Does pre-diabetes predict the extent of coronary artery disease?

Funding Acknowledgements

Type of funding sources: None.

Background

Extensive coronary artery disease (CAD) is common in diabetes mellitus. This relation between the extent of CAD and prediabetes (pDM)is less well established.

Purpose

To explore whether non-diabetic hyperglycaemia, assessed by HbA1c, is associated with extent of angiographic CAD, independent of traditional cardiovascular risk factors.

Methods

Retrospective cohort analysis of consecutive patients, without known DM undergoing coronary angiography for stable angina, who were screened for hyperglycaemia over 18 months. HbA1c was measured; pre-diabetes was defined as HbA1c 5.7-6.4%.Extent of CAD was assessed using the SYNTAX score. Presence of CAD was defined as visually estimated ≥50% luminal obstruction in arteries ≥1.5 mm diameter. Age, BMI, risk factors for CAD, HbA1c, total and LDL-cholesterol were recorded. The pre-diabetes and normal groups were compared using Mann-Whitney test for continuous variables and chi-squared test for categorical variables. Multiple logistic and linear regressions were used to assess the effect variables on SYNTAX score. Spearman rank correlation was used to assess the relation between HbA1c and SYNTAX score.

Results

1071 patients had angiograms done. 207 had DM, 19 had new diagnosis of DM and 181 missed the screening leaving 664 who had HbA1c measured. 51 poor quality angiograms were excluded from SYNTAX calculation. Data was analysed for 613 (306 normal, 307 pDM) patients. The patients with prediabetes were older, had higher prevalence of risk factors, BMI, fasting glucose and SYNTAX score. HbA1c (OR 2.07, 95% CI 1.32 to 3.25, p=0.002) and the presence of pDM (OR 1.89, 95% CI 1.32 to 2.69, p<0.001) independently predicted the presence of CAD. HbA1c (Coefficient 2.42, SE 1.09, p=0.027) and the presence of pDM (Coefficient 2.25, SE 0.92, p=0.015) independently predicted the SYNTAX score. The correlation between HbA1c and SYNTAX score was weak but significant (Spearman's coefficient 0.206, 95% CI 0.129 to 0.281, p<0.0001).

Conclusion

HbA1c predicts the extent of CAD as measured by SYNTAX score in patients without known diabetes. Presence of pre-diabetes is an independent predictor of extent of CAD.

Polyanhydride based nanovaccine promotes long term humoral and cellular response to PDAC associated protein MUC4β

Patients diagnosed with pancreatic ductal adenocarcinoma (PDAC) have an unrelentingly poor prognosis, in part because of the lack of neoantigen targets associated with PDAC tumors. However, another approach would be to take advantage of differentially expressed antigens on PDAC tumor cells. It has been demonstrated that mucin 4 (MUC4) is overexpressed on the tumor cells of many PDAC patients and is considered a promising antigenic target for PC immunotherapy. Previous work by our lab has demonstrated that poly-anhydride (PA) nanovaccines based on 20:80 1,8-bis(p-carboxyphenoxy)-3,6-dioxaoctane (CPTEG) and 1,6-bis(p-carboxyphenoxy)hexane (CPH) nanoparticles (NPs) both induced a humoral immune response to the beta subunit of MUC4 (MUC4β) and an anti-tumor response against OVA in an EG-7 tumor model. In these studies, we show that both a PA-based nanovaccine formulation and a PLGA-based nanovaccine induced MUC4β-specific T cell response. Results demonstrated that restimulation of LN and splenic lymphocytes 40 days after initial vaccination induced both CD4+ and CD8+ MUC4β-specific T cells. The MUC4ß-specific T cells could be detected for at least 180 days post-vaccination. Cytokine secretions from the antigen specific T cells included IL-2, INFγ, and TNF-α; in addition, tetramer analysis detected MUC4ß-specific CD8+ T cells using the MUCβ peptide FTPVFYSQL. Collectively, these results demonstrate that a PA nanovaccine can function as an effective vaccine platform for induction of MUC4ß-specific cellular immunity, and lays the ground work for forthcoming studies in MUC4β-expressing tumor model systems.

Supported by the National Institute of Health (U01 CA213862) and the Iowa State University Nanovaccine Institute. B. N. is grateful to the Vlasta Klima Balloun Faculty Chair.

