The immunopathogenesis of tuberculous pericarditis.

Tuberculous pericarditis is a severe form of extrapulmonary tuberculosis and is the commonest cause of pericardial effusion in high incidence settings. Mortality ranges between 8 and 34%, and it is the leading cause of pericardial constriction in Africa and Asia. Current understanding of the disease is based on models derived from studies performed in the 1940-50s. This review summarises recent advances in the histology, microbiology and immunology of tuberculous pericarditis, with special focus on the effect of Human Immunodeficiency Virus (HIV) and the determinants of constriction.

Sensitivity analysis for the generalized shared-parameter model framework.

In this paper, we assess the effect of tuberculosis pericarditis treatment (prednisolone) on CD4 count changes over time and draw inferences in the presence of missing data. We accounted for the missing data and performed sensitivity analyses to assess robustness of inferences, from a model that assumes that the data are missing at random, to models that assume that the data are not missing at random. Our sensitivity approaches are within the shared-parameter model framework. We implemented the approach by Creemers and colleagues to the CD4 count data and performed simulation studies to evaluate the performance of this approach. We also assessed the influence of potentially influential subjects, on parameter estimates, via the global influence approach. Our results revealed that inferences from missing at random analysis model are robust to not missing at random models and influential subjects did not overturn the study conclusions about prednisolone effect and missing data mechanism. Prednisolone was found to have no significant effect on CD4 count changes over time and also did not interact with anti-retroviral therapy. The simulation studies produced unbiased estimates of prednisolone effect with lower mean square errors and coverage probabilities approximately equal the nominal coverage probability.

Host-directed therapies for tuberculous pericarditis.

TB Pericarditis is associated with significant inflammatory and immune responses which can paradoxically cause injury to the pericardium and myocardium. Management with anti-TB therapy alone does not prevent complications or reduce mortality. Thus the prevailing view is that adjunct host-directed therapies such as use of glucocorticoid treatment could attenuate destructive inflammatory responses and improve morbidity and mortality rates. A recent trial showed no advantage of using adjunct corticosteroid treatment on the combined endpoint of death, cardiac tamponade or constriction. The current lack of effective medical treatment for reducing the significant morbidity and mortality associated with TB pericarditis, highlights the urgent need for newer approaches to treating the disease. Newer treatment options for pericarditis using adjunct host-directed therapies, including autologous bone-marrow-derived Mesenchymal Stromal Cells (MSCs) therapy, now require evaluation in randomized placebo-controlled controlled trials.

Poor Penetration of Antibiotics Into Pericardium in Pericardial Tuberculosis.

Pericardial tuberculosis (TB) is associated with high therapy failure and high mortality rates. Antibiotics have to penetrate to site of infection at sufficient non-protein bound concentrations, and then enter bacteria to inhibit intracellular biochemical processes. The antibiotic concentrations achieved in pericardial fluid in TB pericarditis have never been measured before. We recruited two cohorts of patients with TB pericarditis, and left a pigtail catheter in-situ for serial drug concentration measurements over 24 h. Altogether, 704 drug concentrations were comodeled for pharmacokinetic analyses. The drug concentrations achieved in pericardial fluid were compared to the minimum inhibitory concentrations (MICs) of clinical Mycobacterium tuberculosis isolates. The total rifampicin concentration pericardial-to-serum ratios in 16 paired samples were 0.19 ± 0.33. The protein concentrations of the pericardial fluid in TB pericarditis were observed to be as high as in plasma. The non-protein bound rifampicin concentrations in pericardial fluid were 4-fold lower than rifampicin MICs in the pilot study, and the peak concentration was 0.125 versus 0.208 mg/L in the second (p = 0.001). The rifampicin clearance from pericardial fluid was 9.45 L/h versus 7.82 L/h in plasma (p = 0.002). Ethambutol peak concentrations had a pericardial-to-plasma ratio of 0.55 ± 0.22; free ethambutol peak concentrations were 2.30-lower than MICs (p < 0·001). The pericardial fluid pH was 7.34. The median pyrazinamide peak concentrations were 42.93 mg/L versus a median MIC of 800 mg/L at pH 7.34 (p < 0.0001). There was no significant difference between isoniazid pericardial fluid and plasma concentrations, and isoniazid peak concentrations were above MIC. This is the first study to measure anti-TB drug concentrations, pH and protein in the pericardial TB fluid. Pericardial concentrations of the key sterilizing drugs for TB were below MIC, which could contribute to poor outcomes. A new regimen that overcomes these limitations might need to be crafted.

