SEARCH · Search PubMed

Results for “Pathogenesis”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

SourceResearch connectionFrom yearThrough year

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 181 records · Page 10Linked to original sources

PubMed2005

Cytokine network in the pathogenesis of idiopathic pulmonary fibrosis.

Idiopathic pulmonary fibrosis (IPF) remains a relentlessly progressive lung disorder despite four decades of interest in its pathogenesis and treatment. It is important to emphasize that IPF is a progressive and irreversible illness, and, until now, there has been no available drug that has been capable of modifying the progressive natural course of IPF and its usual terminal outcome. Although the pathogenesis of this disease is complex and poorly understood, growth factors, cytokines, chemokines, and regulators of apoptosis have all been implicated in its pathogenesis and disease progression. This review summarizes the evidence implicating these molecules as primarily involved in the pathogenesis of IPF such as cytokines, chemokines and growth factors, with particular emphasis to novel interactions. The elucidation of mediators that orchestrate this aberrant tissue repair will allow the development of novel interventions to treat this devastating disorder.

Animals↗

PubMed2006

Plaques and tangles and the pathogenesis of Alzheimer's disease.

Since the earliest descriptions, senile plaques (SP) and neurofibrillary tangles (NFT) have been regarded as the pathological hallmarks of Alzheimer's disease (AD). Consequently, studies of the morphology, distribution, and molecular composition of SP and NFT have played an important role in developing theories as to the pathogenesis of AD; the most important being the 'Amyloid Cascade Hypothesis (ACH)'. Nevertheless, the significance of SP and NFT to the pathogenesis of AD remains controversial. This review examines three questions: 1) is there a relationship between the lesions and the degree of clinical dementia, 2) is the pathogenesis of the NFT linked to that of the SP, and 3) what is the relationship of SP and NFT to the pathogenesis of AD? These questions are discussed with reference to the morphology and molecular composition of SP and NFT, the effects of gene mutations, studies of head injury patients, experimental studies involving brain lesions and transgenes, and the degeneration of specific anatomical pathways. It was concluded that SP and NFT are not closely related to the developing dementia in AD, arise as relatively independent lesions, and may be the products of a degenerative process rather than being their cause.

Alzheimer Disease↗

PubMed1989

Alcohol-induced pancreatic injury (Part I). Unexplained features and ductular theories of pathogenesis.

The pathogenesis of alcoholic pancreatitis continues to be a puzzle. Classical theories of pathogenesis tend to overlook the dual nature of the disease, i.e., symptomatic acute attacks and chronic progressive parenchymal destruction. Furthermore, it is unknown why only a small minority of alcoholics develop clinical pancreatic injury. In addition, there is a lack of basic data concerning the natural history of the condition after cessation of alcohol consumption. The most widely accepted theory of pathogenesis postulates the deposition of protein plugs in peripheral pancreatic ducts as the initial lesion. However, it has not been established that these plugs are the cause rather than a result of pancreatic injury. The so-called "Big Duct" theories of pathogenesis (biliary-pancreatic reflux, duodeno-pancreatic reflux, and obstruction-hypersecretion) are confounded by a lack of agreement concerning the effect of alcohol on the sphincter of Oddi. Nutritional factors and heredity may be responsible for the selectivity of alcohol in this condition; in this regard, a number of dietary and HLA studies have been performed, but these have generally been inadequately controlled. Subcellular pancreatic injury (fat droplets, autophagic vacuoles, and mitochondrial lesions) has been observed in alcoholics without pancreatitis and in animals fed alcohol. In addition, ethanol feeding in animals has been shown to affect pancreatic cholesterol, phospholipid, and fatty acid metabolism as well as pancreatic content of digestive enzymes. Research is hampered by the lack of a suitable animal model of the disease.

Alcohol Drinking↗

PubMed1989

Genetics and molecular pathogenesis of Legionella pneumophila, an intracellular parasite of macrophages.

