[Molecular pathology of tuberculosis : Status, methodology, and limits]. / Molekularpathologie der Tuberkulose : Stellenwert, Methodik und Grenzen.

In the diagnosis of mycobacterioses, microbiological examination with culture and antibiogram, possibly in combination with molecular biological testing of the fresh material, still represents the gold standard. However, these methods are not available for formalin-fixed paraffin-embedded (FFPE) material or other fixed samples. For this reason, the first step in pathology is to attempt microscopic pathogen detection (ZN/Fite/rhodamine-auramine). Subsequently, molecular pathological examination for the detection of mycobacterial gene sequences should also be considered mandatory today. Although this has clear limits due to the material, it is nevertheless well suited, if carried out correctly, to detect a mycobacterial infection or make it unlikely. A negative result may favor an alternative diagnosis but does not completely rule out mycobacteriosis.For the therapy of tuberculosis or nontuberculous mycobacterial (NTM) disease, the reliable detection of the species and the determination of resistance is of utmost importance. With regard to therapy, the clinician cannot afford to make a false diagnosis. In case of doubt, a rebiopsy for sampling native material, particularly for microbiological testing, should be discussed.

Palliative care and symptom relief for people affected by multidrug-resistant tuberculosis.

The World Health Organization (WHO) defines palliative care as the prevention and relief of the physical, psychological, social and spiritual suffering of adults and children with life-threatening illnesses and psycho-social support for their families. Palliative care and symptom relief (PCSR) also addresses suffering in nonlife-threatening situations such as after cure. PCSR should never be considered a substitute for tuberculosis (TB) prevention and treatment, but should be accessible by everyone in need. PCSR can reduce suffering and improve quality of life of patients with end-stage chronic illnesses while reducing costs for health care systems and providing financial risk protection for patients' families. It also may help enable patients to adhere to long and noxious treatments and thereby reduce mortality and help protect public health. Basic PCSR can be taught easily to TB specialists as well as primary care clinicians and delivered in hospitals, clinics or patients' homes combined with infection control. For these reasons, integration of PCSR into multidrug-resistant (MDR) and extensively drug-resistant TB (XDR-TB) treatment programs is medically and morally imperative. We propose an essential package of PCSR for people with M/XDR-TB that includes a set of safe, effective and inexpensive medicines and equipment, social supports for patients and caregivers living in extreme poverty, and necessary human resources. The package aligns with WHO guidance on programmatic management of drug-resistant (DR) TB and should be universally accessible by people affected by M/XDR-TB. We also describe the ethical practice of PCSR for people with M/XDR-TB and identify needed areas of research in PCSR for people with M/XDR-TB.

Cigarette smoking and culture conversion in patients with susceptible and M/XDR-TB.

BACKGROUND: Tuberculosis (TB) is a leading cause of morbidity and mortality worldwide. Active cigarette smoking may have a significant impact on treatment responses to anti-tuberculosis treatment. OBJECTIVE: To ascertain the effect of smoking on Mycobacterium tuberculosis sputum culture conversion rates following treatment initiation in patients with susceptible, multidrug-resistant and extensively drug-resistant TB (M/XDR-TB). METHOD: Sputum cultures of smoking and non-smoking patients with pulmonary TB (PTB) treated at a referral centre in Germany were evaluated. RESULTS: Between January 2012 and March 2017, 247 patients with PTB treated at the Medical Clinic of Research Center Borstel, Borstel, Germany, were included in the study. Of 247 patients, 65 (26.3%) were infected with multidrug-resistant strains of M. tuberculosis (MDR-TB). Sputum culture examinations were performed on a weekly basis. Active smoking (n = 111; time to culture conversion [TCC] 50.7 days, interquartile range [IQR] 26.5-73.0) and former smoking (n = 72; TCC 43.1 days, IQR 19.8-56.0) significantly delayed culture conversion rates (P < 0.001) when compared with never smoking (n = 64; TCC 33.2 days, IQR 8.0-50.3). Delay in TCC among smoking, non-MDR-TB patients (n = 138; TCC 47.3 days, IQR 19.0-89.0) was comparable with non-smoking, MDR-TB patients (n = 20; TCC 53.0 days, IQR 18.0-71.0). The shortest TCC was observed in non-smoking, non-MDR-TB patients (n = 44; TCC 33.0 days, IQR 10.0-48.5), whereas the longest was seen in smoking, MDR-TB patients (n = 45; TCC 60.7 days, IQR 33.3-89.0); P < 0.001). CONCLUSION: Active cigarette smoking and, to a lesser extent, former cigarette smoking, substantially delayed culture conversion in PTB.

