Epidemiology of otitis media with effusion in children

Synergistic Effect of Dermatophagoides farinae and Lipopolysaccharides in Human Middle ear Epithelial Cells

Purpose

Although the concept of "one airway, one disease," which includes the middle ear space as part of the united airway is well recognized, the role of allergens in otitis media with effusion (OME) is not clearly understood. We aimed to investigate the effect of the interaction between Dermatophagoides farinae (Der f) and lipopolysaccharide (LPS) on the induction of epithelial inflammatory response in vitro.

Methods

Primary human middle ear epithelial cells were exposed to Der f, LPS, or both in different sequences, and the magnitude of the immunologic responses was compared. The mRNA expressiona of mucin (MUC) 4, 5AC, 5B, 8, GM-CSF, TNF-α, TLR4, and MD-2 were evaluated using real-time PCR. MUC levels before and after siRNA-mediated knockout of TLR4 and MD-2 were assessed. Lastly, the involved cell signaling pathway was evaluated.

Results

The expressiona of cytokines, and the MUC 4, 5AC, 5B, and 8 genes were augmented by pretreatment with Der f followed by LPS; however, reverse treatment or combined treatment did not induce the same magnitude of response. Increased MUC expression was decreased by TLR4 knockdown, but not by MD-2 knockdown. The signal intensity of MUC 8 was higher in MD-2 over-expressed cells than in those exposed to LPS only. The translocation of nuclear factor-κB was observed in cells pretreated with Der f followed by LPS.

Conclusions

When Der f treatment preceded LPS exposure, Der f and LPS acted synergistically in the induction of pro-inflammatory cytokines and the MUC gene, suggesting an important role in the development of OME in patients with concealed allergy airway sensitization.

Impact of Staphylococcus epidermidis lysates on middle ear epithelial proinflammatory and mucogenic response

BACKGROUND

Chronic otitis media with effusion (COME) develops after sustained inflammation and is characterized by secretory middle ear epithelial metaplasia and effusion, most frequently mucoid. Staphylococcus epidermidis, typically considered a commensal organism, is very frequently recovered in chronic middle ear fluid and in middle ear biofilms. Although it has been shown to drive inflammation in sinonasal epithelium, the impact of S. epidermidis on COME is markedly understudied. The goal of this study was to examine the in vitro effects of S. epidermidis lysates on murine and human middle ear epithelial cells.

METHODS

Staphylococcus epidermidis lysates were generated and used to stimulate submerged and differentiated human and murine epithelial cells (MEECs) for 24 to 48 hours. Quantitative real time-polymerase chain reaction, Western blot, enzyme-linked immunosorbent assay, and immunocytochemistry techniques were performed to interrogate the mucin gene MUC5AC and MUC5B expression and protein production, chemokine response, as well as NF-κB activation. Luciferase reporter assays were performed to further evaluate nuclear factor κB (NF-κB) activation and query specific promoter responses after S. epidermidis exposure.

RESULTS

Staphylococcus epidermidis induced a time- and dose-dependent MUC5AC and MUC5B overexpression along with a parallel overexpression of Cxcl2 in mouse MEEC and IL-8 in human MEEC. Further investigations in mMEEC showed a 1.3 to 1.5 induction of the MUC5AC and MUC5B promoters. As potential mechanisms for these responses, induction of an oxidative stress marker, along with early nuclear translocation and activation of NF-κB, was found. Finally, chronic exposure induced marked epithelial thickening of cells differentiated at the air liquid interface.

CONCLUSIONS

Staphylococcus epidermidis lysates activate a proinflammatory response in MEEC, including mucin gene expression and protein production. Although typically considered a nonpathogenic commensal organism in the ear, these results suggest that they may play a role in the perpetuation of an inflammatory and mucogenic response in COME.

Effects of Active and Passive Smoking on Ear Infections

Otitis media (OM) is one of the most frequent diseases in young children, causing to visit a physician, and also the most common indication for antibiotic prescription. The peak incidence and prevalence of OM is 6 to 18 months of age. In children, second-hand smoke (SHS) exposure is associated with upper and lower respiratory tract infections, such as acute otitis media (AOM), pneumonia, and bronchitis. Despite the overwhelming evidence of the role of SHS exposure on infant health, a very high proportion of children still continue to be exposed. This important relationship between all kinds of smoking and poor health may not be appreciated universally. With this article, we aim to review tobacco smoke exposure and OM connection. How this exposure may cause OM especially in young children? What can be done to prevent and to reduce the harmfull effects of tobacco smoking?