In addition to providing a powerful approach for identifying bacterial factors required for full infectivity and disease production, genetic analysis of Legionella pathogenesis should also lend critical insight into the biology of the macrophage and into the pathogenesis of other intracellular parasites. The interaction between L. pneumophila and the macrophage exhibits many features found in a wide variety of prokaryotic and eukaryotic intracellular human pathogens. For example, binding to complement receptors has been shown to occur for Mycobacterium tuberculosis, M. leprae, Leishmania donovani, Leishmania major and Histoplasma capsulatum. Coiling phagocytosis has been observed during entry of L. donovani. Phagosomes that contain Toxoplasma gondii or M. tuberculosis fail to fuse with lysosomes and, in the case of T. gondii, have been shown to remain close to neutral pH. Although the molecular bases for these phenomena are unknown, their functional similarities to the L. pneumophila-macrophage interaction provide optimism that generally applicable principles are involved. The genetic techniques reviewed here will provide the molecular tools with which such questions of a general biologic nature can be framed and eventually answered. Together with more traditional methods in biochemistry, microbiology and cell biology, molecular genetics offers a robust means toward identifying and understanding the bacterial factors involved in the pathogenesis of Legionnaires' disease. Molecular studies of L. pneumophila can also help address questions concerning the epidemiology, diagnosis and prevention of disease. For example, the distribution of virulence factors might help explain and predict the attack rates of different L. pneumophila strains or Legionella species. Moreover, bacterial genes/factors that are shown to be conserved in Legionella strains could be used to develop such diagnostic tools as DNA probes. Novel types of vaccines consisting of genetically constructed, avirulent L. pneumophila strains or subunit vaccines based on the molecular characterization of virulence factors might be developed and tested as protective immunogens. In this way, the capacity to analyze and to manipulate L. pneumophila genetically may facilitate the use of Legionnaires' disease as a model infection for studying protective cell-mediated immunity. Apart from its clinical significance as the etiologic agent of Legionnaires' disease, L. pneumophila may be a key to broader understandings in microbial pathogenesis and human cell biology and immunology. Although the extremely complex processes of bacterial infection and virulence are best understood when a variety of experimental approaches are employed, we believe that the evolving molecular genetic techniques reviewed here will be critical elements in many important breakthroughs in the future.

Animals↗

PubMed1987

[Cytotoxicity of bile acids and lysolecithin--a factor in the pathogenesis of stomach ulcer?].

The role of bile acids and lysolecithin in the pathogenesis of peptic ulcer is as yet not unequivocally defined. Based on the physiochemical properties of bile acids and animal experiments they have damaging potential on the mucosal cell. However, the majority of results reported in patients do not favour a significant role of bile acids in the pathogenesis of peptic ulcer. With regard to lysolecithin a sufficient data base is missing. Based on the damaging potential in animal experiments and the few reported patient studies a role in pathogenesis is more probable than for bile acids. Studies on concentrations and effects of both, bile acids and lysolecithin over prolonged periods of time in patients with ulcer disease are necessary to further clarify their role in pathogenesis of ulcer disease.

Animals↗

PubMed1983

Hypersensitivity pneumonitis--pathology and pathogenesis.

Early reports of hypersensitivity pneumonitis postulated that the disease was infectious or resulted from the toxic properties of the inhaled organic dusts. The finding of precipitating antibodies to moldy hay in farmers afflicted with farmer's lung suggested a role for antibody in pathogenesis, and a type III (antigen-antibody complex-mediated or Arthus) hypersensitivity reaction based on the classification of allergic reactions by Gell and Coombs was postulated. Subsequent studies have indicated the importance of cell-mediated (delayed) hypersensitivity (type IV). It must be recognized that hypersensitivity mechanisms are quite complicated and that the classification of Gell and Coombs is an oversimplification; interreacting humoral and cellular responses are typical of most hypersensitivity reactions of whatever classic type as originally defined. The prime importance of T-cell- and macrophage-mediated inflammation in HP, however, is indicated by histopathology, animal models, and in vitro correlates in humans. Major difficulties in defining completely the exact effector mechanisms involved in the pathogenesis of HP include the absence of a reliable in vitro correlate of antigen-specific effector T cells (the so called TDH cell) and the overwhelming versatility of the macrophage. There is no direct evidence to support contributions by precipitins, complement, or genetic host factors in the pathogenesis of hypersensitivity pneumonitis, nor are there studies as yet of cellular cytotoxicity contributions. Cellular and antibody interactions may lead to immunosuppressive processes modulating inflammatory responses and preventing disease despite immunogenesis. Animal models are helpful in dissecting mechanisms and defining effector functions. The eventual goal in studies of pathogenesis is to provide better tools for definitive diagnosis and methods of disease prevention, modulation, and cure.

Alveolitis, Extrinsic Allergic↗

PubMed1982

[Morphology and pathogenesis of visceral manifestations of chronic alcoholism].

