Multiorgan MRI findings after hospitalisation with COVID-19 in the UK (C-MORE): a prospective, multicentre, observational cohort study

INTRODUCTION

The multiorgan impact of moderate to severe coronavirus infections in the post-acute phase is still poorly understood. We aimed to evaluate the excess burden of multiorgan abnormalities after hospitalisation with COVID-19, evaluate their determinants, and explore associations with patient-related outcome measures.

METHODS

In a prospective, UK-wide, multicentre MRI follow-up study (C-MORE), adults (aged ≥18 years) discharged from hospital following COVID-19 who were included in Tier 2 of the Post-hospitalisation COVID-19 study (PHOSP-COVID) and contemporary controls with no evidence of previous COVID-19 (SARS-CoV-2 nucleocapsid antibody negative) underwent multiorgan MRI (lungs, heart, brain, liver, and kidneys) with quantitative and qualitative assessment of images and clinical adjudication when relevant. Individuals with end-stage renal failure or contraindications to MRI were excluded. Participants also underwent detailed recording of symptoms, and physiological and biochemical tests. The primary outcome was the excess burden of multiorgan abnormalities (two or more organs) relative to controls, with further adjustments for potential confounders. The C-MORE study is ongoing and is registered with ClinicalTrials.gov, NCT04510025.

FINDINGS

Of 2710 participants in Tier 2 of PHOSP-COVID, 531 were recruited across 13 UK-wide C-MORE sites. After exclusions, 259 C-MORE patients (mean age 57 years [SD 12]; 158 [61%] male and 101 [39%] female) who were discharged from hospital with PCR-confirmed or clinically diagnosed COVID-19 between March 1, 2020, and Nov 1, 2021, and 52 non-COVID-19 controls from the community (mean age 49 years [SD 14]; 30 [58%] male and 22 [42%] female) were included in the analysis. Patients were assessed at a median of 5·0 months (IQR 4·2-6·3) after hospital discharge. Compared with non-COVID-19 controls, patients were older, living with more obesity, and had more comorbidities. Multiorgan abnormalities on MRI were more frequent in patients than in controls (157 [61%] of 259 vs 14 [27%] of 52; p<0·0001) and independently associated with COVID-19 status (odds ratio [OR] 2·9 [95% CI 1·5-5·8]; padjusted=0·0023) after adjusting for relevant confounders. Compared with controls, patients were more likely to have MRI evidence of lung abnormalities (p=0·0001; parenchymal abnormalities), brain abnormalities (p<0·0001; more white matter hyperintensities and regional brain volume reduction), and kidney abnormalities (p=0·014; lower medullary T1 and loss of corticomedullary differentiation), whereas cardiac and liver MRI abnormalities were similar between patients and controls. Patients with multiorgan abnormalities were older (difference in mean age 7 years [95% CI 4-10]; mean age of 59·8 years [SD 11·7] with multiorgan abnormalities vs mean age of 52·8 years [11·9] without multiorgan abnormalities; p<0·0001), more likely to have three or more comorbidities (OR 2·47 [1·32-4·82]; padjusted=0·0059), and more likely to have a more severe acute infection (acute CRP >5mg/L, OR 3·55 [1·23-11·88]; padjusted=0·025) than those without multiorgan abnormalities. Presence of lung MRI abnormalities was associated with a two-fold higher risk of chest tightness, and multiorgan MRI abnormalities were associated with severe and very severe persistent physical and mental health impairment (PHOSP-COVID symptom clusters) after hospitalisation.

INTERPRETATION

After hospitalisation for COVID-19, people are at risk of multiorgan abnormalities in the medium term. Our findings emphasise the need for proactive multidisciplinary care pathways, with the potential for imaging to guide surveillance frequency and therapeutic stratification.

FUNDING

UK Research and Innovation and National Institute for Health Research.

Clinical characteristics with inflammation profiling of long COVID and association with 1-year recovery following hospitalisation in the UK: a prospective observational study

BACKGROUND

No effective pharmacological or non-pharmacological interventions exist for patients with long COVID. We aimed to describe recovery 1 year after hospital discharge for COVID-19, identify factors associated with patient-perceived recovery, and identify potential therapeutic targets by describing the underlying inflammatory profiles of the previously described recovery clusters at 5 months after hospital discharge.

