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Antigenic Stimuli (antigenic + stimulus)

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Medical Sciences	100%

Selected Abstracts

Erythema nodosum and erythema induratum (nodular vasculitis): diagnosis and management

DERMATOLOGIC THERAPY, Issue 4 2010
Heidi Gilchrist
ABSTRACT Erythema nodosum is the most common type of panniculitis; it may be due to a variety of underlying infectious or otherwise antigenic stimuli. The pathogenesis remains to be elucidated, but both neutrophilic inflammation and granulomatous inflammation are implicated. Beyond treating underlying triggers, therapeutic options consist mainly of nonsteroidal anti-inflammatory drugs, symptomatic care, potassium iodide, and colchicine. Erythema induratum (nodular vasculitis) is a related but distinctly different clinicopathologic reaction pattern of the subcutaneous fat. It is classically caused by an antigenic stimulus from Mycobacterium tuberculosis but may be associated with several other underlying disorders. After appropriate antimicrobial treatment in tuberculous cases, therapy for erythema induratum is similar to options for erythema nodosum. [source]

Prominent Langerhans' cell migration in the arthropod bite reactions simulating Langerhans' cell histiocytosis

JOURNAL OF CUTANEOUS PATHOLOGY, Issue 12 2007
Se Hoon Kim
Background:, Epidermal Langerhans' cells (LCs) play pivotal roles in cutaneous immune responses. An encounter with antigens or other stimuli causes the mobilization and migration of LCs. Therefore, some dermatoses, which originated from antigenic stimuli or trauma, can show LC migration. Recently, we experienced several cases of anthropod bites that showed marked inflammatory infiltrates with eosinophils and CD1a-positive LCs. It was difficult to differentiate these cases from Langerhans' cell histiocytosis (LCH). Methods:, The degree and pattern of LC infiltration in the skin of arthropod bite reaction was evaluated. The characteristics of CD1a immunohistochemical expression in the arthropod bite reactions were compared with those of LCH. Results:, A few arthropod bite cases (approximately 36%) showed extensive CD1a-positive LCs in the dermis, especially in the perivascular area. In addition, the CD1a expression patterns of LCs in the arthropod bite reactions were dendritic, whereas that of tumor cells in LCH were distinctly membranous and cytoplasmic. Conclusion:, Some arthropod bite reactions can show marked CD1a-positive LCs in the dermis, especially in the perivascular area. The dendritic CD1a immunohistochemical staining pattern in arthropod bite reactions is useful in helping to differentiate from LCH. [source]

Post-transplant EBV-negative anaplastic large-cell lymphoma with dual rearrangement: a propos of two cases and review of the literature

JOURNAL OF CUTANEOUS PATHOLOGY, Issue 2007
Cynthia M. Magro
Background:, Post-transplant lymphoproliferative disease (PTLD) is a recognized complication of the immunosuppressive regimens associated with solid organ transplantation. The vast majority of these lesions represent monomorphic B-cell lymphoproliferative disease. Rarely, however, T-cell malignancies may emerge, the commonest being anaplastic large-cell lymphoma (ALCL). Materials and methods:, We describe two patients who developed a post-transplant ALCL several years after transplantation. Comprehensive phenotypic and molecular studies were conducted. The technique of capillary gel electrophoresis was employed. Results:, One patient died of unrelated causes, while the other patient did achieve clinical remission. The neoplastic cell populace was composed of CD4-positive cytotoxic T cells exhibiting CD30 positivity. There were very few B cells. Striking and prominent clonally restricted infiltrates were identified whereby there was both a heavy chain and T-cell beta gene rearrangement. There was no evidence of lytic Epstein-Barr virus (EBV) infection. Conclusion:, T-cell-associated PTLD does not appear to be directly attributable to EBV infection. Iatrogenic immune dysregulation may result in excessive T-cell proliferation to various antigenic stimuli, hence resembling other drug-associated cell lymphoproliferative conditions such as angioimmunoblastic lymphadenopathy. The dual rearrangement may have some implications regarding the cell of origin. [source]

