Absence of Epstein-Barr virus in smooth muscle cells of idiopathic hypertrophic pyloric stenosis.
BACKGROUND
The etiology of idiopathic hypertrophic pyloric stenosis (IHPS) is unknown. Epstein-Barr virus (EBV) infects smooth muscle cells and is associated with leiomyomas and leiomyosarcomas of immunocompromised persons, including persons with the acquired immunodeficiency syndrome.


OBJECTIVE
To determine whether EBV is causally associated with IHPS.


METHODS
Biopsy samples of the pylorus were obtained from 10 infants with projectile vomiting and pyloric hypertrophy on ultrasound, with confirmation of hypertrophy at the time of pyloromyotomy. The presence of EBV infection was tested by in situ hybridization for EBV-encoded RNA 1 (EBER1) in smooth muscle cells of IHPS.


METHODS
Biopsy specimens were obtained from children treated for IHPS at a tertiary referral hospital and were tested in a clinical molecular diagnostics laboratory.


RESULTS
All of the 10 smooth muscle biopsies were negative for EBER1. Cellular U6 RNA was detected in all smooth muscle samples, confirming that the RNA in the specimens was intact and capable of detection by in situ hybridization.


CONCLUSIONS
The absence of EBER1 in 10 cases of clinically diagnosed and histopathologically confirmed cases of IHPS effectively excludes EBV infection of smooth muscle cells as a causal factor in the pathogenesis of IHPS.
Department of Pediatrics , The University of Texas Health Science Center at San Antonio, 78229-3900, USA.
H B
HB
Jenson
M L
ML
Gulley
P
P
Puri
D001706:Biopsy; D020031:Epstein-Barr Virus Infections / Q000000981:diagnostic imaging / Q000473:pathology / Q000821:virology*; D005260:Female; D004854:Herpesvirus 4, Human / Q000235:genetics / Q000302:isolation & purification* / Q000472:pathogenicity; D006801:Humans; D006984:Hypertrophy / Q000473:pathology*; D017403:In Situ Hybridization; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D009130:Muscle, Smooth / Q000821:virology*; D011707:Pyloric Stenosis / Q000000981:diagnostic imaging / Q000473:pathology / Q000821:virology*; D012367:RNA, Viral / Q000032:analysis; D014463:Ultrasonography
C099537:Epstein-Barr virus encoded RNA 1; D012367:RNA, Viral