Communicating computational workflows in a regulatory environment.

The volume of nucleic acid sequence data has exploded recently, amplifying the challenge of transforming data into meaningful information. Processing data can require an increasingly complex ecosystem of customized tools, which increases difficulty in communicating analyses in an understandable way yet is of sufficient detail to enable informed decisions or repeats. This can be of particular interest to institutions and companies communicating computations in a regulatory environment. BioCompute Objects (BCOs; an instance of pipeline documentation that conforms to the IEEE 2791-2020 standard) were developed as a standardized mechanism for analysis reporting. A suite of BCOs is presented, representing interconnected elements of a computation modeled after those that might be found in a regulatory submission but are shared publicly - in this case a pipeline designed to identify viral contaminants in biological manufacturing, such as for vaccines.

Performance of the Enhanced Liver Fibrosis Score, Comparison with Vibration-controlled Transient Elastography Data, and Development of a Simple Algorithm to Predict Significant Liver Fibrosis in a Community-based Liver Service: A Retrospective Evaluation.

Background and Aims: Liver fibrosis is a key risk factor for cirrhosis, hepatocellular carcinoma and end stage liver failure. The National Institute for Health and Care Excellence guidelines for assessment for advanced (≥F3) liver fibrosis in people with nonalcoholic fatty liver disease recommend the use of enhanced liver fibrosis (ELF) test, followed by vibration-controlled transient elastography (VCTE). Performance of ELF at predicting significant (≥F2) fibrosis in real-world practice is uncertain. To assess the accuracy of ELF using VCTE; investigate the optimum ELF cutoff value to identify ≥F2 and ≥F3; and develop a simple algorithm, with and without ELF score, for detecting ≥F2. Methods: Retrospective evaluation of patients referred to a Community Liver Service for VCTE, Jan-Dec 2020. Assessment included: body mass index (BMI), diabetes status, alanine aminotransferase (ALT) levels, ELF score and biopsy-validated fibrosis stages according to VCTE. Results: Data from 273 patients were available. n=110 patients had diabetes. ELF showed fair performance for ≥F2 and ≥F3, area under the curve (AUC) = 0.70, 95% confidence interval (CI) 0.64-0.76 and AUC=0.72, 95% CI: 0.65-0.79 respectively. For ≥F2 Youden's index for ELF=9.85 and for ≥F3, ELF=9.95. Combining ALT, BMI, and HbA1c (ALBA algorithm) to predict ≥F2 showed good performance (AUC=0.80, 95% CI: 0.69-0.92), adding ALBA to ELF improved performance (AUC=0.82, 95% CI: 0.77-0.88). Results were independently validated. Conclusions: Optimal ELF cutoff for ≥F2 is 9.85 and 9.95 for ≥F3. ALT, BMI, and HbA1c (ALBA algorithm) can stratify patients at risk of ≥F2. ELF performance is improved by adding ALBA.

An Update on Clinical Trials and Potential Therapeutic Strategies in T-Cell Acute Lymphoblastic Leukemia.

Current therapies for T-cell acute leukemia are based on risk stratification and have greatly improved the survival rate for patients, but mortality rates remain high owing to relapsed disease, therapy resistance, or treatment-related toxicities/infection. Patients with relapsed disease continue to have poor outcomes. In the past few years, newer agents have been investigated to optimize upfront therapies for higher-risk patients in the hopes of decreasing relapse rates. This review summarizes the progress of chemo/targeted therapies using Nelarabine/Bortezomib/CDK4/6 inhibitors for T-ALL in clinical trials and novel strategies to target NOTCH-induced T-ALL. We also outline immunotherapy clinical trials using monoclonal/bispecific T-cell engaging antibodies, anti-PD1/anti-PDL1 checkpoint inhibitors, and CAR-T for T-ALL therapy. Overall, pre-clinical studies and clinical trials showed that applying monoclonal antibodies or CAR-T for relapsed/refractory T-ALL therapy is promising. The combination of target therapy and immunotherapy may be a novel strategy for T-ALL treatment.

Tandem mass tag-based quantitative proteomic profiling identifies candidate serum biomarkers of drug-induced liver injury in humans.