Chronic alcoholism is accompanied by systemic involvement of the internal organs. Clinico-morphological forms of chronic alcoholism are distinguished on the basis of the prevailing organ pathology, Morphological data are presented, and pathogenesis of the lesions of the liver, heart, pancreas, and kidneys in patients with chronic alcoholism is analysed. The hepatic form may present alcoholic dystrophy, hepatitis or cirrhosis which are stages of progressing hepatopathy. The toxic and metabolic effect of ethanol is important in the pathogenesis of liver lesion. The cardiac form is characterized by the development of alcoholic myocardiodystrophy. In addition to the toxic influence of ethanol, hormonal and electrolyte changes and microcirculatory disorders play a role in its pathogenesis. Chronic calcifying pancreatitis in chronic alcoholism is associated with the effect of ethanol on the mediatory system. The renal form any present necronephrosis, hepatorenal syndrome, glomerulonephritis or pyelonephritis. Their pathogenesis is determined by toxicity of ethanol, circulation of immune complexes in the blood, or immunosuppression.

Alcoholism↗

PubMed1981

Theories of pathogenesis.

Theories of pathogenesis can be influenced by shared unconscious fantasies. This may determine the speedy enthusiasm with which some theories are accepted. In keeping with primitive, pleasure-seeking trends, it is appealing to blame illness on others and to view pathogenesis in terms of the intrusion into the self of some alien, noxious agent. These ideas can be seen in certain current theories that ascribe pathogenesis to inadequate, unempathic mothering. Such theories influence psychoanalytic technique. Analysis becomes a form of replacement therapy, in which the analyst facilitates normal development by serving as an appropriate object. This approach may gratify unconscious needs in analyst and analysand alike. The attempt to isolate one specific pathogenic factor as crucial fails to do justice to the complexity of pathogenesis and may lead to the failure to recognize the role of unconscious conflict and to analyze resistances.

Fantasy↗

PubMed1988

Amyotrophic lateral sclerosis. Recent advances in pathogenesis and therapeutic trials.

We reviewed the current status of pathogenesis and therapeutic trials in amyotrophic lateral sclerosis (ALS). Clinical studies have identified several rare but definable causes for apparent ALS. Certain clinical features previously considered unlikely to occur in ALS are found on careful examination. Epidemiologic surveillance and recent studies of neurotoxic plant seeds used in Guam have shed light on the pathogenesis of endemic ALS. Extensive analyses of biochemical, metabolic, immunologic, viral, and toxic factors have provided provocative results requiring further studies. Reflecting on some of these hypotheses, therapeutic trials have been performed more vigorously than ever. Amyotrophic lateral sclerosis is now investigated at the molecular genetic level. Human autopsy and experimental animal studies have expanded our understanding of basic mechanisms involving motoneuronal degeneration. In the future, we must continue a relentless search for the pathogenesis of ALS, prospective clinical studies to define the limits of ALS, and well-designed, controlled therapeutic trials.

Amyotrophic Lateral Sclerosis↗

PubMed2004

Current concepts in the pathogenesis of age-related macular degeneration.

OBJECTIVE: To review and synthesize information concerning the pathogenesis of age-related macular degeneration (AMD). METHODS: Review of the English-language literature. RESULTS: Five concepts relevant to the cell biology of AMD are as follows: (1) AMD involves aging changes plus additional pathological changes (ie, AMD is not just an aging change); (2) in aging and AMD, oxidative stress causes retinal pigment epithelial (RPE) and, possibly, choriocapillaris injury; (3) in AMD (and perhaps in aging), RPE and, possibly, choriocapillaris injury results in a chronic inflammatory response within the Bruch membrane and the choroid; (4) in AMD, RPE and, possibly, choriocapillaris injury and inflammation lead to formation of an abnormal extracellular matrix (ECM), which causes altered diffusion of nutrients to the retina and RPE, possibly precipitating further RPE and retinal damage; and (5) the abnormal ECM results in altered RPE-choriocapillaris behavior leading ultimately to atrophy of the retina, RPE, and choriocapillaris and/or choroidal new vessel growth. In this sequence of events, both the environment and multiple genes can alter a patient's susceptibility to AMD. Implicit in this characterization of AMD pathogenesis is the concept that there is linear progression from one stage of the disease to the next. This assumption may be incorrect, and different biochemical pathways leading to geographic atrophy and/or choroidal new vessels may operate simultaneously. CONCLUSIONS: Better knowledge of AMD cell biology will lead to better treatments for AMD at all stages of the disease. Many unanswered questions regarding AMD pathogenesis remain. Multiple animal models and in vitro models of specific aspects of AMD are needed to make rapid progress in developing effective therapies for different stages of the disease.

