Detection of CMV DNA in the perilymph of a 6-year-old boy with congenital cytomegalovirus infection.

We present the case of a 6-year-old boy who received a cochlear implant for profound sensorineural hearing loss after being born with cytomegalovirus (CMV) infection. Even after 6 years, CMV DNA was still found in the perilymph of the cochlea. Our case shows that CMV DNA can be present in the cochlea years after congenital CMV infection, and it can explain why progressive and/or late-onset hearing loss occurs in these children.

Presence of cytomegalovirus in the perilymphatic fluid of patients with profound sensorineural hearing loss caused by congenital cytomegalovirus infection.

CONCLUSION: Not all patients diagnosed with congenital infection using umbilical cord assay were found to be positive for CMV-DNA by perilymphatic fluid assay. In addition, a CMV-DNA-positive result was observed in one patient who had not been diagnosed with congenital infection. Sampling of perilymphatic fluid from a large population of patients with congenital SNHL caused by congenital CMV infection or of unknown etiology is required to determine the prevalence of CMV-related profound HL. OBJECTIVES: Sensorineural hearing loss (SNHL) is one of the most frequent manifestations in patients with congenital cytomegalovirus (CMV) infection. Using dried umbilical cord, a PCR-based assay was recently developed for the retrospective detection of congenital CMV infection. This study analyzed the presence of CMV in the perilymphatic fluid and evaluated differences in the effect of cochlear implantation between CMV-positive and -negative groups. METHOD: Perilymphatic fluid was collected from each patient at the time of cochlear implantation and analyzed for the presence of CMV using a PCR method. RESULTS: The perilymphatic fluid in two of the five patients suffering from congenital CMV infection and in one of the 17 patients without congenital CMV infection was found to be positive for CMV.

Cytomegalovirus DNA detection in dried blood spots and perilymphatic fluids from pediatric and adult cochlear implant recipients with prelingual deafness.

BACKGROUND: Congenital cytomegalovirus (CMV) infection is the leading cause of non-genetic congenital hearing loss. The contribution of congenital CMV to prelingual deafness and the pathophysiology is largely unknown. OBJECTIVE: (1) To analyze the prevalence of congenital CMV among cochlear implant (CI) recipients with prelingual deafness. (2) To genotype CMV present in dried blood spots (DBS) and in the inner ear years after birth. STUDY DESIGN: Children and adults with prelingual deafness who received a CI in 2010-2011 were included prospectively. Perilymphatic fluids were collected during CI surgery and, in the pediatric cases, DBS were retrieved for CMV DNA detection. Furthermore, a cohort of children with prelingual deafness who received a CI between 2003 and 2008 were included retrospectively. CMV detection in DBS and perilymph was followed by gB and gH genotyping. RESULTS: Seventysix pediatric CI recipients were included. Seventy DBS were tested for CMV DNA, resulting in a prevalence of congenital CMV of 14% (10/70). Perilymphatic fluid was available from 29 pediatric CI recipients. One perilymph fluid, of a 21-month old girl with congenital CMV, asymptomatic at birth, was CMV DNA positive. The CMV strain in the perilymph was genotypically identical to the strain present in her DBS (gB1/gH2). Perilymph samples from 21 adult CI recipients were CMV DNA negative. CONCLUSIONS: Our study stresses the important contribution of congenital CMV among pediatric CI recipients. Furthermore, our genotyping data support the hypothesis that CMV-related hearing loss is associated with ongoing viral replication in the inner ear up to years after birth.

Viral infections detected by serology and PCR of perilymphatic fluid in children with idiopathic sensorineural hearing loss.

The etiology of sensorineural hearing loss (SNHL) in children may be viral. This cross-sectional study aimed to determine the role of viral infectious agents in children with idiopathic SNHL. Of 119 children with SNHL aged 3-168 months undergoing cochlear implant surgery at a hospital in Tehran, no cause could be established in 18 cases (15.1%). Cytomegalovirus (CMV) and herpes simplex virus (HSV) active infections (detected by DNA-PCR, confirmed by serology) were found in the perilymphatic fluid of 16.7% (3/18) cases of idiopathic SNHL. Serology was performed on blood samples from 11 of these cases: specific antibodies against CMV, Toxoplasma spp., HSV and rubella were determined in all cases; acute T. gondii infection was detected in 7 cases and rubella IgG was found in only 1 case. Neonatal screening for CMV, HSV and T gondii may be helpful in the Islamic Republi of Iran.