METHODS

The Post-hospitalisation COVID-19 study (PHOSP-COVID) is a prospective, longitudinal cohort study recruiting adults (aged ≥18 years) discharged from hospital with COVID-19 across the UK. Recovery was assessed using patient-reported outcome measures, physical performance, and organ function at 5 months and 1 year after hospital discharge, and stratified by both patient-perceived recovery and recovery cluster. Hierarchical logistic regression modelling was performed for patient-perceived recovery at 1 year. Cluster analysis was done using the clustering large applications k-medoids approach using clinical outcomes at 5 months. Inflammatory protein profiling was analysed from plasma at the 5-month visit. This study is registered on the ISRCTN Registry, ISRCTN10980107, and recruitment is ongoing.

FINDINGS

2320 participants discharged from hospital between March 7, 2020, and April 18, 2021, were assessed at 5 months after discharge and 807 (32·7%) participants completed both the 5-month and 1-year visits. 279 (35·6%) of these 807 patients were women and 505 (64·4%) were men, with a mean age of 58·7 (SD 12·5) years, and 224 (27·8%) had received invasive mechanical ventilation (WHO class 7-9). The proportion of patients reporting full recovery was unchanged between 5 months (501 [25·5%] of 1965) and 1 year (232 [28·9%] of 804). Factors associated with being less likely to report full recovery at 1 year were female sex (odds ratio 0·68 [95% CI 0·46-0·99]), obesity (0·50 [0·34-0·74]) and invasive mechanical ventilation (0·42 [0·23-0·76]). Cluster analysis (n=1636) corroborated the previously reported four clusters: very severe, severe, moderate with cognitive impairment, and mild, relating to the severity of physical health, mental health, and cognitive impairment at 5 months. We found increased inflammatory mediators of tissue damage and repair in both the very severe and the moderate with cognitive impairment clusters compared with the mild cluster, including IL-6 concentration, which was increased in both comparisons (n=626 participants). We found a substantial deficit in median EQ-5D-5L utility index from before COVID-19 (retrospective assessment; 0·88 [IQR 0·74-1·00]), at 5 months (0·74 [0·64-0·88]) to 1 year (0·75 [0·62-0·88]), with minimal improvements across all outcome measures at 1 year after discharge in the whole cohort and within each of the four clusters.

INTERPRETATION

The sequelae of a hospital admission with COVID-19 were substantial 1 year after discharge across a range of health domains, with the minority in our cohort feeling fully recovered. Patient-perceived health-related quality of life was reduced at 1 year compared with before hospital admission. Systematic inflammation and obesity are potential treatable traits that warrant further investigation in clinical trials.

FUNDING

UK Research and Innovation and National Institute for Health Research.

Chemical constituents and their biological activities from Taunggyi (Shan state) medicinal plants

Medicinal plants are essential aspects of readily available primary healthcare remedies. Phytochemical constituents of medicinal plants cover a broad variety of chemical fields to explore medicines. This review highlights selected empirical data on traditional uses, phytochemistry, and pharmacological properties of Taunggyi medicinal plants, Andrographis paniculata, Physalis peruviana, and Cassia fistula. Historically, these plants have been used for many infections and diseases in Taunggyi. More than 361 chemical compounds have been isolated and identified from the selected plants. Some of the chemical constituents have substantial pharmacological properties. It is clear that these herbs have significant potential for useful natural supplements in many contemporary diseases. Thus, the aim of this review compiles an ethnobotanical survey and documentation of medicinal plants in Taunggyi (Myanmar). This review will also inspire Myanmar researcher's to further investigate the potential of these plants in their future work into new compound and new drugs.

Frailty has a stronger association with inflammation than age in older veterans

BACKGROUND

Upregulation of pro-inflammatory cytokines has not only been associated with increased morbidity and mortality in older adults but also has been linked to frailty. In the current study we aimed to compare the relative relationship of age and frailty on inflammation and thrombosis in older veterans.

RESULTS

We analyzed 117 subjects (age range 62-95 years; median 81) divided into 3 cohorts: non-frail, pre-frail and frail based on the Fried phenotype of frailty. Serum inflammatory markers were determined using commercially available ELISA kits. Frail and pre-frail (PF) subjects had higher levels than non-frail (NF) subjects of IL-6 (NF vs. PF: p = 0.002; NF vs. F: p < 0.001), TNFR1 (NF vs. F: p = 0.012), TNFRII (NF vs. F: 0.002; NF vs. PF: p = 0.005) and inflammatory index: = 0.333*log(IL-6) + 0.666*log(sTNFR1) (NF vs. F: p = 0.009; NF vs. PF: p < 0.001). Frailty status explained a greater percent of variability in markers of inflammation than age: IL-6 (12 % vs. 0.3 %), TNFR1 (5 % vs. 4 %), TNFR2 (11 % vs. 6 %), inflammatory index (16 % vs. 8 %). Aging was significantly associated with higher fibrinogen (p = 0.04) and D-dimer levels (p = 0.01) but only among NF subjects.

