Inner ear lesions in congenital cytomegalovirus infection of human fetuses.
Congenital cytomegalovirus (CMV) infection is the leading cause of non-hereditary congenital sensorineural hearing loss (SNHL). The natural course and the pathophysiology of inner ear lesions during human fetal CMV infection have not yet been reported. Inner ear lesions were investigated in six CMV-infected fetuses aged 19-35 postconceptional weeks and correlated with central nervous system (CNS) lesions. All the fetuses had high viral loads in the amniotic fluid and severe visceral and CNS lesions visible by ultrasound. Diffuse lesions consisting of both cytomegalic cells containing inclusion bodies and inflammation were found within all studied structures including the inner ear, brain, other organs, and placenta, suggesting hematogenous dissemination. Cochlear infection was consistently present and predominated in the stria vascularis (5/6), whereas the supporting cells in the organ of Corti were less often involved (2/6). Vestibular infection, found in 4/6 cases, was florid; the non-sensory epithelia, including the dark cells, were extensively infected. The endolymphatic sac was infected in 1 of 3 cases. The severity of inner ear infection was correlated with the CNS lesions, confirming the neurotropism of CMV. This study documenting infection of the structures involved in endolymph secretion and potassium homeostasis in fetuses with high amniotic fluid viral loads suggests that potassium dysregulation in the endolymphatic compartment of the inner ear may lead to secondary degeneration of the sensory structures. In addition, the occurrence of SNHL depends on the intensity and duration of the viral infection and inflammation.
Pediatric ENT Department, Robert Debré Hospital, APHP, Paris, France.
Natacha
N
Teissier
Anne-Lise
AL
Delezoide
Anne-Elisabeth
AE
Mas
Suonavy
S
Khung-Savatovsky
Bettina
B
Bessières
Jeannette
J
Nardelli
Christelle
C
Vauloup-Fellous
Olivier
O
Picone
Nadira
N
Houhou
Jean-François
JF
Oury
Thierry
T
Van Den Abbeele
Pierre
P
Gressens
Homa
H
Adle-Biassette
D000653:Amniotic Fluid / Q000821:virology; D001344:Autopsy; D016022:Case-Control Studies; D002493:Central Nervous System Diseases / Q000151:congenital / Q000473:pathology / Q000821:virology; D003051:Cochlea / Q000473:pathology / Q000821:virology; D003586:Cytomegalovirus Infections / Q000151:congenital* / Q000378:metabolism / Q000473:pathology*; D004712:Endolymphatic Sac / Q000473:pathology / Q000821:virology; D005260:Female; D005315:Fetal Diseases / Q000378:metabolism / Q000473:pathology* / Q000821:virology*; D005333:Fetus / Q000821:virology*; D006706:Homeostasis; D006801:Humans; D007759:Labyrinth Diseases / Q000151:congenital* / Q000473:pathology / Q000821:virology*; D009925:Organ of Corti / Q000473:pathology / Q000821:virology; D011188:Potassium / Q000378:metabolism; D011247:Pregnancy; D011262:Pregnancy Trimester, Second; D011263:Pregnancy Trimester, Third; D012189:Retrospective Studies; D014722:Vestibule, Labyrinth / Q000473:pathology / Q000821:virology; D019562:Viral Load
D011188:Potassium