Increased risk of lower limb osteoarthritis among former professional soccer (football) players.

BACKGROUND: Soccer is a high-speed contact sport with risk of injury. Despite long-standing concern, evidence to date remains inconsistent as to the association between playing professional-level soccer and lifelong musculoskeletal consequences. AIMS: The objectives were to assess risk of osteoarthritis in former professional soccer players compared to matched general population controls, and subsequently assess associated musculoskeletal disorders which may contribute to, or result from, osteoarthritis-specifically meniscal injury and joint replacement. METHODS: We conducted a retrospective cohort study using national electronic health records (EHRs) on a cohort of 7676 former professional soccer players aged 40 or over at recruitment, matched on year of birth, sex (all male) and socio-economic status with 23 028 general population controls. Outcomes of interest were obtained by utilizing individual-level record linkage to EHRs from general hospital inpatient and day-case admissions. RESULTS: Compared to controls, former soccer players showed a greater risk of hospital admission for osteoarthritis (hazard ratio [HR] 3.01; 95% confidence interval [CI] 2.80-3.25; P < 0.001). This increased risk appeared age dependant, normalizing over age 80 years and reflective of increased risk of lower limb osteoarthritis. Further, risk of hospital admissions for meniscal injury (HR 2.73; 95% CI 2.42-3.08; P < 0.001) and joint replacement (HR 2.82; 95% CI 2.23-3.57; P < 0.001) were greater among former soccer players. CONCLUSIONS: We report an increased risk of lower limb osteoarthritis in former soccer players when compared with matched population controls. The results of this research add data in support of lower limb osteoarthritis among former soccer players representing a potential industrial injury.

Loss of Cdh1 and Trp53 in the uterus induces chronic inflammation with modification of tumor microenvironment.

Type II endometrial carcinomas (ECs) are estrogen independent, poorly differentiated tumors that behave in an aggressive manner. As TP53 mutation and CDH1 inactivation occur in 80% of human endometrial type II carcinomas, we hypothesized that mouse uteri lacking both Trp53 and Cdh1 would exhibit a phenotype indicative of neoplastic transformation. Mice with conditional ablation of Cdh1 and Trp53 (Cdh1(d/d)Trp53(d/d)) clearly demonstrate architectural features characteristic of type II ECs, including focal areas of papillary differentiation, protruding cytoplasm into the lumen (hobnailing) and severe nuclear atypia at 6 months of age. Further, Cdh1(d/d)Trp53(d/d) tumors in 12-month-old mice were highly aggressive, and metastasized to nearby and distant organs within the peritoneal cavity, such as abdominal lymph nodes, mesentery and peri-intestinal adipose tissues, demonstrating that tumorigenesis in this model proceeds through the universally recognized morphological intermediates associated with type II endometrial neoplasia. We also observed abundant cell proliferation and complex angiogenesis in the uteri of Cdh1(d/d)Trp53(d/d) mice. Our microarray analysis found that most of the genes differentially regulated in the uteri of Cdh1(d/d)Trp53(d/d) mice were involved in inflammatory responses. CD163 and Arg1, markers for tumor-associated macrophages, were also detected and increased in the uteri of Cdh1(d/d)Trp53(d/d) mice, suggesting that an inflammatory tumor microenvironment with immune cell recruitment is augmenting tumor development in Cdh1(d/d)Trp53(d/d) uteri. Further, inflammatory mediators secreted from CDH1-negative, TP53 mutant endometrial cancer cells induced normal macrophages to express inflammatory-related genes through activation of nuclear factor-κB signaling. These results indicate that absence of CDH1 and TP53 in endometrial cells initiates chronic inflammation, promotes tumor microenvironment development following the recruitment of macrophages and promotes aggressive ECs.

Subjective functional assessments and the return to competitive sport after anterior cruciate ligament reconstruction.

