The CD8+ T cell tolerance checkpoint triggers a distinct differentiation state defined by protein translation defects.

Peripheral CD8+ T cell tolerance is a checkpoint in both autoimmune disease and anti-cancer immunity. Despite its importance, the relationship between tolerance-induced states and other CD8+ T cell differentiation states remains unclear. Using flow cytometric phenotyping, single-cell RNA sequencing (scRNA-seq), and chromatin accessibility profiling, we demonstrated that in vivo peripheral tolerance to a self-antigen triggered a fundamentally distinct differentiation state separate from exhaustion, memory, and functional effector cells but analogous to cells defectively primed against tumors. Tolerant cells diverged early and progressively from effector cells, adopting a transcriptionally and epigenetically distinct state within 60 h of antigen encounter. Breaching tolerance required the synergistic actions of strong T cell receptor (TCR) signaling and inflammation, which cooperatively induced gene modules that enhanced protein translation. Weak TCR signaling during bystander infection failed to breach tolerance due to the uncoupling of effector gene expression from protein translation. Thus, tolerance engages a distinct differentiation trajectory enforced by protein translation defects.

Isolation and characterisation of PR3-specific B cells and their immunoglobulin sequences.

BACKGROUND: PR3 autoantibodies are essential to the diagnosis and monitoring of granulomatosus with polyangiitis, but to date no PR3 autoantibody sequences have been published. OBJECTIVES: To identify and characterise PR3-specific B cells from the peripheral blood of patients with PR3 autoantibodies. METHODS: Peripheral blood mononuclear cells from seven patients with PR3 autoantibodies were stained with PR3. B cells that bound PR3 underwent single cell sorting, transcriptome sequencing, and their immunoglobulin sequences expressed as antibodies and tested for PR3-specificity by ELISA. RESULTS: We identified 19 PR3-specific B cells from only one PR3-seropositive patient at a low frequency (0.0075 % of B cells) in the peripheral blood. These were polyclonal, IgG+ and enriched for IgG4, lambda pairing, IGHJ6 gene usage, CDRH3 length, IGHE and CD71 expression. They demonstrated relatively low levels of somatic hypermutation and variably reduced PR3 binding when reverted to germline. CONCLUSIONS: Identifying PR3-specific B cells in the peripheral blood is possible but challenging and those we did identify exhibited features suggesting that PR3-self reactivity may occur early in B-cell development.

Identification of human progenitors of exhausted CD8+ T cells associated with elevated IFN-γ response in early phase of viral infection.

T cell exhaustion is a hallmark of hepatitis C virus (HCV) infection and limits protective immunity in chronic viral infections and cancer. Limited knowledge exists of the initial viral and immune dynamics that characterise exhaustion in humans. We studied longitudinal blood samples from a unique cohort of individuals with primary infection using single-cell multi-omics to identify the functions and phenotypes of HCV-specific CD8+ T cells. Early elevated IFN-γ response against the transmitted virus is associated with the rate of immune escape, larger clonal expansion, and early onset of exhaustion. Irrespective of disease outcome, we find heterogeneous subsets of progenitors of exhaustion, based on the level of PD-1 expression and loss of AP-1 transcription factors. Intra-clonal analysis shows distinct trajectories with multiple fates and evolutionary plasticity of precursor cells. These findings challenge the current paradigm on the contribution of CD8+ T cells to HCV disease outcome and provide data for future studies on T cell differentiation in human infections.

STAT3 gain-of-function mutations connect leukemia with autoimmune disease by pathological NKG2Dhi CD8+ T cell dysregulation and accumulation.

The association between cancer and autoimmune disease is unexplained, exemplified by T cell large granular lymphocytic leukemia (T-LGL) where gain-of-function (GOF) somatic STAT3 mutations correlate with co-existing autoimmunity. To investigate whether these mutations are the cause or consequence of CD8+ T cell clonal expansions and autoimmunity, we analyzed patients and mice with germline STAT3 GOF mutations. STAT3 GOF mutations drove the accumulation of effector CD8+ T cell clones highly expressing NKG2D, the receptor for stress-induced MHC-class-I-related molecules. This subset also expressed genes for granzymes, perforin, interferon-γ, and Ccl5/Rantes and required NKG2D and the IL-15/IL-2 receptor IL2RB for maximal accumulation. Leukocyte-restricted STAT3 GOF was sufficient and CD8+ T cells were essential for lethal pathology in mice. These results demonstrate that STAT3 GOF mutations cause effector CD8+ T cell oligoclonal accumulation and that these rogue cells contribute to autoimmune pathology, supporting the hypothesis that somatic mutations in leukemia/lymphoma driver genes contribute to autoimmune disease.

