Clinical and Laboratory ObservationsSurfactant protein-A gene locus associated with recurrent otitis media☆,☆☆
Section snippets
Subjects and Methods
Altogether, 147 DNA samples were collected from children admitted to Oulu University Central Hospital for adenoidectomy, tympanotomy, or both caused by ROM and analyzed for SP-A haplotypes. We also analyzed 278 consecutive samples from infants born in the hospital to evaluate the overall distribution of haplotypes among the present population. Written informed consent was obtained from the parents of all the participants. The Ethics Committee of the hospital approved the protocol.
Genotyping for
Results
The 96 boys and 51 girls with ROM had at least 5 episodes of AOM by the age of 1 to 10 years. The mean age of the first episode of AOM was 8.4 (SD 5.2) months. As shown in the Table, the SP-A haplotype distribution in the ROM group (n = 147) differed from that of the general population (n = 278) in terms of an over-representation of the 6A4-1A5 haplotype.Innate immunity is presumably critically important during early life, before the acquisition of specific immunity. Therefore the ROM group was
Discussion
We have produced evidence of a specific gene locus that is associated with recurrent otitis media. Previously, mice lacking expression of the SP-A gene have been shown to be susceptible to infections by specific microbes deposited on the airways.4, 10 SP-A binds to and increases the phagocytosis of Streptococcus pneumoniae and Haemophilus influenzae, 5 the most common pathogens in AOM. This is the first human study to point to evidence of a role for SP-A in susceptibility to infection.
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Cited by (58)
Expression of surfactant Protein-A in the Haemophilus influenzae-induced otitis media in a rat model
2018, International Journal of Pediatric OtorhinolaryngologyCitation Excerpt :Paananen et al. found that SP-A is the most abundant surfactant protein in the eustachian tube, especially on the tubal floor where ciliated cells were predominant [12]. Ramet et al. found relationships between SP-A expression and OM by analyzing human DNA samples [13]. Their results showed a significant difference between the normal group and the group with acute and recurrent OM in the haplotype distribution of SP-A1 and SP-A2, which is required for production of the fully functional SP-A [13].
Middle Ear and Eustachian Tube Mucosal Immunology
2015, Mucosal Immunology: Fourth EditionImmunity genes and susceptibility to otitis media: A comprehensive review
2014, Journal of Genetics and GenomicsCitation Excerpt :Surfactants are phospholipoproteins known primarily for their function as surface tension-reducing complexes in the alveolar lining of the lung. However, surfactants are also expressed in other organs and are a crucial component of innate immunity (Rämet et al., 2001). Surfactant protein-A (SP-A or SFTPA), for example, is expressed in the Eustachian tube and is thought to have a crucial role in the OM pathophysiology (Paananen et al., 1999).
Mouse models for human otitis media
2009, Brain ResearchProtective role of the lung collectins surfactant protein A and surfactant protein D in airway inflammation
2008, Journal of Allergy and Clinical ImmunologyCitation Excerpt :Although the most important source of SP-A and SP-D is the lung,56 transcripts for these molecules were also detected in mesothelial tissues (mesentery, peritoneum, and pleura), synovial cells, the eustachian tube and nasal sinuses, the gastrointestinal tract, and the genitourinary tract.56-62 The importance of extrapulmonary collectin expression was supported by studies showing that specific SP-A haplotypes differ between children susceptible to recurrent otitis media63 and that SP-D expression in the human gastric mucosa is significantly increased in Helicobacter pylori infection.64 Collectins were also demonstrated to enhance phagocytosis of chlamydial pathogens65 and to inhibit Chlamydia trachomatis infection (a frequent cause of infertility) in the female reproductive tract.66
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Supported by the Finnish Academy and the Foundation for Pediatric Research in Finland.
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Reprint requests: Mikko Hallman, MD, Department of Pediatrics, University of Oulu, Kajaanintie 50, FIN-90220 Oulu, Finland.