Effect of systemic inflammation biomarkers on overall survival after lung cancer radiotherapy: a single-center large-cohort study

INTRODUCTION

Recent studies suggest that immune-related cells can be recruited for anti-tumor functions as well as tumor progression and the interplay between systemic inflammation and local immune response may play a major role in the development and progression of various cancers including lung cancer. Inflammatory markers, such as neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and systemic immune-inflammation index (SII) can be used as surrogate biomarkers of host immune status. In this work, associations between neutrophils, lymphocytes, platelets, NLR, PLR, SII and overall survival (OS) are investigated in two cohorts of non-small cell lung cancer (NSCLC) patients treated with fractionated radiotherapy (RT) and stereotactic body radiation therapy (SBRT) and a cohort of small cell lung cancer (SCLC) patients treated with fractionated RT.

MATERIAL AND METHODS

Data from 2513 lung cancer patients were retrospectively analyzed. Baseline NLR, PLR, and SII (NLR × platelet count) were calculated from full blood test prior to RT initiation. Cox proportional hazards regression analyses were used to evaluate the association between systemic inflammation markers and known clinical factors with OS.

RESULTS

The two-year OS was 42%, 63%, and 62% in the NSCLC fractionated RT, SBRT, and SCLC cohort. NLR (per 1 unit: hazard ratio [HR]: 1.04, p < 0.05) and SII (per 100 × 109/L: HR: 1.01, p < 0.05) remained the strongest independent factors of OS in multivariable Cox analyses, correcting for clinical factors in early-stage and locally advanced NSCLC and SCLC patients treated with RT.

DISCUSSION

This single-center large-cohort study suggests that baseline NLR and SII are independent prognostic biomarkers associated with OS in locally advanced and early-stage NSCLC patients treated with either curative-intent fractionated RT or SBRT and SCLC patients treated with curative-intent fractionated RT. External validation is warranted to evaluate the utility of these biomarkers for patients' stratification and adapting new treatment approaches.

Left ventricular global longitudinal strain alteration in young patient and correlation with post-COVID syndrome (TUN END COV Study)

Background

Several protocols are in study to understand mechanisms of these persistent symptoms of COVID-19. The conventional echocardiography can be a good tool to detect abnormalities in the cardiovascular system induced by long COVID-19.

Objective

Correlation between echocardiographic parameters and symptoms of long COVID and the spontaneous evolution at one month of follow-up.

Patients and methods

A prospective multicentric study including a total of 630 patients diagnosed with COVID-19, 2 weeks to one month after recovering from COVID-19. Young patients without any medical history other than recent SARS-CoV2 infection are selected. A meticulous interrogation and clinical examination as well as an echocardiography are performed in all of patients. In addition to symptoms, we assessed echocardiographic parameters including initial left ventricular global longitudinal strain (initial SLG: SLGi) and after one month (SLG control: SLGc).

Results

Mean SLGi was −18.1 ± 2.4 in study group (−19.6 ± 1.5; P < 0.001). Forty-two patients (52.5%) had initially altered strain versus 38 patients (47.5%) with normal strain. The threshold value for SLG in our study has been established using ROC curve which was −17.95% with sensibility (52.5%) and specificity (83.7%). we found a statistically significative correlation between the initial alteration of SLG and persistent symptoms in multivariate test: dyspnea (P < 0.002); chest pain (P = 0.031). At one month of follow-up, 87.5% of patients improved their SLG. And there was a correlation between control GS value (mean SLGc was −18.91 ± 3.33; P = 0.002) associated with a marked improvement in symptoms (P = 0.001).

Conclusion

We reported here an original case series of SLG alteration induced by SARS-CoV2 infection that is correlated with the presence of chest pain and dyspnea. However, this affection seems to be spontaneously significantly reversible and associated with significant clinical improvement.

Intra-Articular Adeno-Associated Virus-Mediated Proteoglycan 4 Gene Therapy for Preventing Post-Traumatic Osteoarthritis

OBJECTIVE

Lubricin, a glycoprotein encoded by the proteoglycan 4 (PRG4) gene, is an essential boundary lubricant that reduces friction between articular cartilage surfaces. The loss of lubricin subsequent to joint injury plays a role in the pathogenesis of post-traumatic osteoarthritis (PTOA). Here we describe the development and evaluation of an adeno-associated virus (AAV)-based PRG4 gene therapy intended to restore lubricin in injured joints. The green fluorescent protein (GFP) gene was inserted the PRG4 gene to facilitate tracing the distribution of the transgene product (AAV-PRG4-GFP) in vivo.

