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Lymphocytic Infiltration (lymphocytic + infiltration)
Selected AbstractsLymphocytic infiltration (Jessner,Kanof): lupus erythematosus tumidus or a manifestation of borreliosis?BRITISH JOURNAL OF DERMATOLOGY, Issue 2 2007M. Kaatz No abstract is available for this article. [source] Beta2-microglobulin mutations in microsatellite unstable colorectal tumorsINTERNATIONAL JOURNAL OF CANCER, Issue 2 2007Matthias Kloor Abstract Defects of DNA mismatch repair (MMR) cause the high level microsatellite instability (MSI-H) phenotype. MSI-H cancers may develop either sporadically or in the context of the hereditary nonpolyposis colorectal cancer (HNPCC) syndrome that is caused by germline mutations of MMR genes. In colorectal cancer (CRC), MSI-H is characterized by a dense lymphocytic infiltration, reflecting a high immunogenicity of these cancers. As a consequence of immunoselection, MSI-H CRCs frequently display a loss of human leukocyte antigen (HLA) class I antigen presentation caused by mutations of the ,2 -microglobulin (,2m) gene. To examine the implications of ,2m mutations during MSI-H colorectal tumor development, we analyzed the prevalence of ,2m mutations in MSI-H colorectal adenomas (n = 38) and carcinomas (n = 104) of different stages. Mutations were observed in 6/38 (15.8%) MSI-H adenomas and 29/104 (27.9%) MSI-H CRCs. A higher frequency of ,2m mutations was observed in MSI-H CRC patients with germline mutations of MMR genes MLH1 or MSH2 (36.4%) compared with patients without germline mutations (15.4%). The high frequency of ,2m mutations in HNPCC-associated MSI-H CRCs is in line with the hypothesis that immunoselection may be particularly pronounced in HNPCC patients with inherited predisposition to develop MSI-H cancers. ,2m mutations were positively related to stage in tumors without distant metastases (UICC I-III), suggesting that loss of ,2m expression may promote local progression of colorectal MSI-H tumors. However, no ,2m mutations were observed in metastasized CRCs (UICC stage IV, p = 0.04). These results suggest that functional ,2m may be necessary for distant metastasis formation in CRC patients. © 2007 Wiley-Liss, Inc. [source] Effect of IL-2-Bax, a novel interleukin-2-receptor-targeted chimeric protein, on bleomycin lung injury,INTERNATIONAL JOURNAL OF EXPERIMENTAL PATHOLOGY, Issue 5 2005Michael J. Segel Summary The role of lymphocytes in the pathogenesis of lung fibrosis is not clear, but the weight of the evidence supports a pro-fibrotic effect for lymphocytes. The high-affinity interleukin-2 receptor (haIL-2R) is expressed on activated, but not quiescent, T lymphocytes. This selective expression of haIL-2R provides the basis for therapeutic strategies that target IL-2R-expressing cells. We hypothesized that elimination of activated lymphocytes by IL-2R-targeted chimeric proteins might ameliorate lung fibrosis. We investigated the effects of IL-2-Bax, a novel apoptosis-inducing IL-2R-targeted chimeric protein, on bleomycin-induced lung injury in mice. Treatment groups included (i) a single intratracheal instillation of bleomycin and twice-daily intraperitoneal injections of IL-2-Bax; (ii) intratracheal bleomycin and intraperitoneal IL-2-PE664Glu, an older-generation chimeric protein; (iii) intratracheal bleomycin/intraperitoneal PBS; (iv) intratracheal saline/intraperitoneal PBS. Lung injury was evaluated 14 days after intratracheal instillation by cell count in bronchoalveolar lavage (BAL) fluid, semi-quantitative and quantitative histomorphological measurements and by biochemical analysis of lung hydroxyproline. Bleomycin induced a BAL lymphocytosis that was significantly attenuated by IL-2-Bax and IL-2-PE664Glu. However, morphometric parameters and lung hydroxyproline were unaffected by the chimeric proteins. These results show that IL-2-Bax reduces the lymphocytic infiltration of the lungs in response to bleomycin, but this effect is not accompanied by a decrease in lung fibrosis. [source] Cutaneous marginal zone B-cell lymphoma in the setting of fluoxetine therapy: a hypothesis regarding pathogenesis based on in vitro suppression of T-cell-proliferative responseJOURNAL OF CUTANEOUS PATHOLOGY, Issue 7 2006Thomas S. Breza Jr Introduction:, Drugs