Autoimmune mechanisms in antibiotic treatment-resistant lyme arthritis

In about 10% of patients with Lyme arthritis in the United States, joint inflammation persists for months or even several years after the apparent eradication of the spirochete, Borrelia burgdorferi, from the joint with antibiotic treatment. We propose a model of molecular mimicry affecting genetically susceptible individuals to explain this treatment-resistant course. The majority of patients with treatment-resistant Lyme arthritis have HLA-DRB1*0401 or related alleles, and the severity and duration of their arthritis correlate with cellular and humoral immune responses to outer-surface protein A OspA) of the spirochete. Using an algorithm, the immunodominant epitope of OspA presented by the DRB1*0401 molecule was predicted to be located at aa 165-173. In a search of the Genetics Computer Group gene bank, only one human protein was identified, lymphocyte function associated antigen-1 (hLFA-1), that had sequence homology with OspA(165-173)and predicted binding in the DRB1*0401 molecule. Synovial fluid T cells from most patients with treatment-resistant arthritis responded to both OspA and hLFA-1, whereas those from patients with other forms of chronic inflammatory arthritis did not. Molecular mimicry between a dominant T cell epitope of OspA and hLFA-1 may be an important factor in the persistence of joint inflammation in genetically susceptible patients with treatment-resistant Lyme arthritis.     

T lymphocytes in synovia of patients with rheumatoid arthritis

Conclusions The observation that rheumatoid synovial-derived lymphocytes display clonal dominance may have important implications in the understanding of the underlying pathogenic processes in RA. Isolation of the relevant T cell clones will allow further characterization including the development of anti-clonotypic mAb which could be used for diagnostic and possibly even for therapeutic purposes. Functional analysis of the clones could be used as an approach to identify the antigen(s) that trigger the disease.Our observations, however, raise a number of points. First, the detection of clonal dominance in a T cell population within a tissue or in blood has been considered a marker of malignancy [9, 13]. Recent studies of several skin diseases suggest that T cell oligoclonality observed in some of these lesions represents a selected repertoire of responding T cells; our study shows that T cell clonality is not restricted to lymphoproliferative diseases but may indeed be a feature of certain inflammatory processes as well.     

类风湿性关节炎患者T细胞亚群失衡与炎性粘附分子的关系

目的：探讨类风湿性关节炎（RA）患者细胞免疫调节功能异常与参与介导免疫炎性损伤的细胞粘附分子之间的关系。方法：以ELISA方法检测40例RA患者外周血中IL－2、IL－10、 sICAM-1、sVCAM-1水平。结果：RA患者TH1，细胞因子IL－2水平明显低于健康对照组；TH2细胞因子IL－10及细胞粘附分子sICAM-1/sVCAM-1水平明显高于健康对照组，各组间比较均具有显著性差异（P＜0．01）。结论：RA患者高水平的 IL－10与低水平的IL－2提示TH2细胞功能亢进，进而TH1细胞被抑制，并导致细胞因子谱的偏移；高水平的sICAM-1、sVCAM-1是RA患者慢性炎症损伤的重要介质；异常升高的IL－10与细胞粘附分子的共同作用是导致RA患者病理损伤的重要原因。     

Expression of adhesion molecules in allergic lung diseases

Endothelial adherence and migration of leukocytes into tissue is mediated by different sets of adhesion molecules. The expression of these sets might not only preselect the types of leukocytes that enter the inflammatory sites, but also activate these leukocytes, induce adherence to epithelial cells, and cause the release of cytokines. Atopic asthma, extrinsic allergic alveolitis, and sarcoidosis as examples of immunologic lung diseases were investigated for the expression of adhesion molecules. Bronchial biopsies in chronic obstructive lung disease (COPD) and resected lung tissue of juvenile emphysema were chosen for controls. Immunohistochemistry was done on sections from bronchial and transbronchial biopsies and on smears from bronchoalveolar lavage cells. In all three types of immune disorders, lymphocytes expressed the integrins alpha4/beta1 (VLA4) and ICAM3, whereas lymphocytes in COPD bronchitis and in emphysema controls were unreactive. Eosinophils in atopic asthma bronchitis in contrast to COPD bronchitis also expressed both VLA4 and ICAM3. The expression of VCAM1 on endothelial cells was only seen in atopic asthma and was related to disease activity. The expression of other adhesion molecules was nonspecific. Expression of VCAM1 on endothelial cells and its ligand VLA4 on lymphocytes and eosinophils seems to be a specific event in atopic asthma. Expression of VLA4 and ICAM3 on lymphocytes, however, might be a specific event in all three immune reactions.     

