense labeling with COL1 is predominantly found in the superficial layer of cutaneous mucinosis. Cases of FTP revealed decreased COL3 reactivity at the superficial layer.

Is Graves' dermopathy a generalized disorder?

The pathogenesis of the extrathyroidal manifestations of Graves' disease-ophthalmopathy and pretibial myxedema (Graves' dermopathy)-involves fibroblast activation and increased mucin (glycosaminoglycan) production. It is nuclear why fibroblasts are activated at these sites and evidence for site-specific and generalized fibroblast activation is conflicting. One previous report has demonstrated an increase in glycosaminoglycan deposition in the forearm skin of patients with Graves' disease but without pretibial myxedema. We have sought to confirm the existence of subclinical dermopathy in the forearm tissue from patients with untreated (UG) and treated (TG) Graves' disease and compared the histological changes with normal controls (C), treated toxic nodular goiter (MNG) and Graves' dermopathy specimens (PTM), using stains for mucin, elastin, glycosaminoglycans (GAGs), and HLA-DR molecules. Four of 4 PTM specimens stained positive for mucin, with varying sparse, fragmented, or dense elastin fibers. Four of 5 PTM specimens stained heavily for GAGs using colloidal iron and 2 of 5 stained heavily using colloidal gold. None of the patients in groups UG, TG, MNG, or the controls, showed mucin deposition or elastin changes. Mild staining with colloidal gold for GAGs was seen in 1 each of the UG, the TG, and MNG groups, and 4 of 8 controls. Heavy staining with colloidal iron for GAGs was seen in 1 TG patient and 1 control, while moderate staining was found in several TG, UG, and controls. In 2 of 4 PTM specimens the monoclonal antibody CR3/43 (against HLA-DR) stained frequent dermal fibroblast-like cells and in 2 a lymphocytic infiltrate was seen. Only 1 of 8 UG patients had multiple CR3/43 staining cells present in the dermis: 3 of 8 TG and 1 of 8 controls had a few CR3/43 stained cells. Overall we found no evidence of dermal mucin deposition in the forearms of 16 patients with Graves' disease and a similar GAG distribution to normal controls. HLA-DR expression by fibroblast-like cells in the dermis suggests activation of these cells in the dermis of the PTM specimens, but no evidence of widespread fibroblast activation was found in the forearms of patients with Graves' disease.

Analysis of T-cell antigen receptor variable region gene usage in patients with thyroid-related pretibial dermopathy

It is unknown whether T cells infiltrating the pretibial skin of patients with thyroid-related pretibial dermopathy represent a primary immune response or participate in a nonspecific inflammatory process. To characterize these T cells at the molecular level, we examined the T-cell antigen receptor variable region gene usage in pretibial skin biopsy specimens obtained from patients with early and late stages of pretibial dermopathy and from individuals with unrelated inflammatory conditions of the pretibial skin. RNA extracted from pretibial biopsy specimens and peripheral blood lymphocytes was reverse transcribed and amplified with the polymerase chain reaction and 22 V alpha and 23 V beta gene-specific oligonucleotide primers. The resulting T-cell receptor (TcR) V alpha and V beta transcripts were verified by Southern hybridization analysis using TcR C-region-specific, digoxigenin-labeled oligonucleotide probes. Compared with matched peripheral blood lymphocytes, the pretibial TcR V alpha and V beta gene repertoire expressed was heterogeneous but revealed marked restriction of V alpha and V beta gene usage in samples derived from patients with active inflammatory pretibial dermopathy of recent onset. In contrast, greater diversity of the TcR V alpha gene repertoire and loss of TcR V beta gene restriction were noted in patients with long-standing, clinically inactive pretibial dermopathy. TcR V gene usage in pretibial tissue and peripheral blood lymphocyte samples obtained from control subjects was unrestricted. Limited variability of TcR V gene usage in early pretibial dermopathy may reflect a primary immune response of antigen-specific T lymphocytes infiltrating the pretibial skin in thyroid-related pretibial dermopathy.