Evaluation of OMNIgene®â€¢SPUTUM reagent for mycobacterial culture.

SETTING: National Mycobacterium Reference Laboratory, Borstel, Germany. OBJECTIVE: To evaluate the effectiveness of OMNIgene®â€¢SPUTUM (OM-S) reagent in comparison with a method using N-acetyl-L-cysteine-sodium hydroxide (NALC-NaOH) with regard to mycobacterial recovery and contamination of broth and solid cultures. DESIGN: Sputum samples from patients with tuberculosis and other respiratory diseases underwent decontamination with NALC-NaOH-based (MycoDDR™) or OM-S reagent. The decontamination procedure was assigned by block randomisation. Samples were inoculated on Löwenstein-Jensen, Stonebrink and MGIT™ (Mycobacterial Growth Indicator Tubes). Mycobacterial recovery from samples spiked with Mycobacterium tuberculosis following decontamination was determined. RESULTS: Eighty-five samples were randomised to NALC-NaOH and 84 to OM-S reagent. Mycobacterial recovery was significantly lower for samples processed with OM-S reagent compared with the NALC-NaOH method across all media types. Culture contamination was lower with NALC-NaOH reagent on solid media (9.4-12.9% vs. 28.6-29.8%). Growth was not observed in MGIT among samples spiked with 10 600-16 800 colony-forming units of M. tuberculosis following decontamination with OM-S reagent. CONCLUSION: Low mycobacterial recovery, especially in MGIT, observed in the present study suggests that OM-S reagent might not be compatible with the MGIT system. More extensive field evaluations of the OM-S reagent are warranted to demonstrate a significant benefit over currently used methods.

Treatment responses in multidrug-resistant tuberculosis in Germany.

BACKGROUND: Excellent treatment outcomes have recently been reported for patients with multi/extensively drug-resistant tuberculosis (M/XDR-TB) in settings where optimal resources for individualised therapy are available. OBJECTIVE: To ascertain whether differences remain in treatment responses between patients with M/XDR-TB and those with non-M/XDR-TB. METHOD: Patients with TB were prospectively enrolled between March 2013 and March 2016 at five hospitals in Germany. Treatment was conducted following current guidelines and individualised on the basis of drug susceptibility testing. Two-month and 6-month sputum smear and sputum culture conversion rates were assessed. A clinical and radiological score were used to assess response to anti-tuberculosis treatment. RESULTS: Non-M/XDR-TB (n = 29) and M/XDR-TB (n = 46) patients showed similar rates of microbiological conversion: 2-month smear conversion rate, 90% vs. 78%; culture conversion rate, 67% vs. 61%; time to smear conversion, 19 days (IQR 10-32) vs. 31 days (IQR 14-56) (P = 0.066); time to culture conversion, 39 days (IQR 17-67) vs. 39 days (IQR 6-85) (P = 0.191). Both clinical and radiological scores decreased after the introduction of anti-tuberculosis treatment. CONCLUSION: There were no significant differences in scores between the two groups until 6 months of treatment. Under optimal clinical conditions, with the availability of novel diagnostics and a wide range of therapeutic options for individualised treatment, patients with M/XDR-TB achieved 6-month culture conversion rates that were compatible with those in patients with non-M/XDR-TB.

