Correlation between Clinical Symptoms and Lab Tests with Endoscopic Severity Indexes in Patients with Inflammatory Bowel Diseases

Role of C-Reactive Protein in Predicting the Severity and Response of Immune-Mediated Diarrhea and Colitis in Patients with Cancer

Background: Immune-mediated diarrhea and colitis (IMDC) frequently develop after treatment with immune checkpoint inhibitors. C-reactive protein (CRP) is a serum inflammatory biomarker used to stratify and monitor disease severity in many inflammatory conditions. However, CRP level is not specific and is widely influenced by various factors non-specific to bowel inflammation. We aimed to study the utility of CRP as a predictor of disease severity and therapy response in IMDC. Methods: We performed a retrospective analysis of patients diagnosed with IMDC who had CRP measured at IMDC onset and after treatment with selective immunosuppressive therapy (SIT: infliximab and vedolizumab), between 01/2016 and 02/2022 at MD Anderson Cancer Center. Patient demographics, clinical characteristics, and IMDC data were collected and analyzed. Results: Our sample of 128 patients had a median age of 67 years; most were white (89.8%); and male (65.6%). Prior to development of IMDC, 15 (11.7%) were initially treated with anti-CTLA-4, 42 (32.8%) with anti-PD-1 or PD-L1, and 71 (55.5%) with a combination of both. We found higher CRP level was associated with higher CTCAE grade of clinical symptoms such as diarrhea (p=0.015), colitis (p=0.013), and endoscopic findings (p=0.016). While CRP levels decreased after IMDC treatment, there was no significant association between CRP levels with clinical remission, endoscopic remission or histologic remission. There also was no significant correlation between CRP level and recurrence of IMDC, or with fecal calprotectin levels. Conclusion: CRP level may be useful to assess initial severity of IMDC, including grade of diarrhea and colitis and degree of endoscopic inflammation. However, CRP is not a robust surrogate biomarker for assessing treatment response or disease recurrence. Despite the reduction of CRP levels observed following IMDC treatment, this finding might be nonspecific and potentially confounded by concurrent clinical factors, such as underlying malignancy, other inflammatory processes, and systemic anti-cancer therapy. Further studies of the role of CRP are warranted in patients with cancer and IMDC.

Expression of CD44 in Leukocyte Subpopulations in Patients with Inflammatory Bowel Diseases

CD44 expressed in monocytes and lymphocytes seems to play a crucial role in gastrointestinal inflammation, such as the one occurring in the context of inflammatory bowel diseases. Differentially methylated genes are distinctly expressed across monocyte subpopulations related to the state of Crohn’s disease. Hence, the aim of this study was to detect CD44 expression in leukocyte subpopulations in relation to the type of IBD, therapy, and disease duration. Monocyte subpopulations CD14++CD16−, CD14++CD16++, and CD14+CD16+ as well as other leukocytes were analyzed for their CD44 expression using flow cytometry in 46 patients with IBD and 48 healthy controls. Patients with Crohn’s disease treated with non-biological therapy (NBT) exhibited a lower percentage of anti-inflammatory CD14+CD16++ monocytes, whereas NBT-treated patients with ulcerative colitis had lower expression of CD44 on CD14+CD44+ lymphocytes in comparison to controls, respectively. Conversely, patients with Crohn’s disease treated with biological therapy had a higher percentage of CD44+ granulocytes but lower expression of CD44 on anti-inflammatory monocytes compared to controls. Median fluorescence intensity (MFI) of CD44 on CD44+CD14+ lymphocytes was higher in ulcerative colitis patients treated with biological therapy compared to NBT. The percentage of classical CD14++CD16− monocytes was lower in the <9 years of IBD duration subgroup compared with the longer disease duration subgroup. The present study addresses the putative role of differentiation and regulation of leukocytes in tailoring IBD therapeutic regimes.