OBJECTIVES: To examine (a) return to competitive sport within 12 months of anterior cruciate ligament (ACL) reconstruction, (b) maintenance of competitive participation at follow up, and (c) the relation of the level of sports activity and competitive participation at follow up to subjective functional assessments. Also to address the incidence of continued competitive participation despite notable functional problems with the operated knee at 12 months and follow up. METHODS: All patients were competitive athletes before injury and had undergone ACL reconstruction by the transtibial endoscopic technique with either a bone-patellar tendon-bone or a multiple looped hamstring autograft. Evaluation was carried out a mean of 43 months (range 24-73) after surgery by a postal questionnaire in which the Cincinnati sports activity scale (CSAS) and Cincinnati sports function scales were presented in conjunction with closed questions on change in competitive level and the presence of complaints. RESULTS: Of 109 selected patients, 77 (71%) responded. At follow up, 62 of 77 patients (81%) reported that they had returned to competition within 12 months of surgery. Within the same time frame, 55 of the above 62 patients (89%) also claimed to have returned to the level at which they were competing before injury (or higher). At follow up, 30 of the above 55 patients (54%) reported to still be competing at this high level. Twelve of the above 55 patients (22%) also admitted to major problems with the operated knee at that time. The overall incidence of patients competing despite major functional impairment in the operated knee was 13 of 62 (21%) at 12 months and six of 47 (13%) at follow up. Thirty eight patients (49%) were active in sport at least four times a week at follow up (CSAS level 1), and, using Spearman's rank correlation between CSAS scores and total sports function scores, r was calculated to be 0.44. Competitive and male patients had higher total sports function scores at follow up than non-competitive (p = 0.005) and female (p = 0.02) patients respectively. CONCLUSIONS: The reported return to competition at the previous level, both within 12 months and at follow up, was high but as expected considering the standard of treatment, patient selection, and study exclusion criteria. Patients with few functional complaints maintained a high level of sporting activity, even after discontinuing competitive participation.

Signal transducer and activator of transcription 6 controls chemokine production and T helper cell type 2 cell trafficking in allergic pulmonary inflammation.

Antigen-specific CD4 T helper type 2 (Th2) cells play a pivotal role in the induction of allergic asthma, but the mechanisms regulating their recruitment into the airways are unknown. Signal transducer and activator of transcription factor (Stat)6 is a transcription factor essential for Th2 cell differentiation. Here we show that Stat6 also controls Th2 cell recruitment and effector function in allergic inflammation in vivo. To isolate the role of Stat6 in regulating Th2 cell trafficking and effector function from its role in Th2 cell differentiation, we used a murine model of asthma in which in vitro-differentiated Stat6(+/+) antigen-specific Th2 cells were adoptively transferred into naive Stat6(-/-) and Stat6(+/+) mice followed by aerosol antigen challenge. We found that all of the features of asthma, including Th2 cell accumulation, Th2 and eosinophil-active chemokine production, and airway eosinophilia, mucus production, and hyperresponsiveness seen in Stat6(+/+) mice, were dramatically absent in Stat6(-/)- mice that received Stat6(+/)+ antigen-specific Th2 cells. Our findings establish Stat6 as essential for Th2 cell trafficking and effector function and suggest that interruption of Stat6 signaling in resident cells of the lung is a novel approach to asthma therapy.

The transcription factor early growth-response factor 1 modulates tumor necrosis factor-alpha, immunoglobulin E, and airway responsiveness in mice.

Early growth-response factor 1 (Egr-1) is a sequence-specific transcription factor that plays a regulatory role in the expression of many genes important in inflammation, cell growth, apoptosis, and the pathogenesis of disease. In vitro studies suggest that Egr-1 is capable of regulating the expression of tumor necrosis factor-alpha (TNF-alpha) and other genes involved in airway inflammation and reactivity following allergen stimulation. On the basis of these data, we hypothesized that in the absence of Egr-1, the TNF-alpha response and subsequent downstream inflammatory events that usually follow allergen challenge would be diminished. To test our hypothesis Egr-1 knock-out (KO) mice were examined in an ovalbumin (OVA)-induced model of airway inflammation and reactivity, and compared with identically treated wild-type (WT) control mice. In response to OVA sensitization and airway challenge, KO mice had diminished TNF-alpha mRNA and protein in the lungs and mast cells compared with WT mice. Interestingly, the KO mice had elevated IgE levels at baseline and after allergen challenge compared with WT mice. Furthermore, the airways of KO mice were hyporesponsive to methacholine challenge at baseline and after allergen challenge. These data indicate that Egr-1 modulates TNF-alpha, IgE, and airway responsiveness in mice.