Expression of adhesion molecules in Langerhans' cell histiocytosis

Expression of adhesion molecules was investigated in six biopsy specimens of Langerhans' cell histiocytosis using immunocytochemistry. Cells with Langerhans' cell histiocytosis morphology were stained for ICAM-1, for the beta-1 integrins alpha-4 (VLA-4) and alpha-5 (VLA-5), and for the beta-2 integrins LFA-1, MAC-1 and p150,95. This pattern of reactivity was different from that of epidermal Langerhans' cells of the normal skin which were not immunostained. A variable number of CD68+ multinucleated giant cells was present in five biopsies. They were less reactive than the cells of Langerhans' cell histiocytosis for alpha-4 (VLA-4) and LFA-1, were positive for MAC-1 and p150,95 and were characterized by prominent expression of the beta-1 integrins alpha-2 (VLA-2), alpha-3 (VLA-3) and of VnR (alpha-v/ beta-3). The repertoire of adhesion molecules expressed by giant cells is indicative of profound cell-matrix interactions, whereas that of Langerhans' histiocytosis cells suggests particularly active cell–cell interactions. Blood vessels of the lesions were stained for beta-1 integrins, for vitronectin receptor and for molecules involved in adhesion and trans-endothelial migration of circulating leukocytes, such as ICAM-1, VCAM-1 and E-selectin. Additional findings were the observation of CD1a+ multinucleated giant cells in a single case, suggesting a possible lineage relationship with the histiocytosis cells, and the demonstration of some Ki-67+ Langerhans' cell histiocytosis cells and CD1a+ mitotic figures in four of six cases, indicating local proliferation of Langerhans' histiocytosis cells.     

Expression of adhesion molecules in leprosy lesions.

Leprosy presents as a clinical spectrum that is precisely paralleled by a spectrum of immunological reactivity. The disease provides a useful and accessible model, in this case in the skin, in which to study the dynamics of cellular immune responses to an infectious pathogen, including the role of adhesion molecules in those responses. In lesions characterized by strong delayed-type hypersensitivity against Mycobacterium leprae (tuberculoid, reversal reaction, and Mitsuda reaction), the overlying epidermis exhibited pronounced keratinocyte intracellular adhesion molecule 1 (ICAM-1) expression and contained lymphocytes expressing the ICAM-1 ligand, LFA-1. Conversely, in lesions in which delayed-type hypersensitivity was lacking (lepromatous), keratinocyte ICAM-1 expression was low and LFA-1+ lymphocytes were rare. Expression of these adhesion molecules on the cells within the dermal granulomas was equivalent throughout the spectrum of leprosy. The percentage of lymphocytes in these granulomas containing mRNA coding for gamma interferon and tumor necrosis factor alpha, synergistic regulators of ICAM-1 expression, paralleled epidermal ICAM-1 expression. In lesions of erythema nodosum leprosum, a reactional state of lepromatous leprosy thought to be due to immune complex deposition, keratinocyte ICAM-1 expression and gamma interferon mRNA+ cells were both prominent. Antibodies to LFA-1 and ICAM-1 blocked the response of both alpha beta and gamma delta T-cell clones in vitro to mycobacteria. Overall, the expression of adhesion molecules by immunocompetent epidermal cells, as well as the cytokines which regulate such expression, correlates with the outcome of the host response to infection.     

Expression of leukocyte adhesion molecules in human endometrium

In the present investigation the distribution of molecules that are involved in the leukocyte binding was studied in human endometrium. The expression of intercellular adhesion molecule-1 (ICAM-1), lymphocyte function-associated antigen (LFA-1), and HLA-DR molecules was studied in 13 proliferative and 10 secretory endometria as well as cultures of endometrial glands and stroma by avidin-biotin complex (ABC) procedure using monoclonal antibodies. The ICAM-1 and HLA-DR molecules were both strongly expressed in the lymphoid and endothelial cells. ICAM-1 expression was uniform in the epithelium, whereas the HLA-DR molecules were preferentially expressed in the epithelial cells in the basalis. Expression of both epithelial HLA-DR and ICAM-1 molecules was enhanced adjacent to lymphoid aggregates. ICAM-1 molecule was uniformly expressed in the stromal cells in the basalis and the functionalis, whereas the HLA-DR molecules were expressed exclusively in the stromal cells surrounding the lymphoid cells. ICAM-1 expression in the epithelial and stromal cells was confirmed in the isolated intact stromal cells and glands by immunohistochemistry. Although stromal and epithelial cells propagated in vitro expressed ICAM-1, they were rarely HLA-DR positive. The expression of LFA-1 was confined to the lymphoid cells. The high level of expression of ICAM-1, LFA-1, and HLA-DR molecules in human endometrial constituents may contribute to the presence, aggregation, and preferential distribution of lymphoid cells in human endometrium.     

