Background Cardiovascular disease had a global prevalence of 523 million cases and 18.6 million deaths in 2019. The current standard for diagnosing coronary artery disease (CAD) is coronary angiography. Surprisingly, despite well-established clinical indications, up to 40% of the one million invasive cardiac catheterizations return a result of ‘no blockage’. The present studies employed RNA sequencing of whole blood to identify an RNA signature in patients with angiographically confirmed CAD. Methods Whole blood RNA was depleted of ribosomal RNA (rRNA) and analyzed by single-molecule sequencing of RNA (RNAseq) to identify transcripts associated with CAD (TRACs) in a discovery group of 96 patients presenting for elective coronary catheterization. The resulting transcript counts were compared between groups to identify differentially expressed genes (DEGs). Results Surprisingly, 98% of DEGs/TRACs were down-regulated ~ 1.7-fold in patients with mild to severe CAD (> 20% stenosis). The TRACs were independent of comorbid risk factors for CAD, such as sex, hypertension, and smoking. Bioinformatic analysis identified an enrichment in transcripts such as FoxP1, ICOSLG, IKZF4/Eos, SMYD3, TRIM28, and TCF3/E2A that are likely markers of regulatory T cells (Treg), consistent with known reductions in Tregs in CAD. A validation cohort of 80 patients confirmed the overall pattern (92% down-regulation) and supported many of the Treg-related changes. TRACs were enriched for transcripts associated with stress granules, which sequester RNAs, and ciliary and synaptic transcripts, possibly consistent with changes in the immune synapse of developing T cells. Conclusions These studies identify a novel mRNA signature of a Treg-like defect in CAD patients and provides a blueprint for a diagnostic test for CAD. The pattern of changes is consistent with stress-related changes in the maturation of T and Treg cells, possibly due to changes in the immune synapse.

RATIONALE: Cardiovascular disease had a global prevalence of 523 million cases and 18.6 million deaths in 2019. The current standard for diagnosing coronary artery disease (CAD) is coronary angiography. Surprisingly, despite well-established clinical indications, up to 40% of the one million invasive cardiac catheterizations return a result of ‘no blockage’. OBJECTIVE: The present studies employed RNA sequencing of whole blood to identify an RNA signature in patients presenting with a clinical suspicion of CAD.METHODS AND RESULTS: Whole blood RNA was depleted of ribosomal RNA (rRNA) and analyzed by single-molecule sequencing of RNA (RNAseq) to identify transcripts associated with CAD (TRACs) in a discovery group of 96 patients presenting for elective coronary catheterization. The resulting transcript counts were compared between groups to identify differentially expressed genes (DEGs). Surprisingly, 98% of DEGs/TRACs were down-regulated ~1.7-fold in patients with mild to severe CAD (>20% stenosis). The TRACs were independent of comorbid risk factors for CAD, such as gender, hypertension, and smoking. Bioinformatic analysis identified an enrichment in transcripts such as FoxP1, ICOSLG, IKZF4/Eos, SMYD3, TRIM28, and TCF3/E2A that are likely markers of regulatory T cells (Treg), consistent with known reductions in Tregs in CAD. A validation cohort of 80 patients confirmed the overall pattern (92% down-regulation) and supported many of the Treg-related changes. TRACs were enriched for transcripts associated with stress granules, which sequester RNAs, and ciliary and synaptic transcripts, possibly consistent with changes in the immune synapse of developing T cells.CONCLUSIONS: These studies identify a novel mRNA signature of a Treg-like defect in CAD patients and provides a blueprint for a diagnostic test for CAD. The pattern of changes is consistent with stress-related changes in the maturation of T and Treg cells, possibly due to changes in the immune synapse.

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BACKGROUND: Laboratory testing is important in the overall management of chronic diseases. Aging results in increased utilization of laboratory services. Individuals with inflammatory bowel disease (IBD) require laboratory tests as objective measurements of disease activity and assessment of medication side effects. There is limited data which has specifically evaluated the use of laboratory testing in the different age ranges of adult patients with inflammatory bowel disease. This study evaluated the frequency of laboratory testing in geriatric and younger patients with IBD. METHODS: A retrospective medical record review of inflammatory bowel disease patients at a university medical center during an 18 month period was performed using a multispecialty electronic health record. There were no exclusion factors. Patient age, disease type, and laboratory testing performed by gastroenterologists were obtained. An assessment of the frequency of laboratory tests in patients <65 and .65 years was performed. A database, maintaining patient confidentiality, was created. Statistical analysis was performed using unpaired t-testing, with statistical significance was set at P < 0.05. The study was approved by the university institutional review board. RESULTS: Three hundred sixteen medical records were reviewed. There were 189 women and 127 men, with a mean age of 41.8 years. One hundred seventy-one patients had Crohn's disease, 143 ulcerative colitis and 2 with indeterminate colitis. There were 24 patients .65 years. Patients .65 years had 5.17 labs and patients <65 had 8.74 labs performed for evaluation of IBD status in 1.5 years. Geriatric patients had significantly less (P ¼ 0.0004) labs than younger patients. There was no significant difference in the rate of laboratory testing in geriatric and younger patients based upon gender (P ¼ 0.74), ethnicity (P ¼ 0.46) or disease type (P ¼ 0.86). CONCLUSIONS: Individuals with chronic diseases have more health care encounters than others. Aging results in increased frequency of physician visits and laboratory tests. This is one of the few studies that evaluated the utilization of outpatient laboratory testing in geriatric patients with inflammatory bowel disease. In this study there was significantly less lab testing in the older patients than those who were <65. The significance of this finding is uncertain. The result may correlate with less gastroenterology visits by the geriatric IBD patient. However, it may also suggest that inflammatory bowel disease does not worsen aging. Further study is necessary to increase the knowledge about inflammatory bowel disease in the elderly patient.