Pathogenesis of cytomegalovirus-associated labyrinthitis in a guinea pig model.

Cytomegalovirus infects fetuses through the placenta, resulting in various congenital disorders in newborns, including hearing loss. We developed a monoclonal antibody to guinea pig cytomegalovirus (GPCMV) that was available for immunohistochemistry, and investigated the expression of the GPCMV antigen in animal models of direct and congenital infections. Injection of GPCMV, directly to the inner ear, increased the sound pressure level and resulted in labyrinthitis with severe inflammation. Immunohistochemistry detected GPCMV-infected cells mainly in the scala tympani, scala vestibule and spinal ganglion, but rarely in the cochlear duct. Injection of GPCMV to 5-week pregnant guinea pigs resulted in severe labyrinthitis in fetuses. Immunohistochemistry detected GPCMV-infected cells in the perilymph area and spinal ganglion, but not in the endolymph area, including hair cells. These data suggest that the virus spreads via the perilymph and neural routes in the inner ear of both models of direct and congenital infections.

Measles virus and otosclerosis.

Measles virus (MeV) might play an important role as an environmental stimulus in the etiopathogenesis of otosclerosis. Chronic inflammation was shown in morphologic investigations of otosclerotic foci and MeV N, P, and F proteins were detected within cells of the otosclerotic focus by immunohistochemical investigations. MeV RNA was extracted from fresh-frozen otosclerotic tissue by the use of in vitro RT-PCR. This result was validated through amplification of MeV genome sequences by RT-PCR from celloidin-embedded sections with morphologically ascertained otosclerotic foci. In searching for an immune response of the inner ear immune system against MeV proteins, elevated anti-MeV IgG levels were detected in the perilymph of patients with otosclerosis in comparison with the serum levels. In situ RT-PCR allowed the localization of MeV sequences in osteoclasts, osteoblasts, chondrocytes, macrophages, and epithelial cells in middle ear mucosa of otosclerotic tissue. Further evidence for MeV persistence has recently been given. Genotyping of MeV in otosclerotic foci demonstrated the presence of MeV genotype A, which circulated in Europe around 1960. All the above results confirm a strong association between MeV and otosclerosis.

Cytomegalovirus in the perilymphatic fluid.

OBJECTIVE: The incidence of congenital cytomegalovirus (CMV) infection is approximately 1% of neonates. Ninety percent of congenitally infected infants are "asymptomatic;" they have no signs or symptoms at birth. The prevalence of congenital CMV in the profoundly deaf population and the pathogenesis of deafness from CMV are unknown. The objective of this study is to determine whether CMV can be demonstrated and quantified in perilymphatic fluid of patients with congenital CMV infection and sensorineural hearing loss (SNHL) using a quantitative real-time polymerase chain reaction (QRTPCR). STUDY DESIGN: Prospective case series. METHODS: Perilymphatic fluid was collected at the time of cochlear implantation from children with known or radiologic evidence of congenital CMV infection and analyzed for the presence of CMV using QRTPCR. Blood was collected and analyzed for CMV using QRTPCR, serology, and culture. CMV was quantified in perilymphatic fluid and compared with that present in the patient's blood. RESULTS: Perilymphatic fluid and blood was collected from six children. QRTPCR was positive for CMV in the perilymphatic fluid of four patients. Blood analyzed with QRTPCR, and culture was negative in all patients. CONCLUSIONS: CMV can be demonstrated and quantified in perilymphatic fluid using QRTPCR. Refinements in our technique and sampling of perilymphatic fluid from a large population of children with congenital SNHL and unknown etiology can determine the prevalence of CMV-mediated profound HL.

Detection of herpesvirus DNAs in perilymph obtained from patients with sensorineural hearing loss by real-time polymerase chain reaction.