Expression of adhesion molecules on infiltrating T cells in thyroid glands from patients with Graves' disease.

The present study was performed to elucidate the role of adhesion molecules in the pathogenesis of Graves' disease. Peripheral blood and intrathyroidal mononuclear cells were obtained from 14 patients with Graves' disease. The expression of adhesion molecules and HLA-DR antigen on CD4+ cells and CD4+ cell subpopulations was analysed by the two- or three-colour immunofluorescence method. The expression of adhesion molecules including LFA-1 alpha, LFA-1 beta, CD2, VLA-4 alpha and VLA-5 alpha on CD4+ cells in the thyroid gland was markedly higher than that in peripheral blood. In peripheral blood CD4+ cell subsets, the CD4+ CD45RO+ cell population had an enhanced expression of the adhesion molecules compared with the CD4+ CD45RA+ cell population. However, there was no significant difference in the expression of adhesion molecules by CD4+ cell populations and subsets between Graves' disease and healthy subjects. The thyroid gland from Graves' disease contained a higher percentage of CD4+ CD45RO+ cells and a lower percentage of CD4+ CD45RA+ cells. In intrathyroidal CD4+ cell subsets, the CD4+ CD45RO+ cell population had an increased expression of LFA-1 and CD2 compared with the CD4+ CD45RA+ cell population, but there was no significant difference in VLA-4 and VLA-5 expression between the two cell subsets. Furthermore, the expression of LFA-1 and CD2 on the CD4+ CD45RO+ cell population in the thyroid was significantly higher than that in matched peripheral blood. A similar finding was also observed for the CD4+ CD45RA+ cell population. The thyroid gland had an increased percentage of CD4+ HLA-DR+ cells compared with matched or healthy peripheral blood. However, there was no significant difference in the percentage of HLA-DR+ cells in the thyroid gland between CD4+ CD45RO+ cell and CD4+ CD45RA+ cell populations. These results suggest that increased expression of adhesion molecules on CD4+ cells may be responsible for the migration of these cells into thyroid glands and cellular interactions between these cells and thyroid epithelial cells.     

Expression of cadherin adhesion molecules on human gametes

The presence of cadherins, Ca(2+)-dependent cell-cell adhesion molecules which may be involved in gamete interaction, was investigated in human gametes. Expression of cadherin molecules was demonstrated using an anti-pan-cadherin antibody and specific antibodies against the three classical cadherins: E- (epithelial), P- (placental) and N- (neural) cadherins. Samples of 48 h old unfertilized oocytes and spermatozoa from in-vitro fertilizing semen samples were lysed and separated by electrophoresis. Localization of cadherins was determined on intact, fixed, permeabilized spermatozoa and oocytes by immunocytochemisty assessed by confocal microscopy. Immunoblotting with the pan-cadherin antibody revealed a single band of approximately 120 kDa in spermatozoa (whether 'fresh', capacitated, or frozen-thawed) and oocyte extracts. Oocytes presented all three classical cadherins with the appropriate molecular weights of 120-130 kDa. In sperm lysate we demonstrated the presence of E-cadherin but not N-cadherin. The anti-P antibody detected a 90 kDa peptide as the only immunoreactive antigen. Following immunocytochemistry of human oocytes all cadherin molecules were allocated predominantly to the plasma membrane with only traces in the cytoplasm. In spermatozoa, several staining patterns were observed with each of the pan-cadherin, N-cadherin and E-cadherin antibodies mostly confined to different head regions. We conclude that cadherin molecules are present on plasma membranes of both human spermatozoa and oocytes and may play a role in the intricate recognition process preceding gamete fusion.     

Induction of lyme arthritis in LSH hamsters.