CONCLUSION

In conclusion, these data suggest that among older veterans, frailty status has a stronger association with inflammation and the inflammatory index than age does. Larger studies, in more diverse populations are needed to confirm these findings.

CD4 T-cell cytokine correlates of diagnostic tests for latent tuberculous infection in HIV-1-infected subjects

SETTING

Public human immunodeficiency virus (HIV) clinic and tuberculosis (TB) clinics in Kampala, Uganda.

OBJECTIVE

To examine TB-specific CD4 T-cell single and polyfunctional cytokine correlates of clinical diagnostic tests for latent tuberculous infection (LTBI) in HIV-1-infected subjects.

DESIGN

Thirty antiretroviral therapy-naïve HIV-1-infected adults without active TB disease underwent clinical tuberculin skin test (TST), interferon-gamma release assay (IGRA), and in vitro flow cytometry analysis on cells stimulated with purified protein derivative (PPD) and TB antigens early secreted antigenic target 6 + culture filtrate protein 10 (EC) for frequencies of interleukin (IL) 2, IL-17, interferon-gamma (IFN-γ) and tumor necrosis factor alpha (TNF-α) expressing cells.

RESULTS

PPD-specific CD4 T-cell expression of TNF-α and IFN-γ was higher in the TST-positive than in the TST-negative group. EC-specific CD4 T-cell expression of TNF-α and IL-2 was higher in the TST+ group than in the TST- group. Expression of both PPD and EC-specific expression of IL-2, IFN-γ and TNF-α were greater in IGRA-positive than in IGRA-negative subjects. The TST+ group exhibited greater polyfunctionality than the TST- group. All cytokine combinations that contained TNF-α correlated strongly with TST size.

CONCLUSION

While IL-2, IFN-γ and TNF-α correlate with clinical tests of LTBI, TNF-α is the dominant cytokine correlating with both TST size and magnitude of IGRA response.

Inhibition of Mycobacterium tuberculosis-induced signalling by transforming growth factor-β in human mononuclear phagocytes

Tuberculosis (TB) is associated with excessive production and bioactivation of transforming growth factor bets (TGF-β) in situ. Here, modification of expression of components of plasminogen/plasmin pathway in human monocytes (MN) by inhibitors of TGF-β signalling was examined. Smad3 siRNA effectively inhibited TGF-β-induced urokinase plasminogen activator receptor (uPAR). Agents known to interfere with TGF-β signalling, including the Smad inhibitors SIS3 and erythromycin derivatives, and ALK5 receptor inhibitor (SB 431542) in inhibition of uPAR expression in response to Mycobacterium tuberculosis (MTB) were examined. Inhibition by SIS3 only inhibited uPAR mRNA significantly. SIS3 may prove to be an effective adjunct to TB therapy.

Polyfunctional Mycobacterium tuberculosis-specific effector memory CD4+ T cells at sites of pleural TB

Pleural tuberculosis (TB) is a common presentation of Mycobacterium tuberculosis (MTB) infection, and despite spontaneous resolution remains a strong risk factor for reactivation pulmonary TB in a majority of individuals. This study was undertaken to further understand the characteristics of immune cells at sites of pleural TB. A significant shift toward memory CD4+ T cells with an effector phenotype and away from naïve CD4+ T cells in pleural fluid as compared to blood mononuclear cells was found. These data suggest that effector T cells are capable of migrating to sites of active TB infection and/or the differentiation to effector phenotype T cells in situ is highly amplified. Using multi-parameter flow cytometry analysis, a significant portion of MTB-specific CD4+ T cells in the pleural space were polyfunctional demonstrating two, three or four simultaneous functions including IFN-gamma, IL-2, TNF-alpha, and or MIP-1 alpha production. A greater proportion of these polyfunctional cells were of effector memory rather than central memory phenotype. The role of these polyfunctional MTB-specific CD4+ T cells at sites of pleural TB requires further study.

Preserved MHC-II antigen processing and presentation function in chronic HCV infection

Individuals with chronic HCV infection have impaired response to vaccine, though the etiology remains to be elucidated. Dendritic cells (DC) and monocytes (MN) provide antigen uptake, processing, presentation, and costimulatory functions necessary to achieve optimal immune responses. The integrity of antigen processing and presentation function within these antigen presenting cells (APC) in the setting of HCV infection has been unclear. We used a novel T cell hybridoma system that specifically measures MHC-II antigen processing and presentation function of human APC. Results demonstrate MHC-II antigen processing and presentation function is preserved in both myeloid DC (mDC) and MN in the peripheral blood of chronically HCV-infected individuals, and indicates that an alteration in this function does not likely underlie the defective HCV-infected host response to vaccination.

