Bronchoalveolar lavage enzyme-linked immunospot for a rapid diagnosis of tuberculosis: a Tuberculosis Network European Trialsgroup study.

RATIONALE: The rapid diagnosis of pulmonary tuberculosis (TB) is difficult when acid fast bacilli (AFB) cannot be detected in sputum smears. OBJECTIVES: Following a proof of principle study, we examined in routine clinical practice whether individuals with sputum AFB smear-negative TB can be discriminated from those with latent TB infection by local immunodiagnosis with a Mycobacterium tuberculosis-specific enzyme-linked immunospot (ELISpot) assay. METHODS: Subjects suspected of having active TB who were unable to produce sputum or with AFB-negative sputum smears were prospectively enrolled at Tuberculosis Network European Trialsgroup centers in Europe. ELISpot with early-secretory-antigenic-target-6 and culture-filtrate-protein-10 peptides was performed on peripheral blood mononuclear cells (PBMCs) and bronchoalveolar lavage mononuclear cells (BALMCs). M. tuberculosis-specific nucleic acid amplification (NAAT) was performed on bronchoalveolar lavage fluid. MEASUREMENTS AND MAIN RESULTS: Seventy-one of 347 (20.4%) patients had active TB. Out of 276 patients who had an alternative diagnosis, 127 (46.0%) were considered to be latently infected with M. tuberculosis by a positive PBMC ELISpot result. The sensitivity and specificity of BALMC ELISpot for the diagnosis of active pulmonary TB were 91 and 80%, respectively. The BALMC ELISpot (diagnostic odds ratio [OR], 40.4) was superior to PBMC ELISpot (OR, 10.0), tuberculin skin test (OR, 7.8), and M. tuberculosis specific NAAT (OR, 12.4) to diagnose sputum AFB smear-negative TB. In contrast to PBMC ELISpot and tuberculin skin test, the BALMC ELISpot was not influenced by previous history of TB. CONCLUSIONS: Bronchoalveolar lavage ELISpot is an important advancement to rapidly distinguish sputum AFB smear-negative TB from latent TB infection in routine clinical practice.

Decreased apoptosis of pulmonary PMN in COPD patients with community-acquired pneumonia.

INTRODUCTION: Chronic obstructive pulmonary disease (COPD) predisposes for the acquisition of community-acquired pneumonia (CAP). OBJECTIVE/METHODS: To assess clinically and scientifically suggested disorders in innate immune response during acute phrase and resolution CAP (T2), we evaluated peripheral and pulmonary polymorphnuclear neutrophils (PMN), recovered by induced sputum, from CAP patients with and without COPD with regard to cell activation, interleukin-8 (CXCL-8) and CXCL-8 receptor expression, and apoptosis rate. RESULTS: At T1, COPD patients displayed significantly lower pulmonary PMN apoptosis rates, while total cell count, the amount of macrophages, and vital and necrotic neutrophils in sputum samples were similar between study groups. At T2, there were no differences between study groups or between pulmonary and peripheral compartment. While under systemic steroid treatment apoptosis rates of peripheral and pulmonary PMN at T1 were slightly decreased, there were no significant differences in intrapulmonary CXCL-8 levels. Regarding cell activation, no significant differences could be seen, neither in comparing study groups nor in pulmonary to peripheral PMN. CONCLUSION: Elucidating the pathology of suspected disorder in innate immune response, we found decreased apoptosis rates of pulmonary neutrophils in COPD at the peak of CAP indicating an increased inflammatory response, which is independent from anti-apoptotic cytokines such as CXCL-8, severity of disease and isolation of bacteria from sputum cultures.

Potential role for IL-2 ELISpot in differentiating recent and remote infection in tuberculosis contact tracing.

Interferon (IFN)-gamma release assays (IGRA) have improved tuberculosis contact tracing, but discrimination of recent from remote Mycobacterium tuberculosis contacts is not possible by IGRA alone. We present results of a tuberculosis contact investigation with a new early-secretory-antigenic-target (ESAT)-6 and culture-filtrate-protein (CFP)-10 specific interleukin (IL)-2 ELISpot in addition to ESAT-6 and CFP-10 specific IFN-gamma ELISpot and tuberculin skin testing (TST). Results of the TST, IFN-gamma ELISpot and IL-2 ELISpot were positive in 6/172 (3.4%), 7/167 (4.2%) and 6/196 (3.1%) of contacts, respectively. Close contact (> or =100 hours) to the index case increased the risk of positive results in the IFN-gamma ELISpot, TST, and IL-2 ELISpot by 40.8, 19.3, and 2.5 times, respectively. Individuals with a positive IFN-gamma ELISpot/negative IL-2 ELISpot result had a median (IQR) duration of index case exposure of 568 hours (133_1000) compared to individuals with a positive IFN-gamma ELISpot/positive IL-2 ELISpot result (median = 24 hours; 20_130; p-value = 0.047). Combination of a M. tuberculosis specific IFN-gamma ELISpot with a M. tuberculosis specific IL-2 ELISpot significantly improved the identification of individuals with the highest risk of recent M. tuberculosis infection and is a promising method that should be explored to target tuberculosis preventive chemotherapy.