Diagnosis of drug-induced liver injury (DILI) and its distinction from other liver diseases are significant challenges in drug development and clinical practice. Here, we identify, confirm, and replicate the biomarker performance characteristics of candidate proteins in patients with DILI at onset (DO; n = 133) and follow-up (n = 120), acute non-DILI at onset (NDO; n = 63) and follow-up (n = 42), and healthy volunteers (HV; n = 104). Area under the receiver operating characteristic curve (AUC) for cytoplasmic aconitate hydratase, argininosuccinate synthase, carbamoylphosphate synthase, fumarylacetoacetase, fructose-1,6-bisphosphatase 1 (FBP1) across cohorts achieved near complete separation (range: 0.94-0.99) of DO and HV. In addition, we show that FBP1, alone or in combination with glutathione S-transferase A1 and leukocyte cell-derived chemotaxin 2, could potentially assist in clinical diagnosis by distinguishing NDO from DO (AUC range: 0.65-0.78), but further technical and clinical validation of these candidate biomarkers is needed.

Communicating regulatory high-throughput sequencing data using BioCompute Objects.

This project demonstrates the use of the IEEE 2791-2020 Standard (BioCompute Objects [BCO]) to enable the complete and concise communication of results from next generation sequencing (NGS) analysis. One arm of a clinical trial was replicated using synthetically generated data made to resemble real biological data and then two independent analyses were performed. The first simulated a pharmaceutical regulatory submission to the US Food and Drug Administration (FDA) including analysis of results and a BCO. The second simulated an FDA review that included an independent analysis of the submitted data. Of the 118 simulated patient samples generated, 117 (99.15%) were in agreement in the two analyses. This process exemplifies how a template BCO (tBCO), including a verification kit, facilitates transparency and reproducibility, thereby reinforcing confidence in the regulatory submission process.

Transient elastography in patients at risk of liver fibrosis in primary care: a follow-up study over 54 months.

BACKGROUND: Liver fibrosis assessment services using transient elastography are growing in primary care. These services identify patients requiring specialist referral for liver fibrosis, and provide an opportunity for recommending lifestyle change. However, there are uncertainties regarding service design, effectiveness of advice given, and frequency of follow-up. AIM: To assess the following: (a) effectiveness of standard care lifestyle advice for weight management and alcohol consumption; (b) uptake for liver rescan; and (c) usefulness of a 4.5-year time interval of rescanning in monitoring progression of liver fibrosis. DESIGN & SETTING: Analysis of patient outcomes 4.5 years after the first 'liver service' attendance that included transient elastography in five GP practices in Southampton, UK. METHOD: Outcomes included weight, alcohol consumption, rescan uptake, time interval between scans, and change in liver fibrosis stage. RESULTS: A total of 401 participants were recontacted. Mean standard deviation (± SD) weight loss was 1.2 kg±8.4 kg (P = 0.005); Alcohol Use Disorders Identification Test (AUDIT) grade increased by 7.8% (P ≤0.001). A total of n = 116/401 participants were eligible for liver rescanning and n = 59/116 (50.9%) agreed to undergo rescanning. Mean ± SD time interval between scans was 53.6±3.4 months. Liver fibrosis progressed from mild (≥6.0 kPa-8.1 kPa) to significant fibrosis (8.2 kPa-9.6 kPa) in 3.4% of patients; from mild to advanced fibrosis (9.7 kPa-13.5 kPa) and cirrhosis (≥13.6 kPa) in 15.3% of patients, and did not progress in 81.3%. No baseline factors were independently associated with liver fibrosis progression at follow-up. CONCLUSION: Rescan recall attendance and adherence to lifestyle changes needs improving. Optimum time interval between scans remains uncertain. After a mean interval of 53.6 months between scans, and with no specific predictors indicated, a substantial minority (18.7%) experienced a deterioration in fibrosis grade.

Update on cardiovascular risk in nonalcoholic fatty liver disease.