Lower extremity manifestations of Graves' disease

Pretibial myxedema (not to be confused with myxedema suggestive of hypothyroidism) is one of the extrathyroidal manifestations observed in some patients with Graves' disease. Graves' disease is commonly described as a disease that consists of one or more of the following characteristics: goiter, exophthalamos, acropachy, and pretibial myxedema. In order to facilitate a better understanding of the pathology and etiology of pretibial myxedema, a review of current research focusing on the immunological basis of Graves' disease is presented. An examination of the signs, symptoms, diagnosis, treatment, and differential diagnosis is also presented, as well as a case study that demonstrates Graves' disease and its extrathyroidal manifestations and complications.

Interferon gamma regulation of de novo protein synthesis in human dermal fibroblasts in culture is anatomic site dependent

The propensity of the skin of the lower anterior leg to be involved in Graves' dermopathy prompted an examination of the specific protein synthesis and response to interferon gamma in cultured fibroblasts from this area. Confluent cultures from normal skin of the lower leg and from the abdomen of the same three donors were pulse labeled with [35S]methionine for 3 h and subjected to two-dimensional protein gel electrophoresis and fluorography. Protein spots were mapped using a computer-driven program and the relative densities of the resolvable spots analyzed. Fibroblasts from the two anatomic sites display distinct patterns of de novo protein synthesis. Of the 157 abundant spots arbitrarily chosen for analysis, 31% varied substantially in levels of expression between the sites. A number of proteins appear to be expressed only in cultures derived from one of the two anatomic sites. Interferon gamma (100 U/ml) present in the culture medium for 48 h influenced the abundance of a number of proteins in a site-specific manner. Among them, plasminogen activator inhibitor type-1 was induced three to five times in the leg cultures, whereas this same polypeptide was down-regulated in abdominal fibroblasts. A 54-kD protein was induced in interferon-treated cultures from both sites at least 50 times. It appears that fibroblasts from different regions of the integument are intrinsically distinct in terms of both their protein synthetic programs and their responses to cytokines.

Analysis of fibroblast-stimulating activity in IgG from patients with Graves' dermopathy

Conflicting results have been reported on the effect of IgGs from patients with Graves' dermopathy on dermal fibroblast function. We have analyzed 14 dermopathy IgGs prepared by protein G affinity chromatography. These caused FRTL-5 thyroid cells to synthesize significantly greater amounts of glycosaminoglycans (GAG) and protein than IgGs from normal controls (p < 0.05). [3H]Thymidine incorporation was also significantly increased (p < 0.05) and there was a significant correlation between all three parameters and the ability of these IgGs to stimulate iodide incorporation (p < 0.001). Dermopathy and control IgGs caused a modest increase in GAG synthesis by dermal fibroblasts but there was no significant difference between the two types of IgG. Increased GAG production was detectable in both culture medium and the extracellular matrix, and there was no difference between fibroblasts derived from the arm and leg. Conditioned medium from thyroid cells treated with dermopathy or control IgGs caused a greater increase in GAG production than the IgGs alone, but again there was no difference between the two sources of IgG. Neither control nor dermopathy IgG affected fibroblast protein synthesis or [3H]thymidine incorporation. Our results argue against a role for circulating IgGs in mediating Graves' dermopathy and make it unlikely that the TSH receptor antibodies are acting directly on a functional receptor expressed by dermal fibroblasts in this disorder.

Graves' immunoglobulins and cytokines stimulate the expression of intercellular adhesion molecule-1 (ICAM-1) in cultured Graves' orbital fibroblasts