Inhibition of human immunodeficiency virus-1 (HIV-1) by beta-chemokine analogues in mononuclear cells from HIV-1-infected patients with active tuberculosis

Tuberculosis (TB) enhances human immunodeficiency virus-1 (HIV-1) activity in patients with dual HIV-1/TB infection. Therapies that control augmentations of HIV-1 activity at sites of Mycobacterium tuberculosis (MTB) infection may be useful in inhibition of viral expansion. Regulated upon activation, normal T-cell expressed and secreted (RANTES) analogues (AOP and NNY) are potent in inhibiting the entry of primary HIV-1 isolates into host mononuclear cells. These analogues were used to inhibit MTB-induced HIV-1 entry in blood monunuclear cells (PBMC) from patients with pulmonary TB, and pleural fluid mononuclear cells (PFMC) from patients with pleural TB. PBMC or PFMC were cultured with and without MTB in presence and absence of RANTES analogues. HIV-1 strong stop DNA was assessed by real-time polymerase chain reaction (PCR) as a measure of infection. CCR5 mRNA was assessed by real-time reverse transcription (RT)-PCR and by immunostaining and FACS analysis. HIV-1 infection was induced by MTB in vitro in PBMC from the majority (14 of 20) of HIV-1/TB subjects, and new infection was inhibited by AOP- or NNY-RANTES. HIV-1 infection was also inhibited by these reagents in MTB-induced PFMC from three of three patients with pleural TB. Expression of CCR5 mRNA was significantly induced by MTB in PBMC from patients with pulmonary TB. Further, expression of CCR5 was higher in PFMC compared to PBMC from patients with pleural TB. Also, CCR5 was fourfold higher on CD14(+) pleural mononuclear cells than on CD4(+) lymphocytes. Blocking new HIV-1 infection of mononuclear cells may be useful in control of HIV-1 during dual HIV-1/TB infection.

Bioactivation of latent transforming growth factor beta1 by Mycobacterium tuberculosis in human mononuclear phagocytes

Biologically active transforming growth factor beta 1 (TGFbeta1) has been identified at sites of Mycobacterium tuberculosis (MTB) infection in the lung; however, the underlying mechanism(s) for its activation is not clear. Here using an enzyme-linked immunospot assay for TGFbeta1, we show that human blood monocytes (MN) and alveolar macrophages (AM) produce bioactive TGFbeta1 upon stimulation by MTB. However, only MTB-stimulated MN increased TGFbeta1 production on a per cell basis. The frequency of TGFbeta1-producing MN was reduced by an inhibitor of plasmin, bdellin, indicating a role for plasmin pathways in the bioactivation of cytokine. The expression of urokinase plasminogen activator receptor (uPAR) mRNA and both surface and soluble uPAR (CD87) was increased in MTB-activated MN. However, antibody neutralization of uPAR suppressed bioactive TGFbeta1 in MN alone. Thus, the more immature MN, which are continuously recruited to the lung during tuberculosis (TB), have a higher capacity to bioactivate TGFbeta1 by expression of components of the plasmin pathway. Excess production and bioactivation of TGFbeta1 at sites of MTB infection may undermine host immune responses during TB.

Increased replication of HIV-1 at sites of Mycobacterium tuberculosis infection: potential mechanisms of viral activation

Tuberculosis (TB) enhances HIV-1 replication and the progression to AIDS in dually infected patients. We employed pleural TB as a model to understand the interaction of the host with HIV-1 during active TB, at sites of Mycobacterium tuberculosis (MTB) infection. HIV-1 replication was enhanced both in the cellular (pleural compared with blood mononuclear cells) and acellular (pleural fluid compared with plasma) compartments of the pleural space. Several potential mechanisms for expansion of HIV-1 in situ were found, including augmentation in expression of tumor necrosis factor (TNF)-alpha and the HIV-1 noninhibitory beta-chemokine (MCP-1), low presence of HIV-1 inhibitory beta-chemokines (MIP-1 alpha, MIP-1 beta, and RANTES [regulated on activation, normal T expressed and secreted]), and upregulation in expression of the HIV-1 coreceptor, CCR5, by pleural fluid mononuclear cells. Thus, at sites of MTB infection, conditions are propitious both for transcriptional activation of HIV-1 in latently infected mononuclear cells, and facilitation of viral infection of newly recruited cells. These mechanisms may contribute to enhanced viral burden and dissemination during TB infection.

