TLR2, but Not TLR4, Is Required for Effective Host Defence against Chlamydia Respiratory Tract Infection in Early Life

Chlamydia pneumoniae commonly causes respiratory tract infections in children, and epidemiological investigations strongly link infection to the pathogenesis of asthma. The immune system in early life is immature and may not respond appropriately to pathogens. Toll-like receptor (TLR)2 and 4 are regarded as the primary pattern recognition receptors that sense bacteria, however their contribution to innate and adaptive immunity in early life remains poorly defined. We investigated the role of TLR2 and 4 in the induction of immune responses to Chlamydia muridarum respiratory infection, in neonatal wild-type (Wt) or TLR2-deficient (−/−), 4−/− or 2/4−/− BALB/c mice. Wt mice had moderate disease and infection. TLR2−/− mice had more severe disease and more intense and prolonged infection compared to other groups. TLR4−/− mice were asymptomatic. TLR2/4−/− mice had severe early disease and persistent infection, which resolved thereafter consistent with the absence of symptoms in TLR4−/− mice. Wt mice mounted robust innate and adaptive responses with an influx of natural killer (NK) cells, neutrophils, myeloid (mDCs) and plasmacytoid (pDCs) dendritic cells, and activated CD4+ and CD8+ T-cells into the lungs. Wt mice also had effective production of interferon (IFN)γ in the lymph nodes and lung, and proliferation of lymph node T-cells. TLR2−/− mice had more intense and persistent innate (particularly neutrophil) and adaptive cell responses and IL-17 expression in the lung, however IFNγ responses and T-cell proliferation were reduced. TLR2/4−/− mice had reduced innate and adaptive responses. Most importantly, neutrophil phagocytosis was impaired in the absence of TLR2. Thus, TLR2 expression, particularly on neutrophils, is required for effective control of Chlamydia respiratory infection in early life. Loss of control of infection leads to enhanced but ineffective TLR4-mediated inflammatory responses that prolong disease symptoms. This indicates that TLR2 agonists may be beneficial in the treatment of early life Chlamydia infections and associated diseases

Supporting self-management with an internet intervention for low back pain in primary care: a RCT (SupportBack 2)

Background Low back pain is highly prevalent and a leading cause of disability. Internet-delivered interventions may provide rapid and scalable support for behavioural self-management. There is a need to determine the effectiveness of highly accessible, internet-delivered support for self-management of low back pain. Objective To determine the clinical and cost-effectiveness of an accessible internet intervention, with and without physiotherapist telephone support, on low back pain-related disability. Design A multicentre, pragmatic, three parallel-arm randomised controlled trial with parallel economic evaluation. Setting Participants were recruited from 179 United Kingdom primary care practices. Participants Participants had current low back pain without indicators of serious spinal pathology. Interventions Participants were block randomised by a computer algorithm (stratified by severity and centre) to one of three trial arms: (1) usual care, (2) usual care + internet intervention and (3) usual care + internet intervention + telephone support. ‘SupportBack’ was an accessible internet intervention. A physiotherapist telephone support protocol was integrated with the internet programme, creating a combined intervention with three brief calls from a physiotherapist. Outcomes The primary outcome was low back pain-related disability over 12 months using the Roland–Morris Disability Questionnaire with measures at 6 weeks, 3, 6 and 12 months. Analyses used repeated measures over 12 months, were by intention to treat and used 97.5% confidence intervals. The economic evaluation estimated costs and effects from the National Health Service perspective. A cost–utility study was conducted using quality-adjusted life-years estimated from the EuroQol-5 Dimensions, five-level version. A cost-effectiveness study estimated cost per point improvement in the Roland–Morris Disability Questionnaire. Costs were estimated using data from general practice patient records. Researchers involved in data collection and statistical analysis were blind to group allocation. Results Eight hundred and twenty-five participants were randomised (274 to usual primary care, 275 to usual care + internet intervention and 276 to the physiotherapist-supported arm). Follow-up rates were 83% at 6 weeks, 72% at 3 months, 70% at 6 months and 79% at 12 months. For the primary analysis, 736 participants were analysed (249 usual care, 245 internet intervention, 242 telephone support). There was a small reduction in the Roland–Morris Disability Questionnaire over 12 months compared to usual care following the internet intervention without physiotherapist support (adjusted mean difference of −0.5, 97.5% confidence interval −1.2 to 0.2; p = 0.085) and the internet intervention with physiotherapist support (−0.6, 97.5% confidence interval −1.2 to 0.1; p = 0.048). These differences were not statistically significant at the level of 0.025. There were no related serious adverse events. Base-case results indicated that both interventions could be considered cost-effective compared to usual care at a value of a quality-adjusted life-year of £20,000; however, the SupportBack group dominated usual care, being both more effective and less costly. Conclusions The internet intervention, with or without physiotherapist telephone support, did not significantly reduce low back pain-related disability across 12 months, compared to usual primary care. The interventions were safe and likely to be cost-effective. Balancing clinical effectiveness, cost-effectiveness, accessibility and safety findings will be necessary when considering the use of these interventions in practice. Trial registration This trial is registered as ISRCTN14736486. Funding This award was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme (NIHR award ref: 16/111/78) and is published in full in Health Technology Assessment; Vol. 29, No. 7. See the NIHR Funding and Awards website for further award information