may be an important cause of atypical lymphocytic infiltration. Oftentimes, these infiltrates are in the context of pseudolymphomata. We report a patient who developed lymphocytoma cutis temporally associated with initiation of fluoxetine therapy that later went on to develop cutaneous marginal zone B-cell lymphoma. The response of peripheral blood lymphocytes to fluoxetine and other drugs was examined in an attempt to ascertain the potential role for drugs in the propagation of these infiltrates. Materials and Methods:, Routine light microscopic analysis and phenotypic studies were performed on tissue obtained from a skin biopsy. Lymphocyte mitogenic studies were carried out using increasing concentrations of fluoxetine, bupropion, and two anticonvulsants. Results:, An initial biopsy was consistent with lymphocytoma cutis. The patient stopped fluoxetine associated with lesional regression. The lesions recurred despite being off fluoxetine; a repeat biopsy was compatible with marginal zone lymphoma. Lymphocyte proliferation assays revealed a suppressive effect on T-lymphocyte proliferation at physiologic concentrations. Other tested drugs did not have a similar suppressive effect. Conclusion:, Fluoxetine may be associated with pseudolymphomata and marginal zone lymphoma. The inhibitory effects on T-lymphocyte function and more specifically T-suppressor function may lead to excessive antigen-driven B-cell proliferation. [source] Merkel cell carcinoma: a clinicopathologic study with prognostic implicationsJOURNAL OF CUTANEOUS PATHOLOGY, Issue 3 2004Ryan T. Mott Background:, Merkel cell carcinoma (MCC) is a frequently aggressive neuroendocrine malignancy of the skin that presents in sun-exposed areas on elderly patients. Although originally described over 30 years ago, many aspects of MCC remain to be defined. Of particular importance is the need to identify prognostic factors capable of predicting the biological behavior of these tumors. Knowledge of these factors may help in determining which patients require more aggressive treatment regimens. In this study, we examined 25 cases of MCC with an attempt to identify clinical, histopathological, or immunohistochemical features capable of predicting disease outcome. Methods:, Features that we evaluated in each case included age, gender, race, tumor location, tumor size, depth of invasion, growth pattern, lymphocytic infiltration, mitotic activity, ulceration, necrosis, vascular invasion, and perineural invasion. In addition, we examined neural cell adhesion molecule and cytokeratin-20 expression using immunohistochemical methods. Results:, We found that most patients were males (84%) with an average age of 74 years. The tumors were located on the head and neck (68%) and upper extremities (32%). Overall, 64% of the patients developed metastatic disease to regional lymph nodes or distant sites (average follow-up time of 21 months). Local recurrence was also common, occurring in 29% of the patients. The overall 1- and 2-year survival rates were 80 and 53%, respectively. Histopathological examination revealed tumors with an average size of 7.2 mm. Common features included invasion into the subcutaneous adipose tissue, solid growth pattern, tumor necrosis, and vascular and perineural invasion. Findings that had a statistically significant correlation with poor outcome included tumor size ,5 mm (p = 0.047), invasion into the subcutaneous adipose tissue (p = 0.005), diffuse growth pattern (p = 0.040), and heavy lymphocytic infiltration (p = 0.017). The remaining findings, including the immunohistochemical results, did not correlate with disease outcome. Using logistic regression models, we show that depth of invasion and degree of lymphocytic infiltration are strong predictors of disease outcome. Conclusions:, The current controversies regarding the treatment of early-stage MCC (i.e., localized disease) underscore the importance of identifying clinicopathological features capable of predicting tumor behavior. In this study, we have identified several prognostic features in MCC. Perhaps, these features may prove useful in identifying patients who require more aggressive treatment regimens. [source] Focal lymphocytic infiltration in aging human palatal salivary glands: a comparative