PURPOSE OF REVIEW: To summarize recent evidence demonstrating increased cardiovascular disease (CVD) risk, and how CVD risk may be reduced, in patients with nonalcoholic fatty liver disease (NAFLD). RECENT FINDINGS: NAFLD is a multisystem disease, defined by a spectrum of liver fat-associated conditions extending from simple steatosis, to inflammation, fibrosis and cirrhosis. NAFLD not only increases the risk of liver morbidity and mortality but also increases the risk of CVD morbidity and mortality and is associated with recognized CVD risk factors such as hypertension, atherogenic dyslipidaemia, type 2 diabetes mellitus and chronic kidney disease. Evidence suggests that the liver fibrosis stage may be a strong CVD risk factor. Lifestyle measures (e.g. weight loss and increased physical activity) are effective in improving CVD risk factors. Hypoglycaemic agents, such as the peroxisome proliferator-activated receptor gamma agonist pioglitazone and the glucagon-like peptide-1 receptor agonist liraglutide, reduce cardiovascular risk and may improve liver histology. Statin and antihypertensive treatments are well tolerated and currently it is unclear whether novel antifibrotic drugs will reduce CVD risk. SUMMARY: Assessment and treatment of increased cardiovascular risk is important in patients with NAFLD. If not contra-indicated, pioglitazone or a glucagon-like peptide 1 agonist should be considered and may benefit both CVD risk and early liver disease.

Bioinformatics tools developed to support BioCompute Objects.

Developments in high-throughput sequencing (HTS) result in an exponential increase in the amount of data generated by sequencing experiments, an increase in the complexity of bioinformatics analysis reporting and an increase in the types of data generated. These increases in volume, diversity and complexity of the data generated and their analysis expose the necessity of a structured and standardized reporting template. BioCompute Objects (BCOs) provide the requisite support for communication of HTS data analysis that includes support for workflow, as well as data, curation, accessibility and reproducibility of communication. BCOs standardize how researchers report provenance and the established verification and validation protocols used in workflows while also being robust enough to convey content integration or curation in knowledge bases. BCOs that encapsulate tools, platforms, datasets and workflows are FAIR (findable, accessible, interoperable and reusable) compliant. Providing operational workflow and data information facilitates interoperability between platforms and incorporation of future dataset within an HTS analysis for use within industrial, academic and regulatory settings. Cloud-based platforms, including High-performance Integrated Virtual Environment (HIVE), Cancer Genomics Cloud (CGC) and Galaxy, support BCO generation for users. Given the 100K+ userbase between these platforms, BioCompute can be leveraged for workflow documentation. In this paper, we report the availability of platform-dependent and platform-independent BCO tools: HIVE BCO App, CGC BCO App, Galaxy BCO API Extension and BCO Portal. Community engagement was utilized to evaluate tool efficacy. We demonstrate that these tools further advance BCO creation from text editing approaches used in earlier releases of the standard. Moreover, we demonstrate that integrating BCO generation within existing analysis platforms greatly streamlines BCO creation while capturing granular workflow details. We also demonstrate that the BCO tools described in the paper provide an approach to solve the long-standing challenge of standardizing workflow descriptions that are both human and machine readable while accommodating manual and automated curation with evidence tagging. Database URL:  https://www.biocomputeobject.org/resources.

Causes of Mortality in Non-Alcoholic Fatty Liver Disease (NAFLD) and Alcohol Related Fatty Liver Disease (AFLD).

Non-alcoholic fatty liver disease (NAFLD) and alcohol related fatty liver disease (AFLD) both represent a spectrum of liver disease severity from hepatic steatosis to fibrosis and cirrhosis. Both NAFLD and AFLD are common diseases in the general population. NAFLD affects ~25% of the adult global population whilst AFLD has become the commonest indication for liver transplantation in the United States. It is often not possible to distinguish between NAFLD and AFLD on examination of liver histology, consequently, differentiation between NAFLD and AFLD is heavily reliant on a history of alcohol consumption. Age, smoking, alcohol consumption and sex appear to influence the risk of mortality in NAFLD or AFLD. In NAFLD and AFLD, the key causes of increased liver-related mortality are advanced liver fibrosis and cirrhosis leading to complications such as hepatocellular carcinoma and decompensated cirrhosis. NAFLD and AFLD are also associated with an increased risk of all-cause mortality including an increased risk of extra-hepatic malignancy. Non-invasive biomarkers of liver disease severity in NAFLD and AFLD perform poorly to predict mortality. However, alanine aminotransferase, gamma-glutamyl transpeptidase, FIB-4 and the NAFLD Fibrosis Score are independently associated with increased mortality in NAFLD. Both NAFLD and AFLD are associated with extra-hepatic risk factors and complications such as metabolic syndrome encompassing obesity, hypertension, type 2 diabetes mellitus, and chronic kidney disease. AFLD is associated with hypertension and cardiovascular disease as well as other organ damage. This narrative review discusses the associations, risk factors and diagnostic biomarkers linking NAFLD and AFLD with increased mortality.