MUC5B Is the predominant mucin glycoprotein in chronic otitis media fluid

Chronic otitis media (COM), e.g. "glue" ear is characterized by middle ear effusion and conductive hearing loss. Although mucous glycoproteins (mucins), which contribute to increased effusion viscosity, have been analyzed in ear tissue specimens, no studies have been reported that characterize the molecular identity of secreted mucin proteins present in actual middle ear fluid. For this study, effusions from children with COM undergoing myringotomy at Children's National Medical Center, Washington, DC were collected. These were solubilized and gel fractionated, and the protein content was identified using a liquid chromatography tandem mass spectrometry (LC-MS/MS) proteomics approach. Western blot analyses with mucin specific antibodies and densitometry were performed to validate the mass spectrometry findings. LC-MS/MS results identified mucin MUC5B by >26 unique peptides in six of six middle ear effusion samples, whereas mucin MUC5AC was only identified in one of six middle ear effusions. These findings were validated by Western blot performed on the same six and on an additional 11 separate samples where densitometry revealed on average a 6.4-fold increased signal in MUC5B when compared with MUC5AC (p = 0.0009). In summary, although both MUC5AC and MUC5B mucins are detected in middle ear effusions, MUC5B seems to be predominant mucin present in COM secretions.

Cigarette smoke activates NF kappa B and induces Muc5b expression in mouse middle ear cells

OBJECTIVES

Cigarette smoke exposure is a significant risk factor in the development of otitis media (OM). Nuclear factor kappa B (NF-kappa B) is a ubiquitous transcription factor known to mediate cigarette smoke effects on gene regulation in multiple cell types. The MUC5B mucin gene contains several putative NF-kappa B sites in its promoter and is the predominant mucin expressed in human OM. We hypothesized that in vitro stimulation of a recently developed model system, murine middle ear epithelial cells (MEEC), with cigarette smoke condensate (CSC) activates NF-kappa B and subsequently induces Muc5b gene expression.

METHODS

Luciferase reporter assays, electromobility shift assays (EMSA), and quantitative microplate transcription factor assays (TFA) were performed to evaluate NF-kappaB activation with CSC in immortalized murine MEEC (mMEEC). Reverse transcriptase polymerase chain reaction (RT-PCR) assays and quantitative real time RT-PCR were performed to determine whether time course CSC stimulation upregulates Muc5b mRNA levels in differentiated mMEEC. Luciferase reporter assays were performed to determine whether CSC activates the Muc5b promoter.

RESULTS

Reporter assays, EMSA, and TFA demonstrated three- to five-fold dose-dependent activation of NF-kappa B with CSC in mMEEC. CSC stimulation likewise increased Muc5b mRNA abundance and induced reporter activity 1.8- to 4.8-fold in plasmids containing -556 and -255 base pairs upstream of the Muc5b transcriptional start site in mMEEC.

CONCLUSIONS

CSC activates NF-kappaB in immortalized MEEC. Furthermore, this activation correlates with CSC-induced Muc5b promoter activation and gene expression. Taken together, these results hint that much as in lung cells, the activation of mucins by cigarette smoke is mediated in part by NF-kappa B.

A feasibility study of chiropractic spinal manipulation versus sham spinal manipulation for chronic otitis media with effusion in children

BACKGROUND

Pediatric otitis media with effusion is a common and costly condition. Although chiropractors have anecdotally claimed success in treating otitis media, there is little research to support their claims.

OBJECTIVE

A pilot study was undertaken for the purpose of assessing the feasibility of conducting a full-scale randomized clinical trial investigating the efficacy of chiropractic spinal manipulative therapy (SMT) for children with chronic otitis media with effusion.

METHODS

This study was a prospective, parallel-group, observer-blinded, randomized feasibility study. Twenty-two patients, ages 6 months to 6 years, received either active chiropractic SMT or placebo chiropractic SMT. Otoscopy and tympanometry were used to create a middle ear status profile, and daily diaries were collected.

RESULTS

Five newspaper advertisements over 6 months generated 105 responses. Twenty patients subsequently qualified and were randomized into the study. Collection of tympanometric and otoscopic data proved to be challenging. Compliance with the treatment and evaluation protocols and daily diaries was excellent. There were no reports of serious side effects as a result of either the active or placebo chiropractic treatments.

CONCLUSION

Recruitment for a randomized controlled trial is feasible and could be enhanced by medical collaboration. Patients and parents are able and willing to participate in a study comparing active SMT and placebo SMT. Parents were extremely compliant with the daily diaries, suggesting that similar quality-of-life and functional status measures can be successfully used in a larger trial. We found the objective outcomes assessment involving tympanometry and otoscopy extremely challenging and should be performed by experienced examiners in future studies.

