***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Objective Psychological factors increase the risk to develop  postinfectious IBS ( PI-IBS ) , but the mechanisms involved are unclear . As stress affects the immune system , we investigated the potential interaction between psychological factors , the immune response against infectious gastroenteritis ( IGE ) and the development of IGE and PI-IBS in a large cohort exposed to contaminated drinking water . Design 18 620 people exposed to contaminated drinking water ( norovirus , Giardia lamblia , Campylobacter jejuni )  were invited to participate in a prospect i ve controlled cohort study . They were asked to complete question naires assessing demographic , psychological and clinical data during the outbreak and 1 year later . At both time points , in-depth immune function ( peripheral blood and rectal biopsies ) was studied in a subgroup of subjects . Results 1379 subjects completed the question naires during the outbreak , of which 271 developed IGE . Risk factors for IGE included younger age , pre-existing dyspepsia-like symptoms , anxiety and drinking contaminated tap water . Anxiety scores before the outbreak inversely correlated with interleukin-2-expressing CD4 + T cells ( r=0.6 , p=0.01 , n=23 ) . At follow-up , 34 of 172 ( 20 % ) IGE subjects developed IBS compared with 24/366 exposed participants ( 7 % , p<0.0001 , χ2 test ) . A Th2 cytokine phenotype at time of infection was associated with increased risk for PI-IBS 1 year later . Except for increased B cell numbers , no evidence for systemic or rectal mucosal immune activation in PI-IBS was demonstrated at follow-up . Conclusions Our study shows that the increased risk of patients with psychological comorbidity to develop PI-IBS may partly result from an increased susceptibility to develop IGE , possibly result ing from a Th2-immune bias . Trial registration number ( Clinical Trials.gov NCT01497847 ) Prenatal anxiety has been linked with altered immune function in offspring in animal studies , but the relevance for human health is unknown . We examined prenatal maternal anxiety as a predictor of adaptive immunity in infants at 2 and 6 months of age as part of a prospect i ve longitudinal study . The humoral immune response to hepatitis B vaccine was assessed at 2 months ( n=80 ) and 6 months ( n=76 ) of age . Prenatal anxiety predicted lower hepatitis B antibody titers at 6 months of age independent of obstetric and socio-demographic covariates ; the effects were limited to those infants who had not completed the 3-dose vaccine series ( for transformed titer values , r=-.36 , p<.05 ) . Cell-mediated immune responses at 2 ( n=56 ) and 6 ( n=54 ) months of age were examined by ELISpot assays for interferon(IFN)-γ , interleukin(IL)-2 , and IL-4 responder cell frequencies to three antigens : hepatitis B surface antigen , tetanus toxoid , and phytohaemagglutinin ( PHA ) . Prenatal maternal  anxiety was associated with reduced IFN-γ and increased IL-4 responder cell frequencies at 6 months of age , independent of obstetric and socio-demographic covariates . No effect of prenatal anxiety was found on adaptive immunity at 2 months of age . The findings provide the first demonstration in humans that prenatal anxiety alters adaptive immunity in the infant Afghanistan provides a unique setting in which to appraise psychosocial stress , given the context of persistent insecurity and widening economic ine quality . In Kabul , people experience widespread frustrations , hinging on restricted opportunities for social advancement , education , and employment . We appraised social aspirations , every‐day stressors , psychosocial distress , and mental health problems for a r and om sample of 161 male and female students at Kabul University . The survey featured both existing and newly‐developed instruments ( Self‐Reported Question naire SRQ‐20 ; Afghan Symptom Checklist ; Afghan Daily Stressor Scale ; and Social Aspirations and Frustrations ) , implementing both internationally‐used and culturally‐grounded measures of mental health assessment . We also included indicators of physical health ( blood pressure , immune responses to Epstein‐Barr virus ( EBV ) , C‐reactive protein , and body mass index ) , to map physiological function with reported psychosocial distress . This young , urban elite expressed major feelings of frustrations , related to physical , economic , social , and political stressors of day‐to‐day life in Kabul . There were striking gender differences for psychosocial and physiological markers