OBJECTIVES/HYPOTHESIS: Perilymph and peripheral blood mononuclear cells (PBMCs) from patients with bilateral severe sensorineural hearing loss (SNHL) were evaluated for the presence of DNA from cytomegalovirus (CMV), herpes simplex virus (HSV), and human herpesvirus (HHV)6. STUDY DESIGN: A prospective clinical study. METHODS: The subjects were 14 patients who underwent cochlear implantation and 1 patient who underwent gentamicin injection in the inner ear. We attempted to detect viral DNA from perilymph and PBMCs by real-time polymerase chain reaction (rtPCR). RESULTS: CMV DNA was detected in two perilymph specimens obtained from patients who were diagnosed as congenitally symptomatic CMV infection, although no CMV DNA was detected in PBMCs. Neither HSV DNA nor HHV6 DNA was detected in any other perilymph specimens. CMV DNA was detected in three PBMC samples, HSV DNA was detected in two samples, and HHV6 DNA was detected in six samples. CONCLUSION: CMV may persistently infect the inner ear of patients with congenital CMV infection, and rtPCR analysis may prove to be a valuable tool for investigating the etiology of SNHL.

Detection of human cytomegalovirus DNA in perilymph of patients with sensorineural hearing loss using real-time PCR.

Although cytomegalovirus (CMV) has been detected in the inner ear fluid of patients who succumbed to the complications of symptomatic congenital CMV infection, it has not been detected in the inner ear fluid of living patients. In this study, real-time polymerase chain reaction (PCR) was used to measure CMV DNA in clinical samples (including perilymph) collected from five patients with deafness. In case 1, diagnosed as a symptomatic congenital CMV infection, 3 copies/microl of CMV DNA were detected in perilymph, although no viral DNA was detected in peripheral blood mononuclear cells (PBMCs) or urine samples. In case 4, a suspected asymptomatic congenital CMV infection, 36 copies/microg of CMV DNA were detected in PBMCs, but neither perilymph nor urine contained viral DNA. Likewise, in case 5, a case of deafness of unknown origin, 48 copies/microg of CMV DNA were detected in the PBMCs, but none in the perilymph or urine. CMV DNA was not detected in the samples obtained from the remaining two cases with deafness of unknown etiology. To our knowledge, this is the first report to detect CMV DNA in an inner ear sample obtained from a living human subject.

Herpes simplex virus antibodies in the perilymph of patients with Menière disease.

OBJECTIVE: To evaluate the presence of IgG antibodies directed to herpes simplex virus (HSV) in the perilymph of patients with Menière disease. DESIGN: Antibodies to HSV, Epstein-Barr virus, cytomegalovirus, and measles virus were analyzed in serum and perilymph samples by enzyme-linked immunosorbent assay. Total IgG and albumin in serum and perilymph samples were measured by nephelometer analysis. The relation of specific antivirus IgG in the perilymph vs the serum was expressed as an index. PATIENTS: Perilymph and serum samples from 7 patients with long-standing, disabling Menière disease were collected during therapeutic vestibulotomy. Perilymph and serum samples from 7 patients with otosclerosis and 2 recipients of cochlear implants were used as controls. RESULTS: Compared with the corresponding serum sample, the perilymph from the patients with Menière disease disclosed a higher level of specific anti-HSV IgG. An elevated level of specific anti-measles virus IgG in the perilymph was detected in patients with otosclerosis. Patients of all groups showed no variation of specific anti-Epstein Barr virus IgG and anti-cytomegalovirus IgG in the serum or in the perilymph. CONCLUSIONS: Our results show the presence of HSV IgG in the perilymph of patients with Menière disease and support the hypothesis that HSV may play an important role in the etiopathogenesis of Menière disease.

Measles virus in otosclerosis and the specific immune response of the inner ear.

Histologic and immunohistochemical studies of otosclerotic lesions have shown that there is a chronic inflammatory reaction of the otic capsule with bone resorption resulting from vascular invasion accompanied by inflammatory cells. During the active lytic stage of otosclerosis, paramyxoviral structures have been identified by electron microscopy and measles virus antigen expression by immunohistochemistry. Recently, measles virus related sequences have been detected in tissue of otosclerotic lesions. Because the otosclerotic focus has a close relation to the perilymphatic space, the expression of measles virus antigens within it should represent an immunologic challenge to the immune system of the endolymphatic sac. In this study, measles virus specific antibodies were detected in all of the perilymph samples from 19 patients suffering from otosclerosis, and the relative amount of these IgG antibodies was much higher than in serum samples of the same patients or in perilymph of control patients. These findings support the hypothesis that measles viruses play an crucial role in the pathogenesis of otosclerosis.