Classification of otitis media

OBJECTIVES

To review the International Classification of Diseases (ICD) system of classifying otitis media. To highlight the failings of this system and to propose an alternative (Read version 3).

STUDY DESIGN

An historical review of the literature and a presentation of two distinct classification schemes.

METHODS

The advantages and disadvantages of the alternative schemes are analyzed and an algorithm for the classification of otitis media is presented that describes the decisions taken to reach a diagnosis.

RESULTS

The proposed classification of otitis media as used in the Read Codes thesaurus is more logical than the ICD classification.

CONCLUSIONS

The widely used ICD schema of otitis media fails to provide the otologist or general medical practitioner with a logically organized set of terms to describe inflammatory middle ear disease. This article proposes a simple, hierarchical classification that can be used by specialists, generalists and epidemiologists alike.

Childhood imbalance and chronic otitis media with effusion: effect of tympanostomy tube insertion on standardized tests of balance and locomotion

The goal of this study was to investigate the role of chronic otitis media with effusion as a cause of childhood imbalance. Nineteen 4- to 6-year-old children with chronic otitis media with effusion and 14 matched control children underwent a series of laboratory tests, including two standardized tests of balance and locomotion: the Peabody Developmental Motor Scales (PDMS) and the Bruininks-Oseretsky Test of Motor Proficiency (BOTMP). The children in the chronic otitis media with effusion group underwent tympanostomy tube insertion. Both groups underwent the same battery of tests within 6 to 8 weeks of initial testing. Analysis of variance for the PDMS and BOTMP demonstrated significantly lower performance in the balance subscales for the otitis group before (P < .01). Both otitis and control groups improved when retested. The improvement was greater and approaching significance in the otitis group on the PDMS and BOTMP (P = .056 and .097, respectively). It is concluded that chronic otitis media with effusion significantly affects balance and coordination skills in 4- to 6-year-old children. These skills improve after tympanostomy tube insertion at a rate greater than that of the control group.

[Bacteriological study of purulent otitis media in children in CHU in the tropical zone]

BACKGROUND

Haemophilus influenzae and S pneumoniae are the most common causative agents of acute otitis media in Europe and the USA. This work aimed to identify the agents in Senegal and to study their sensitivity to antibiotics.

POPULATION AND METHODS

Two hundred and one patients, aged 0 to 15 years, with persistent middle-ear effusion, were included in this study from 1983 to 1993. Purulent samples aspirated from the external canal were analysed for bacteriology and sensitivity testing.

RESULTS

Eighty two percent of cultures were positive for Staphylococcus aureus (37%), Pseudomonas aeruginosa (25%), Proteus (18%) and Klebsiella (8%). Positive cultures were found mainly in children aged between 1 and 5 years. Amikacin and cefotaxim were the most active antibiotics against the majority of strains. Staphylococcus aureus was always resistant to penicillin.

CONCLUSIONS

Prevalence of Staphylococcus aureus as the causative agent of persistent middle-ear effusion may be explained by late examination. Its resistance to penicillin favors early administration of third generation cephalosporins or pristanimycin.

Does the type of middle ear aspirate have any prognostic significance in otitis media with effusion in children?

Two hundred and twenty-two children with chronic, bilateral middle ear effusions were assessed during a 2 year follow-up period. At initial myringotomy the middle ear aspirate was found to be serous in 44 children and mucoid in 178 children. Evaluation at 1 and 2 years post-operatively showed no difference in otoscopic fluid clearance or mean hearing threshold at either follow-up time in relation to either type of fluid. There was no greater need for ventilation tube reinsertion in either group during the overall follow-up period. There was found to be no significant difference between the children with serous or mucoid effusions in relation to a range of pre-operative and operative variables. The study suggests that outcome in terms of fluid clearance and hearing thresholds is independent of the fluid type and there appears no greater need for revision ventilation tube insertion in relation to the findings at myringotomy. The type of effusion found on aspiration prior to ventilation tube insertion has no prognostic value. Children with serous fluid should be managed in an identical manner to those in which the fluid is thicker and mucoid in character.

Otitis media update: pathogenesis and treatment

Otitis media primarily affects children, but can also lead to lifelong sequelae. Middle ear histopathologic changes and clinical manifestations can represent any part of a disease continuum, from acute to recurrent to chronic otitis media. Acute otitis media is most often caused by an acute respiratory viral infection and secondary replication of bacteria in the middle ear space and tissues, leading to symptoms and signs of infection (ie, fever, pain, tympanic membrane erythema). Antimicrobial therapy is the mainstay of management, and clinical response to different antimicrobial drugs appears to be similar. The bacteriologic efficacy of these drugs, however, is quite variable. Clearly, antimicrobial treatment of acute otitis media, which currently is largely empiric, must be fine-tuned on the basis of patient and disease variation.