study with labial salivary glandsJOURNAL OF ORAL PATHOLOGY & MEDICINE, Issue 1 2001Marilena Vered Abstract: Investigation of age-related prevalence of various types of focal lymphocytic infiltration (FLI) and degrees of histomorphologic changes was conducted on 120 biopsies of palatal and labial salivary glands (PSG and LSG, respectively) obtained from autopsy subjects free of salivary gland tumors/diseases. Biopsies were divided into young (<30 years, n=30), adult (30,60 years, n=45) and old (>60 years, n=45) age groups. A modified Chisholm & Mason grading system was used to record grades of FLI and a modified Greenspan et al. system was used to evaluate the severity of histomorphologic changes. The prevalence of FLI in PSG increased significantly from 10% in the young group to 46.6% in the old group (P=0.0012). No significant changes were found with aging in LSG. FLI was significantly more prevalent in the adult and old age groups in PSG as compared with LSG (P=0.015 and P=0.003, respectively). Both glands demonstrated significant histomorphologic changes among age groups (p<0.0001); however, these changes were significantly less common in the old age group in PSG as compared to LSG (P=0.003). In cases showing severe histomorphologic changes, FLI was not present. Therefore, FLI should not be considered as part of the deteriorating histomorphologic changes that are usually encountered in salivary glands with aging. The immunologic profile of these infiltrates should be further clarified to understand their role, both in physiologic and pathologic conditions. [source] Pulsed-dye laser treatment of Jessner lymphocytic infiltration of the skinJOURNAL OF THE EUROPEAN ACADEMY OF DERMATOLOGY & VENEREOLOGY, Issue 5 2009J Borges da Costa [source] Primary Gougerot,Sjögren syndrome: a dermatological approachJOURNAL OF THE EUROPEAN ACADEMY OF DERMATOLOGY & VENEREOLOGY, Issue 3 2006A-M Roguedas Abstract Gougerot,Sjögren syndrome (GSS) is a chronic heterogeneous non-organ-specific autoimmune disease, encompassing a wide spectrum of clinical manifestations. It is characterized by a lymphocytic infiltration of the exocrine glands, also called epitheliitis, resulting in xerostomia and keratoconjunctivitis sicca. The skin can also be involved; for example, xerosis is a consequence of epitheliitis. Dermatological consequences of polyclonal reactivity are vasculitis and manifestations of B-cell proliferation vary from plasma cell infiltrates to B-cell lymphoma. [source] An autopsy case of Fabry disease with neuropathological investigation of the pathogenesis of associated dementiaNEUROPATHOLOGY, Issue 5 2008Riki Okeda The pathogenesis of dementia associated with Fabry disease was examined neuropathologically in an autopsy case. The patient was a 47-year-old computer programmer who developed renal failure at the age of 36, necessitating peritoneal dialysis, and thereafter suffered in succession episodic pulmonary congestion, bradyacusia, heart failure, and dementia, before dying of acute myocardial infarction. MRI of the brain demonstrated leuko-araiosis. The CNS parenchyma showed widespread segmental hydropic swelling of axons in the bilateral cerebral and cerebellar deep white matter in addition to neuronal ballooning due to glycolipid storage in a few restricted nuclei and multiple tiny lacunae. Hydropic axonal swelling was also sparsely distributed in the pyramidal tract, pedunculus cerebellaris superior and brachium colliculi inferioris, but wallerian degeneration of these tracts was absent. Additional features included angiopathy of the subarachnoidal arteries due to Fabry disease, such as medial thickening resulting from glycolipid deposition in smooth muscle cells (SMCs) and adventitial fibrosis with lymphocytic infiltration, together with widespread subtotal or total replacement of medial SMCs by fibrosis, associated with prominent intimal fibrous thickening and undulation of the internal elastic membrane of medium-sized (1000,100 ,m diameter) arteries. The findings in this case suggest that axonopathic leukoencephalopathy due to multisegmental hydropic swelling of axons in the bilateral cerebral deep white matter is responsible for the dementia associated with Fabry disease, and may be caused by ischemia resulting from