Comprehensive methylome sequencing reveals prognostic epigenetic biomarkers for prostate cancer mortality.

BACKGROUND: Prostate cancer is a clinically heterogeneous disease with a subset of patients rapidly progressing to lethal-metastatic prostate cancer. Current clinicopathological measures are imperfect predictors of disease progression. Epigenetic changes are amongst the earliest molecular changes in tumourigenesis. To find new prognostic biomarkers to enable earlier intervention and improved outcomes, we performed methylome sequencing of DNA from patients with localised prostate cancer and long-term clinical follow-up. METHODS: We used whole-genome bisulphite sequencing (WGBS) to comprehensively map and compare DNA methylation of radical prostatectomy tissue between patients with lethal disease (n = 7) and non-lethal (n = 8) disease (median follow-up 19.5 years). Validation of differentially methylated regions (DMRs) was performed in an independent cohort (n = 185, median follow-up 15 years) using targeted multiplex bisulphite sequencing of candidate regions. Survival was assessed via univariable and multivariable analyses including clinicopathological measures (log-rank and Cox regression models). RESULTS: WGBS data analysis identified cancer-specific methylation patterns including CpG island hypermethylation, and hypomethylation of repetitive elements, with increasing disease risk. We identified 1420 DMRs associated with prostate cancer-specific mortality (PCSM), which showed enrichment for gene sets downregulated in prostate cancer and de novo methylated in cancer. Through comparison with public prostate cancer datasets, we refined the DMRs to develop an 18-gene prognostic panel. Applying this panel to an independent cohort, we found significant associations between PCSM and hypermethylation at EPHB3, PARP6, TBX1, MARCH6 and a regulatory element within CACNA2D4. Strikingly in a multivariable model, inclusion of CACNA2D4 methylation was a better predictor of PCSM versus grade alone (Harrell's C-index: 0.779 vs. 0.684). CONCLUSIONS: Our study provides detailed methylome maps of non-lethal and lethal prostate cancer and identifies novel genic regions that distinguish these patient groups. Inclusion of our DNA methylation biomarkers with existing clinicopathological measures improves prognostic models of prostate cancer mortality, and holds promise for clinical application.

Uncontrolled CD21low age-associated and B1 B cell accumulation caused by failure of an EGR2/3 tolerance checkpoint.

CD21low age-associated or atypical memory B cells are autoantibody enriched and poised for plasma cell differentiation. These cells overaccumulate in chronic infections, autoimmune disease, and immunodeficiency, posing the question of what checkpoints normally oppose their accumulation. Here, we reveal a critical role for paralogous calcium-NFAT-regulated transcription factors EGR2 and EGR3 that are induced in self-reactive B cells. CD21low and B1 B cells lacking EGR2 and EGR3 accumulate and circulate in young mice in numbers 10- to 20-fold greater than normal and overexpress a large set of EGR2 ChIP-seq target genes, including known drivers of plasma cell differentiation. Most follicular B cells constitutively express Egr2 proportionally to surface IgM downregulation by self-antigens, and EGR2/3 deficiency abolishes this cardinal feature of B cell anergy. These results explain the cardinal features of B cell anergy, define a key transcriptional checkpoint repressing CD21low B cell formation, and inform how NFATC1 or EGR2 mutations promote B1 cell-derived chronic lymphocytic leukemias.

Antigen-driven EGR2 expression is required for exhausted CD8+ T cell stability and maintenance.

Chronic stimulation of CD8+ T cells triggers exhaustion, a distinct differentiation state with diminished effector function. Exhausted cells exist in multiple differentiation states, from stem-like progenitors that are the key mediators of the response to checkpoint blockade, through to terminally exhausted cells. Due to its clinical relevance, there is substantial interest in defining the pathways that control differentiation and maintenance of these subsets. Here, we show that chronic antigen induces the anergy-associated transcription factor EGR2 selectively within progenitor exhausted cells in both chronic LCMV and tumours. EGR2 enables terminal exhaustion and stabilizes the exhausted transcriptional state by both direct EGR2-dependent control of key exhaustion-associated genes, and indirect maintenance of the exhausted epigenetic state. We show that EGR2 is a regulator of exhaustion that epigenetically and transcriptionally maintains the differentiation competency of progenitor exhausted cells.

