C-reactive Protein/Albumin Ratio as a Marker to Predict Clinical and Endoscopic Response to Medical Treatment in Mexican Outpatients With Ulcerative Colitis

Background:
Despite many investigations on possible associations between various biomarkers and ulcerative colitis (UC) disease activity, available serum biomarkers still have lower sensitivity and specificity to predict disease severity than fecal markers. In recent years, the C-reactive protein/albumin ratio (CAR), an inflammatory marker that has been shown to be related to disease activity, its progression, endoscopic findings, and response to treatment, has been studied. Therefore, our study aims to evaluate whether CAR is associated with response to treatment measured by the Truelove and Witts, Mayo score, and UCEIS scales.
Methods:
An observational, cross-sectional, retrospective study was carried out in the Hospital Juárez de México. Patients ≥18 years old, of both sexes, with a diagnosis of ulcerative colitis, and with baseline and control colonoscopy in a range of 2 to 3 years of follow-up were included. Data are presented in frequencies (%), mean ± SD, and median (IQR). Group comparison was performed using Chi-square, independent Student t, and Mann-Whitney U tests. AUC of the ROC curve and Youden’s index were further used for the calculation of cutoff value with their specificity and sensitivity.
Results:
Of 31 patients, 19 (61.3) were women and the mean age was 36.55 ± 11.07 years with a median basal CAR of 0.75 (0.68-0.92). A CAR cut-off of 0.735 was obtained as the highest sensitivity and specificity for clinical response by Truelove and Witts and endoscopic response by UCEIS. When comparing patients with CAR < 0.735 and >0.735, it was found that 14 (93.3%) patients obtained remission by Truelove and Witts in the first group and 8 (50%) in the second (p=0.008), 7 (46.6%) and 3 (18.7%) patients remitted by Mayo Score (p=0.097), 6 (40%) and 2 (12.5%) patients by UCEIS by vascular pattern (p=0.080), 12 (80%) and 6 (37.5%) by UCEIS by erosions and ulcers (p=0.017) and 15 (100%) and 10 (62.5%) by UCEIS by bleeding (p=0.008), respectively.
Conclusions:
There was a statistically significant association between the CAR and clinical and endoscopic response to treatment in Mexican patients with UC in a range of 2 to 3 years, and the cut-off with the highest sensitivity and specificity was 0.735.