Activation of β‐Chemokines and CCR5 in Persons Infected with Human Immunodeficiency Virus Type 1 and Tuberculosis

Tuberculosis (TB) in human immunodeficiency virus type 1 (HIV-1)-infected persons is associated with progression of HIV-1 disease. The expression of macrophage inflammatory protein (MIP)-1alpha and CCR5 was assessed in HIV-1-infected patients with pulmonary TB (HIV-1/PTB) and without PTB (HIV-1/C), PTB patients not infected with HIV-1 (PTB), and control subjects. Mycobacterium tuberculosis (MTB)-induced MIP-1alpha production was lower in peripheral blood mononuclear cells (PBMC) of HIV-1/PTB patients than in those of PTB patients (P< .05) and was lower in PBMC of HIV-1/C patients than in those of control subjects (P< .005). However, MIP-1alpha production was higher in PBMC of HIV/PTB patients than in those of HIV-1/C patients (P< .01). The pattern of MTB-induced RANTES production was similar to that of MIP-1alpha. However, MTB induced greater expression of mRNA for CCR5 in PBMC of HIV-1/PTB patients than in those of HIV-1/C patients (P< .04). Furthermore, the MTB-induced HIV p24 antigen level in PBMC of HIV-1/PTB patients with a CD4 cell count <500 cells/microL was higher (P< .05) than that in HIV-1/C patients. Thus, perturbations in chemokine pathways in HIV-1/PTB patients may accelerate HIV-1 disease.

Macrophage‐Activating Cytokines in Human Immununodeficiency Virus Type 1–Infected and –Uninfected Patients with Pulmonary Tuberculosis

Tuberculosis (TB) is the most common opportunistic infection in human immunodeficiency virus type 1 (HIV-1)-infected patients globally and occurs throughout the course of HIV-1 disease. Here the production of interferon (IFN)-gamma and tumor necrosis factor (TNF)-alpha by peripheral blood mononuclear cells (PBMC) of HIV-1-infected versus -uninfected patients with newly diagnosed pulmonary TB (PTB) was compared. Findings were correlated with cytokine profiles, clinical presentation, and expression of inducible nitric oxide (iNOS). Most HIV-1/PTB patients with a CD4 cell count of 200-500 cells/microL had high IFN-gamma production and radiographic evidence of atypical PTB. Low IFN-gamma production and radiographic evidence of reactivated PTB characterized both HIV-1/PTB patients with a CD4 cell count >or=500 cells/microL and HIV-1-uninfected patients. TNF-alpha levels were similar in all HIV-1/PTB patients, regardless of CD4 cell count. Induction of iNOS in PBMC was low and was associated with low IFN-gamma production. These data underscore the potential pathogenic role of macrophage-activating cytokines in TB in HIV-1-infected patients.

Dysregulation of beta-chemokines in the lungs of HIV-1-infected patients

The beta-chemokines, macrophage inflammatory protein (MIP)-1 alpha, MIP-1 beta, monocyte chemotactic protein (MCP)-1 and regulated-on-activation normal T cell, expressed and secreted (RANTES) are not only chemotactic for mononuclear cells but may be important in suppression of HIV-1 replication through competitive binding to the chemokine receptor, CCR5, which is critical to viral entry. In this study, bronchoalveolar cells (BACs) and autologous peripheral blood mononuclear cells (PBMCs) were obtained from HIV-1-infected participants who did not manifest clinical signs of lung disease with peripheral CD4 T-cell count >200/mm(3) (n = 7, group with high CD4 count), or CD4 T-cell count <200/mm(3) (n = 12, group with low CD4 count), and from healthy study subjects (n = 5). The capacity to express beta-chemokines and CCR5 was assessed. Induction of MIP-1 alpha by lipopolysaccharide (LPS) in BAC of HIV-1-infected study subjects from the low CD4 group was less than BAC from healthy study subjects (p <.001), and also was less than in BACs from the group with a high CD4 group (p <.001). Moreover, the intracellular expression of MIP-1 alpha in LPS-induced monocytes of HIV-1-infected patients was significantly less than that from healthy study subjects (p <.01). In addition, spontaneous expression of mRNAs for CCR5 and MIP-1 alpha in BAC was significantly lower in HIV-1-infected patients compared with in healthy study subjects (p <.03 and p <.02, respectively). In contrast to the findings with MIP-1 alpha, LPS stimulated MCP-1 in BAC from the group of HIV-1-infected patients with high CD4 count was significantly higher than healthy study subjects (p <.001). These dysregulations in the ability to express beta-chemokines by BAC may be important in the progression of HIV-1 infection in the lung.