Lymphoma Driver Mutations in the Pathogenic Evolution of an Iconic Human Autoantibody.

Pathogenic autoantibodies arise in many autoimmune diseases, but it is not understood how the cells making them evade immune checkpoints. Here, single-cell multi-omics analysis demonstrates a shared mechanism with lymphoid malignancy in the formation of public rheumatoid factor autoantibodies responsible for mixed cryoglobulinemic vasculitis. By combining single-cell DNA and RNA sequencing with serum antibody peptide sequencing and antibody synthesis, rare circulating B lymphocytes making pathogenic autoantibodies were found to comprise clonal trees accumulating mutations. Lymphoma driver mutations in genes regulating B cell proliferation and V(D)J mutation (CARD11, TNFAIP3, CCND3, ID3, BTG2, and KLHL6) were present in rogue B cells producing the pathogenic autoantibody. Antibody V(D)J mutations conferred pathogenicity by causing the antigen-bound autoantibodies to undergo phase transition to insoluble aggregates at lower temperatures. These results reveal a pre-neoplastic stage in human lymphomagenesis and a cascade of somatic mutations leading to an iconic pathogenic autoantibody.

DNA Hypermethylation Encroachment at CpG Island Borders in Cancer Is Predisposed by H3K4 Monomethylation Patterns.

Promoter CpG islands are typically unmethylated in normal cells, but in cancer a proportion are subject to hypermethylation. Using methylome sequencing we identified CpG islands that display partial methylation encroachment across the 5' or 3' CpG island borders. CpG island methylation encroachment is widespread in prostate and breast cancer and commonly associates with gene suppression. We show that the pattern of H3K4me1 at CpG island borders in normal cells predicts the different modes of cancer CpG island hypermethylation. Notably, genetic manipulation of Kmt2d results in concordant alterations in H3K4me1 levels and CpG island border DNA methylation encroachment. Our findings suggest a role for H3K4me1 in the demarcation of CpG island methylation borders in normal cells, which become eroded in cancer.

Replication timing and epigenome remodelling are associated with the nature of chromosomal rearrangements in cancer.

DNA replication timing is known to facilitate the establishment of the epigenome, however, the intimate connection between replication timing and changes to the genome and epigenome in cancer remain largely uncharacterised. Here, we perform Repli-Seq and integrated epigenome analyses and demonstrate that genomic regions that undergo long-range epigenetic deregulation in prostate cancer also show concordant differences in replication timing. A subset of altered replication timing domains are conserved across cancers from different tissue origins. Notably, late-replicating regions in cancer cells display a loss of DNA methylation, and a switch in heterochromatin features from H3K9me3-marked constitutive to H3K27me3-marked facultative heterochromatin. Finally, analysis of 214 prostate and 35 breast cancer genomes reveal that late-replicating regions are prone to cis and early-replication to trans chromosomal rearrangements. Together, our data suggests that the nature of chromosomal rearrangement in cancer is related to the spatial and temporal positioning and altered epigenetic states of early-replicating compared to late-replicating loci.

Enduring epigenetic landmarks define the cancer microenvironment.

The growth and progression of solid tumors involves dynamic cross-talk between cancer epithelium and the surrounding microenvironment. To date, molecular profiling has largely been restricted to the epithelial component of tumors; therefore, features underpinning the persistent protumorigenic phenotype of the tumor microenvironment are unknown. Using whole-genome bisulfite sequencing, we show for the first time that cancer-associated fibroblasts (CAFs) from localized prostate cancer display remarkably distinct and enduring genome-wide changes in DNA methylation, significantly at enhancers and promoters, compared to nonmalignant prostate fibroblasts (NPFs). Differentially methylated regions associated with changes in gene expression have cancer-related functions and accurately distinguish CAFs from NPFs. Remarkably, a subset of changes is shared with prostate cancer epithelial cells, revealing the new concept of tumor-specific epigenome modifications in the tumor and its microenvironment. The distinct methylome of CAFs provides a novel epigenetic hallmark of the cancer microenvironment and promises new biomarkers to improve interpretation of diagnostic samples.

Flexible Bronchoscopy Is Safe and Effective in Adult Subjects Supported With Extracorporeal Membrane Oxygenation.