CC chemokine receptor-2 is not essential for the development of antigen-induced pulmonary eosinophilia and airway hyperresponsiveness.

Monocyte chemoattractant proteins-1 and -5 have been implicated as important mediators of allergic pulmonary inflammation in murine models of asthma. The only identified receptor for these two chemokines to date is the CCR2. To study the role of CCR2 in a murine model of Ag-induced asthma, we compared the pathologic and physiological responses of CCR2(-/-) mice with those of wild-type (WT) littermates following immunization and challenge with OVA. OVA-immunized/OVA-challenged (OVA/OVA) WT and CCR2(-/-) mice developed significant increases in total cells recovered by bronchoalveolar lavage (BAL) compared with their respective OVA-immunized/PBS-challenged (OVA/PBS) control groups. There were no significant differences in BAL cell counts and differentials (i.e., macrophages, PMNs, lymphocytes, and eosinophils) between OVA/OVA WT and CCR2(-/-) mice. Serologic evaluation revealed no significant difference in total IgE and OVA-specific IgE between OVA/OVA WT mice and CCR2(-/-) mice. Lung mRNA expression and BAL cytokine protein levels of IL-4, IL-5, and IFN-gamma were also similar in WT and CCR2(-/-) mice. Finally, OVA/OVA CCR2(-/-) mice developed increased airway hyper-responsiveness to a degree similar to that in WT mice. We conclude that following repeated airway challenges with Ag in sensitized mice, the development of Th2 responses (elevated IgE, pulmonary eosinophilia, and lung cytokine levels of IL-4 and IL5) and the development of airway hyper-responsiveness are not diminished by a deficiency in CCR2.

IP-10 is critical for effector T cell trafficking and host survival in Toxoplasma gondii infection.

The generation of an adaptive immune response against intracellular pathogens requires the recruitment of effector T cells to sites of infection. Here we show that the chemokine IP-10, a specific chemoattractant for activated T cells, controls this process in mice naturally infected with Toxoplasma gondii. Neutralization of IP-10 in infected mice inhibited the massive influx of T cells into tissues and impaired antigen-specific T cell effector functions. This resulted in >1000-fold increase in tissue parasite burden and a marked increase in mortality compared to control antibody-treated mice. These observations suggest that IP-10 may play a broader role in the localization and function of effector T cells at sites of Th1 inflammation.

Rapid oral challenge-desensitization for patients with aspirin-related urticaria-angioedema.

BACKGROUND: Acetylsalicylic acid (ASA), commonly known as aspirin, is indicated in the treatment of coronary artery disease (CAD). Many patients are denied treatment with ASA because of a history of ASA or nonsteroidal anti-inflammatory drug (NSAID)-induced urticaria or angioedema. OBJECTIVE: We sought to develop a safe and practical protocol to allow the administration of ASA to patients with a history of ASA- or NSAID-induced urticaria-angioedema. METHODS: Eleven subjects with a history of ASA- or NSAID-induced urticaria-angioedema were challenged-desensitized by oral protocols based on rapidly escalating doses of ASA. Most had CAD, one had a history of pulmonary embolism, and one had refractory chronic sinusitis and asthma. Starting doses ranged from 0.1 to 10 mg and were administered at intervals of 10 to 30 minutes. Dosing was individualized for each patient but followed this general sequence (in milligrams): 0.1, 0.3, 1, 3, 10, 20, 40, 81, 162, 325. RESULTS: Nine patients tolerated the procedure without adverse effects and continued taking ASA for periods ranging from 1 to 24 months, without development of urticaria or angioedema. A patient who had a history of chronic idiopathic urticaria in addition to aspirin-induced urticaria had chest tightness during the protocol. Another patient who had continuing urticaria and angioedema associated with antithyroid antibodies developed angioedema several hours after completing the protocol. CONCLUSION: In patients with historical ASA- or NSAID-induced urticaria-angioedema reactions but who did not have urticaria and angioedema independent of ASA/NSAID, rapid oral challenge-desensitization to ASA was performed safely and permitted patients with CAD and other diseases to receive treatment with ASA.

Contribution of nitric oxide synthases 1, 2, and 3 to airway hyperresponsiveness and inflammation in a murine model of asthma.