Role of interleukin-17F in chronic inflammatory and allergic lung disease

CLINICAL & EXPERIMENTAL ALLERGY, Issue 9 2006
N. Hizawa
Summary IL-17 family members belong to a distinct category of cytokines that coordinate local tissue inflammation by inducing the release of pro-inflammatory and neutrophil-mobilizing cytokines. The importance of the IL-17 family in inflammatory and autoimmune disease is becoming increasingly apparent. IL-17F is a recently discovered member of the IL-17 family that has a number of biological activities through induction of various cytokines, chemokines, and mediators. IL-17A, the founding member of the IL-17 family, and IL-17F are produced by several inflammatory cells, including activated T cells, in response to infectious and antigenic stimuli. Overexpression of IL-17A or IL-17F in the lungs results in induction of CXC chemokines and neutrophil recruitment. In a case,control study of 1125 unrelated Japanese subjects, a His161 to Arg161 (H161R) substitution in the third exon of the IL17F gene was shown to be associated with asthma and chronic obstructive pulmonary disease (COPD). Functionally, this variant failed to induce cytokines and chemokines, and interestingly, was able to antagonize the activity of wild-type IL-17F. These results provide an experimental basis for the observed genetic association with chronic inflammatory lung diseases, and also suggest the potential therapeutic utility of this antagonistic variant of IL-17F. Given that asthma and COPD are complex diseases involving a number of genetic and environmental factors, the genetic impact of IL-17F H161R with regard to the development of chronic airway inflammation likely varies among individuals with different genetic backgrounds and environmental exposures. [source]

Contact allergy, irritancy and ,danger'

CONTACT DERMATITIS, Issue 3 2000
J. P. McFadden
Conventional models of the immune response are based on distinguishing self and non-self. However, we consider that the more recently proposed ,danger' model may be an illuminating alternative for studying allergic contact dermatitis. In this model, an antigenic signal on its own would tend to produce tolerance. In contrast, in the presence of a ,danger' signal, which, in the case of allergic contact dermatitis, we suggest is usually cutaneous irritancy, the immune system would become activated, leading first to the induction of sensitization and then subsequently to the elicitation of a contact hypersensitivity response. In most cases, both the antigenic signal and irritant signal will come from the hapten, although, e.g., in an occupational setting, traumiterative dermatitis would be the source of the ,danger' signal. Typically, the irritant signal tends to be more concentration-dependent and thus is the overriding factor in the determination of the effective sensitizing and eliciting concentrations of the hapten. A further prediction of this hypothesis is that successful experiments demonstrating low-dose tolerance with contact allergens may be explained by the loss of the irritant effect at lower dilutions, whilst an antigenic stimulus remains present. [source]

Erythema nodosum and erythema induratum (nodular vasculitis): diagnosis and management

Identification of antigenic targets of paraproteins by expression cloning does not support a causal role of chronic antigenic stimulation in the pathogenesis of multiple myeloma and MGUS

INTERNATIONAL JOURNAL OF CANCER, Issue 2 2007
Klaus-Dieter Preuss
Abstract Antigenic targets of monoclonal gammopathy of undetermined significance (MGUS) and multiple myeloma (MM) paraproteins have been suggested to play an important role as growth stimulators in the pathogenesis of these neoplasms. To identify such targets, we screened cDNA libraries from human testis, lung and breast cancer, bovine and porcine muscle and wheat germ for reactivity with paraproteins in the sera from 115 patients with MGUS and MM. Of >6 × 108 paraprotein,antigen interactions screened, an IgA paraprotein from a female patient bound to sperm-specific cylicin-2, and 3 IgG paraproteins bound to tripeptidyl-peptidase-II (TPP-2), insulin-like growth-factor binding-protein-2 (IGFBP-2) and porcine kinesin. Specificity was confirmed by reverse Western blots using recombinant antigens. The broad spectrum of auto-, allo- and heteroantigens as targets of human paraproteins in patients without signs of chronic antigenic stimulation renders a causal role of the antigenic stimulus in the pathogenesis of MGUS and MM unlikely. © 2007 Wiley-Liss, Inc. [source]

,Specific' cutaneous infiltrate of B-cell chronic lymphocytic leukemia at the site of a florid herpes simplex infection

JOURNAL OF CUTANEOUS PATHOLOGY, Issue 8 2005
Mirjana Ziemer
Background:, Specific cutaneous infiltrates in patients with leukemia generally carry a grim prognosis. However, non-neoplastic skin diseases may be associated with recruitment of normal and neoplastic leukocytes circulating in the peripheral blood. In those instances, neoplastic cells may be detected in skin lesions without an adverse effect on prognosis. Methods:, In a patient with B-cell chronic lymphocytic leukemia, a specific infiltrate developed at the site of a florid herpes simplex infection. Clinically, the lesion presented itself as an ulcerated tumor. Results:, Histopathologically, the lesion was characterized by a dense, diffuse infiltrate of small hyperchromatic lymphocytes throughout the entire dermis. Lymphocytes showed an aberrant CD20+/CD43+/CD5+ phenotype of neoplastic B cells, and monoclonal rearrangement of immunoglobulin gamma genes could be demonstrated by polymerase chain reaction. Although criteria for leukemia cutis were fulfilled, the patient did well. Conclusions:, The cutaneous infiltrate of neoplastic cells seemed to be part of a physiologic response to the antigenic stimulus, rather than indicating an exacerbation of leukemia. [source]