In studies of experimental Lyme disease, a major obstacle has been the unavailability of a suitable animal model. We found that irradiated LSH/Ss Lak hamsters developed arthritis after injection of Borrelia burgdorferi in the hind paws. When nonirradiated hamsters were injected in the hind paws with B. burgdorferi, acute transient synovitis was present. A diffuse neutrophilic infiltrate involved the synovia and periarticular structures. The inflammation was associated with edema, hyperemia, and granulation tissue. Numerous spirochetes were seen in the synovial and subsynovial tissues. The histopathologic changes were enhanced in irradiated hamsters. The onset and duration of the induced swelling were dependent on the dose of radiation and the inoculum of spirochetes. Inoculation of irradiated hamsters with Formalin-killed spirochetes or medium in which B. burgdorferi had grown for 7 days failed to induce swelling. This animal model should prove useful for studies of the immune response to B. burgdorferi and the pathogenesis of Lyme arthritis.     

Expression of adhesion molecules in chronic serum sickness in rats

Peripheral blood leukocytes infiltrate the kidney in chronic serum sickness (CSS). We therefore studied the expression of CD54 and its ligands CD18 and CD11b/c in CSS in 10 rats with CSS, 6 rats immunized similarly who did not developed proteinuria (no-CSS group), and 10 normal rats (control group). Intense (6 to 35 times more than controls) leukocyte infiltration was observed in CSS. The CSS group over-expressed CD54 in glomeruli and interstitium in association with increments in CD18- and CD11b/c-positive cells ranging 2.5 to 7 times the number found in controls. 75% of infiltrating leukocytes expressed CD18 and 87% expressed CD11b/c. The non-CSS group had leukocyte infiltration and expression of adhesion molecules similar to control group. Adherence of CD43-positive cells to renal tissues was 4 times higher in renal tissue from CSS rats than to normal kidney. Pretreatment with corresponding Mabs reduced adherence by half. We concluded that over-expression of CD54 and its ligands CD18 and CD11b/c in infiltrating leukocytes occur in CSS. Binding experiments suggest the functional relevance of these molecules.     

Soluble endothelium-associated adhesion molecules in patients with Graves' disease.

The targeting and recruitment of inflammatory cells to vascular endothelium in Graves' disease (GD) is mediated by intercellular adhesion molecule-1 (ICAM-1), endothelial leucocyte adhesion molecule-1 (ELAM-1), and vascular cell adhesion molecule-1 (VCAM-1). We have studied serum levels of soluble ICAM-1 (sICAM-1), soluble ELAM-1 (sELAM-1), and soluble VCAM-1 (sVCAM-1) in patients with GD (n = 21) and in patients with iodine-deficient goitre (IDG) (n = 23). The serum levels of sICAM-1 were markedly elevated in patients with GD before treatment with thiamazole (median 560 ng/ml versus 185 ng/ml in patients with IDG). In addition, elevated serum concentrations of sELAM-1 (median 85 ng/ml versus 33 ng/ml, respectively) and sVCAM-1 (median 42 ng/ml versus 15 ng/ml, respectively) were observed in patients with GD (P < 0.01 for all). The serum levels of sELAM-1 and sVCAM-1 dropped significantly after initiation of therapy and were within the normal range after 4, and 8 weeks of therapy, respectively. Serum levels of sICAM-1 were elevated even after 8 weeks of therapy. Serum levels of sVACM-1 and sICAM-1 correlated with the serum concentrations of anti-thyroid-stimulating hormone (TSH)-receptor antibodies (TSHR-R) (n = 21; r = 0.929 and r = 0.810, respectively) and anti-thyroid peroxidase antibodies (TPO-Ab) (n = 21; r = 0.673 and r = 0.750, respectively). However, no correlation between sELAM-1 and TPO-Ab, TSHR-R, and anti-thyroglobulin antibodies (Tg-Ab), respectively, could be found. In addition to thyroid hormones and autoantibodies, serum concentrations of sELAM-1 and sVCAM-1, but not sICAM-1, could be useful as clinical markers for disease activity.     