of wellbeing ; specifically , women showed poorer mental health ( SRQ‐20 , P = 0.01 ) and elevated EBV antibody titers ( P = 0.003 ) . Both diastolic blood pressure ( P = 0.018 ) and EBV ( P = 0.038 ) were associated with a subscale of family stressors among women , but not among men , consistent with women 's social vulnerabilities to stressful family dynamics . This is the first study to integrate approaches from anthropology , cross‐cultural psychiatry , and human biology to document social stressors , psychosocial distress , and physiological wellbeing in the challenging setting of present‐day Afghanistan . Am . J.Hum . Biol . , 2008 . © 2008 Wiley‐Liss , OBJECTIVE In a previous study we observed a continuous reduction of salivary IgA concentration ( [ sIgA ] ) during a period of academic stress . This reduction of sIgA concentration exceeded the stress period by at least 1 week . The present study aim ed to replicate and extend our previous finding . In particular , we wanted to examine the time of recovery of [ sIgA ] alterations associated with academic stress . METHOD Twenty-seven participants in a major medical exam and 27 controls not participating in any exam during the study provided daily saliva sample s ( immediately after awakening ) , from the 6th day prior to their last exam until the 14th day afterwards , for analysis of salivary IgA. Data were averaged for the last weeks of exams and the first and second week after exams , respectively . RESULTS A prolonged reduction of sIgA in exam students as compared to controls was observed . Fourteen days post-stress sIgA concentrations of exam students were still significantly lower than control levels ( P=0.004 ) . No recovery was observable . At the same time exam students and controls did not differ in terms of self-reported stress and recovery . CONCLUSIONS Psychological and immunological stress effects may be dissociated , the latter considerably exceeding the stress period . A closer look at the temporal dynamics of stress-induced immune alterations might increase our underst and ing of psychoimmuno relationships Background / objective Tuberculosis ( TB ) and depression were major public health issues worldwide and the mutual causative relationships between them were not exhaustive . This study was performed to explore the association between depression , comorbidities , and the risk of pulmonary TB in Taiwan . Methods The cohort study used the data base of the Taiwan National Health Insurance Program . The depression group included 34,765 subjects aged 20–84 years with newly diagnosed depression from 2000 to 2012 , and the non-depression group included 138,187 r and omly selected subjects without depression . Both depression and non-depression groups were matched with respect to sex , age , and comorbidities . We explored the incidence of pulmonary TB at the end of 2013 in both the groups and used multivariable Cox proportional hazards regression model to explore the hazard ratio ( HR ) and 95 % confidence interval ( CI ) for the risk of pulmonary TB associated with depression . Results The overall incidence of pulmonary TB was 1.16-fold greater in the depression group than that in the non-depression group ( 1.52 vs. 1.31 per 1,000 person-years , 95 % CI 1.12 , 1.21 ) . The multivariable Cox proportional hazards regression analysis revealed that the adjusted HR of pulmonary TB was 1.15 for the depression group ( 95 % CI 1.03 , 1.28 ) , compared with the non-depression group . Conclusion Depression is associated with 1.15-fold increased hazard of pulmonary TB in Taiwan Objective To analyze the relationship of anxiety state with CD4 + level and CD4+/CD8 + ratio and to observe the effect of Chinese medicine ( CM ) treatment on anxiety in chronic hepatitis B ( CHB ) patients . Methods The anxiety state of 120 CHB patients was evaluated based on Hamilton Anxiety Scale ( HAMA ) scoring . According to the scores , 63 patients with scores ≥14 were classified to anxiety and 57 patients with scores < 14 to non-anxiety . The differences in CD4 + cells and CD4+/CD8 + ratio between patients with anxiety and non-anxiety were analyzed . Moreover , 63 patients with anxiety were r and omized into two groups : 31 in the control group were treated with lamivudine ( 100 mg per day ) alone and 32 in the observation group were given equal dosage lamivudine combined with CM treatment depending on syndrome differentiation , all for 12 weeks . The effects of treatment on anxiety state and T-lymphocyte subsets as well as its impact on some CHB-related indices were observed