METHODS

Transduction efficiency of AAV-PRG4-GFP was evaluated in joint cells, and the conditioned medium containing secreted PRG4-GFP was used for shear loading/friction and viability tests. In vivo transduction of joint tissues following intra-articular injection of AAV-PRG4-GFP was confirmed in the mouse stifle joint in a surgical model of destabilization of the medial meniscus (DMM), and chondroprotective activity was tested in a rabbit anterior cruciate ligament transection (ACLT) model.

RESULTS

In vitro studies showed that PRG4-GFP has lubricin-like cartilage binding and anti-friction properties. Significant cytoprotective effects were seen when cartilage was soaked in PRG4-GFP prior to cyclic shear loading (n = 3). Polymerase chain reaction and confocal microscopy confirmed the presence of PRG4-GFP DNA and protein, respectively, in a mouse DMM (n = 3 per group). In the rabbit ACLT model, AAV-PRG4-GFP gene therapy enhanced lubricin expression (p = 0.001 versus AAV-GFP: n = 7-14) and protected the cartilage from degeneration (p = 0.014 versus AAV-GFP: n = 9-10) when treatments were administered immediately post-operation, but efficacy was lost when treatment was delayed for 2 weeks.

CONCLUSION

AAV-PRG4-GFP gene therapy protected cartilage from degeneration in a rabbit ACLT model; however, data from the ACLT model suggest that early intervention is essential for efficacy.

Abstract 6641: In situ immunization with the TLR9-agonist CMP-001 enhances anti-PD1 therapy in head and neck tumors

Immunotherapy involving immune checkpoint inhibitors (i.e. anti-PD1) has shown promise for the treatment of head and neck squamous cell carcinoma (HNSCC). However, only a small subset of HNSCC patients respond to these therapies. Therefore, the identification of alternative immunotherapeutic strategies is necessary to improve HNSCC patient outcomes. CMP-001 is a novel toll-like receptor-9 agonist that consists of an unmethylated CpG motif-rich G10 oligonucleotide encapsulated in virus-like particles. In situ vaccination of CMP-001 is believed to activate tumor-associated plasmacytoid dendritic cells (pDCs) leading to tumor antigen presentation to T cells and anti-tumor T cell responses. This study is designed to investigate if CMP-001 would enhance HNSCC tumor response to anti-PD1 therapy in a human papilloma virus-positive (HPV+) tumor mouse model. C57BL/6 mice were subcutaneously inoculated with murine HPV+ mEERL HNSCC cells on both left and right flanks of each mouse. CMP-001 (100 µg/mouse) was administered intratumorally (i.t.) 3 times over the course of 1 week into the left tumor as a single agent and in combination with anti-PD1 (50 µg/mouse, intraperitoneally (i.p.)) 3 times per week for 2 weeks. Succinate buffer i.t. in combination with human IgG i.p. was administered as controls. The role of anti-tumor immune response due to CMP-001+anti-PD1 treatment was investigated by the depletion of NK cells, CD4+ and CD8+ T cells. Tumor growth, survival and immune cell recruitment was monitored and analyzed in response to drug treatment. Results showed that in situ vaccination of CMP-001 alone and in combination with anti-PD1 therapy induced tumor regression in the injected tumors and the regression of CMP-001+anti-PD1-injected tumors was durable. Additionally, CMP-001+anti-PD1 induced tumor regression at the distant sites which was not observed in the other treatment groups. CMP-001+anti-PD1 also significantly prolonged mouse survival compared with other groups. The anti-tumor effect of CMP-001+anti-PD1 was accompanied by increased DCs, macrophages, IFNγ+ CD4+/CD8+ T cells, HPV+ CD8+ T cells and activated NK cells in tumors and lymph nodes near the injected site compared with control. The therapeutic and abscopal effect of CMP-001+anti-PD1 therapy was partially abrogated by NK cell depletion and completely abrogated by CD8+ T cell depletion. These results demonstrate the synergistic anti-tumor efficacy of CMP-001 combined with α-PD1 therapy and warrants further study of this combination as a novel immunotherapeutic strategy for the treatment of HNSCC.

Citation Format: Yinwen Cheng, Caitlin D. Lemke-Miltner, Carlos H. Chan, Aliasger Salem, George Weiner, Andrean Simons. In situ immunization with the TLR9-agonist CMP-001 enhances anti-PD1 therapy in head and neck tumors [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 6641.