Impact of tuberculosis (TB) on HIV-1 activity in dually infected patients

Active TB in HIV-1-infected subjects is associated with increased HIV-1-related immunodeficiency and mortality. We assessed plasma viral load in HIV-1-infected patients with pulmonary TB (HIV/TB) and non-TB symptomatic HIV-1-infected patients (HIV). HIV-1 load was higher in HIV/TB compared with HIV at higher CD4 counts (> 500/microl) (P < 0.01), but not at lower CD4 counts (< 500/microl). We also evaluated the status of HIV-1 gene expression in peripheral blood mononuclear cells (PBMC) and serum from HIV/TB and CD4-matched healthy HIV-infected patients (HIV/C) by reverse transcriptase-polymerase chain reaction over a range of CD4 (> 900/microl to < 200/microl). HIV-1 RNA in serum and PBMC correlated to one another, and both were markedly higher in HIV/TB compared with HIV/C with higher CD4 counts. Also, during a longitudinal study of anti-tuberculous chemoprophylaxis in HIV-1-infected patients, 10 subjects who developed TB had serologies before, at the time, and after the diagnosis of TB. These HIV/TB patients had an increase in viral load (average 2.5-fold) at the time of diagnosis of TB (P < 0.05). Overall, these data indicate that the transcriptional activity of HIV-1 is enhanced in HIV-1-infected patients with active TB, especially during early HIV-1 disease. As TB often is an early HIV-1 opportunistic infection, it may particularly favour early viral replication and dissemination, and therefore contribute to progression of HIV-1 disease.

Latency-associated peptide of transforming growth factor beta enhances mycobacteriocidal immunity in the lung during Mycobacterium bovis BCG infection in C57BL/6 mice

Latency-associated peptide of transforming growth factor beta (TGF-beta) (LAP) was used to determine whether in vivo modulation of TGF-beta bioactivity enhanced pulmonary immunity to Mycobacterium bovis BCG infection in C57BL/6 mice. LAP decreased BCG growth in the lung and enhanced antigen-specific T-cell proliferation and gamma interferon mRNA expression. Thus, susceptibility of the lung to primary BCG infection may be partially mediated by the immunosuppressive effects of TGF-beta.

Expression of transforming growth factor-beta but not tumor necrosis factor-alpha, interferon-gamma, and interleukin-4 in granulomatous lung lesions in tuberculosis

The expression of transforming growth factor (TGF-beta 1), tumor necrosis factor-alpha (TNF-alpha), interferon-gamma (IFN-gamma) and interleukin-4 (IL-4) were assessed in lung tissues from patients with tuberculosis. Vimentin, a constitutively expressed cellular protein, was present in 12 of 19 tissue sections indicating adequate preservation of tissue proteins in these cases. Immunohistochemical studies for cytokines were done in the vimentin positive sections only. TGF-beta 1 was localized to mononuclear phagocytes of tuberculous lung lesions in 4 of 12 tuberculosis patients. TNF-alpha, IFN-gamma, and IL-4 were absent in sections from all tuberculosis patients. The failure to detect the latter cytokines may indicate that these molecules may not be expressed at the site of disease, or are not a feature of the late stages of tuberculous granulomas. TGF beta-1, although not universally expressed, may be involved in the development and/or consequences of tuberculous granuloma formation. These data substantiate further the role of TGF-beta 1 in the immunopathology of tuberculosis.

Modulation of transforming growth factor beta-1 gene expression by interleukin-12

The interaction of cytokines and their net balance with regard to macrophage activation (or deactivation) and immune stimulation (or suppression), ultimately determines the success of host-immune response at sites of active infection. A regulatory role for interleukin (IL)-12 in production of transforming growth factor (TGF)-beta1 has been suggested, however, remains controversial. In this study, we analyzed the effect of IL-12 on TGF-beta1 expression in the human lines, K562 and A549, and in primary human monocytes and macrophages. We found that IL-12 down-regulates TGF-beta1 mRNA expression in K562, monocytes and bone marrow cells, and to a lesser extent in the A549 cells. Using constructs containing different regions of the first promoter of the TGF-beta1 gene and a reporter gene, we also demonstrate that this effect is mediated through the TGF-beta1 gene promoter in the K562 and monocytic cell types. In conclusion, the critical role of IL-12 in the early activation of the immune response to pathogens may include down-modulation of TGF-beta1 gene activity.

