SESSION TYPE: ILD - Bench to Bedside
PRESENTED ON: Wednesday, October 24, 2012 at 02:45 PM - 04:15 PM
PURPOSE: Detecting circulating fibrocytes (CFs) described in various pulmonary and non-pulmonary diseases, currently involves complicated techniques. Also, the response of CFs during hypoxia or exercise has not been previously studied in interstitial lung disease (ILD) patients.
METHODS: One hundred ILD patients and 35 healthy control subjects underwent a six- minute-walk test (6MWT). Three samples of venous blood and oxygen saturation (SpO2) recordings were collected at rest (sample 1), immediately after (sample 2), and 10 minutes after the 6MWT (sample 3). CFs co-expressing CD45, collagen-1, and CD34 were detected by flow-cytometry-based method using lysed whole blood.
RESULTS: CFs were detected in 89% of the ILD patients and in 28.5% of the control subjects in blood samples collected at rest. There was a progressive rise in the percentage of CFs during experiments, and CFs were significantly elevated among ILD patients in sample 3 versus sample 1 [median interquartile range (IQR): 2.19% (1.91) and 1.48% (1.38), respectively; p<0.0001]. Comparison of patients with and without oxygen desaturation showed significantly more CFs in sample 3 versus sample 1 in both groups [SpO2 <90%, median% (IQR): sample 1, 1.61% (1.24) and sample 3, 2.51% (2.13), p=0.002; SpO2 >90%: sample 1, 1.42% (1.61) and sample 3, 2.06% (1.46), p=0.01]. Although the percentage of CFs tended to be higher among patients with oxygen desaturation compared to patients without oxygen desaturation, there was no significant between-group difference in the median percentage of CFs in all three samples (all p > 0.05).
CONCLUSIONS: We demonstrate a simple method for detection of CFs and provide the first report of exercise-induced increases in CFs among ILD patients.
CLINICAL IMPLICATIONS: This study demonstrates a simple method for detecting circulating fibrocytes, and further assesses the effect of the six-minute-walk test on the circulating fibrocytes of patients with interstitial lung disease.
DISCLOSURE: The following authors have nothing to disclose: Esam Alhamad, Zahid Shakoor, Feisal Al-Kassimi, Adel Almogren, Mohamed GadElRab, Shaffi Shaik
No Product/Research Disclosure InformationKing Saud University, College of Medicine, Riyadh, Saudi Arabia