BACKGROUND: Previous studies have demonstrated the safety of flexible bronchoscopy (FB) in mechanically ventilated subjects. However, the safety of FB in adult subjects receiving extracorporeal membrane oxygenation (ECMO) has not been described previously. METHODS: A retrospective review was conducted of all adult subjects who underwent FB while receiving ECMO support at the University of Alabama at Birmingham Hospital from January 1, 2013, to December 31, 2014. Physiologic variables, pre- and post-FB ECMO, and ventilator settings were recorded. RESULTS: 79 adult subjects underwent FB receiving ECMO with a total of 223 bronchoscopies. The most common indications for bronchoscopy included diagnostic evaluation of infection in subjects with pneumonia (29%) and clearance of excessive secretions (22%). In 70% of subjects, moderate or greater amounts of secretions were noted. FB yielded positive culture data in 37 subjects (47%), which resulted in a change to the antibiotic regimen in 14 subjects (38%) with positive culture data. No significant differences in mean PaO2 /FIO2 , mean ECMO flow, mean sweep gas, ventilator settings, or hemodynamic parameters (heart rate, oxygen saturation, and mean blood pressure) were noted before and after FB. Complications were mild and transient: blood-tinged secretions after FB in 21% cases, which resolved spontaneously, intraprocedural hypoxemia in 2.2% of cases, and dysrhythmia in <1% of cases. There were no episodes of ECMO cannula dislodgement or inadvertent extubation. CONCLUSIONS: FB can be used safely in adult subjects supported with ECMO and is not associated with significant hemodynamics changes, bleeding, or mechanical complications during ECMO support.

Coherence analysis discriminates between retroviral integration patterns in CD34(+) cells transduced under differing clinical trial conditions.

Unequivocal demonstration of the therapeutic utility of γ-retroviral vectors for gene therapy applications targeting the hematopoietic system was accompanied by instances of insertional mutagenesis. These events stimulated the ongoing development of putatively safer integrating vector systems and analysis methods to characterize and compare integration site (IS) biosafety profiles. Continuing advances in next-generation sequencing technologies are driving the generation of ever-more complex IS datasets. Available bioinformatic tools to compare such datasets focus on the association of integration sites (ISs) with selected genomic and epigenetic features, and the choice of these features determines the ability to discriminate between datasets. We describe the scalable application of point-process coherence analysis (CA) to compare patterns produced by vector ISs across genomic intervals, uncoupled from association with genomic features. To explore the utility of CA in the context of an unresolved question, we asked whether the differing transduction conditions used in the initial Paris and London SCID-X1 gene therapy trials result in divergent genome-wide integration profiles. We tested a transduction carried out under each condition, and showed that CA could indeed resolve differences in IS distributions. Existence of these differences was confirmed by the application of established methods to compare integration datasets.

One third of middle ear effusions from children undergoing tympanostomy tube placement had multiple bacterial pathogens.

BACKGROUND: Because previous studies have indicated that otitis media may be a polymicrobial disease, we prospectively analyzed middle ear effusions of children undergoing tympanostomy tube placement with multiplex polymerase chain reaction for four otopathogens. METHODS: Middle ear effusions from 207 children undergoing routine tympanostomy tube placement were collected and were classified by the surgeon as acute otitis media (AOM) for purulent effusions and as otitis media with effusion (OME) for non-purulent effusions. DNA was isolated from these samples and analyzed with multiplex polymerase chain reaction for Haemophilus influenzae, Streptococcus pneumoniae, Alloiococcus otitidis, and Moraxella catarrhalis. RESULTS: 119 (57%) of 207 patients were PCR positive for at least one of these four organisms. 36 (30%) of the positive samples indicated the presence of more than one bacterial species. Patient samples were further separated into 2 groups based on clinical presentation at the time of surgery. Samples were categorized as acute otitis media (AOM) if pus was observed behind the tympanic membrane. If no pus was present, samples were categorized as otitis media with effusion (OME). Bacteria were identified in most of the children with AOM (87%) and half the children with OME (51%, p < 0.001). A single bacterial organism was detected in middle ear effusions from children with AOM more often than those with OME (74% versus 33%, p < 0.001). Haemophilus influenzae was the predominant single organism and caused 58% of all AOM in this study. Alloiococcus otitidis and Moraxella catarrhalis were more frequently identified in middle ear effusions than Streptococcus pneumoniae. CONCLUSIONS: Haemophilus influenzae, Streptococcus pneumoniae, Alloiococcus otitidis, and Moraxella catarrhalis were identified in the middle ear effusions of some patients with otitis media. Overall, we found AOM is predominantly a single organism infection and most commonly from Haemophilus influenzae. In contrast, OME infections had a more equal distribution of single organisms, polymicrobial entities, and non-bacterial agents.