Expression of adhesion molecules in endemic and epidemic Kaposi's sarcoma

Spindle cells and vascular endothelium in nodular lesions of AIDS associated (epidemic) and endemic Kaposi's sarcoma showed similar immunohistochemical patterns of expression for cell adhesion molecules and extracellular matrix proteins. Spindle cells as well as endothelium also expressed both α5 and αV integrin subunits and ICAM-1 suggesting a possible role for inflammatory cytokines in spindle cell formation. The spindle cell compartment was rich in collagen, laminin, fibronectin and tenascin suggesting an important reactive component in the evolution of Kaposi's sarcoma. The lack of thrombospondin expression in the spindle cells favours the contention that they could be transitional, proliferating cells of endothelial origin. Specific expression of tat protein was not seen suggesting minimal if any HIV replication in these lesions. Our findings suggest similar histopathogenetic mechanisms for endemic and epidemic Kaposi's sarcoma. The clinically more malignant features of most AIDS related cases may reflect an important effect of systemic and focal cytokines in HIV patients and possibly other cofactor(s), i. e. tat protein in the induction and growth of the lesions.     

神经细胞黏附分子在老年乳腺癌中表达的研究

目的:研究神经细胞黏附分子(neural cell adhesion molecules,NCAM)在乳腺肿瘤中的表达并讨论其临床意义。方法:选择老年(60~72岁)乳腺癌组织25例(神经侵袭的8例,无神经侵袭的17例)、癌旁组织25例,乳腺良性病变26例(乳腺纤维腺瘤16例,乳腺腺病4例,囊性乳腺病6例),用免疫组织化学方法检测NCAM在这些组织中的表达。用酶联免疫吸附法(ELISA)测定NCAM在乳腺癌、乳腺良性病病和正常对照(n=30,61~68岁)血清中含量。结果经统计学处理。结果:NCAM在部分乳腺癌细胞质和细胞膜呈宗黄色阳性表达,癌旁组织和良性病变表达很少。乳腺癌组、癌旁组及乳腺良性病变NCAM阳性率分别为28.0%(7/25),4.0%(1/25)和3.8%(1/26),腺癌组织明显高于癌旁组和乳腺良性病变(P0.05)。NCAM阳性表达在乳腺癌有神经侵袭病例阳性率50.0%(4/8)明显高于无神经侵袭病例23.5%(4/17,P0.05)。血清NCAM浓度(pg/ml)结果,乳腺癌(69.8±29.4)显著高于乳腺良性病变(16.7±6.3)和正常对照(14.9±3.1),具有明显统计学差异(P0.05)。结论:NCAM在老年乳腺癌有明显表达,且伴发神经侵袭和转移时表达更为明显,表明NCAM表达影响乳腺癌发生发展,这为临床防治老年乳腺癌提供重要的参考依据。     

Expression of adhesion molecules in human intestinal graft-versus-host disease.

The distribution of three cellular adhesion molecules, ICAM-1, ELAM-1 and VCAM-1, was studied in normal rectal mucosa and in graft-versus-host disease (GvHD) using immunohistological and morphometric techniques. In normal controls, ICAM-1 was demonstrable on endothelial cells and leucocytes within the lamina propria, ELAM-1 on endothelial cells only and VCAM-1 on lamina propria leucocytes, many of which exhibited long dendritic processes surrounding the glands. In GvHD, the enterocytes became positive for ICAM-1 and this was often associated with the presence of intra-epithelial LFA-1+ lymphocytes and macrophages, the latter containing debris of apoptotic cells. The staining was, however, restricted to the luminal membrane of the epithelial cells, raising doubts about the role of ICAM-1 as a ligand for LFA-1 on mucosal leucocytes in rectal GvHD. ELAM-1 expression was increased in GvHD both in terms of the length of positive endothelium and staining intensity. VACM-1 was increased on endothelial cells but not leucocytes in the lamina propria in contrast to our previous findings in cutaneous GvHD where VCAM-1+ dendritic cells were increased and endothelial cells remained negative. Normal patterns of adhesion molecule staining were seen in two biopsies exhibiting no morphological evidence of GvHD, from patients who had strong clinical evidence of the disease, indicating that immunostaining for these molecules is unlikely to be of help in improving the sensitivity of histological diagnosis. However, the possibility that adhesion molecule staining may be useful in improving diagnostic specificity by helping to distinguish GvHD from identical histological changes produced by irradiation and cytotoxic drugs is worthy of further investigation.     

