title: Lymphocytic follicles and aggregates are a determinant of mucosal damage and duration of diarrhea.
abstract: BACKGROUND
  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.
  
  
  METHODS
  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 lymphoid follicles and aggregates (P  =  .003, r  =  .43), density of lymphoid follicles and aggregates (P  =  .009, r  =  .38), and total lymphoid follicles and aggregates per biopsy (P  =  .004, r  =  .42) and the number of mast cells (P  =  .001, r  =  .52). The number of mast cells and Treg cells showed significant difference between resolved and unresolved cases (P  =  .001 and P  =  .01 respectively).
  
  
  CONCLUSIONS
  Lymphocytic follicles and aggregates colitis, previously regarded as of negligible diagnostic significance, allows the prediction of the behavior of chronic diarrhea in a subset of patients with nonspecific changes on colonic biopsy. The increased number of mast cells and paucity of Treg cells further helps to identify such unresolved cases.
authors.affiliation: Cancer Science Institute of Singapore, Singapore.
authors.forename: Nilesh
authors.initials: N
authors.lastname: Shah
authors.forename: Bhavin
authors.initials: B
authors.lastname: Thakkar
authors.forename: Emily
authors.initials: E
authors.lastname: Shen
authors.forename: Marie
authors.initials: M
authors.lastname: Loh
authors.forename: Pei Yi
authors.initials: PY
authors.lastname: Chong
authors.forename: Wee Hoe
authors.initials: WH
authors.lastname: Gan
authors.forename: Tian Ming
authors.initials: TM
authors.lastname: Tu
authors.forename: Liang
authors.initials: L
authors.lastname: Shen
authors.forename: Richie
authors.initials: R
authors.lastname: Soong
authors.forename: Manuel
authors.initials: M
authors.lastname: Salto-Tellez
mesh_terms: D000328:Adult; D000368:Aged; D001706:Biopsy; D016022:Case-Control Studies; D002908:Chronic Disease; D015331:Cohort Studies; D003967:Diarrhea / Q000276:immunology / Q000378:metabolism / Q000473:pathology*; D005260:Female; D051858:Forkhead Transcription Factors / Q000378:metabolism; D006801:Humans; D018928:Immunity, Mucosal; D007150:Immunohistochemistry; D007249:Inflammation / Q000378:metabolism / Q000473:pathology; D007413:Intestinal Mucosa / Q000276:immunology / Q000378:metabolism / Q000473:pathology*; D008221:Lymphoid Tissue / Q000276:immunology / Q000378:metabolism / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D019009:Proto-Oncogene Proteins c-kit / Q000378:metabolism; D013997:Time Factors; D055815:Young Adult
chemical_list: C418974:FOXP3 protein, human; D051858:Forkhead Transcription Factors; D019009:Proto-Oncogene Proteins c-kit