Published online Sep 21, 2014. doi: 10.3748/wjg.v20.i35.12559
Revised: April 8, 2014
Accepted: June 20, 2014
Published online: September 21, 2014
AIM: To investigate whether the heat shock protein 70-2 (HSP70-2) polymorphism is associated with enterocutaneous fistulas in a Chinese population.
METHODS: This study included 131 patients with enterocutaneous/enteroatmospheric fistulas. Patients with inflammatory bowel disease or other autoimmune diseases were excluded from this study. All patients with enterocutaneous/enteroatmospheric fistulas were followed up for three months to observe disease recurrence. In addition, a total of 140 healthy controls were also recruited from the Jinling Hospital, matched according to the sex and age of the patient population. Genomic DNA was extracted from peripheral blood from each participant. The HSP70-2 restriction fragment length polymorphism related to the polymorphic PstI site at position 1267 was characterized by polymerase chain reaction (PCR). First PCR amplification was carried out, and then PCR products were digested with PstI restriction enzyme. The DNA lacking the polymorphic PstI site within HSP70-2 generates a product of 1117 bp in size (allele A), whereas the HSP70-2 PstI polymorphism produces two fragments of 936 bp and 181 bp in size (allele B).
RESULTS: The frequency of the HSP70-2 PstI polymorphism did not differ between patients and controls; however, the A allele was more predominant in patients with enterocutaneous fistulas than in controls (60.7% vs 51.4%, P = 0.038, OR = 1.425, 95%CI: 1.019-1.994). Sixty-one patients were cured by a definitive operation, drainage operation, or percutaneous drainage while 52 patients were cured by nonsurgical treatment. There was no significant difference in the frequency of the HSP70-2 PstI polymorphism between the patients who had surgery compared to those who did not (P = 0.437, OR = 1.237, 95%CI: 0.723-2.117). Moreover, 11 patients refused any treatment for economic reasons or tumor burden, and 7 patients with enterocutaneous fistulas (5.8%) died during the follow-up period. However, there was no significant difference in the frequency of the HSP70-2 PstI polymorphism between the patients who survived compared to those who died (P = 0.403, OR = 0.604, 95%CI: 0.184-1.986).
CONCLUSION: The A allele of the HSP70-2 PstI polymorphism was associated with enterocutaneous fistulas in this Chinese population.
Core tip: Postoperative enterocutaneous fistulas are one of the most devastating abdominal complications after surgery. Currently, enterocutaneous/enteroatmospheric fistulas may be caused by trauma or surgery as a result of traumatic or iatrogenic bowel injury, infection, or anastomotic leakage. However, genetic or epigenetic factors may increase the risk for individual patients to develop enterocutaneous/enteroatmospheric fistulas. We found the frequency of the HSP70-2 PstI polymorphism did not differ between patients and controls; however, the A allele was more predominant in patients with enterocutaneous fistulas than in controls. To our knowledge, this study was the first study about the enterocutaneous fistula and single nucleotide polymorphism.