Detection of group A Streptococcus in tonsils from pediatric patients reveals high rate of asymptomatic streptococcal carriage.

BACKGROUND: Group A Streptococcus (GAS) causes acute tonsillopharyngitis in children, and approximately 20% of this population are chronic carriers of GAS. Antibacterial therapy has previously been shown to be insufficient at clearing GAS carriage. Bacterial biofilms are a surface-attached bacterial community that is encased in a matrix of extracellular polymeric substances. Biofilms have been shown to provide a protective niche against the immune response and antibiotic treatments, and are often associated with recurrent or chronic bacterial infections. The objective of this study was to test the hypothesis that GAS is present within tonsil tissue at the time of tonsillectomy. METHODS: Blinded immunofluorescent and histological methods were employed to evaluate palatine tonsils from children undergoing routine tonsillectomy for adenotonsillar hypertrophy or recurrent GAS tonsillopharyngitis. RESULTS: Immunofluorescence analysis using anti-GAS antibody was positive in 11/30 (37%) children who had tonsillectomy for adenotonsillar hypertrophy and in 10/30 (33%) children who had tonsillectomy for recurrent GAS pharyngitis. Fluorescent microscopy with anti-GAS and anti-cytokeratin 8 & 18 antibodies revealed GAS was localized to the tonsillar reticulated crypts. Scanning electron microscopy identified 3-dimensional communities of cocci similar in size and morphology to GAS. The characteristics of these communities are similar to GAS biofilms from in vivo animal models. CONCLUSION: Our study revealed the presence of GAS within the tonsillar reticulated crypts of approximately one-third of children who underwent tonsillectomy for either adenotonsillar hypertrophy or recurrent GAS tonsillopharyngitis at the Wake Forest School of Medicine. TRIAL REGISTRATION: The tissue collected was normally discarded tissue and no patient identifiers were collected. Thus, no subjects were formally enrolled.

Clostridium septicum myonecrosis complicating diarrhea-associated hemolytic uremic syndrome.

We report the case of a 19-month-old male child with diarrhea-associated hemolytic uremic syndrome (HUS) who developed swelling of the right arm at the site of a peripherally inserted central venous catheter (PICC), fever, and later, ecchymosis. Wound cultures at the time of surgical debridement grew Clostridium septicum. The child subsequently required amputation of the right arm and prolonged therapy with parenteral penicillin and clindamycin. Clostridium septicum infections in children with HUS have been associated with a high rate of mortality. Along with colon cancer, diarrhea-associated HUS comprises a clinical entity which appears to predispose to atraumatic C. septicum infection, where acidic and anaerobic conditions in the diseased colon favor C. septicum invasion. Though not well recognized among pediatric nephrologists, C. septicum infection constitutes a severe, albeit rare, complication of diarrhea-associated HUS, but one in which a high index of suspicion is warranted as aggressive surgical and antibiotic therapy may be life-saving.

Bartonella henselae endocarditis in a child.

14-year-old white male with a past medical history of congenital bicuspid aortic valve, Streptococcus viridans endocarditis, and pulmonary valve homograft presented with culture-negative endocarditis. Molecular studies identified the causative organism as Bartonella henselae and subsequent serologic studies supported this diagnosis. This rare cause of endocarditis may be under recognized in children. Bartonella henselae endocarditis should be considered in all children with culture-negative endocarditis, and molecular studies using a polymerase chain reaction-based assay should be routinely utilized in the evaluation of all endocarditis cases that are culture negative to rapidly diagnosis this treatable cause of endocarditis.

Iron and cadmium uptake by duodenum of hypotransferrinaemic mice.

