Distinct Inflammation Biomarkers in Healthy Individuals and Patients with Schizophrenia: A Reliability Testing of Multiplex Cytokine Immunoassay by Bland-Altman Analysis
	    		
		   		
		   			
		   		
	    	
    	- Author:
	        		
		        		
		        		
			        		Ta Chuan YEH
			        		
			        		
			        		
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			        		Hsuan Te CHU
			        		
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			        		Chia Kuang TSAI
			        		
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			        		Hsin An CHANG
			        		
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			        		Fu Chi YANG
			        		
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			        		San Yuan HUANG
			        		
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			        		Chih Sung LIANG
			        		
			        		
		        		
		        		
		        		
			        		
			        		Author Information
			        		
 - Publication Type:Original Article
 - Keywords: Multiplex immunoassay; Cytokine; Reliability; Inflammation; Schizophrenia
 - MeSH: Bias (Epidemiology); Biomarkers; Cytokines; Humans; Immunoassay; Inflammation; Interferon-gamma; Interleukin-10; Interleukin-12; Interleukin-13; Interleukin-17; Interleukin-4; Interleukin-5; Interleukins; Loa; Macrophages; Reproducibility of Results; Schizophrenia; Tumor Necrosis Factor-alpha
 - From:Psychiatry Investigation 2019;16(8):607-614
 - CountryRepublic of Korea
 - Language:English
 - Abstract: OBJECTIVE: Since the inflammatory process has been implicated in the pathophysiology of psychiatric disorder, an important issue emerging is to assess the test-retest reliability of cytokine measurement in healthy individuals and patients with schizophrenia. The objective of the present study was to investigate the test-retest reliability of bead-based multiplex immunoassay technology (BMIT) for cytokine measurement by using a Bland-Altman plot (BAP). METHODS: Twenty healthy individuals and twenty patients with schizophrenia were enrolled, and a 17-plex cytokine assay was used to measure inflammatory biomarkers at baseline and two weeks later. The test-retest reliability was examined by BAP, 95% limits of agreement (LOA), intraclass correlation coefficient (ICC), and coefficient of repeatability (CoR). RESULTS: In the healthy controls, only interleukin (IL)-2, IL-13, IL-10, IL-17, and macrophage inflammatory protein-1β showed excellent ICC. The BAP with 95% LOA determined that 13 cytokines showed acceptable 95% LOA for a 2-week test-retest reliability, and only IL-1β, IL-12 and tumor necrosis factor (TNF)-α had significant test-retest bias. The CoR of cytokines varied significantly, ranging from 1.72 to 218.1. Compared with healthy controls, patients with schizophrenia showed significantly higher levels of IL-5, IL-13, and TNF-α and significantly lower levels of IL-4, IL-12, and interferon-gamma (IFN-γ). Of these six cytokines, IL-12 and TNF-α were considered suboptimal reliability. CONCLUSION: The findings from ICC and CoR implied that the test-retest reliability of BMIT for cytokine measurement were suboptimal. However, the BAP with 95% LOA confirmed that BMIT can reliably distinguish schizophrenia from healthy individuals in cytokine measurement, while significant within-subject variation and between-group overlapping were evident in cytokine expression.
 
            