A simplified in vivo drug sensitivity test for malaria in the field

The study was intended to develop a simple and reliable in vivo field test for monitoring of sensitivity of P.falciparum to antimalarials. The test is to be used as a built in sustainable monitoring system and applied at regular frequencies to provide guidance in developing a country-wide antimalarial drug policy. The study was conducted as a hospital based study in Mon State in Mudon, Kamawet and Pa-auk hospitals. The criteria matched malaria patients were treated with standard dosages of chloroquine, sulfadoxine-pyrimethamine and mefloquine and blood films were taken on days 0, 2, 3, 4, 7, 14 and 28. The assessment of the in vivo drug response of P.falciparum on days 2, 3 and 4 were compared with WHO standard 28 days and 7 day tests. The following successful tests were carried out for 7 days with different antimalarials: 171 tests with chloroquine and sulfadoxine-pyrimethamine and 167 tests with mefloquine. Tests were also carried out for 28 days: 59 tests with chloroquine, 77 tests with sulfadoxine-pyrimethamine and 78 tests with mefloquine. The results found that 3 day tests, taking blood films on days 0 and 3, can be reliably used as an adjunct to 28-day tests. Since the test is simple and can be used extensively and sustainably throughout the country and the results are applicable to be used for epidemiological purposes, the method is suggested for use as a built-in monitoring method for the malaria control program.

Induction of monocyte expression of tumor necrosis factor alpha by the 30-kD alpha antigen of Mycobacterium tuberculosis and synergism with fibronectin

Native 30-kD antigen, also known as alpha antigen, is a fibronectin-binding protein that is secreted by live Mycobacterium tuberculosis. This antigen may play an important biological role in the host-parasite interaction since it elicits delayed type hypersensitivity response and protective immunity in vivo and T lymphocyte blastogenesis and IFN-gamma production in vitro. In the present study, we show that, TNF-alpha protein is produced in monocyte culture supernatants in response to 30-kD antigen and the level is as high as that to purified protein derivative of M. tuberculosis. This stimulatory effect was not due to contamination with either bacterial lipopolysaccharide or mycobacterial lipoarabinomannan. The preincubation of monocytes with plasma fibronectin significantly enhanced the release of TNF-alpha into the culture supernatants in response to 30-kD antigen. This effect was blocked by polygonal antibody to plasma fibronectin. In contrast, the monocytic cell line U937 failed to release TNF-alpha protein in the culture supernatants in response to 30-kD antigen with or without preincubation with plasma fibronectin. To determine whether this observation was due to differential binding of the 30-kD to fibronectin on these cells, a cell based ELISA was used. Pretreatment of monocytes with fibronectin enhanced their binding of the 30-kD antigen. U937 cells bound the 30-kD antigen weakly with or without fibronectin pretreatment. These results indicate that 30-kD antigen which is a known secretary antigen of M. tuberculosis is a stimulus for human monocytes to express TNF-alpha and that stimulatory effect may be mediated through plasma fibronectin.

Regulation of production of tumor necrosis factor alpha in monocytes stimulated by the 30-kilodalton antigen of Mycobacterium tuberculosis

The 30-kDa secreted antigen of Mycobacterium tuberculosis was a strong inducer of tumor necrosis factor alpha in human monocytes. Our findings suggest that tumor necrosis factor alpha production may be up-regulated at both the posttranscriptional and transcriptional levels. Regulation at the posttranscriptional level probably reflects enhanced translational efficiency.

[The mechanism and specificity of IL-1 inhibitory factor released from human alveolar macrophages]

We have previously reported the presence of interleukin 1 (IL-1) inhibitory factor in the culture supernatants of alveolar macrophages. The activity is decreased in healthy smokers and patients with interstitial lung diseases (sarcoidosis, idiopathic pulmonary fibrosis), compared with healthy non-smokers. In this study, we further examined the mechanism and specificity of IL-1 inhibitory factor. The inhibitory factor exhibited specific inhibition of augmentation by IL-1 of PHA induced murine thymocyte proliferation, whereas there was no inhibition of the augmentation by IL-2, IL-4, IL-6 or TNF. This IL-1 inhibitory factor competitively blocked the binding of IL-1 to the IL-1 receptor on PHA-stimulated murine thymocytes. These results indicate that alveolar macrophages produce a specific IL-1 inhibitory factor which functions as a IL-1 receptor antagonist.