Intercellular adhesion molecule-1 (ICAM-1) and lymphocyte function-asociated antigen-1 (LFA-1) are cell surface adhesion receptors that bind to one another and promote a variety of effector/target cell interactions in tissues affected by inflammatory or immune processes. Local infiltration of the thyroid gland and the retro-ocular space by mononuclear cells is a hallmark of Graves' disease and Graves' ophthalmopathy (GO). Thus, we studied the role of these adhesion receptors in the interaction of inflammatory cells with retro-ocular fibroblasts (OF) derived from patients undergoing transantral decompression for severe GO, and from normal individuals. Confluent OF-monolayers were incubated with various cytokines or protein-A affinity-purified IgGs prepared from sera of patients with severe GO, Hashimoto's thyroiditis (HT), rheumatoid arthritis (RA) and normal individuals. As determined by immunocytochemistry and immunoprecipitation using a monoclonal anti-ICAM-1 antibody, interleukin-1-alpha (IL-1a), tumour necrosis factor-alpha (TNFa) and interferon-gamma (IFNg) strongly enhanced surface expression of ICAM-1 in both GO- and normal OF. By contrast, Graves' IgGs stimulated ICAM-1 expression only in GO-, but not in normal OF. No effect was observed in either cell type with interleukin-2, transforming growth factor-beta, or IgGs from patients with HT, RA and normal individuals. Using phorbol ester-activated, 51Cr-labelled peripheral blood mononuclear cells (PBMCs) in a cell adhesion assay, we demonstrated potent adhesive activity of ICAM-1 in GO-OF pretreated with IL-1a, TNFa, IFNg or Graves' IgGs, while all other compounds did not affect PBMC adhesion to GO-OF.(ABSTRACT TRUNCATED AT 250 WORDS)

Ultrastructural signs of altered intracellular metabolism in acral persistent papular mucinosis

An asymptomatic 24-year-old woman presented with multiple discrete papules on the extensor surfaces of the hands and wrists. Light microscopy revealed focal increase in the amount of dermal fibroblasts as well as deposition of hyaluronidase-labile mucoid substance. The collagen and elastin were decreased. The changes were consistent with acral persistent papular mucinosis (APPM). In electron microscopy, the intercellular glycosaminoglycans showed small ruthenium red-positive granules and thin filaments indicating normal morphology. The fibroblastic cells, however, were conspicuously altered. Endoplasmic reticulum was dilated, cytoplasm contained large amounts of osmiophilic, concentric lysosomal structures, and there was distinct fibrous lamina in the nuclear membrane. It was concluded that the primary event in APPM probably affects the intracellular metabolism of the dermal fibroblast. The accumulation of lysosomal structures may be a distinct feature of APPM differentiating it from the other reactive cutaneous mucinoses, or it may only reflect nonspecific degeneration in a long-standing lesion.

Localized myxedema on the nasal dorsum in a patient with Graves' disease: report of a case

We report the case of a 56-year-old Japanese female with Graves' disease associated with localized myxedema on the nasal dorsum. The patient developed localized myxedema concomitantly with hyperthyroidism before antithyroid therapy was given. The lesion was totally removed surgically, as it was small and well circumscribed. Although unusual locations of localized myxedema have been reported elsewhere, there is to date no case of localized myxedema on the nasal dorsum without involvement of the pretibial area reported in the literature. We discuss this unique feature of our patient.

Elephantiasis-like appearance of upper and lower extremities in Graves' dermopathy

Graves' dermopathy, affecting upper as well as lower extremities, is reported in a 50-year-old male patient addicted to multiple narcotic drugs. The narcotic drug administration routes include subcutaneous and intravenous injection in all limbs over a period of 29 years. The combination of drug injection trauma and Graves' dermopathy produced elephantiasis-like appearance of upper and lower limbs with impairment of their function; the left hand required amputation. Other features of Graves' disease, ie, hyperthyroidism and ophthalmopathy were severe and required multiple modes of therapy. Although the pathogenesis of Graves' dermopathy is unclear, it is surmised that trauma to skin might exacerbate it and preventive measures for trauma might be helpful in the management of dermopathy.

An ultrastructural study of pretibial myxedema utilizing improved ruthenium red stain

A case of pretibial myxedema associated with Graves' diseases has been studied by electron microscopy utilizing an improved ruthenium red stain. An organized network of microfibrils with knobs were found within the widened interfibrous spaces. This network was clearly demonstrated by the ruthenium red stain, but only a weak trace could be observed when conventional staining techniques were utilized. Knobs of the network seemed to be composed of ruthenium red-positive granules which surrounded normal fibers and granules of degrading collagen fibers. Many fibroblasts showed dilated rough endoplasmic reticulum containing much amorphous material which indicated a significant role of fibroblasts in the pathogenesis of this disease.