Asthma is a chronic disease characterized by increased airway responsiveness and airway inflammation. The functional role of nitric oxide (NO) and the various nitric oxide synthase (NOS) isoforms in human asthma is controversial. To investigate the role of NO in an established model of allergic asthma, mice with targeted deletions of the three known isoforms of NOS (NOS1, 2, and 3) were studied. Although the inducible (NOS2) isoform was significantly upregulated in the lungs of ovalbumin (OVA)-sensitized and -challenged (OVA/OVA) wild-type (WT) mice and was undetectable in similarly treated NOS2-deficient mice, airway responsiveness was not significantly different between these groups. OVA/OVA endothelial (NOS3)-deficient mice were significantly more responsive to methacholine challenge compared with similarly treated NOS1 and NOS1&3-deficient mice. Airway responsiveness in OVA/OVA neuronal (NOS1)-deficient and neuronal/endothelial (NOS1&3) double-deficient mice was significantly less than that observed in similarly treated NOS2 and WT groups. These findings demonstrate an important function for the nNOS isoform in controlling the inducibility of airway hyperresponsiveness in this model of allergic asthma.

Antigen-induced airway hyperresponsiveness, pulmonary eosinophilia, and chemokine expression in B cell-deficient mice.

Murine models of allergen-induced pulmonary inflammation share many features with human asthma, including the development of antigen-induced pulmonary eosinophilia, airway hyperresponsiveness, antigen-specific cellular and antibody responses, the elaboration of Th2 cytokines (interleukin [IL]-4 and IL-5), and the expression of chemokines with activity for eosinophils. We examined the role of B cells and antigen-specific antibody responses in such a model by studying the histopathologic and physiologic responses of B cell-deficient mice compared with wild-type controls, following systemic immunization and airway challenge with ovalbumin (OVA). Both OVA-challenged wild-type and B cell-deficient mice developed (1) airway hyperresponsiveness, (2) pulmonary inflammation with activated T cells and eosinophils, (3) IL-4 and IL-5 secretion into the airway lumen, and (4) increased expression of the eosinophil active chemokines eotaxin and monocyte chemotactic protein-3. There were no significant differences in either the pathologic or physiologic responses in the B cell-deficient mice compared with wild-type mice. These data indicate that B cells and antigen-specific antibodies are not required for the development of airway hyperresponsiveness, eosinophilic pulmonary inflammation, and chemokine expression in sensitized mice following aerosol challenge with antigen.

Interleukin-8 receptor modulates IgE production and B-cell expansion and trafficking in allergen-induced pulmonary inflammation.

We examined the role of the interleukin-8 (IL-8) receptor in a murine model of allergen-induced pulmonary inflammation using mice with a targeted deletion of the murine IL-8 receptor homologue (IL-8r-/-). Wild-type (Wt) and IL-8r-/- mice were systemically immunized to ovalbumin (OVA) and were exposed with either single or multiple challenge of aerosolized phosphate-buffered saline (OVA/PBS) or OVA (OVA/OVA). Analysis of cells recovered from bronchoalveolar lavage (BAL) revealed a diminished recruitment of neutrophils to the airway lumen after single challenge in IL-8r-/- mice compared with Wt mice, whereas multiply challenged IL-8r-/- mice had increased B cells and fewer neutrophils compared with Wt mice. Both Wt and IL-8r-/- OVA/OVA mice recruited similar numbers of eosinophils to the BAL fluid and exhibited comparable degrees of pulmonary inflammation histologically. Both total and OVA-specific IgE levels were greater in multiply challenged IL-8r-/- OVA/OVA mice than in Wt mice. Both the IL-8r-/- OVA/OVA and OVA/PBS mice were significantly less responsive to methacholine than their respective Wt groups, but both Wt and IL-8r mice showed similar degrees of enhancement after multiple allergen challenge. The data demonstrate that the IL-8r modulates IgE production, airway responsiveness, and the composition of the cells (B cells and neutrophils) recruited to the airway lumen in response to antigen.

Delayed wound healing and disorganized neovascularization in transgenic mice expressing the IP-10 chemokine.