Comparison of molecular and immunological methods for the rapid diagnosis of smear-negative tuberculosis.

SETTING: The rapid diagnosis of pulmonary tuberculosis (TB) can be challenging if acid-fast bacilli are not detected by sputum smear microscopy. OBJECTIVE: To compare the results of the GeneXpert® MTB/RIF assay on a single sputum or bronchoalveolar lavage (BAL) specimen test with local immunodiagnosis from the site of disease using the T-SPOT®.TB assay on BAL (BAL T-SPOT). DESIGN: The Xpert and BAL T-SPOT tests were compared in 96 patients suspected of having sputum smear-negative pulmonary TB admitted to a referral centre in Germany. RESULTS: BAL T-SPOT identified 10 of 11 patients with pulmonary TB (including 3/4 patients with culture-confirmed TB) with a negative Xpert test. Using Xpert, the sensitivity, specificity and positive and negative likelihood ratios (LRs) were respectively 60.0%, 97.4%, 30.0% and 0.4% in culture-confirmed cases and 42.1%, 97.4%, 21.1% and 0.6% in all TB patients. In contrast, using BAL T-SPOT, the sensitivity, specificity and positive and negative LRs were respectively 80.0%, 62.6%, 2.1% and 0.3% in culture-confirmed cases and 89.4%, 62.6%, 2.4% and 0.2% in all TB patients. CONCLUSION: In sputum smear-negative TB suspects, a positive Xpert result is strongly indicative of culture confirmation; however, a negative result is insufficient to rule out active TB. Where clinical suspicion of pulmonary TB persists despite a negative Xpert result, local immunodiagnosis using T-SPOT on BAL may increase diagnostic accuracy.

[Clinical features and diagnosis of tuberculosis]. / Klinik und Diagnose der Tuberkulose.

Recently, major advances have been accomplished in the diagnosis of active tuberculosis. A comprehensive diagnostic approach for a patient with possible tuberculosis includes a detailed medical history and clinical examination as well as the results of radiological, microbiological, immunological, molecular-biological and histological methods. In concert, these results enable the clinician to rapidly develop a decision with a high probability for the diagnosis or exclusion of active tuberculosis. Therapeutic intervention can thus be made early, even though corrections in these decisions need to be considered depending on the results of Mycobacterium tuberculosis culture and sensitivity testing.

Local immunodiagnosis of pulmonary tuberculosis by enzyme-linked immunospot.

Lymphocytes are crucial in the immune defence against Mycobacterium tuberculosis (MTB) infection. The aim of the present study was to ascertain whether or not MTB-specific lymphocytes are selectively compartmentalised in the lungs of patients with minimal active pulmonary tuberculosis (PTB). Patients with smear-negative MTB-culture-confirmed PTB were prospectively recruited. Differential cell counts, immunophenotyping with monoclonal antibodies directed against the cell surface markers CD4, CD8, CD4CD45RA, CD4CD45R0, CD38, human leukocyte antigen DR, CD19, CD3, CD57 and CD16 and MTB-specific enzyme-linked immunospot assays of peripheral blood mononuclear cells and bronchoalveolar lavage (BAL) mononuclear cells with 6-kDa early secretory antigenic target and culture filtrate protein 10 were performed. Among 12 patients with culture-confirmed smear-negative PTB, no differences were found in the distribution of total CD4 or CD8 T-cells in peripheral blood or BAL fluid (BALF). Activated human leukocyte antigen-DR-positive cells, as well as memory CD4CD45R0-positive T-cells, were expanded among cells of the BALF. Compared with a group of control patients with alternative pulmonary pathologies, there was no significant difference in lymphocyte subpopulations. However, 6-kDa early secretory antigenic target- and culture filtrate protein 10-specific lymphocytes were more concentrated, with a median BALF:peripheral blood ratio of 9.9 and 8.9, respectively, in patients with PTB. Mycobacterium tuberculosis-specific T-cells are highly selectively compartmentalised at the site of infection in active pulmonary tuberculosis.