title: Prevalence and Association of Mycobacterium avium subspecies paratuberculosis with Disease Course in Patients with Ulcero-Constrictive Ileocolonic Disease.
abstract: BACKGROUND
  Association of Mycobacterium avium subspecies paratuberculosis (MAP) and Crohn's disease (CD) has been controversial due to contradictory reports. Therefore, we determined the prevalence of MAP in patients with CD and intestinal tuberculosis (ITB) and its association with clinical course.
  
  
  METHODS
  Blood and intestinal biopsies were taken from 69 CD, 32 ITB patients and 41 patients with haemorrhoidal bleed who served as controls. qPCR targeting of MAP-specific IS900 gene was used to detect the presence of MAP DNA. qPCR results were further validated by sequencing. Immunohistochemistry (IHC) was used to detect the presence of MAP antigen in biopsy specimens. CD and ITB patients were followed-up for disease course and response to therapy.
  
  
  RESULTS
  The frequency of MAP-specific DNA in biopsies by qPCR was significantly higher in CD patients (23.2%, p = 0.03) as compared to controls (7.3%). No significant difference in intestinal MAP presence was observed between ITB patients (12.5%, p = 0.6) and controls (7.3%). MAP presence in blood of CD patients was 10.1% as compared to 4.9% in controls while no patients with ITB were found to be positive (p = 0.1). Using IHC for detection of MAP antigen, the prevalence of MAP in CD was 2.9%, 12.5% in ITB patients and 2.4% in controls. However, long-term follow-up of the patients revealed no significant associations between clinical characteristics and treatment outcomes with MAP positivity.
  
  
  CONCLUSIONS
  We report significantly high prevalence of MAP in intestinal biopsies of CD patients. However, the presence of MAP does not affect the disease course and treatment outcomes in either CD or ITB patients.
authors.affiliation: Department of Gastroenterology and Human Nutrition, All India Institute of Medical Sciences, New Delhi, India.
authors.forename: Imteyaz Ahmad
authors.initials: IA
authors.lastname: Khan
authors.affiliation: Department of Gastroenterology and Human Nutrition, All India Institute of Medical Sciences, New Delhi, India.
authors.forename: Sucharita
authors.initials: S
authors.lastname: Pilli
authors.affiliation: Department of Gastroenterology and Human Nutrition, All India Institute of Medical Sciences, New Delhi, India.
authors.forename: Surendranath
authors.initials: S
authors.lastname: A
authors.affiliation: Department of Gastroenterology and Human Nutrition, All India Institute of Medical Sciences, New Delhi, India.
authors.forename: Ritika
authors.initials: R
authors.lastname: Rampal
authors.affiliation: Department of Gastroenterology and Human Nutrition, All India Institute of Medical Sciences, New Delhi, India.
authors.forename: Sudhir Kumar
authors.initials: SK
authors.lastname: Chauhan
authors.affiliation: Department of Gastroenterology and Human Nutrition, All India Institute of Medical Sciences, New Delhi, India.
authors.forename: Veena
authors.initials: V
authors.lastname: Tiwari
authors.affiliation: Department of Gastroenterology and Human Nutrition, All India Institute of Medical Sciences, New Delhi, India.
authors.forename: Venigalla Pratap
authors.initials: VP
authors.lastname: Mouli
authors.affiliation: Department of Gastroenterology and Human Nutrition, All India Institute of Medical Sciences, New Delhi, India.
authors.forename: Saurabh
authors.initials: S
authors.lastname: Kedia
authors.affiliation: Department of Gastroenterology and Human Nutrition, All India Institute of Medical Sciences, New Delhi, India.
authors.forename: Baibaswata
authors.initials: B
authors.lastname: Nayak
authors.affiliation: Department of Pathology, All India Institute of Medical Sciences, New Delhi, India.
authors.forename: Prasenjit
authors.initials: P
authors.lastname: Das
authors.affiliation: Department of Gastroenterology and Human Nutrition, All India Institute of Medical Sciences, New Delhi, India.
authors.forename: Govind K
authors.initials: GK
authors.lastname: Makharia
authors.affiliation: Department of Gastroenterology and Human Nutrition, All India Institute of Medical Sciences, New Delhi, India.
authors.forename: Vineet
authors.initials: V
authors.lastname: Ahuja
mesh_terms: D000328:Adult; D000941:Antigens / Q000097:blood; D003424:Crohn Disease / Q000150:complications / Q000382:microbiology / Q000473:pathology; D004269:DNA, Bacterial / Q000737:chemistry / Q000378:metabolism; D018450:Disease Progression; D005260:Female; D006484:Hemorrhoids / Q000382:microbiology / Q000473:pathology; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D016927:Mycobacterium avium subsp. paratuberculosis / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D010283:Paratuberculosis / Q000150:complications / Q000453:epidemiology / Q000382:microbiology; D010641:Phenotype; D015995:Prevalence; D060888:Real-Time Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D014385:Tuberculosis, Gastrointestinal / Q000150:complications / Q000382:microbiology / Q000473:pathology
chemical_list: D000941:Antigens; D004269:DNA, Bacterial