IP-10 is a member of the alpha or cysteine-X amino acid-cysteine (CXC) chemokine family of chemotactic cytokines. High levels of IP-10 expression have been detected in a number of chronic human inflammatory conditions, including psoriasis, a common inflammatory disease of the skin. IP-10 has been shown to chemoattract activated T cells, inhibit the proliferation of endothelial cells, and inhibit the growth of tumors in vivo. To determine the capacity of IP-10 to modulate the inflammatory response in vivo, we have created transgenic mice that constitutively express IP-10 from keratinocytes. These mice developed normally and, in general, did not spontaneously recruit leukocytes into the skin or other organs that expressed the transgene. In addition, the transgenic mice had a normal cutaneous contact hypersensitivity cellular immune response. However, IP-10 transgenic mice had an abnormal wound healing response characterized by a more intense inflammatory phase and a prolonged and disorganized granulation phase with impaired blood vessel formation. These results have demonstrated that IP-10 can inhibit the neovascularization associated with a physiological response in vivo and have revealed a novel biologic activity of IP-10 as an inhibitor of wound healing.

Targeted disruption of the chemokine eotaxin partially reduces antigen-induced tissue eosinophilia.

The chemokines are a large group of chemotactic cytokines that regulate leukocyte trafficking and have recently been shown to inhibit human immunodeficiency virus entry into cells. Eotaxin is a C-C chemokine implicated in the recruitment of eosinophils in a variety of inflammatory disorders and, unlike all other eosinophil chemoattractants, is eosinophil specific. However, given the large number of chemoattractants that have activities on eosinophils, it is unclear whether eotaxin has an important role in vivo. Furthermore, it remains unclear why there is constitutive expression of eotaxin in healthy states in the absence of eosinophilic inflammation. To begin to determine the significance of eotaxin at baseline and during eosinophil-mediated disease processes, we have used targeted gene disruption to generate mice that are deficient in eotaxin. Such mice demonstrate that eotaxin enhances the magnitude of the early (but not late) eosinophil recruitment after antigen challenge in models of asthma and stromal keratitis. Surprisingly, a role for eotaxin in regulating the constitutive number of eosinophils in the peripheral circulation is also demonstrated. These results indicate a contributory role for eotaxin in the generation of peripheral blood and antigen-induced tissue eosinophilia.

Murine monocyte chemoattractant protein (MCP)-5: a novel CC chemokine that is a structural and functional homologue of human MCP-1.

The chemokines are a large family of cytokines that control the recruitment of leukocytes in immune and inflammatory responses. We describe the isolation of a novel murine CC chemokine that, based on its biological and structural features, we have named monocyte chemoattractant protein (MCP)-5. MCP-5 mapped to the CC chemokine cluster on mouse chromosome 11 and was most closely related to human MCP-1 in structure (66% amino acid identity). Purified recombinant MCP-5 protein was a potent chemoattractant for peripheral blood monocytes, was only weakly active on eosinophils at high doses, and was inactive on neutrophils. MCP-5 induced a calcium flux in peripheral blood mononuclear cells, but not in purified murine eosinophils or neutrophils. Consistent with these results, MCP-5 induced a calcium flux in human embryonic kidney (HEK)-293 cells transfected with human and murine CCR2, a CC chemokine receptor expressed on monocytes. MCP-5 did not induce a calcium flux in HEK-293 cells transfected with CCR1, CCR3, or CCR5. Constitutive expression of MCP-5 mRNA was detected predominantly in lymph nodes, and its expression was markedly induced in macrophages activated in vitro and in vivo. Moreover, MCP-5 expression was up-regulated in the lungs of mice following aerosolized antigen challenge of sensitized mice, and during the host response to infection with Nippostrongylus brasiliensis. These data indicate that MCP-5 is a novel and potent monocyte active chemokine that is involved in allergic inflammation and the host response to pathogens.

T cell-dependent regulation of eotaxin in antigen-induced pulmonary eosinophila.