Synbiotics Alter Fecal Microbiomes, But Not Liver Fat or Fibrosis, in a Randomized Trial of Patients With Nonalcoholic Fatty Liver Disease.

BACKGROUND & AIMS: Dysbiosis of the intestinal microbiota has been associated with nonalcoholic fatty liver disease (NAFLD). We investigated whether administration of a synbiotic combination of probiotic and prebiotic agents affected liver fat content, biomarkers of liver fibrosis, and the composition of the fecal microbiome in patients with NAFLD. METHODS: We performed a double-blind phase 2 trial of 104 patients with NAFLD in the United Kingdom. Participants (mean age, 50.8 ± 12.6 years; 65% men; 37% with diabetes) were randomly assigned to groups given the synbiotic agents (fructo-oligosaccharides, 4 g twice per day, plus Bifidobacterium animalis subspecies lactis BB-12; n = 55) or placebo (n = 49) for 10-14 months. Liver fat content was measured at the start and end of the study by magnetic resonance spectroscopy, and liver fibrosis was determined from a validated biomarker scoring system and vibration-controlled transient elastography. Fecal samples were collected at the start and end of the study, the fecal microbiome were analyzed by 16S ribosomal DNA sequencing. RESULTS: Mean baseline and end-of-study magnetic resonance spectroscopy liver fat percentage values were 32.3% ± 24.8% and 28.5% ± 20.1% in the synbiotic group and 31.3% ± 22% and 25.2% ± 17.2% in the placebo group. In the unadjusted intention-to-treat analysis, we found no significant difference in liver fat reduction between groups (ß = 2.8; 95% confidence interval, -2.2 to 7.8; P = .30). In a fully adjusted regression model (adjusted for baseline measurement of the outcome plus age, sex, weight difference, and baseline weight), only weight loss was associated with a significant decrease in liver fat (ß = 2; 95% confidence interval, 1.5-2.6; P = .03). Fecal samples from patients who received the synbiotic had higher proportions of Bifidobacterium and Faecalibacterium species, and reductions in Oscillibacter and Alistipes species, compared with baseline; these changes were not observed in the placebo group. Changes in the composition of fecal microbiota were not associated with liver fat or markers of fibrosis. CONCLUSIONS: In a randomized trial of patients with NAFLD, 1 year of administration of a synbiotic combination (probiotic and prebiotic) altered the fecal microbiome but did not reduce liver fat content or markers of liver fibrosis. (ClinicalTrials.gov, Number: NCT01680640).

Multi-drug approaches to NASH: what's in the development pipeline?

Introduction: The pandemic of obesity over the last two decades has triggered a rise in the prevalence of nonalcoholic fatty liver disease (NAFLD). NAFLD is associated with liver-related and cardiovascular complications. Despite this, the first licensed drug for NAFLD is yet to be approved. Given the scale of the problem and unmet needs, there is a myriad of agents in the development pipeline.Areas covered: We discuss promising agents in early phase clinical trials and categorize these agents based on their action on steatosis, steatohepatitis, and fibrosis. Furthermore, given the multisystemic nature of NAFLD, we consider the effects of these agents on the liver, their cardiometabolic effects, and the potential future strategies of combination therapies.Expert opinion: The paradigm for the ideal drug is the targeting of both steatohepatitis and fibrosis and the amelioration of cardiometabolic risk factors. New drugs that confer benefit in nonalcoholic steatohepatitis (NASH) must also be tested for their effects on type 2 diabetes mellitus and cardiovascular disease. The treatment of NASH will become analogous to the treatment of hypertension; it is very likely that multiple classes of drugs targeting different mechanistic pathways will be necessary because no single agent is likely to control all aspects of this complex liver disease.

Identification of upper gastrointestinal malignancy in patients with uncomplicated dyspepsia referred under the two-week-wait cancer pathway: a single-centre, 10-year experience.