Diagnostic accuracy of quantitative PCR (Xpert MTB/RIF) for tuberculous pericarditis compared to adenosine deaminase and unstimulated interferon-γ in a high burden setting: a prospective study.

BACKGROUND: Tuberculous pericarditis (TBP) is associated with high morbidity and mortality, and is an important treatable cause of heart failure in developing countries. Tuberculous aetiology of pericarditis is difficult to diagnose promptly. The utility of the new quantitative PCR test (Xpert MTB/RIF) for the diagnosis of TBP is unknown. This study sought to evaluate the diagnostic accuracy of the Xpert MTB/RIF test compared to pericardial adenosine deaminase (ADA) and unstimulated interferon-gamma (uIFNγ) in suspected TBP. METHODS: From October 2009 through September 2012, 151 consecutive patients with suspected TBP were enrolled at a single centre in Cape Town, South Africa. Mycobacterium tuberculosis culture and/or pericardial histology served as the reference standard for definite TBP. Receiver-operating-characteristic curve analysis was used for selection of ADA and uIFNγ cut-points. RESULTS: Of the participants, 49% (74/151) were classified as definite TBP, 33% (50/151) as probable TBP and 18% (27/151) as non TBP. A total of 105 (74%) participants were human immunodeficiency virus (HIV) positive. Xpert-MTB/RIF had a sensitivity and specificity (95% confidence interval (CI)) of 63.8% (52.4% to 75.1%) and 100% (85.6% to 100%), respectively. Concentration of pericardial fluid by centrifugation and using standard sample processing did not improve Xpert MTB/RIF accuracy. ADA (≥35 IU/L) and uIFNγ (≥44 pg/ml) both had a sensitivity of 95.7% (88.1% to 98.5%) and a negative likelihood ratio of 0.05 (0.02 to 0.10). However, the specificity and positive likelihood ratio of uIFNγ was higher than ADA (96.3% (81.7% to 99.3%) and 25.8 (3.6 to 183.4) versus 84% (65.4% to 93.6%) and 6.0 (3.7 to 9.8); P = 0.03) at an estimated background prevalence of TB of 30%. The sensitivity and negative predictive value of both uIFNγ and ADA were higher than Xpert-MT/RIF (P < 0.001). CONCLUSIONS: uIFNγ offers superior accuracy for the diagnosis of microbiologically confirmed TBP compared to the ADA assay and the Xpert MTB/RIF test.

Myopericarditis in tuberculous pericardial effusion: prevalence, predictors and outcome.

OBJECTIVE: The prevalence, predictors and outcome of myopericarditis in patients with tuberculous (TB) pericarditis are unknown. METHODS: Eighty-one patients (mean age±SD, 36.1±13.3 years; 54 (66.7%) men; 58 (71.6%) HIV seropositive) with TB pericarditis were recruited between January 2006 and September 2008. Myopericarditis was defined as echocardiographic LV systolic dysfunction (immediately after pericardiocentesis), elevated peripheral blood troponin T (>0.03 ng/mL), or elevated peripheral blood creatine kinase (CK >174 IU/L) with a CK:CK-myocardial band (MB) mass ratio of >6%. The outcome measure was case fatality rate at 6 months of follow-up. RESULTS: Myopericarditis was present in 43 (53.1%) patients. Patients with myopericarditis, as compared with those without, were more likely to be HIV seropositive (35 (81.4%) vs 23 (60.5%) respectively, p=0.038) and have lower peripheral CD4 count (median (IQR) 98 (54-290) vs 177 (104-429), p=0.026). Electrocardiographic ST segment elevation was more common in myopericarditis (15 (36.6%) vs 4 (10.8%), p=0.008) and predicted myopericarditis independently of CD4 count on multiple logistic regression analysis (OR 4.36, 95% CI 1.34 to 17.34, p=0.0132). At 6 months, 14 (18%) patients had died with no significant difference between those with or without myopericarditis (6/42 (14%) vs 8/36 (22%), respectively (p=0.363)). CONCLUSIONS: Myopericarditis is common in TB pericardial effusion and associated with HIV-related immunosuppression. It can be identified by electrocardiographic ST-elevation, particularly when peripheral CD4 count is low. There was no significant difference in case fatality rate in those with or without myopericarditis.