Characterization of IL-1 inhibitory factor released from human alveolar macrophages as IL-1 receptor antagonist

IL-1 possesses pleiotropic properties on various cells and its activity may be stringently regulated in several ways. We have previously reported that both IL-1 and its inhibitory factor are concomitantly released from alveolar macrophages in both healthy subjects and patients with chronic inflammatory lung diseases. An increase in IL-1 activities and a decrease in inhibitory activities are characteristics found in both healthy smokers and patients with interstitial lung diseases. In this study, we further examined the biological properties of IL-1 inhibitory factor. The inhibitor exhibited a dose-dependent specific inhibition of an augmentation by IL-1 of PHA-induced murine thymocyte proliferation, while no inhibition of the augmentation by IL-2, IL-4, IL-6, or tumour necrosis factor (TNF) was found. 125I-labelled IL-1 alpha binding on PHA-stimulated murine thymocytes revealed two types of IL-1 binding sites, 44 sites/cell with a Kd of 2.7 x 10(-10) M and 230 sites/cell with a Kd of 2.5 x 10(-9) M. Alveolar macrophage culture supernatants blocked the binding of labelled IL-1 to the IL-1 receptor in a dose-dependent fashion. Scatchard plot analysis revealed that the inhibitory factor in the supernatants blocked the binding competitively. These results indicate that alveolar macrophages produce a specific IL-1 inhibitory factor, functioning as an IL-1 receptor antagonist.

IL-1 and IL-1 inhibitory activity in the culture supernatants of alveolar macrophages from patients with interstitial lung diseases

Under normal conditions, the release of interleukin 1 (IL-1) and IL-1 inhibitors play a role in tissue homeostasis. We have already reported an increase in IL-1 activity and a decrease in IL-1 inhibitory activity (IHA) in the supernatants of alveolar macrophages from healthy long-term smokers as compared with healthy nonsmokers. In this study, we report an alteration in the release of IL-1 and IL-1 IHA from alveolar macrophages in patients with interstitial lung diseases (sarcoidosis and idiopathic pulmonary fibrosis [IPF]). IL-1 activity released from alveolar macrophages stimulated by lipopolysaccharide was increased in patients with active sarcoidosis (mean +/- SD, 2.52 +/- 1.33 U/ml [n = 6] vs 1.38 +/- 0.62 U/ml [n = 15] for healthy non-current smokers [HNS]; p less than 0.05). IL-1 IHA released from alveolar macrophages was significantly different among the groups examined: a decrease of IL-1 IHA occurred in patients with active sarcoidosis (61.4 +/- 19.2 [n = 6] vs 85.9 +/- 13.9 percent:HNS; p less than 0.05) and IPF (64.7 +/- 18.5 [n = 9]; p less than 0.05). Prednisolone in the culture medium at physiologic concentrations suppressed the release of IL-1 and enhanced the release of IL-1 IHA. IL-1 IHA inhibited not only mouse thymocyte proliferation but also human fibroblast proliferation in the presence of IL-1.

Study of vector, amplifier, and human infection with Japanese encephalitis virus in a Rangoon community

A prospective serologic study was undertaken in a Rangoon community in 1982 to quantify Japanese encephalitis virus infections in humans and in pigs. The prevalence, relative abundance, and host preference of Culex mosquitoes in the area were also determined. Japanese encephalitis virus infection was detected in 52.1% of the pigs, although concurrent human Japanese encephalitis virus infection was not detected. The known Japanese encephalitis virus vector mosquito species were prevalent in the study area. Host preference determination for the Culex species revealed that they were zoophilic and that the most frequent hosts were cows. The absence of concurrent human Japanese encephalitis virus infection in the presence of Japanese encephalitis virus infection in pigs and of vector mosquito species is discussed.

Smoking and interleukin-1 activity released from human alveolar macrophages in healthy subjects

To evaluate the activation of alveolar macrophages from smoking, we studied interleukin-1 (IL-1) activity released from alveolar macrophages in eight healthy smokers, compared to 12 healthy nonsmokers. We used 24-hour culture supernatants containing IL-1 of bronchoalveolar lavage fluid (BALF) macrophages/blood monocytes with or without LPS stimulation. Using C3H/HeJ thymocyte PHA costimulation assay, we found that IL-1 activity released from LPS stimulated BALF macrophages was significantly higher in smokers (2.39 +/- 0.33 U/ml) than in nonsmokers (1.47 +/- 0.19 U/ml, p less than 0.05). We also detected IL-1 inhibitory activity in supernatants by using IL-1 inhibitory assay. The inhibitory activity was higher in nonsmokers than in smokers especially under LPS stimulation. The presence of inhibitory factors other than prostaglandin-E2 was suggested from the differential response to the addition of indomethacin into cultures from nonstimulated and LPS-stimulated supernatants of BALF macrophages.