Lymphocytic Follicles and Aggregates Are a Determinant of Mucosal Damage and Duration of Diarrhea

Context.—Nonspecific changes (nonspecific chronic inflammation) in patients with chronic diarrhea represent the commonest diagnosis in colorectal biopsy interpretation, but these changes are of little clinical significance. Objective.—To find, within this group, histologic and immunohistologic diagnostic criteria to predict the duration and resolution of diarrhea. Design.—Detailed clinical features and histologic findings were analyzed in a cohort of 47 patients with chronic diarrhea, with near-normal histology and no clear-cut known etiologic agent. Immunohistochemistry to mast cells (CD117) and Treg cells (FOXP3) was also assessed in 39 patients. Results.—Increased number of lymphoid follicles and aggregates, increased number of mast cells, and paucity of Treg were the statistically significant key findings (P  =  .003, P  =  .008, and P  =  .04, respectively). The duration of diarrhea was correlated with the number of large lymphoid follicles and aggregates (P  =  .001, r  =  .48), number of total lymp...