widespread narrowing and stiffening of medium-sized subarachnoidal arteries and progressive heart failure. [source] Disseminated intraparenchymal microgranulomas in the brainstem in central nervous system sarcoidosisNEUROPATHOLOGY, Issue 4 2005Makoto Nishie We report a 70-year-old woman with sarcoidosis and multiple cranial nerve palsy. The patient suffered from dysarthria, dysphagia and weakness of the upper and lower extremities and died of sepsis. No abnormalities were noted in brain MRI. At autopsy, numerous epithelioid granulomas with Langhans giant cells were present in the bilateral lungs, including the hilar lymph nodes. The brain had a normal external appearance. Histologically, there were brainstem parenchymal lesions consisting of many microgranulomas, lymphocytic infiltration, activated microglias and astrocytosis. Perivascular lympocytic cuffing was also seen. Neither granulomas nor lymphocytic infiltration were seen in the leptomeninges. The present case was considered to be a peculiar type of neurosarcoidosis, that is, "sarcoid brainstem encephalitis". [source] Peculiar venous lesions in fatal hyponatremic brain edemaNEUROPATHOLOGY, Issue 1 2005Makoto Nishie A 19-year-old woman with a 3-year history of schizophrenia suddenly began to vomit, and rapidly developed a coma an hour after the onset of vomiting. A brain CT scan showed diffuse brain edema with compression of the ventricles. Laboratory tests showed a low serum sodium concentration of 117 mmol/L. She died 67 h after the onset of the first symptom. A postmortem examination showed diffuse swelling of the brain with bilateral uncal and tonsillar herniations. Histologically, no necrotic, hemorrhagic or encephalitic changes were seen. However, microvacuolar changes with lymphocytic infiltration were found in the venous walls (media and adventitia) mainly in the basal ganglia, thalamus and brainstem. To our knowledge, this is the first demonstration of venous alterations in fatal hyponatremic brain edema. These changes may have participated in the exacerbation of the brain edema due to functional disturbance of venous drainage. [source] Hepatitic pattern of graft versus host disease in childrenPEDIATRIC BLOOD & CANCER, Issue 5 2007Héctor Melín-Aldana MD Abstract Background Liver involvement by graft-versus-host disease (GVHD) is characterized histologically by bile duct damage, which may be severe. A different pattern, "hepatitic GVHD," has been described in adult patients. This pattern also shows marked lobular hepatitis and hepatocellular damage. We report the development of hepatitic GVHD in six pediatric patients. Procedure Clinical information and histologic features of liver biopsy samples were retrospectively reviewed. Results Patients' ages ranged from 3 to 11 years. Underlying diagnosis, pre-transplant conditioning and GVHD prophylaxis varied. Peripheral blood stem cells were the source of the allograft in four patients, matched sibling in one, and matched-unrelated donor in one. Hepatic GVHD was detected between 149 and 310 days post-transplant. Prior acute GVHD had developed in two patients, and involved the skin and/or gastrointestinal tract. No patients had significant ductopenia. Only one patient had significant lymphocytic infiltration of bile ducts (ductitis). Bile duct epithelial damage and significant portal/periportal inflammation were present in all patients. Lobular necro-inflammation was present in five patients. Five patients improved with immunosuppression and one died with progressive GVHD. Conclusions This series focuses on hepatitic GVHD in pediatric patients. Clinical and histologic patterns are similar to what has been described in adults. Specific etiology and pathogenesis of this entity remain unclear. Pediatr Blood Cancer 2007;49:727,730. © 2006 Wiley-Liss, Inc. [source] Two Cases of Lymphomatoid Papulosis in ChildrenPEDIATRIC DERMATOLOGY, Issue 2 2003Eri Aoki Histologically there was an infiltration of small lymphocytic cells with scattered large atypical cells expressing CD30. Characterization of T-cell receptor gene rearrangement showed monoclonality of the infiltrating cells. The second patient, a 15-year-old Japanese girl, had a 2-week history of self-healing papulovesicular eruptions on her face and limbs. Large CD30+ atypical cells were also noted in the perivascular lymphocytic infiltration. Immunohistochemical studies revealed CD8 expression on almost all CD30+ cells in the second case. In the literature, there have been two reports of children with large CD30+ atypical cells expressing CD8 and two cases expressing CD4, whereas all adult cases reported have had cells expressing only CD4. [source] Prolonged Survival of Allogeneic Islets in Cynomolgus Monkeys After Short-Term Anti-CD154-Based Therapy: Nonimmunologic Graft Failure?AMERICAN JOURNAL OF TRANSPLANTATION, Issue 4 2006M. Koulmanda Conventional drug therapy and several anti-CD154 mAb-based regimens were tested in the nonhuman primate (NHP) islet allograft model and found to be inadequate because islets were lost to rejection. Short-term therapy with an optimized donor-specific transfusion (DST) + rapamycin (RPM) + anti-CD154 mAb regimen enables immunosuppression drug-free islet allograft function for months following cessation of therapy in the NHP islet allograft model. After a substantial period of drug-free graft function, these allografts slowly and progressively lost function. Pathologic studies failed to identify islet allograft rejection as a destructive islet invasive lymphocytic infiltration of the allograft was not detected. To evaluate the mechanism, immunologic versus nonimmunologic, of the late islet allograft loss in hosts receiving the optimized therapeutic regimen, we performed experiments with islet autografts and studied islet function in NHPs with partial pancreatectomy. The results in both experiments utilizing autologous islet allografts and partially pancreatectomized hosts reinforce the view that the presence of a marginal islet mass leads to slowly progressive nonimmunological islet loss. Long-term clinically successful islet cell transplantation cannot be realized in the absence of parallel improvements in tolerizing regimens and in the preparation of adequate numbers of islets. [source] Interferon-,,dependent inhibition of B cell activation by bone marrow,derived mesenchymal stem cells in a murine model of systemic lupus erythematosusARTHRITIS & RHEUMATISM, Issue 9 2010Francesca Schena Objective Bone marrow,derived mesenchymal stem cells (BM-MSCs) are multipotent cells characterized by immunomodulatory properties and are therefore considered a promising tool for the treatment of immune-mediated diseases. This study was undertaken to assess the influence of murine BM-MSCs on the activation of B cells in (NZB × NZW)F1 mice as an animal model of systemic lupus erythematosus (SLE). Methods We evaluated the in vitro effects of BM-MSCs on the proliferation and differentiation to plasma cells of splenic mature B cell subsets, namely follicular and marginal zone B cells isolated from (NZB × NZW)F1 mice. Lupus mice were also treated with BM-MSCs, and serum autoantibodies, proteinuria, histologic changes in the kidney, and survival rates were monitored. Results BM-MSCs inhibited antigen-dependent proliferation and differentiation to plasma cells of follicular and marginal zone B cells in vitro. This inhibitory effect was dependent on interferon-, (IFN,) and was mediated by cell-to-cell contact, involving the programmed death 1 (PD-1)/PD ligand pathway. In vivo treatment with BM-MSCs did not affect the levels of anti,double-stranded DNA antibodies or proteinuria. However, a reduction in glomerular immune complex deposition, lymphocytic infiltration, and glomerular proliferation was observed. Conclusion Our findings indicate that BM-MSCs affect B cell receptor,dependent activation of both follicular and marginal zone B cells from lupus mice. This inhibitory effect is IFN,-dependent and cell contact,dependent. MSCs in vivo do not affect the production of autoantibodies, the level of proteinuria, or the mortality rates. Nonetheless, the significant improvement in histologic findings in the kidney supports the potential role of MSCs in the prevention of glomerular damage. [source] Regulation of pulmonary inflammation and fibrosis through expression of integrins ,V,3 and ,V,5 on pulmonary T lymphocytesARTHRITIS & RHEUMATISM, Issue 5 2009Irina G. Luzina Objective Pulmonary diseases associated with fibrosis, including scleroderma lung disease, are characterized by