Objective To evaluate comparability of two different assay system for detecting CRP.Methods Following the profile of Clinical and Laboratory Standard Institute (CLSI)document EP9-A2,50 blood samples with anti-coagulant ED-TA-2K were collected from emergency patients at Changhai Hospital.The test result of samples by the i-CHROMA Reader was compared and evaluated with those by Beckman Immage 800.Results The linear regression equation for plasma CRP was:Y=1.076 5X-3.031 5,R2=0.986.The linear regression equation for whole blood CRP was:Y=0.882 6X-1.180 8, R2=0.931 1.For whole blood samples with low HCT (<30.45%).Used correction equation:CRP (after corrected)=CRP (before corrected)/(1-HCT).The regression equation (after corrected)was:Y=1.006 8X-3.612 2,R2=0.950 9.Con-clusion CRP concentration detected by i-CHROMA showed good correlation and comparability compared to laboratory ref-erence system by using plasma samples.Results form whole blood samples with low HCT should be corrected to improve comparability.

Objective: To investigate the clinical significance of combined examinations for neutrophil-lymphocyte ratio (NLR), C-reactive protein (CRP), erythrocyte sedimentation rate (ESR) and fecal occult blood (OB) in the differential diagnosis of Crohn′s disease and irritable bowel syndrome. Methods: A total of 129 patients with Crohn′s disease and 120 patients with irritable bowel syndrome from October 2014 to October 2017 in Changhai Hospital were enrolled in this study. The results of NLR, CRP, ESR and OB were recorded. Logistic regression was used to study the association of the four indicators. The combined impact of the four indicators was explored with multivariable regression. ROC curve was used to compare the diagnostic value of the combined examinations with the four indicators for Crohn′s disease. The diagnosis was performed by substituting the data of individual patient into regression model. Results: The levels of NLR, CRP, ESR and OB in Crohn′s disease group were higher than those in irritable bowel syndrome group (Z=-7.067--4.148, P＜0.01). The area under the curve of combined diagnostic indicator was 0.881, which was higher than that of single NLR, CRP, ESR or OB (0.759, 0.695, 0.652, 0.643) respectively (Z=3.19-5.60, P＜0.01). When the cutoff value was 0.498, the sensitivity was 79.1%, the specificity was 83.3% and the diagnostic accuracy was 81.1%. A patient who was not included within the statistical range of this experimental study was randomly assigned to the model and 0.831 of P value was obtained, which was higher than the cutoff value of 0.498, indicating that the patient suffered from Crohn′s disease with accuracy of 81.1%. Conclusion The logistic regression model established with the combined diagnostic indicators, which was formulated by examinations of NLR, CRP, ESR and OB, exhibited higher diagnostic value than any single indicator in the differential diagnosis of Crohn′s disease and irritable bowel syndrome.