Aging↗

PubMed2000

Role of spleen macrophages in the clearance of scrapie agent early in pathogenesis.

The involvement of spleen macrophages in the early stages of scrapie pathogenesis was studied by applying the 'macrophage-suicide technique' to scrapie-infected mice. This method comprises critically the intravenous administration to mice of dichloromethylene disphosphonate encapsulated into liposomes. Depletion of spleen macrophages before scrapie infection induced an increased amount of scrapie inoculum in the spleen, consequently leading to accelerated scrapie agent replication in the early phase of pathogenesis, as followed by PrPres accumulation, a specific hallmark of scrapie. The same effect was observed when spleen macrophages were depleted just before the beginning of scrapie agent replication. These findings suggest that macrophages may partly control scrapie infection in peripheral tissues by sequestration of the scrapie inoculum and may thus impair early scrapie agent replication in the spleen. In addition to macrophages, most follicular dendritic cells and B lymphocytes, which are thought to support scrapie agent replication, were also transiently depleted by dichloromethylene disphosphonate administration. This suggests that a compensatory mechanism is sufficient to ensure the persistence of infection in these early stages of pathogenesis.

Analgesics, Non-Narcotic↗

PubMed1998

Muscle contractility decrement and correlated morphology during the pathogenesis of streptozotocin-diabetic mice.

BACKGROUND: Peripheral neuropathy of both motor and sensory nerves has been well documented in diabetes mellitus, but the evidence for physiological and correlated morphological changes during the pathogenesis of myopathy is scarce. In the present report, we have chosen the dorsiflexor muscle of adult male mice as a model for studying in situ muscle contraction and neuromuscular ultrastructure during the pathogenesis of streptozotocin-induced diabetes. METHODS: Thirty mice (30 g bodyweight) were injected once i.p. with streptozotocin solution (200 mg/Kg) to induce experimental diabetes mellitus. Comparative analyses of in situ muscle isometric contractile characteristics were studied (at 1 Hz, 5 Hz and 30 Hz nerve stimulation) in urethane-anesthetized (2 mg/g, i.p.) control and diabetic mice at three time points, 2 weeks, 4 weeks, and 8 weeks postinjection. Synaptic delay was also recorded in diabetic and age-matched control mice. RESULTS: There was a significant increase in synaptic delay in both 4-week and 8-week diabetic mice compared with control mice (8.9 +/- 1.2 msec and 7.6 +/- 0.6 msec, respectively, compared with 6.1 +/- 0.5 msec). At all three stimulation frequencies, diabetes did not affect muscle contractile speed but significantly reduced the twitch tension after 8 weeks, with no changes at 2 weeks or 4 weeks. The recorded single-twitch tension values were 2.6 +/- 0.3 g, 2.1 +/- 0.6 g, 2.2 +/- 0.7 g, and 1.2 +/- 0.1 g for control, 2 weeks, 4 weeks, and 8 weeks, respectively. At 30 Hz, the recorded tension values were 4.6 +/- 1.6 g, 3.1 +/- 1.2 g, 3.1 +/- 1.1 g, and 2.1 +/- 1.0 g for control, 2 weeks, 4 weeks, and 8 weeks, respectively. Ultrastructural changes in neuromuscular junctions were similar to those that have been described in disuse and aging. These changes were observed after 8 weeks and included serve loss of synaptic vesicles, electron-dense bodies, and myelin-like figures as well as degeneration of mitochondria. CONCLUSIONS: The results reveal that streptozotocin-induced diabetes affects presynaptically the neuromuscular junction as well as muscle itself. Actions at both sites may contribute to the functional alterations seen in muscle contractile properties and may play a role in the pathogenesis of diabetic neuromyopathy.

Animals↗

PubMedDate not supplied

Paramyxovirus replication and pathogenesis. Reverse genetics transforms understanding.