the accumulation of T cells in the lungs. These cells are thought to facilitate lung fibrosis, but the exact mechanisms of their profibrotic action are not clear. Several ,V-containing integrins, including ,V,3 and ,V,5, have been shown to directly activate transforming growth factor , (TGF,) and promote collagen accumulation. The aim of this study was to investigate whether pulmonary T cells express profibrotic integrins and regulate collagen accumulation. Methods Expression of integrins was assessed by immunohistochemical analysis of lung tissue, by flow cytometry using bronchoalveolar lavage fluid from patients with systemic sclerosis (SSc), and in a CCL18 overexpression animal model of pulmonary T cell infiltration. Experiments in cell cultures were performed to determine whether integrin-expressing T cells are profibrotic in cocultures with pulmonary fibroblasts and, if so, through what possible mechanism. Results Lymphocytes and integrin-positive cells were present in the lungs, and pulmonary T cells expressed integrins ,V,3 and ,V,5 in patients with SSc and in the animal model. Systemic administration of neutralizing anti,integrin ,V antibody or a genetic deficiency of integrin ,3 in the CCL18 overexpression model significantly attenuated CCL18-driven pulmonary lymphocytic infiltration and collagen accumulation. Jurkat T cells overexpressing integrin ,V,3 or integrin ,V,5 in cocultures with primary pulmonary fibroblasts stimulated collagen accumulation and Smad2 nuclear translocation. Neutralizing anti-TGF, antibody attenuated the profibrotic effect of integrin-expressing T cells. Conclusion Pulmonary infiltrating T lymphocytes may express integrins ,V,3 and ,V,5 that are necessary for lymphocytic infiltration and T cell,associated TGF, activation and collagen accumulation. [source] Induction of prolonged infiltration of T lymphocytes and transient T lymphocyte,dependent collagen deposition in mouse lungs following adenoviral gene transfer of CCL18ARTHRITIS & RHEUMATISM, Issue 8 2006Irina G. Luzina Objective Levels of CCL18 are elevated in patients with scleroderma lung disease and other fibrotic pulmonary diseases associated with T lymphocyte involvement. We sought to determine whether CCL18 alone can induce pulmonary T lymphocytic infiltration and fibrosis in mouse lungs. Methods An adenovirus vector was constructed and used for CCL18 delivery to mouse lungs in vivo. Immunohistochemical, flow cytometric, and enzyme-linked immunosorbent assay analyses were used to assess the resulting changes. Results Overexpression of CCL18 led to massive perivascular and peribronchial infiltration of T lymphocytes. Although the expression of CCL18 peaked on day 7, the infiltration persisted up to day 64 after infection. The infiltrates were negative for proliferating cell nuclear antigen and TUNEL, suggesting the role of cell trafficking, rather than proliferation and apoptosis, in the infiltration dynamics. Patchy destruction of the alveolar architecture and collagen accumulation in association with the infiltrates were also noticed. These changes were infiltration-dependent, rather than CCL18-dependent, since treatment with antilymphocyte serum completely abrogated the CCL18-induced changes. The infiltrates consisted almost exclusively of T lymphocytes that were minimally activated, with a minimal increase in the expression of CD69 and no changes in the expression of CD25, Fas, FasL, or CD40L. There was no increase in total pulmonary levels of profibrotic cytokines transforming growth factor ,1 (TGF,1) or interleukin-13, although active TGF,1 was present locally in association with the infiltrates and areas of distorted alveolar architecture. Prestimulation of primary T lymphocytes with CCL18 in vitro caused an up-regulation of TGF,1 and collagen production in T lymphocyte/fibroblast cocultures. Conclusion CCL18 promotes selective, long-term pulmonary infiltration of T lymphocytes and infiltration-dependent accumulation of collagen through a TGF,1-dependent mechanism. [source] Focal myositis of the tongue presenting as macroglossiaCLINICAL & EXPERIMENTAL DERMATOLOGY, Issue 8 2009M.