{
  "abstract": "Introduction Exacerbations of COPD are associated with cardiovascular events. Biomarkers are needed to identify those at risk. Cystatin-C (Cys-C) is a cysteine protease inhibitor that predicts future cardiovascular risk and is a sensitive marker of renal function. Though Cys-C is known to be elevated in COPD 1 its pattern at exacerbation is uncertain. This study aimed to determine how Cys-C levels change over the course of an exacerbation, and the relationship of this to important biomarkers of cardiorenal disease.Methods Patients from the London COPD exacerbation cohort (EXCEL) were reviewed at stability, exacerbation-onset, 2-weeks and 6-weeks post-exacerbation. At each visit, serum Cys-C was measured, together with inflammatory (CRP, fibrinogen); renal (urea, creatinine, eGFR) and cardiovascular (troponin, BNP) biomarkers. An in-house enzyme-linked immunosorbent assay was developed to determine Cys-C levels, whereas other markers were processed by the local clinical laboratory. The absolute and percentage change in Cys-C across exacerbation time points was measured. We used Spearman’s rank to test the correlation between Cys-C and other biomarkers.Results The study included 22 patients with COPD who had a mean age of 74.05 (± 9.31) years and 8 (36.36%) were female. The median (interquartile range) of Cys-C values at stability, exacerbation, 2-weeks and 6-weeks post-exacerbation were 9.32 (6.38–15.50), 11.76 (6.30–18.13), 8.02 (5.75–13.39) and 7.35 (4.96–9.58) ng/ml respectively. There was a non-significant increase from baseline to exacerbation. Cys-C was statistically increased at exacerbation compared to 6-weeks post-exacerbation (p=0.021). There was only one significant correlation between Cys-C and the other biomarkers at any timepoint or interval: with CRP at baseline (p=0.47, p=0.0376).Conclusion This study demonstrated a non-significant increase in Cys-C from baseline to exacerbation, in line with existing literature, whilst also demonstrating a significant decrease at 6-weeks post-exacerbation to below baseline; a unique profile which correlates with no other biomarker tested. Further work is needed to validate this finding and to determine the relationship of Cys-C to systemic complications of exacerbation.Reference Zhang M, Li Y, Yang X, Shan H, Zhang Q, Ming Z, et al. Serum cystatin C as an inflammatory marker in exacerbated and convalescent COPD patients. Inflammation. 2016 Apr;39(2):625–31.",
  "authors": [
    {
      "affiliations": [
        "National Heart and Lung Institute, Imperial College, London, UK"
      ],
      "name": "Y Owadally"
    },
    {
      "affiliations": [
        "National Heart and Lung Institute, Imperial College, London, UK"
      ],
      "name": "MA MacLeod"
    },
    {
      "affiliations": [
        "National Heart and Lung Institute, Imperial College, London, UK"
      ],
      "name": "S Bartlett-Pestell"
    },
    {
      "affiliations": [
        "National Heart and Lung Institute, Imperial College, London, UK"
      ],
      "name": "S Tan"
    },
    {
      "affiliations": [
        "National Heart and Lung Institute, Imperial College, London, UK"
      ],
      "name": "R Lopez"
    },
    {
      "affiliations": [
        "National Heart and Lung Institute, Imperial College, London, UK"
      ],
      "name": "A Braddy-Green"
    },
    {
      "affiliations": [
        "Chelsea and Westminster Hospital NHS Foundation Trust, London, UK"
      ],
      "name": "D Wiseman"
    },
    {
      "affiliations": [
        "National Heart and Lung Institute, Imperial College, London, UK"
      ],
      "name": "J Mah"
    },
    {
      "affiliations": [
        "National Heart and Lung Institute, Imperial College, London, UK"
      ],
      "name": "A Marion"
    },
    {
      "affiliations": [
        "National Heart and Lung Institute, Imperial College, London, UK"
      ],
      "name": "LA Moreira"
    },
    {
      "affiliations": [
        "National Heart and Lung Institute, Imperial College, London, UK",
        "Royal Brompton Hospital, London, UK"
      ],
      "name": "JP Allinson"
    },
    {
      "affiliations": [
        "National Heart and Lung Institute, Imperial College, London, UK"
      ],
      "name": "JA Wedzicha"
    },
    {
      "affiliations": [
        "National Heart and Lung Institute, Imperial College, London, UK"
      ],
      "name": "H Shahbakhti"
    },
    {
      "affiliations": [
        "National Heart and Lung Institute, Imperial College, London, UK"
      ],
      "name": "LJ Finney"
    }
  ],
  "title": "P162 Changes in blood Cystatin C during COPD exacerbations",
  "uid": "2da99b24-c399-54ed-9eaf-cb1e886156fd"
}