T lymphocytes have been implicated in controlling the recruitment of eosinophils into the lung in murine models of allergic asthma. The mechanism by which T cells assist in the recruitment of eosinophils to the lung in these models is not completely understood. We hypothesized that eosinophil-active chemokines might be regulated by antigen (Ag)-induced T cell activation in vivo and thereby mediate T cell-dependent eosinophil recruitment. To test this hypothesis, we examined the effect of an anti-CD3 mAb on Ag-induced pulmonary eosinophilia and correlated this with the expression of three eosinophil-active chemokines: eotaxin, macrophage inflammatory protein (MIP)-1 alpha, and RANTES. We found that Ag-induced pulmonary eosinophilia was associated with the induction of eotaxin and MIP-1 alpha, but not RANTES mRNA. Prechallenge treatment with anti-CD3 mAb inhibited eotaxin, but not MIP-1 alpha and RANTES mRNA induction, and significantly reduced eosinophil accumulation in the lung. In addition, Ag-specific antibody responses and mast cell degranulation after Ag challenge in sensitized mice were not affected by T cell elimination, and were not sufficient to induce the expression of eotaxin and cause pulmonary eosinophilia. These findings suggest that eotaxin is one of the molecular links between Ag-specific T cell activation and the recruitment of eosinophils into the airways.

The effect of an anti-CD3 monoclonal antibody on bleomycin-induced lymphokine production and lung injury.

Acute lung injury was produced in C57BL/6 mice by the intratracheal (i.t.) administration of bleomycin (BLM). Following injection of 0.1 U BLM, CD3+ lymphocytes and the production of the T-helper-1 (Th1) lymphokines interleukin-2 (IL-2) and interferon-gamma (IFN-gamma) were increased in lung and lymph nodes. The production of the Th2 cytokine IL-4 by lung lymphocytes was decreased. Intraperitoneal (i.p.) injection of a rat antimurine CD3 (YCD3) monoclonal antibody (mAb) blocked the accumulation of pulmonary CD3+ cells for up to 14 d and effectively suppressed IL-2 and IL-4 but not IFN-gamma production by lung lymphocytes throughout the protocol. Secretion of all of the above lymphokines by lymph node cells was inhibited by YCD3 treatment. Administration of YCD3 diminished pulmonary fibrosis and increased survival (p < 0.01) following BLM administration compared with mice treated with an isotype-matched control mAb. Initiating treatment with YCD3 at Days 5-7 following BLM also decreased pulmonary fibrosis and significantly reduced mortality (p < 0.02). We conclude that BLM yields a potentially lethal fibroinflammatory response in the lung that is markedly diminished by antagonizing the functional activities of CD3+ cells in vivo.

Sequestration of inhaled particulate antigens by lung phagocytes. A mechanism for the effective inhibition of pulmonary cell-mediated immunity.

Dendritic cells (DCs) have emerged as the dominant antigen-presenting cells (APCs) of the lung, playing a vital role in the induction of cell-mediated immunity to inhaled antigens. We have previously demonstrated that an airway challenge with the soluble antigen hen egg lysozyme yields rapid acquisition of specific antigen-presenting cell activity by purified pulmonary DCs and a cell-mediated immune response in the lung upon secondary challenge. To examine how a particulate antigen leads to a cell-mediated response in vivo, graded concentrations of heat-killed Listeria (HKL) were injected intratracheally into Lewis rats. The bacteria were rapidly ingested by lung macrophages and polymorphonuclear leukocytes. The ability of purified pulmonary DCs pulsed in vivo by an airway challenge with HKL to subsequently stimulate HKL-specific responses ex vivo showed a threshold response, requiring a dose in excess of 10(9) organisms/rat. By contrast, all dosages of HKL yielded specific sensitization of lymphocytes in the draining bilar nodes. Pulmonary DCs purified from rats after a secondary in vivo airway challenge with HKL at day 14 were ineffective antigen-presenting cells except at high dosages of antigen. The generation of cell-mediated pulmonary inflammation paralleled the antigen-presenting cell activity of pulmonary DCs and was observed only at high antigen dosages. Hen egg lysozyme immobilized onto polystyrene beads and injected intratracheally yielded comparable results to those observed with HKL. We suggest that a pulmonary cellular immune response is generated to an inhaled particulate antigen when the protective phagocytic capacities of the lung are exceeded and antigen is able to interact directly with interstitial DCs. The diversion of particulate antigens by pulmonary phagocytes may help to limit undesirable pulmonary inflammation while allowing the generation of antigen-specific immune lymphocytes in vivo.