Impact of Peer Review in Reducing Uncertainty in the Definition of the Lung Target Volume Among Trainee Oncologists

AIMS

To evaluate the impact of peer review and contouring workshops on reducing uncertainty in target volume delineation for lung cancer radiotherapy.

MATERIALS AND METHODS

Data from two lung cancer target volume delineation courses were analysed. In total, 22 trainees in clinical oncology working across different UK centres attended these courses with priori experience in lung cancer radiotherapy. The courses were made up of short presentations and contouring practice sessions. The participants were divided into two groups and asked to first individually delineate (IND) and then individually peer review (IPR) the contours of another participant. The contours were discussed with an expert panel consisting of two consultant clinical oncologists and a consultant radiologist. Contours were analysed quantitatively by measuring the volume and local distance standard deviation (localSD) from the reference expert consensus contour and qualitatively through visual analysis. Feedback from the participants was obtained using a questionnaire.

RESULTS

All participants applied minor editing to the contours during IPR, leading to a non-statistically significant reduction in the mean delineated volume (IND = 140.92 cm3, IPR = 125.26 cm3, P = 0.211). The overall interobserver variation was similar, with a localSD of 0.33 cm and 0.38 cm for the IND and IPR, respectively (P = 0.848). Six participants (29%) carried out correct major changes by either including tumour or excluding healthy tissue. One participant (5%) carried out an incorrect edit by excluding parts of the tumour, while another observer failed to identify a major contour error. The participants' level of confidence in target volume delineation increased following the course and identified the discussions with the radiologist and colleagues as the most important highlights of the course.

CONCLUSION

IPR could improve target volume delineation quality among trainee oncologists by identifying most major contour errors. However, errors were also introduced after IPR, suggesting the need to further discuss major changes with a multidisciplinary team.

Abstract A80: Mapping immune landscape in clear cell renal carcinoma by single-cell genomics

Human clear cell renal cell carcinoma (ccRCC) is one of the most immunologically distinct tumor types due to high levels of tumor-infiltrating immune cells including T cells, yet not every patient responds to immunotherapy. Interestingly, in contrast to other cancers, infiltration with cytotoxic CD8+ T cells is associated with poorer overall survival in ccRCC, suggesting that subpopulations of CD8+ and other immune cells may underlie this observation. To characterize the tumor immune microenvironment of ccRCC, we applied single-cell RNA sequencing along with T-cell receptor sequencing to map the transcriptomic heterogeneity of 25,688 individual CD45+ lymphoid and myeloid cells in matched tumor and blood from patients with ccRCC. We identified multiple and distinct immune cell phenotypes for B and T (CD4 and CD8) lymphocytes, natural kill (NK) cells, and myeloid cells. Evaluation of T-cell receptor (TCR) sequences revealed limited shared clonotypes between patients, whereas tumor-infiltrating T-cell clonotypes were frequently found in peripheral blood, albeit in lower abundance. Evaluation of myeloid subsets revealed unique gene programs defining monocytes, dendritic cells, and tumor-associated macrophages. In summary, here we have leveraged scRNA-seq to refine our understanding of the relative abundance, diversity, and complexity of the immune landscape of ccRCC. This report represents the first such characterization of the ccRCC immune landscape using scRNA-seq. With further characterization and functional validation, these findings may identify novel subpopulations of immune cells amenable to therapeutic intervention.

Citation Format: Ajaykumar Vishwakarma, Nick Bocherding, Michael Chimenti, Purshottam Vishwakarma, Kenneth Nepple, Aliasger Salem, Russell W. Jenkins, Weizhou Zhang, Yousef Zakharia. Mapping immune landscape in clear cell renal carcinoma by single-cell genomics [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology and Immunotherapy; 2019 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Immunol Res 2020;8(3 Suppl):Abstract nr A80.