Morphometric studies of the continuum of otitis media

Morphometric changes in the epithelium and subepithelium of the middle ear mucosa from children younger than 10 years of age were measured at the promontory in 85 temporal bones with otitis media and in 29 normal temporal bones by use of quantitative and semiquantitative methods. Comparisons of morphologic analysis in different otitis media types showed that acute inflammatory changes were usually seen in purulent otitis media with effusion and serous otitis media with effusion, and chronic inflammatory changes were more severe in mucoid otitis media with effusion and chronic otitis media. There were overlaps, however, in histopathologic findings between different types of otitis media that suggest a continuum of otitis media types, with one type of otitis media changing into another type.

Historical perspectives and concepts in otitis media research at the University of Minnesota

The University of Minnesota Otitis Media Research Center, formed in 1978, comprises a multidisciplinary research team in the clinical fields of otolaryngology, pediatrics, audiology, and infectious disease as well as the basic science fields of histopathology, epidemiology, microbiology, immunology, biostatistics, pharmacology, physiology, and biochemistry. The team has focused on studies designed to elucidate the pathophysiology of the otitis media continuum, and considerable progress has been made in describing this continuum by using the basic science approaches available in the Center. The collaboration of basic and clinical scientists has created a synergy of goals, ideas, and methods leading to new hypotheses and progress, ultimately resulting in improved patient care methods.

Surgery for otitis media with effusion in children and its relationship to parental smoking

A study was conducted to ascertain whether there is any relationship between parenteral smoking and various factors in children undergoing surgery for otitis media with effusion. Information was recorded on 115 children admitted to hospital for grommet insertion. Details of parenteral smoking habits, previous surgery for otitis media with effusion and operative findings were noted. A group of 36 children with healthy ears attending an orthoptic clinic were used as controls. Those children with at least one parenteral smoker were found to have a higher change of being admitted to hospital for grommet insertion and were more likely to have had previous surgery for otitis media with effusion.

Parental smoking and middle ear effusions in children

A study was conducted on seventy children to ascertain any relationship between parental smoking and the presence of middle ear effusions in the children. Information was collected using a questionnaire, clinical examination and audiological tests. Both groups of children (with and without effusions) had similar age, sex and social class distributions. It was found that the presence of middle ear effusions in the children was associated with an increased incidence of parental smoking. Those children with an abnormal tympanometry result were more likely to have at least one parent who smoked than those with normal tympanometry results. There was no relationship between resolution of the effusion and parental smoking. It is therefore suggested that as part of the management of this condition parents should be advised of the effects of smoking on the condition and encouraged to avoid smoking in the same environment as their children.

Defective immunoregulation in children with chronic otitis media with effusion

Otitis media and middle ear effusions (MEE) are most common clinical problems in early childhood, for which an estimated one million tympanostomies are performed each year in the United States. Although many factors have been associated with MEE (age, sex, genetics, otitis media, socioeconomic status, feeding style, atopy or hypersensitivity, certain bacteria and viruses), a defective immunoregulatory mechanism in the host may also contribute to the pathogenesis. During the past 2 years, we have evaluated immune function in 90 randomly selected children who underwent repeated tympanostomy for persistent MEE. The T-cell subset ratio (OKT-4/OKT-8) was reduced (below 1.25) in 16%. In 33 children, generation of T-cell growth factor (IL-2) by peripheral blood lymphocytes (PBL) was evaluated and found to be decreased in 11. The mitogenic response of PBL to phytohemagglutinin (PHA) and pokeweed mitogen (PWM) stimulation was abnormal in almost half of the cases. Imbalance of T-cell subsets and decreased production of IL-2 indicate defective immunoregulatory function in some of these children, which may play a role in the pathogenesis of persistent MEE.

Longitudinal studies of experimental otitis media with Haemophilus influenzae in the gerbil

Haemophilus influenzae non-typable strain 119 was found to cause severe otitis media with sequellae when inoculated into the middle ear cavities of the Mongolian gerbil, Meriones unguiculatus. Acute inflammation was followed by the development of highly vascular granulation tissue and formation of new bone within the middle ear bulla. These changes persisted throughout the 14-week study in the untreated animals. The gerbil was variably susceptible to otitis media caused by inoculating 30-3000 bacterial cells and 100% susceptible to greater than 3000 cells. The susceptibility of the gerbil to common etiological agents of otitis media allows its use as an appropriate model of the disease.