Tuberculous pericarditis with and without HIV.

The human immunodeficiency virus (HIV) has altered the epidemiology, clinical manifestations, treatment considerations and natural history of tuberculous (TB) pericarditis with significant implications for clinicians. The caseload of TB pericarditis has risen sharply in TB endemic areas of the world where co-infection with HIV is common. Furthermore, TB is the cause in greater than 85 % of cases of pericardial effusion in HIV-infected cohorts. In the absence of HIV, the morbidity of TB pericarditis is primarily related to the ferocity of the immune response to TB antigens within the pericardium. In patients with HIV, because TB pericarditis more often occurs as part of a disseminated process, the infection itself has a greater impact on the morbidity and mortality. HIV-associated TB pericarditis is a more aggressive disease with a greater degree of myocardial involvement. Patients have larger pericardial effusions with more frequent hemodynamic compromise and more significant ST segment changes in the electrocardiogram. HIV alters the natural history and outcomes of TB pericarditis. Immunocompromised participants appear less likely to develop constrictive pericarditis and have a significantly higher mortality compared with their immunocompetent counterparts. Finally co-infection with HIV has resulted in a number of areas of uncertainty. The mechanisms of myocardial dysfunction are unclear, new methods of improving the yield of TB culture and establishing a rapid bacterial diagnosis remain a major challenge, the optimal duration of anti-TB therapy has yet to be established, and the role of corticosteroids has yet to be resolved.

Predominance of interleukin-22 over interleukin-17 at the site of disease in human tuberculosis.

The inflammatory response to Mycobacterium tuberculosis (M.tb) at the site of disease is Th1 driven. Whether the Th17 cytokines, IL-17 and IL-22, contribute to this response in humans is unknown. We hypothesized that IL-17 and IL-22 contribute to the inflammatory response in pleural and pericardial disease sites of human tuberculosis (TB). We studied pleural and pericardial effusions, established TB disease sites, from HIV-uninfected TB patients. Levels of soluble cytokines were measured by ELISA and MMP-9 by luminex. Bronchoalveolar lavage or pericardial mycobacteria-specific T cell cytokine expression was analyzed by intracellular cytokine staining. IL-17 was not abundant in pleural or pericardial fluid. IL-17 expression by mycobacteria-specific disease site T cells was not detected in healthy, M.tb-infected persons, or patients with TB pericarditis. These data do not support a major role for IL-17 at established TB disease sites in humans. IL-22 was readily detected in fluid from both disease sites. These IL-22 levels exceeded matching peripheral blood levels. Further, IL-22 levels in pericardial fluid correlated positively with MMP-9, an enzyme known to degrade the pulmonary extracellular matrix. We propose that our findings support a role for IL-22 in TB-induced pathology or the resulting repair process.

Clinical usefulness of ELISPOT assay on pericardial fluid in a case of suspected tuberculous pericarditis.

Rapid and accurate diagnosis of tuberculous pericarditis is often difficult, considering the low specificity of both clinical picture and laboratory tests on pericardial fluid, as well as the low sensitivity of microbiological tests. This report documents the feasibility and clinical usefulness of an Interferon (IFN) - gamma ELISpot - TB assay on pericardial fluid cells in a case of suspected tuberculous pericarditis presenting with tamponade. As large pericardial effusions requiring pericardiocentesis are relatively frequent in tuberculous pericarditis, the physician may consider this particular application of ELISpot-TB as a rapid decision aid for starting the treatment.

The management of tuberculous pericardial effusion: experience in 233 consecutive patients.

AIM: We report on the 30-day and one-year outcome of consecutive effusive pericarditis patients, including those with tuberculous pericarditis, over a six-year-period. METHODS AND RESULTS: Patients with large pericardial effusions requiring pericardiocentesis were included in the study after having given written informed consent. Clinical and radiological evaluations were followed by echo-guided pericardiocentesis, and extended daily intermittent drainage via an indwelling pigtail catheter. A standard short-course anti-tuberculous regimen was initiated. A total of 233 patients was included. One hundred and sixty-two patients had pericardial tuberculosis (TB), including 118 (73%) with microbiological and/ or histological evidence of TB and 44 (27%) diagnosed on clinical and supportive laboratory data. Over the six-year period, two patients developed fibrous constrictive pericarditis after receiving adjuvant corticosteroid therapy. The 30-day mortality (8.0%) was statistically higher for HIV-positive patients (corresponding mortality 9.9%) than for HIV-negative patients (6.2%; p = 0.04). The one year all-cause mortality was 17.3%. It was also higher for HIV-positive (22.2%) than for IV-negative patients (12.3%; p = 0.03). Cardiac mortality was equal for HIV-positive and -negative patients. CONCLUSION: Tuberculous pericardial effusions responded well to closed pericardiocentesis and a six-month treatment of antituberculous chemotherapy. The former was effective and safe irrespective of HIV status.