A recent breakthrough in the field of nonsegmented negative strand RNA viruses (Mononegavirales), including paramyxoviruses, is the establishment of a system to recover an infectious virus entirely from complementary DNA and hence allow reverse genetics. Mutations can now be introduced into viral genomes at will and the resulting phenotypes studied as long as the introduced mutations are not lethal. This technology is being successfully applied to answer outstanding questions regarding the roles of viral components in replication and their contribution to pathogenicity, which are difficult to address using conventional virology. For instance, how the paramyxovirus accessory proteins V and C contribute to actual viral replication and pathogenesis has remained unanswered since their first description more than 20 years ago. Using Sendai virus, which causes fatal pneumonia in mice, it has been shown that the V protein is completely dispensable for viral replication in cell cultures but encodes a luxury function required for pathogenesis in vivo. The Sendai virus C proteins were also defined to be nonessential gene products which greatly contributed to replication both in vitro and in vivo. It is also now possible to design live vaccines by introducing predetermined or plausible attenuating mutations. In addition, the use of paramyxoviruses to express foreign genes has also become feasible. Paramyxovirus reverse genetics is thus renovating our understanding of viral replication and pathogenesis and will further mark an era in recombinant technology for disease prevention and gene therapy.

Animals↗

PubMed1993

Patterns of presentation of Hodgkin disease. Implications for etiology and pathogenesis.

BACKGROUND: The etiology of Hodgkin disease remains uncertain. Patterns of presentation of Hodgkin disease are analyzed by histologic subtype with implications for etiology and pathogenesis. METHODS: The authors performed a detailed analysis of anatomic sites of involvement, histopathologic findings, and clinical features in 719 patients with Hodgkin disease who underwent staging laparotomy with splenectomy between April 1969 and December 1986. The presence of disease in each of 17 sites of potential nodal involvement was determined for each patient from a combination of clinical and surgical staging. Association among nodal sites was assessed in 2 x 2 tables by estimating the odds ratio and testing the significance with the chi-square test. A strict significance level (P = 0.01) was used. Log-linear models were used for assessing association in 2 x 2 tables while adjusting for other factors. RESULTS: The mediastinum, left side of neck, and right side of neck were the most common sites involved for patients with nodular sclerosing (NS) or mixed cellularity (MC) histologic subtypes. Each of these sites was involved 60% of the time. These sites were four or more times as common as other nodal sites above or below the diaphragm. In contrast, the mediastinum was involved in only 8% of patients with lymphocyte predominance (LP) histologic subtype. Significant associations were found between mediastinal disease and low cervical/supraclavicular lymph node disease, mediastinal disease and NS histologic subtypes, peripheral nodal disease and LP histologic subtypes, and between splenic disease and mixed cellularity/lymphocyte depletion (MC/LD) Hodgkin disease. The age at onset and sex of patients with Hodgkin disease and the patterns of nodal distribution were somewhat different for NS and MC/LD histologic subtypes. Even greater differences were seen between LP and other histologic subtypes. CONCLUSIONS: This study supports the conclusion that NS and MC Hodgkin disease spread by continguity, most often originating in the neck or mediastinum, and is consistent with evidence suggesting an infectious agent in the pathogenesis of these subtypes of Hodgkin disease. In contrast, LP Hodgkin disease is characterized by different sites of presentation and patterns of spread. This suggests that two or perhaps three clinicopathologic subtypes of Hodgkin disease exist. Implications for etiology and pathogenesis are discussed.

Adult↗

PubMed2000

Novel pathways in the pathogenesis of respiratory syncytial virus disease.

Respiratory syncytial virus (RSV) is a leading cause of severe respiratory infections in infants and children. Extensive research in past decades has expanded our knowledge regarding the specific mechanisms involved in the pathogenesis of RSV bronchiolitis and subsequent chronic obstructive airway disease. Studies of RSV infection are performed in humans, cell culture models, and animal models, each with their own specific limitations. A recently developed murine model in which pulmonary dysfunction can be monitored and quantified appears to add a powerful tool for the study of specific pathogenic mechanisms of experimental RSV infections. Both immunologic and nonimmunologic factors have been implicated in the pathogenesis of RSV-induced diseases. Recently, a hypothesis that RSV bronchiolitis may be the result of production of Th2-type cytokines has become popular. There are, however, studies in human infants with RSV as well as in RSV-infected mice that suggest this theory is incorrect, or at least an oversimplification. There is compelling evidence that cells producing interferon gamma may contribute to RSV-induced wheezing, possibly through induction of leukotriene release. Among the nonimmunologic factors, pulmonary surfactant has recently attracted attention, especially because of the therapeutic implications for infants with severe bronchiolitis. A better understanding of the pathogenesis of RSV-induced diseases will be of considerable help in developing specific therapeutic strategies and in vaccine development.

Animals↗

PubMed1988

Pathogenesis of experimental scrapie.