INTRODUCTION: In the United Kingdom, the National Institute for Health and Care Excellence 2015 guidance recommend that for suspected gastric or oesophageal cancer, general practitioners consider a non-urgent, direct-access endoscopy in patients over 55 years with only uncomplicated treatment-resistant dyspepsia. In practice, patients are referred under the urgent 2-week-wait cancer pathway. METHODS: We compared the frequency of gastric or oesophageal carcinoma in patients referred to our centre on the 2-week-wait pathway with uncomplicated dyspepsia to those who have a combination of additional alarm symptoms. The four most common indications for endoscopy referral on the 2-week-wait pathway and all combinations of those indications were examined: Dyspepsia ('ulcer-like', 'non-ulcer-like' or 'reflux-like' dyspepsia), anaemia, weight loss or dysphagia. RESULTS: Over 10 years, 9012 two-week-wait gastroscopies were performed, and a tumour was identified in 256 patients (2.84%). One thousand and three hundred six gastroscopies performed for uncomplicated dyspepsia and only 6 patients (0.46%) had a tumour. Therefore, uncomplicated dyspepsia alone had a poor positive predictive value of detecting gastric or oesophageal cancer. Our findings suggest dyspepsia had no significant cumulative effect on the number of patients with anaemia or weight loss found to have a lesion at endoscopy but indeed significantly decreased the likelihood of finding a tumour in those with dysphagia. CONCLUSION: Dyspepsia as a parameter to investigate gastric or oesophageal cancer contributes significantly to the growth in number of 2-week-wait referrals at a time when endoscopy units battle to meet demand. Our data show patients with uncomplicated dyspepsia rarely have gastric or oesophageal cancer and should not undergo endoscopies under the urgent 2-week-wait pathway.

Diagnosis and management of non-alcoholic fatty liver disease.

Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease in Western industrialised countries. The prevalence of NAFLD is increasing in parallel with the global rise in obesity and type 2 diabetes mellitus. NAFLD represents a spectrum of liver disease severity. NAFLD begins with accumulation of triacylglycerols in the liver (steatosis), and is defined by hepatic fatty infiltration amounting to greater than 5% by liver weight or the presence of over 5% of hepatocytes loaded with large fat vacuoles. In almost a quarter of affected individuals, steatosis progresses with the development of liver inflammation to non-alcoholic steatohepatitis (NASH). NASH is a potentially progressive liver condition and with ongoing liver injury and cell death can result in fibrosis. Progressive liver fibrosis may lead to the development of cirrhosis in a small proportion of patients. With the growing prevalence of NAFLD, there is an increasing need for a robust, accurate and non-invasive approach to diagnosing the different stages of this condition. This review will focus on (1) the biochemical tests and imaging techniques used to diagnose the different stages of NAFLD; and (2) a selection of the current management approaches focusing on lifestyle interventions and pharmacological therapies for NAFLD.

Design and rationale of the INSYTE study: A randomised, placebo controlled study to test the efficacy of a synbiotic on liver fat, disease biomarkers and intestinal microbiota in non-alcoholic fatty liver disease.

BACKGROUND: Non-alcoholic fatty liver disease (NAFLD) represents a spectrum of fat-related conditions ranging from simple fatty liver, to non-alcoholic steatohepatitis (NASH), fibrosis and cirrhosis. There is growing evidence that NAFLD is a multisystem disease, affecting several extra-hepatic organs and regulatory pathways. Furthermore, since the gut and liver are linked anatomically via the portal vein, disturbances of the gut microbiota (dysbiosis) can affect the liver. OBJECTIVES: In patients with NAFLD, we are testing the effects of a synbiotic which is the combination of a prebiotic (fructooligosaccharides; 4 g/day) and a probiotic (Bifidobacterium animalis subsp. lactis BB-12 at a minimum of 10 billion CFU/day) on a) liver fat percentage, b) NAFLD fibrosis algorithm scores, c) gut microbiota composition. Additionally, there will be several hypothesis-generating secondary outcomes to understand the metaorganismal pathways that influence the development and progression of NAFLD, type 2 diabetes, and cardiovascular risk. DESIGN: In a randomised double-blind placebo-controlled trial, 104 participants were randomised to 10-14 months intervention with either synbiotic (n = 55) or placebo (n = 49). Recruitment was completed in April 2017 and the last study visit will be completed by April 2018. METHODS: Change in gut microbiota composition will be assessed using 16S ribosomal RNA gene sequencing. Change in mean liver fat percentage will be quantified by magnetic resonance spectroscopy (MRS). In addition, change in liver fat severity will be measured using two NAFLD fibrosis algorithm scores. The INSYTE study was approved by the local ethics committee (REC: 12/SC/0614) and is registered at www.clinicaltrials.gov as NCT01680640.