-W. Lee Summary Focal myositis (FM) is a benign localized inflammatory process of unknown aetiology, which presents as a rapidly enlarging soft-tissue mass that evolves into a localized lesion. It is most often mistaken for a neoplasm. Histologically, it is characterized by marked myopathic changes of the muscle fibres, lymphocytic infiltration and interstitial fibrosis. We describe a case of focal myositis of the tongue and review this rare condition. [source] Role of the transgenic human thyrotropin receptor A-subunit in thyroiditis induced by A-subunit immunization and regulatory T cell depletionCLINICAL & EXPERIMENTAL IMMUNOLOGY, Issue 3 2008Y. Mizutori Summary Transgenic BALB/c mice that express intrathyroidal human thyroid stimulating hormone receptor (TSHR) A-subunit, unlike wild-type (WT) littermates, develop thyroid lymphocytic infiltration and spreading to other thyroid autoantigens after T regulatory cell (Treg) depletion and immunization with human thyrotropin receptor (hTSHR) adenovirus. To determine if this process involves intramolecular epitope spreading, we studied antibody and T cell recognition of TSHR ectodomain peptides (A,Z). In transgenic and WT mice, regardless of Treg depletion, TSHR antibodies bound predominantly to N-terminal peptide A and much less to a few downstream peptides. After Treg depletion, splenocytes from WT mice responded to peptides C, D and J (all in the A-subunit), but transgenic splenocytes recognized only peptide D. Because CD4+ T cells are critical for thyroid lymphocytic infiltration, amino acid sequences of these peptides were examined for in silico binding to BALB/c major histocompatibility complex class II (IA,d). High affinity subsequences (inhibitory concentration of 50% < 50 nm) are present in peptides C and D (not J) of the hTSHR and mouse TSHR equivalents. These data probably explain why transgenic splenocytes do not recognize peptide J. Mouse TSHR mRNA levels are comparable in transgenic and WT thyroids, but only transgenics have human A-subunit mRNA. Transgenic mice can present mouse TSHR and human A-subunit-derived peptides. However, WT mice can present only mouse TSHR, and two to four amino acid species differences may preclude recognition by CD4+ T cells activated by hTSHR-adenovirus. Overall, thyroid lymphocytic infiltration in the transgenic mice is unrelated to epitopic spreading but involves human A-subunit peptides for recognition by T cells activated using the hTSHR. [source] BRAF mutations in an Italian cohort of thyroid cancersCLINICAL ENDOCRINOLOGY, Issue 2 2004Laura Fugazzola Summary objective, Recently, a somatic point mutation of the BRAF gene (V599E) has been identified as the most common genetic event in papillary thyroid carcinoma (PTC) with a variable frequency (about 25,70%) in different series from USA, Japan, Portugal and Ukraine. design, In the present study, the genetic analysis of BRAF in an Italian cohort of 65 thyroid tumours with corresponding normal tissues and 21 thyroid benign disorders is reported. methods, For BRAF analysis, the somatic DNA was PCR amplified by means of specific intronic primers and PCR products were directly sequenced. Statistical analyses were obtained by means of Fisher's exact test. results, All mutations detected involved a T > A transversion at 1796 (V599E) and were heterozygous. Overall, BRAFV599E mutation was found in 18/56 (32·1%) PTCs. According to the histological type of the tumour, the mutation was present in 38·3% of cases of conventional PTC (18/47), in 0/6 follicular variant of PTC, in 0/3 oncocytic variant of PTC. No BRAF mutations were detected either in five follicular carcinomas, or in four poorly differentiated or undifferentiated cancers or in benign thyroid disorders. No statistically significant correlation of BRAF mutation with patient age and gender, with multicentricity of the tumour, with the lymphocytic infiltration of the tissue, with the stage and with the recurrence rate, was found. BRAFV599E tended to be associated, although not significantly, with a greater volume and extension of the tumour and with lymph-nodal metastases at surgery. conclusions, In conclusion, the present study on the first Italian series of thyroid cancers shows a frequency of 38·3% of BRAFV599E in the classical variant of PTC, confirming the key role of this mutation in promoting tumourigenesis. 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