Proctocolectomy Essay

Does IBD serology change after restorative proctocolectomy?
The antimicrobial antibodies seen in patients with IBD likely represent an aberrant immune response to commensal bacterial antigens. Since restorative proctocolectomy leads to anatomical changes in the gut, it is logical to hypothesize that it may lead to alterations in the gut microbiome resulting in changes in the antimicrobial antibodies expression. This hypothesis has been tested in a few studies. In a retrospective study of 501 patients with inflammatory bowel diseases (50% with CD, 25% with UC, and 25% with IPAA for UC), the prevalence of ACCA (24% vs 17%, p value 0.03) and AMCA (27% vs 7%, p value 0.0001) was found to be significantly higher in patients with IPAA than UC patients suggesting that pouch surgery induces differential immune responses to bacterial glycans and possibly other
[34]. This fact was further highlighted in a recent prospective study in which a significant increase in anti-I2 positivity (57% vs 23%, p value 0.007) and mean anti-I2 level (41 vs 22; p value 0.001) was noted postoperatively in patients who developed de novo CD of the pouch as compared to their preoperative serological status. There was also an increase in IgG ASCA seropositivity (though not statistically significant) and increase in the mean IgG ASCA level (17 vs 8.8; p value 0.0001) postoperatively [35]. On the other hand, in a study of 101 patients with UC, pANCA seropositivity rate was 71%, and remained relatively stable at 74% at a median follow up of 2 years postoperatively in patients who underwent total colectomy with IPAA suggesting the possibility that bacterial