and compared . Results The anxiety state of CHB patients was negatively correlated with CD4 + and CD4+/CD8 + ; the level of CD4 + in patients with anxiety was significantly lower than that in non-anxiety patients ( P<0.01 or P<0.05 ) . After treatment , anxiety state in the observation group was significantly improved , with their HAMA scores significantly lowered ( P<0.01 ) , and the levels of CD4 + and CD4+/CD8 + were significantly higher than those in the control group ( P<0.05 or P<0.01 ) . Moreover , the alanine transaminase recovery rate and the HBV-DNA-negative conversion rate in the observation group were significantly higher than those in the control group , respectively ( P<0.05 ) . Conclusions The anxiety state of CHB patients was related to CD4 + and CD4+/CD8 + levels . CM treatment could improve the anxiety state and showed certain regulatory effect on the patients ’ immune system Background Identification of blood biomarkers that prospect ively predict progression of Mycobacterium tuberculosis infection to tuberculosis disease may lead to interventions that impact the epidemic . Methods Healthy , M. tuberculosis infected South African adolescents were followed for 2 years ; blood was collected every 6 months . A prospect i ve signature of risk was derived from whole blood RNA-Sequencing data by comparing participants who ultimately developed active tuberculosis disease ( progressors ) with those who remained healthy ( matched controls ) . After adaptation to multiplex qRT-PCR , the signature was used to predict tuberculosis disease in untouched adolescent sample s and in sample s from independent cohorts of South African and Gambian adult progressors and controls . The latter participants were household contacts of adults with active pulmonary tuberculosis disease . Findings Of 6,363 adolescents screened , 46 progressors and 107 matched controls were identified . A 16 gene signature of risk was identified . The signature predicted tuberculosis progression with a sensitivity of 66·1 % ( 95 % confidence interval , 63·2–68·9 ) and a specificity of 80·6 % ( 79·2–82·0 ) in the 12 months preceding tuberculosis diagnosis . The risk signature was vali date d in an untouched group of adolescents ( p=0·018 for RNA-Seq and p=0·0095 for qRT-PCR ) and in the independent South African and Gambian cohorts ( p values < 0·0001 by qRT-PCR ) with a sensitivity of 53·7 % ( 42·6–64·3 ) and a specificity of 82·8 % ( 76·7–86 ) in 12 months preceding tuberculosis . Interpretation The whole blood tuberculosis risk signature prospect ively identified persons at risk of developing active tuberculosis , opening the possibility for targeted intervention to prevent the disease . Funding Bill and Melinda Gates Foundation , the National Institutes of Health , Aeras , the European Union and the South African Medical Research Council ( detail at end of text ) Vaccines to protect against tuberculosis ( TB ) are urgently needed . We performed a case – control analysis to identify immune correlates of TB disease risk in Bacille Calmette – Guerin ( BCG ) immunized infants from the MVA85A efficacy trial . Among 53 TB case infants and 205 matched controls , the frequency of activated HLA-DR+ CD4 + T cells associates with increased TB disease risk ( OR=1.828 , 95 % CI=1.25–2.68 , P=0.002 , FDR=0.04 , conditional logistic regression ) . In an independent study of Mycobacterium tuberculosis-infected adolescents , activated HLA-DR+ CD4 + T cells also associate with increased TB disease risk ( OR=1.387 , 95 % CI=1.068–1.801 , P=0.014 , conditional logistic regression ) . In infants , BCG-specific T cells secreting IFN-γ associate with reduced risk of TB ( OR=0.502 , 95 % CI=0.29–0.86 , P=0.013 , FDR=0.14 ) . The causes and impact of T-cell activation on disease risk should be considered when design ing and testing TB vaccine c and i date s for these population The authors ' goal was to evaluate 
    Output:
    
The literature provides evidence of a relationship between psychosocial factors and immune biomarkers .
While the direction and strength of associations is heterogenous , some overarching patterns emerged : adverse psychosocial factors ( e.g. stress ) were generally associated with compromised vaccine response and higher antibody titres to herpesviruses , and vice versa for positive psychosocial factors ( e.g. social support ) .
Conclusions The evidence identifies pathways linking psychosocial factors and immune response : co-viral infection and immune suppression , both of which are potentially relevant to TB and BCG response .