Absorption from food is an important route for entry of the toxic metal, cadmium, into the body. Both cadmium and iron are believed to be taken up by duodenal enterocytes via the iron regulated, proton-coupled transporter, DMT1. This means that cadmium uptake could be enhanced in conditions where iron absorption is increased. We measured pH dependent uptake of (109)Cd and (59)Fe by duodenum from mice with an in vitro method. Mice with experimental (hypoxia, iron deficiency) or hereditary (hypotransferrinaemia) increased iron absorption were studied. All three groups of mice showed increased (59)Fe uptake (p<0.05) compared to their respective controls. Hypotransferrinaemic and iron deficient mice exhibited an increase in (109)Cd uptake (p<0.05). Cadmium uptake was not, however, increased by lowering the medium pH from 7.4 to 6. In contrast, (59)Fe uptake (from (59)FeNTA(2)) and ferric reductase activity was increased by lowering medium pH in control and iron deficient mice (p<0.05). The data show that duodenal cadmium uptake can be increased by hereditary iron overload conditions. The uptake is not, however, altered by lowering medium pH suggesting that DMT1-independent uptake pathways may operate.

Urinary cortisol and cortisol metabolite excretion in chronic fatigue syndrome.

OBJECTIVES: Reduced basal hypothalamic-pituitary-adrenal (HPA) axis output in chronic fatigue syndrome (CFS) has been inferred from low cortisol levels in blood, saliva, and urine in some studies. Because > 95% of cortisol is metabolized before excretion, we assessed cortisol output by assay of both cortisol metabolites and free cortisol in 24-hour urine collections and also investigated sex differences in these between CFS and control groups. METHOD: We calculated total urinary cortisol metabolites (TCM) and cortisol metabolite ratios from individual steroid data in 40 patients (20 males and 20 females) with CFS who were free of medication or comorbid psychiatric disorder likely to influence the HPA axis. Results were compared with those of 40 healthy volunteers (20 males and 20 females) well matched for age and body mass index. Data for free cortisol was obtained on 28 of the patients and 27 of the controls. RESULTS: The mean of TCM and cortisol metabolite ratios was not significantly different between patients and controls for either sex (p > .05 for all parameters). Previously established sex differences were confirmed in our controls and were found to be similar in CFS for TCM and the ratios 11OH/11OXO, 5alpha/5beta THF, and 20OH/20OXO (see text) (p < .005, p < .05, p < .05, and p < .005, respectively). Urinary free cortisol values were numerically (but not statistically) lower in patients with CFS than controls, and correlated inversely with fatigue levels in patients. CONCLUSION: The finding of normal urinary cortisol metabolite excretion in patients with CFS is at variance with earlier reports that CFS is a hypocortisolemic state. If serum and saliva cortisol levels are lower in CFS, this would suggest that metabolic clearance of cortisol is faster in patients with CFS than controls. This study also demonstrates that sex differences must be taken into account when interpreting results in patients with CFS.

Opportunistic screening for alcohol use disorders in primary care: comparative study.

OBJECTIVE: To evaluate the efficacy and relative costs of different screening methods for the identification of alcohol use disorders in an opportunistic screening programme in primary care in the United Kingdom. DESIGN: Comparative study. SETTING: Six general practices in south Wales. PARTICIPANTS: 194 male primary care attendees aged 18 or over who completed an alcohol use disorders identification test (AUDIT) questionnaire. MAIN OUTCOME MEASURES: Scores on alcohol use disorders identification test and measures of gamma-glutamyltransferase, aspartate aminotransferase, per cent carbohydrate deficient transferrin, and erythrocyte mean cell volume. Hazardous alcohol consumption, weekly binge consumption, and monthly binge consumption were ascertained using the time line follow back method over the previous 180 days. Alcohol dependence was determined using the Diagnostic and Statistical Manual of Mental Disorders, fourth edition. Unit costs were established from published resource references and from actual costs of analysing the biochemical tests. RESULTS: A significant correlation was observed be alcohol consumption and score on the alcohol use disorders identification test (Pearson's correlation coefficient r = 0.74) and measures of gamma-glutamyltransferase (r = 0.20) and per cent carbohydrate deficient transferrin (r = 0.36) but not aspartate aminotransferase (r = 0.08) or erythrocyte mean cell volume (r = 0.02). The alcohol use disorders identification test exhibited significantly higher sensitivity, specificity, and positive predictive value than all of the biochemical markers for hazardous consumption (69%, 98%, and 95%), weekly binge consumption (75%, 90%, and 71%), monthly binge consumption (66%, 97%, and 91%), and alcohol dependence (84%, 83%, and 41%). The questionnaire was also more cost efficient, with a lower cost per true positive for all consumption outcomes. CONCLUSION: The alcohol use disorders identification test questionnaire is an efficient and cost efficient diagnostic tool for routine screening for alcohol use disorders in primary care.