Antimycobacterial immune responses in patients with pulmonary sarcoidosis.

INTRODUCTION: Sarcoidosis is a multisystem granulomatous disease of unknown origin. Pathogenetic involvement of Mycobacterium tuberculosis has frequently been discussed in the aetiology of sarcoidosis; however, studies still remain contradictory. OBJECTIVE: We addressed the question of mycobacterial involvement in the pathogenesis of sarcoidosis by analysing cellular immune responses to mycobacterial antigens. METHODS: We examined the interferon (IFN)-gamma production by enzyme-linked immunospot in response to purified protein derivate (PPD) mycobacterial-specific antigen early secretory antigenic target (ESAT)-6 and culture filtrate protein (CFP)-10 by peripheral blood mononuclear cells (PBMCs) and bronchoalveolar-lavage mononuclear cells (BALMCs) of patients with pulmonary sarcoidosis, smear-negative tuberculosis and controls. RESULTS: Release of IFN-gamma in response to ex vivo contact with PPD, ESAT-6 or CFP-10 by BALMC and PBMC were comparable among patients with sarcoidosis and controls (PBMC P = 0.2326; BALMC P = 0.1767) and were less frequently observed in both groups compared to patients with tuberculosis (BALMC P < 0.05; PBMC P < 0.0001). Within PBMC, the immunophenotype of sarcoidosis patients differed from that of patients with tuberculosis, as well as from that of controls, while within BALMC it resembled that of patients with tuberculosis. CONCLUSION: In contrast to patients with tuberculosis, the frequency of mycobacteria-specific local and systemic immune responses is not elevated in patients with sarcoidosis when compared to controls. The immunophenotype represents the local resemblance of the granulomatous reaction underlying tuberculosis and sarcoidosis while showing systemical difference. These observations do not support a role of an infection with M. tuberculosis in the pathogenesis of sarcoidosis.

Central sleep apnea is associated with blunted baroreflex sensitivity in patients with myocardial infarction.

OBJECTIVES: The purpose of this study was to investigate the association of central sleep apnea (CSA) and baroreflex sensitivity (BRS) after acute myocardial infarction. BACKGROUND: Both, CSA and blunted BRS have been shown to be independent predictors for cardiovascular mortality in patients with heart failure. But in contrast to BRS, which has been extensively studied in the setting of AMI, the incidence of CSA in patients recovering from AMI is thus far unknown. As previous reports suggested a potential role of sleep apnoea in augmenting reflex autonomic modulation, we hypothesized that there is a strong interrelation between CSA and BRS. METHODS: Seventeen male patients in the subacute phase of a first uncomplicated ST-segment elevation AMI and eight healthy male controls without evidence of coronary artery disease underwent polysomnography with simultaneous beat-to-beat ECG- and blood-pressure recordings. Sleep stage specific spontaneous BRS was calculated from blood pressure and RR-interval fluctuations by using the time domain sequential technique. RESULTS: AMI patients revealed to have a higher incidence and longer duration of central apnoeas in all sleep stages, light sleep, deep sleep and dream sleep. There were no significant sleep stage specific differences regarding BRS between groups, however, AMI patients with central sleep apnea exhibited blunted BRS which was inversely correlated to incidences of central apnea in all sleep stages. CONCLUSIONS: Our findings suggest a direct relationship between impaired BRS and repetitive occurrence of CSA by inverse correlation in all sleep stages in the subacute phase of AMI. Thus, reflex cardiac autonomic nervous control, being represented by the BRS, may be the link between CSA and prognosis.

Ventricular repolarization dynamics during different sleep stages in the subacute phase of myocardial infarction.

BACKGROUND: Ventricular arrhythmias after myocardial infarction (MI) are often nocturnal. However, the arrhythmogenic effects of sleep after MI are unknown. We examined the effects of sleep stages on QT dynamicity and tested the hypothesis of a differential effect of sleep stage on the QT/RR relationship after recent MI, versus in healthy controls (HC). METHODS: Polysomnography and electrocardiograms were simultaneously recorded in 21 men in the subacute phase of a first uncomplicated MI, and in 10 age-matched, male HC. QT dynamicity (QT/RR slope) and parameters of QT interval were measured during wakefulness, stages 1-4 of nonrapid eye movement (non-REM) sleep, and REM sleep. RESULTS: Mean QT and RR intervals increased through all sleep stages in both MI survivors and HC. The Bazett-corrected QT interval remained stable from wakefulness throughout all sleep stages. QT/RR slopes remained stable from wakefulness to stage 3 in both groups. However, unlike in MI survivors, the QT/RR slopes decreased and remained significantly lower during deep sleep and REM sleep in HC. CONCLUSION: An abnormal QT/RR relationship in deep sleep and REM sleep was observed after a recent MI, reflecting an insufficient shortening of ventricular repolarization with increasing heart rates, which might have important implications in the nocturnal distribution of ventricular arrhythmias after MI.