Evaluation of relationship between endoscopic activity index and inflammatory indicators such as fecal calprotectin, C-reactive protein to albumin ratio, neutrophil to lymphocyte ratio, platelet to lymphocyte ratio in ulcerative colitis patients.

BACKGROUND

This study aimed to evaluate the association between low-cost inflammatory biomarkers and disease severity in ulcerative colitis (UC), with a focus on predicting acute severe ulcerative colitis (ASUC) and active disease (Mayo score >1).

METHODS

An analytical cross-sectional study was conducted on 131 patients diagnosed with UC at Imam Khomeini Hospital, Iran, between 2022 and 2024. Demographic, clinical, and laboratory data - including neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), CRP-to-albumin ratio (CAR), and faecal calprotectin - were collected. Disease activity was evaluated using the Mayo Endoscopic Score (MES). Statistical analyses included chi-square tests, ANOVA, and multivariable logistic regression adjusted for age, sex, and body mass index (BMI).

RESULTS

The mean age of participants was 45.8± 15.9 years. Elevated inflammatory markers were observed (CRP: 39.1 ± 32.6 mg/L; ESR: 44 .0± 21.5 mm/hr). Defecation frequency S6/day was significantly associated with ASUC (c2(2) = 101.10, p< 0.001). After adjustment, PLR in the third quartile (14-20) was independently associated with ASUC (O R = 2.57, p= 0.034). The percentage of monocytes was significantly higher in ASUC patients (F(1, 30) = 6.52, p= 0.016). No significant associations were found for NLR or CAR. PLR also differed significantly between active and inactive UC groups (median [ IQR] : 133.87 [96.15-190.63] vs. 129.61 [102.15-209.98], p= 0.029), although its discriminatory power was limited.

CONCLUSIONS

PLR and monocyte percentage may serve as accessible indicators for assessing UC severity and identifying patients at risk for ASUC. These findings support the supplementary use of routine inflammatory blood indices in the management of UC, especially in resource-limited settings.