Abstract B065: TANK-Binding Kinase 1 (TBK1) as a novel cancer immunotherapy target

Despite the unprecedented success of immune checkpoint blockade (ICB) in melanoma and other cancers, tackling innate (primary) resistance remains a major challenge and robust biomarkers to guide treatment are lacking. Clinical trials are already underway evaluating novel immune modulatory agents in combination with anti-PD-1/PD-L1 therapies in an effort to overcome innate resistance. Despite increasing reports of ‘rational’ combination strategies, these therapies remain “one size fits all”, due the lack of robust biomarkers to guide clinical decision-making. There is an unmet need for novel approaches, tools, techniques, and methods for pre-clinical and clinical use to better understand mechanisms of response and resistance to immune checkpoint inhibitors and next-generation anti-tumor immune modulatory drugs. We have adapted a 3D microfluidic device to the short-term culture of murine- and patient-derived organotypic tumor spheroids (MDOTS/PDOTS)for functional ex vivo profiling of PD-1 blockade in a model tumor immune microenvironment (TIME) to facilitate identification of mediators of response and resistance to ICB and to guide development of next-generation immunotherapy combinations. The MDOTS/PDOTS platform provides a window into the complex and dynamic events of the TIME during response (and resistance) to ICB and is an ideal model system for pre-clinical evaluation of novel cancer immunotherapy targets. Focused evaluation of novel treatment combinations using MDOTS identified TANK-binding kinase 1 (TBK1) as a novel cancer immunotherapy target, mirroring in vivoefficacy of this treatment approach. TBK1 is a Ser/Thr kinase involved in innate immune signaling and is an emerging target for anti-cancer therapy. Importantly, independent orthogonal data from two different laboratories has also identified TBK1 as a cancer immunotherapy target.We have confirmed that Tbk1 deletion and/or TBK1 pharmacologic inhibition enhances response to in vivo anti-PD-1 therapy, and have characterized the impact of deletion of Tbk1 (CRISPR) or pharmacologic inhibition of TBK1 (Cmpd1) on the tumor-immune microenvironment.Lastly, we confirmed that resistance to PD-1 blockade can be overcome with pharmacologic TBK1 inhibition using murine- and patient-derived organotypic tumor spheroids in 3D microfluidic culture. These findings confirm TBK1 as a target to overcome resistance to PD-1 blockade, further supporting the pre-clinical and clinical development of this novel combination strategy. REFERENCES 1. Jenkins RW, Barbie DA, Flaherty KT. Mechanisms of resistance to immune checkpoint inhibitors. Br J Cancer. 2018;118(1):9-16. doi: 10.1038/bjc.2017.434. PubMed PMID: 29319049; PMCID: PMC5765236. 2. Manguso RT, Pope HW, Zimmer MD, Brown FD, Yates KB, Miller BC, Collins NB, Bi K, LaFleur MW, Juneja VR, Weiss SA, Lo J, Fisher DE, Miao D, Van Allen E, Root DE, Sharpe AH, Doench JG, Haining WN. In vivo CRISPR screening identifies Ptpn2 as a cancer immunotherapy target. Nature. 2017. doi: 10.1038/nature23270. PubMed PMID: 28723893. 3. Pan D, Kobayashi A, Jiang P, Ferrari de Andrade L, Tay RE, Luoma AM, Tsoucas D, Qiu X, Lim K, Rao P, Long HW, Yuan GC, Doench J, Brown M, Liu XS, Wucherpfennig KW. A major chromatin regulator determines resistance of tumor cells to T cell-mediated killing. Science. 2018;359(6377):770-5. doi: 10.1126/science.aao1710. PubMed PMID: 29301958.

Citation Format: Ajaykumar Vishwakarma, Yi Sun, Amina Fu, Emily Robitschek, Arvin Iracheta-Vellve, Susanna Stinson, Aliasger Salem, Robert Manguso, Russell Jenkins. TANK-Binding Kinase 1 (TBK1) as a novel cancer immunotherapy target [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference on Molecular Targets and Cancer Therapeutics; 2019 Oct 26-30; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2019;18(12 Suppl):Abstract nr B065. doi:10.1158/1535-7163.TARG-19-B065

Streptococcus intermedius masquerading as fungal infective endocarditis

Infective endocarditis remains an important clinical entity with an incidence of 1.7–10/100 000 person years (Marks et al, 2015). Despite improvements in health care, it still results in significant morbidity and in-hospital mortality approaches 16% (Marks et al, 2015). There are likely multiple causes including late diagnosis, poor response to therapy and the challenges in identifying the causative pathogen and instigating the correct treatment. This is particularly the case for causative organisms that are difficult to culture or identify using routine laboratory methods. An example of this is Streptococcus intermedius, which belongs to the S. milleri group along with other two species (S. anginosus group and S. constellatus). It is a commensal organism that can turn into an opportunistic pathogen (Whiley et al, 1992). It is a rare cause of infective endocarditis and may initially present with abscesses in the liver, spleen or brain which may mimic fungal infection (Woo et al, 2004; Rashid et al, 2007; Tran et al, 2008). Difficulty in identifying this organism has led to the development of molecular testing to aid diagnosis. To the authors' knowledge, there are very few cases in the literature of infective endocarditis caused by S. intermedius that have been confirmed using 16S polymerase chain reaction (Woo et al, 2004). This article describes a patient presenting with S. intermedius infective endocarditis which was diagnosed using this method.

