Diagnostic value of prognostic nutritional index and C-reactive protein to albumin ratio in Crohn′s disease complicated with intra-abdominal infection / 中华消化杂志

ABSTRACT

Objective:To investigate the diagnostic value of prognostic nutritional index (PNI) and C-reactive protein to albumin ratio(CAR) in Crohn′s disease complicated with intra-abdominal infection (CD-IAI).Methods:From January 2016 to December 2021, the clinical data of 61 patients with Crohn′s disease (CD) and 61 patients with CD-IAI diagnosed at Nanfang Hospital, Southern Medical University were retrospectively analyzed. Crohn′s disease activity index (CDAI), Crohn′s disease endoscopic index of severity (CDEIS), laboratory parameters(white blood cell count, neutrophil ratio, platelet count, C-reactive protein (CRP), procalcitonin (PCT), D-dimer, prothrombin time (PT), fibrinogen, activated partial thromboplastin time (APTT)), PNI and CAR were compared between CD patients and CD-IAI patients. From January to May in 2022 another 30 patients with CD and 13 patients with CD-IAI diagnosed at Nanfang Hospital, Southern Medical University were selected to verify the accuracy of PNI and CAR in predicting CD-IAI. The optimal cut-off values of PNI and CAR in predicting CD-IAI, area under the curve (AUC), Youden index, sensitivity and specificity were calculated by receiver operating characteristic curve (ROC). Spearman correlation was used to analyze the correlation between PNI, CAR, CDAI, and CDEIS, and logistic regression was performed to analyze the influencing factors of CD-IAI. Independent sample t test and Mann-Whitney U test were used for statistical analysis. Results:CDAI and CDEIS were higher in CD-IAI patients than those of CD patients(256.68±8.50 vs.144.87±7.83; 3.80 (1.80, 5.40) vs. 1.20 (0.20, 2.80)), and the differences were statistically significant( t=-9.67, Z=-4.02, both P<0.001). The white blood cell count, neutrophil ratio, platelet count, CRP, PCT, D-dimer, PT, fibrinogen, and APTT of CD-IAI patients were all higher than those of CD patients (7.81×10 9/L (5.98×10 9/L, 11.39×10 9/L) vs. 5.94×10 9/L (4.86×10 9/L, 7.11×10 9/L); (73.43±10.67)% vs. (62.30±11.03)%; 360.00×10 9/L (266.50×10 9/L, 456.00×10 9/L) vs. 294.00×10 9/L (222.50×10 9/L, 356.00×10 9/L); 44.27 mg/L (16.82 mg/L, 82.65 mg/L) vs. 3.42 mg/L (0.59 mg/L, 18.33 mg/L); 0.07 μg/L (0.04 μg/L, 0.22 μg/L) vs. 0.04 μg/L (0.02 μg/L, 0.05 μg/L); 0.75 mg/L (0.32 mg/L, 2.00 mg/L) vs. 0.26 mg/L (0.15 mg/L, 0.46 mg/L); 11.90 s (11.40 s, 12.90 s) vs. 11.20 s (10.45 s, 11.70 s); 4.58 g/L (3.59 g/L, 5.59 g/L) vs. 2.99 g/L (2.17 g/L, 4.23 g/L); 30.40 s (28.30 s, 32.80 s) vs. 28.00 s (25.45 s, 31.10 s)), and the differences were statistically significant ( Z=-4.48; t=-5.66; Z=-2.71, -6.47, -3.78, -4.87, -4.87, -5.44 and -2.74; all P<0.01). The serum albumin level of CD-IAI patients was lower than that of CD patients (34.10 g/L (31.40 g/L, 36.90 g/L) vs. 39.00 g/L (35.10 g/L, 43.20 g/L)), and the difference was statistically significant( Z=-3.91, P<0.001). The PNI of CD-IAI patients was lower than that of CD patients (41.65, (38.58, 44.58) vs. 47.80 (40.45, 52.98)), while CAR was higher than that of CD patients (1.29 (0.48, 2.67) vs. 0.10 (0.01, 0.46)), and the differences were statistically significant ( Z=-3.83 and -6.44, both P<0.001). The results of Spearman correlation analysis showed that PNI was negatively correlated with CAR, CDAI, and CDEIS ( r=-0.64, -0.53 and -0.50, all P<0.001), and CAR was positively correlated with CDAI and CDEIS ( r=0.63 and 0.52, both P<0.001). The results of logistic regression analysis showed that high level of PNI was a protective factor for CD-IAI ( OR= 0.911, 95% confidence interval 0.864 to 0.961), and high level of CAR was a risk factor for CD-IAI ( OR=2.846, 95% confidence interval 1.745 to 4.644). The results of ROC indicated that the AUC value of combined PNI and CAR in the diagnosis of CD-IAI was 0.829 ( P<0.001), Youden index was 0.541, the sensitivity was 0.934, and the specificity was 0.607. The sensitivity and specificity of optimal cut-off value of the combination of PNI and CAR in predicting CD-IAI were 0.692 and 0.967. Conclusions:PNI and CAR have certain diagnostic value in CD-IAI. The risk of CD-IAI is high when PNI <45.550 and CAR >0.466.