Characterization of the immunological features of tuberculous pericardial effusions in HIV positive and HIV negative patients in contrast with non-tuberculous effusions.

OBJECTIVE: To investigate the immunopathogenesis of pericardial tuberculosis (TB) and the influence of human immunodeficiency virus (HIV) on the anti-tuberculous immune response. DESIGN: Consecutive patients presenting with large pericardial effusions were subjected to a full clinical examination and pericardiocentesis. Aspirated fluid was sent for biochemistry, differential leukocyte count, flow cytometric analysis and determination of cytokine levels. Pericardial tissue was sent for TB culture and histopathological evaluation. Diagnoses were made according to pre-determined criteria. RESULTS: Fifty-six patients were included and divided into HIV positive TB (n = 22), HIV negative TB (n = 21) and non-tuberculous effusions (n = 13). Peripheral blood neutrophil, lymphocyte and monocyte counts were significantly lower in HIV positive TB patients. Lymphocytes were the dominant cell type in tuberculous pericardial effusions. CD4+ cells dominated in HIV negative tuberculous effusions, whereas CD8+ cells dominated in HIV positive TB. The difference in the concentration of IFN-gamma levels in the tuberculous and non-tuberculous pericardial effusions was statistically significant. Despite significant differences in pericardial CD4+ cell counts, IFN-gamma levels were similarly elevated in HIV negative and HIV positive tuberculous effusions. Highest levels of pericardial IL-10 were observed in samples associated with least tissue necrosis, suggesting the possibility of a tissue protective immunoregulatory role for IL-10. CONCLUSIONS: Tuberculous pericardial effusions result from a T helper1 (Th1)-dominant immune response. IFN-gamma producing CD4+ lymphocytes dominate in HIV negative patients, whereas CD8+ seem to play a more important role in HIV positive patients. Infection with HIV leads to the depletion of immunocompetent cells such as monocytes, NK cells and neutrophils.

[Antimycobacterial antibody level in pleural, pericardial and cerebrospinal fluid of patients with tuberculosis]. / Ocena poziomu przeciwcial przeciwpratkowych w plynie oplucnowym, osierdziowym i mózgowo-rdzeniowym u chorych na gruzlice.

The goal of the study was to evaluate IgG, IgA and IgM mediated humoral immune response against 38kDa and 16 kDa or 38kDa and LAM mycobacterial antigens in pleural, pericardial or cerebrospinal fluid from patients with tuberculosis (TB) and to compare to non-tuberculous controls (NTB). 30 cerebrospinal fluids (CSF) (16 TB pts and 14 NTB pts), 17 pericardial fluids (6 TB and 11 NTB) and 20 pleural fluids (7 TB and 13 NTB) were examined. Commercially available ELISA-based assays (Pathozyme Tb complex plus, Myco G, A and M--Omega Diagnostic) were used. Tests were performed and cut off established according to manufacturer instruction. Mean IgG level against 38 + 16kDa was significantly higher in neurotuberculosis group compared to control (p<0.05). Sensitivity of the test in detecting neurotuberculosis was of 42% and specificity of 96%. Mean IgG, IgA and IgM against 38kDa + LAM level was higher in TB group compared to NTB in CSF. No difference was observed between TB and NTB group in pleural effusion. Antimycobacterial antibody levels were non-significantly increased in pericardial fluid in TB. The findings of the study indicate that TB is associated with the presence of detectable levels of antibodies in the CSF and pericardial effusion. Anti 38kDa + 16kDa IgG test can be used in combination with other diagnostic methods to increase diagnostic accuracy of neurotuberculosis.

Cytokine production in patients with tuberculous pericarditis.