Insulin glargine compared to neutral protamine Hagedorn (NPH) insulin in patients with type-2 diabetes uncontrolled with oral anti-diabetic agents alone in Hong Kong: a cost-effectiveness analysis

Background

International guidelines recommend using basal insulin in patients with type-2 diabetes mellitus if glycaemic target cannot be attained on non-insulin anti-diabetic drugs. Available choices of basal insulin include intermediate-acting neutral protamine Hagedorn (NPH) insulin and long-acting insulin analogues like insulin glargine U100. Despite clear advantages of glargine U100, the existing practice in Hong Kong still favours NPH insulin due to lower immediate drug costs.

Objectives

The objective of this study was to assess the cost-effectiveness of insulin glargine U100 compared to NPH insulin in patients with type-2 diabetes uncontrolled with non-insulin anti-diabetic agents alone in Hong Kong.

Methods

The IQVIA™ Core Diabetes Model (CDM) v9.0 was used to conduct the cost-effectiveness analysis of glargine U100 versus NPH. Baseline characteristics were collected from the Hong Kong Diabetes Registry. Efficacy rates were extracted from a published study comparing glargine U100 and NPH in Asia, utilities from published literature, and costs constructed using the Hong Kong Hospital Authority (HA) Gazette (public healthcare setting). The primary outcome was an incremental cost-effectiveness ratio (ICER).

Results

Insulin glargine U100 resulted in an ICER of HKD 98,663 per Quality Adjusted Life Year (QALY) gained. The incremental gains in QALY and costs were 0.217 years and HKD 21,360 respectively. Results from scenario and probabilistic sensitivity analyses were consistent with that from base case analysis.

Conclusion

Insulin glargine U100 is a cost-effective treatment for patients with type 2 diabetes compared to NPH insulin in setting in Hong Kong. This was mainly driven by the significantly lower rates of hypoglycaemia of insulin glargine U100 than NPH insulin.

Electronic supplementary material

The online version of this article (10.1186/s12962-019-0180-9) contains supplementary material, which is available to authorized users.

Laboratory testing of a shuttle car canopy air curtain for respirable coal mine dust control

Canopy air curtain (CAC) technology has been developed by the National Institute for Occupational Safety and Health (NIOSH) for use on continuous miners and subsequently roof bolting machines in underground coal mines to protect operators of these machines from overexposure to respirable coal mine dust. The next logical progression is to develop a CAC for shuttle cars to protect operators from the same overexposures. NIOSH awarded a contract to Marshall University and J.H. Fletcher to develop the shuttle car CAC. NIOSH conducted laboratory testing to determine the dust control efficiency of the shuttle car CAC. Testing was conducted on two different cab configurations: a center drive similar to that on a Joy 10SC32AA cab model and an end drive similar to that on a Joy 10SC32AB cab model. Three different ventilation velocities were tested-0.61, 2.0, 4.3 m/s (120, 400, and 850 fpm). The lowest, 0.61 m/s (120 fpm), represented the ventilation velocity encountered during loading by the continuous miner, while the 4.3 m/s (850 fpm) velocity represented ventilation velocity airflow over the shuttle car while tramming against ventilation airflow. Test results showed an average of the dust control efficiencies ranging from 74 to 83% for 0.61 m/s (120 fpm), 39%-43% for 2.0 m/s (400 fpm), and 6%-16% for 4.3 m/s (850 fpm). Incorporating an airflow spoiler to the shuttle car CAC design and placing the CAC so that it is located 22.86 cm (9 in.) forward of the operator improved the dust control efficiency to 51%-55% for 4.3 m/s (850 fpm) with minimal impact on dust control efficiencies for lower ventilation velocities. These laboratory tests demonstrate that the newly developed shuttle car CAC has the potential to successfully protect shuttle car operators from coal mine respirable dust overexposures.