Clinical deterioration during antituberculosis treatment in Africa: incidence, causes and risk factors.

BACKGROUND: HIV-1 and Mycobacterium tuberculosis cause substantial morbidity and mortality. Despite the availability of antiretroviral and antituberculosis treatment in Africa, clinical deterioration during antituberculosis treatment remains a frequent reason for hospital admission. We therefore determined the incidence, causes and risk factors for clinical deterioration. METHODS: Prospective cohort study of 292 adults who initiated antituberculosis treatment during a 3-month period. We evaluated those with clinical deterioration over the following 24 weeks of treatment. RESULTS: Seventy-one percent (209/292) of patients were HIV-1 infected (median CD4+: 129 cells/microL [IQR:62-277]). At tuberculosis diagnosis, 23% (34/145) of HIV-1 infected patients qualifying for antiretroviral treatment (ART) were receiving ART; 6 months later, 75% (109/145) had received ART. Within 24 weeks of initiating antituberculosis treatment, 40% (117/292) of patients experienced clinical deterioration due to co-morbid illness (n = 70), tuberculosis related illness (n = 47), non AIDS-defining HIV-1 related infection (n = 25) and AIDS-defining illness (n = 21). Using HIV-1 uninfected patients as the referent group, HIV-1 infected patients had an increasing risk of clinical deterioration as CD4+ counts decreased [CD4+>350 cells/microL: RR = 1.4, 95% CI = 0.7-2.9; CD4+:200-350 cells/microL: RR = 2.0, 95% CI = 1.1-3.6; CD4+<200 cells/microL: RR = 3.0, 95% CI = 1.9-4.7]. During follow-up, 26% (30/117) of patients with clinical deterioration required hospital admission and 15% (17/117) died. Fifteen deaths were in HIV-1 infected patients with a CD4+<200 cells/microL. CONCLUSIONS: In multivariate analysis, HIV-1 infection and a low CD4+ count at tuberculosis diagnosis were significant risk factors for clinical deterioration and death. The initiation of ART at a CD4+ count of <350 cells/microL will likely reduce the high burden of clinical deterioration.

Genetic determination of the effect of post-translational modification on the innate immune response to the 19 kDa lipoprotein of Mycobacterium tuberculosis.

BACKGROUND: The 19 kDa lipoprotein of Mycobacterium tuberculosis (MTB) is an important target of the innate immune response. To investigate the effect of post-translation modification of this protein on innate recognition in the context of the whole bacillus, we derived a recombinant M. tuberculosis H37Rv that lacked the 19 kDa gene (Delta19) and complemented this strain by reintroduction of the 19 kDa gene into the chromosome as a single copy to produce Delta19::19. We also reintroduced the 19 kDa gene in two modified forms that lacked motifs for acylation (Delta19::19NA) and O-glycosylation (Delta19::19NOG). RESULTS: Both acylation and O-glycosylation were necessary for the protein to remain within the cell. IL-1 Beta secretion from human monocytes was significantly reduced by deletion of the 19 kDa gene (p < 0.02). Complementation by the wild type, but not the mutagenised gene reversed this phenotype. The effect of deletion and complementation on IL-12p40 and TNF secretion was less marked with no statistically significant differences between strains. Although deletion of the 19 kDa reduced apoptosis, an effect that could also only be reversed by complementation with the wild type gene, the results were variable between donors and did not achieve statistical significance. CONCLUSION: These results confirm in the context of the whole bacillus an important role for post-translational modification of the 19 kDa on both the cellular location and immune response to this protein.

A role for dendritic cells in the dissemination of mycobacterial infection.

The ability of mycobacteria to disseminate from the initial site of infection has an important role in immune priming and in the seeding of disease in multiple organs. To study this phenomenon, we used flow cytometry to analyse the distribution of green fluorescent protein-labelled BCG amongst different populations of antigen-presenting cells in the lungs of mice following intranasal infection, and monitored appearance of live bacteria in the draining mediastinal lymph nodes. BCG predominantly infected alveolar macrophages (CD11c(+)/CD11b(-)) and dendritic cells (CD11c(+)/CD11b(+)) in the lungs. The bacteria that disseminated to the lymph node were found in dendritic cells. The results are consistent with a model in which mycobacterial dissemination from the lung is initiated by the migration of infected dendritic cells to the draining lymph nodes.