SETTING: An academic hospital in the Western Cape, South Africa. OBJECTIVE: To evaluate cytokine production (interferon-gamma [IFN-gamma], interleukin-1 [IL-1], interleukin-2 [IL-2], interleukin-6 [IL-6], interleukin-10 [IL-10], interleukin-4 [IL-4] and tumour necrosis factor-alpha [TNF-alpha]) in patients with tuberculous pericarditis. DESIGN: Subpopulation of a consecutive prospective case series. PATIENTS: Thirty patients presenting with pericardial effusions due to tuberculosis (n = 19), malignancy (n = 6) and non-tuberculous infections (n = 5), and five control subjects who had undergone open heart surgery. RESULTS: The concentration of IFN-gamma was significantly higher in tuberculous pericardial effusions than in the other diagnostic classes (P < 0.0005). The concentration of TNF-alpha was similar in both infective and tuberculous effusions, but was significantly higher than that of malignant effusions. IL-1 and IL-2 were undetectable in malignant effusions, but elevated in both infective and tuberculous pericardial effusions. The levels of IL-1 and IL-2 were furthermore significantly higher in pericardial effusions due to infective compared to tuberculous causes. The concentration of IL-6, while elevated in all diagnostic classes, was significantly higher in the malignant group. Elevated levels of IL-10 and undetectable levels of IL-4 were observed in all three diagnostic groups. CONCLUSION: These findings suggest that tuberculous pericardial effusions arise due to a hypersensitivity reaction that is orchestrated by the TH-1 lymphocytes.

Broad clonal heterogeneity of antigen-specific CD4+ T-cells localizing at the site of disease during tuberculosis.

The repertoire of CD4+ T-lymphocytes was investigated in six patients affected by tuberculosis, who had a negative PPD skin test at diagnosis. Polyclonal CD4+ T-cell lines from the peripheral blood failed to proliferate to PPD and to the 16- or 38-kDa proteins of Mycobacterium tuberculosis, while CD4+ T-cell lines from the site of disease responded to PPD, and to the 16- and 38-kDa proteins, and derived epitopes in vitro. The repertoire of CD4+ T-cells accumulating at the site of disease was found to be widely heterogeneous as demonstrated by the finding that at least seven different peptides from the 16- and 38-kDa proteins were recognized by every patient. These results indicate that CD4+ T-cells localized at the site of disease in tuberculosis recognize a vast array of M. tuberculosis epitopes.

The detection of IgG against a specific mycobacterial antigen (A60) in the diagnosis of tuberculous pericarditis.

Diagnosis of tuberculous pericarditis (TP) is often difficult with standard methods, while prompt recognition of this disease may affect its prognosis. We report a case of tuberculous pericarditis, in which the presumptive diagnosis was obtained by detection of specific immunoglobulin G (IgG) against A60 antigen, the main thermostable component of purified protein derivative (PPD). Serological diagnosis may be a useful approach in the screening of the aetiology of pericarditis.

Immune reactions in tuberculous and chronic constrictive pericarditis. Clinical data and diagnostic significance of antimyocardial antibodies.

Humoral immune reactions were analyzed in 12 patients with exudative tuberculous pericarditis, 10 patients with constrictive pericarditis due to former tuberculosis, 10 patients with viral pericarditis, 20 patients with pulmonary tuberculosis, and 98 healthy donors. Pericarditis occurred in 12.5% of the patients with tuberculosis, whereas the incidence of tuberculosis in the 149 patients with pericarditis was 8%. Repeated pericardial puncture and pericardial effusions of greater than 500 ml with impending cardiac tamponade had to be performed in 4 patients. Clinical data indicated probable myocardial involvement in 4 of 12 patients. Antimyolemmal antibodies, which are a muscle-specific subtype of antisarcolemmal antibodies, were found in all patients with exudative tuberculous pericarditis and viral perimyocarditis, in only 1 of 12 patients with constrictive pericarditis, and in no patients with pulmonary tuberculosis. Antifibrillary antibodies--primarily of the antimyosin type--were missed in patients with viral heart disease but were demonstrated in 75% of patients with tuberculous pericarditis. Only sera with complement-fixing antimyolemmal antibodies of the IgG type in titers greater than 1:40 induced cytolysis of vital adult heterologous cardiocytes isolated and enriched by silica sol gradient centrifugation. These findings suggest not only that antimyolemmal antibodies are diagnostic indicators of perimyocardial involvement in tuberculous pericarditis, but also that they may play a significant role in its pathogenesis.