Direct molecular typing of Borrelia burgdorferi sensu lato species in synovial samples from patients with lyme arthritis

Since Lyme arthritis was first described in the United States, it has now been reported in many countries of Europe. However, very few strains of the causative bacterium, Borrelia burgdorferi, have been isolated from synovial samples. For this reason, different molecular direct typing methods were developed recently to assess which species could be involved in Lyme arthritis in Europe. We developed a simple oligonucleotide typing method with PCR fragments from the flagellin gene of B. burgdorferi sensu lato, which is able to differentiate seven different Borrelia species. Among 10 consecutive PCR-positive patients with Lyme arthritis from the northeastern France, two species were identified in synovial samples: B. burgdorferi sensu stricto in 9 cases and B. garinii in 1 case. Conversely, all B. burgdorferi sensu lato species detected in 10 consecutive PCR-positive biopsies from a second set of patients with erythema migrans from the same geographical area were identified as either B. afzelii or B. garinii (P < 0.001). These results indicate that B. burgdorferi sensu stricto is the principal but not the only Borrelia species involved in Lyme arthritis in northeastern France.     

多种粘附分子基因在原发性肝癌的表达及其临床意义

目的:探讨多种粘附分子基因在原发性肝癌中的表达及其临床意义。方法:取64例用RT-PCR法半定量检测肝癌粘附分子的基因表达情况,分析其临床意义。结果:(1)原发性肝癌各粘附分子的表达率分别为:E-钙粘蛋白 90.62%、细胞间粘附分子-1 93.75%、粘附分子CD44 50.00%、粘附分子CD_44V 96.88%、整合素α₅ 100%、整合素β₁ 100%,CD44与其他粘附分子表达率的差异显著。(2)肝癌组织各粘附分子E-钙粘蛋白 、细胞间粘附分子-1 、粘附分子CD44、粘附分子CD_44V 、整合素α₅、整合素β₁ mRNA的表达量分别为:1.24±0.54、0.96±0.37、0.62±0.73、0.86±0.33、 0.97±0.49、1.41±0.24,其中粘附分子CD44与E-钙粘蛋白、整合素β₁的表达量差异显著。(3)肝癌分期与粘附分子基因mRNA表达量的关系显示:E-钙粘蛋白、粘附分子CD44的表达量随分期增高而下降,其中粘附分子CD44Ⅰ-Ⅱ期和Ⅳ期的表达量差别显著;细胞间粘附分子-1、粘附分子CD_44V,整合素α₅、整合素β₁的表达量随分期增高而增高,其中细胞间粘附分子-1Ⅰ-Ⅱ期和Ⅳ期的表达量差别显著。(4)肝癌粘附分子基因mRNA表达量与临床病理生理特点相关分析显示:肝癌粘附分子基因mRNA表达量与肿瘤大小、有无转移、有无包膜和结节数目有关,与AFP水平、肝硬化情况、肝功能状况无关。结论:肝癌粘附分子基因mRNA的表达存在明显的差异,粘附分子CD44表达缺失率高。肝癌粘附分子基因mRNA的表达与肿瘤大小、有无转移、结节数目、有无包膜相关。     

Expression of adhesion molecules and cytokeratin 20 in merkel cell carcinomas

Merkel cell carcinoma (MCC) is an aggressive neuroendocrine carcinoma of the skin. MCCs often show characteristic paranuclear dot-like immunopositivity for cytokeratin 20 (CK20), a globular aggregation of CK20 intermediate filaments. These aggregates typically form rhabdoid features and fibrous bodies and may be associated with a down-regulation in adhesion molecules (AMs). To date, the relationship between the expression of AMs and CK20 and clinicopathological findings in MCC has not been well examined. In this immunohistochemical study, we assessed the expression of AMs, CK20, and chromogranin A (CgA) on MCCs in 8 men and 23 women with this disease, and also characterized their clinicopathological features. This study is the largest of its kind that has been undertaken to date in Japanese patients. Compared to normal tissue, E-cadherin and α- and β-catenins showed reduced membranous expression in 95.7%, 46.7%, and 45.2% of MCCs, respectively. Nuclear E-cadherin localization was seen in four tumors, all of which predominantly showed a CK20 dot pattern. However, there was no significant relationship between the membranous expression of AMs and a CK20 dot pattern. E-cadherin expression was significantly lower in tumors of ≥2 cm, and tumors negative for E-cadherin more frequently developed outside of the head and neck than within those regions. CgA was more intensely expressed in tumors with uniform nuclei and a dense lymphocytic infiltrate than in those that showed pleomorphisms and that had few, if any, infiltrating lymphocytes. These findings suggest that MCCs have a reduced expression of AMs and that down-regulation of E-cadherin expression may correlate with increased tumor aggressiveness. The fact that no significant relationship was demonstrable between the membranous expression of AMs and the CK20 expression pattern suggests that the mechanism of aggregation of intermediate filaments may be different in different types of tumors.