Most of our understanding of the pathogenesis of the unconventional slow infections comes from studies of experimental scrapie in mice and hamsters. After injection by non-neural peripheral routes, pathogenesis necessarily involves the lymphoreticular system (LRS) before the central nervous system (CNS). Available evidence indicates haematogenous spread from the site of injection to the scrapie replication sites in the LRS; later, infection spreads along visceral autonomic nerves from the LRS to the thoracic spinal cord, and thence to brain. The cells in the LRS which are important to scrapie pathogenesis are long lived. Neuroinvasion and spread of infection within the CNS probably involve neuronal pathways. We suggest that disease develops after infection has reached certain clinical target areas in the CNS but only when scrapie replication there has caused sufficient functional damage. Restriction of the replication process in both LRS and CNS is indicated by the occurrence of plateau concentrations of infectivity, especially in some long incubation scrapie models. A remarkable feature of these is that both neuroinvasion and clinical disease occur long after infectivity plateaux have been reached in the LRS and CNS, respectively. We propose that the slowness of scrapie is related to (1) limitations of cell-to-cell spread of infection from LRS to CNS, and (2) limitations on spread between neurons, coupled with restrictions on replication in brain.

Animals↗

PubMed2002

Biomechanical models for the pathogenesis of specific distal upper extremity disorders.

BACKGROUND: Knowledge of the pathogenesis of most disorders that occur in the distal upper extremity is generally lacking. The individual roles of postulated etiologic factors, such as biomechanical or psychosocial exposures, are poorly understood and their potential interactions even less so. This article proposes biomechanical or physiological models of pathogenesis for specific distal upper extremity disorders. METHODS: Tendon entrapment of the dorsal wrist compartments (tenosynovitis), peritendinitis, lateral epicondylitis, and carpal tunnel syndrome are common specific neuromusculoskeletal disorders of the upper extremities observed among workers. The normal anatomy and function of the targeted structures is considered the initial state; their pathology is considered the final state. Using biomechanical or physiological principles combined with clinical observations and experimental studies, pathways leading from the initial state to the final state are proposed. Each model defined a critical biomechanical or physiological attribute that was considered to best characterize 'dose.' Two temporal patterns of exposure (duration vs. repetition) were used to characterize 'dosage.' The roles of long-term exposure vs. unaccustomed work were mentioned, but not incorporated into the models. RESULTS: Compressive force transmitted to the extensor retinaculum was considered the critical factor in the model for tendon entrapment at the dorsal wrist compartments. Two models were proposed for lateral epicondylitis. One emphasized the role of eccentric exertions; the other emphasized contact pressure from the radial head. The model for peritendinitis relied on localized muscle fatigue. Seven plausible models were presented for carpal tunnel syndrome. CONCLUSIONS: It is possible to propose biologically plausible models of pathogenesis that are both coherent with current knowledge of tissue responses and consistent with clinical observations; however, more than one model was plausible for some conditions. Additional research is needed to determine which, if any, of the proposed models might be correct. Such models may be useful to health care providers and ergonomists in the context of primary, secondary, or tertiary prevention.

Biomechanical Phenomena↗

PubMed2004

Commentary: the role of the IL-18 system and other members of the IL-1R/TLR superfamily in innate mucosal immunity and the pathogenesis of inflammatory bowel disease: friend or foe?

Crohn's disease and ulcerative colitis are examples of inflammatory bowel disease (IBD), and are multifaceted chronic autoimmune disorders with unknown etiology; to date, there is no known cure. IBD is thought to occur as a result of an inappropriate immune response to environmental factors in a genetically predisposed host, and it has become increasingly clear that cytokines play an important role in this process. In recent years, several groups have provided evidence that IL-18 is significantly up-regulated during the course of chronic intestinal inflammation and appears to play a pivotal role in the pathogenesis of human IBD, particularly in Crohn's disease. IL-18 is a pleiotropic cytokine with several biological functions, but is most commonly associated with its ability to synergistically induce the expression of IFN-gamma. However, although IL-18 has been extensively studied in both human IBD as well as in murine models of colitis, no definitive function of IL-18 during the initiation and perpetuation of chronic gut inflammation has been firmly established, and its precise role in the pathogenesis of IBD has yet to be determined. In light of the recent observation that the transcription factor interferon regulatory factor-1 has the ability to regulate the functional activity of IL-18, and concomitantly disease severity, in a murine model of colitis through altered expression of its endogenous inhibitor, IL-18-binding protein, this commentary will review what is currently known regarding the role of IL-18 in normal mucosal immunity and during the pathogenesis of IBD.

Animals↗