BIOMARKERS OF SUPPURATIVE OTITIS MEDIA IN CHILDREN ATTENDING SELECTED HEALTH FACILITIES IN IBADAN

Abstract

Suppurative otitis media or otorrhoea is a major health problem; especially in the first year of life. It could be acute (within 3 months duration) or chronic (greater than 3 months duration). Immunobiologic markers have been identified in otorrhoea, but their role in the outcome of disease remains relatively unknown. This study was aimed at determining the role of these markers in the development of Early Suppurative Otitis Media (ESOM) and the relationship of their levels in the Middle Ear Secretion (MES) and serum to the outcome of Acute Suppurative Otitis Media (ASOM). One tertiary (University College Hospital, Ibadan) and a community health (Bilal Health Center, Agodi) facilities were purposively selected. Participants included 186 consecutively recruited healthy neonates at birth and 228 children (1 to 12 years) who developed ASOM. The ASOM group was compared with 171 age-matched apparently healthy control subjects from among children at the University College Hospital, Ibadan. Blood samples were collected from the neonates and subsequently monitored monthly for 12 months for development of ESOM. Ten milliliters of Blood (two samples taken at presentation and 3 months after) and MES were collected from the ASOM group who were treated and followed up for 10 months to determine resolution or chronicity (CSOM). The MES was cultured for bacterial infection. Neonatal serum and MES were analyzed for retinol and zinc using high performance liquid chromatography and atomic absorption spectrophotometry respectively. Enzyme Linked Immunoassay was used to determine interferon gamma (IFN- ) and immunoglobulins (Ig). Data were analyzed using ANOVA at p=0.05. Incidence of ESOM was 37% among the neonates and the isolates were Pseudomonas aeruginosa. Staphylococcus aureus and Streptococcus spp. There was no significant difference in the mean serum IgG between neonates with ESOM and healthy neonates (1180.0mg/ml+6.3 vs. 1370.2 mg/ml+9.4). Neonatal cord retinol (0.9µg/L+ 0.1 vs 1.1µg/L+0.2), zinc (0.9μg/L+0.1 vs. 1.1μg/L+0.2) and IFN- (45.3pg/ml+4.2 vs. l70.2pg/ml+24.5) were significantly higher in the normal neonates relative to those that developed ESOM. Serum retinol was significantly lower in ASOM children (1.5µg/L+ 0.6) than healthy control (2.6µg/L+ 0.3) whereas there were no significant differences in their serum IgG, IgE, IgM, Zinc and IFN- levels. In the 46% of ASOM children who developed CSOM, serum levels of IgG was significantly higher (1321.1mg/dL+21.2) and retinol was significantly lower (1.6µg/L+ 0.1) than those that had resolved ASOM (666.1mg/dL+14.4 and 2.1µg/L+0.1 respectively). The MES levels of IgG (511.5mg/dL+9.7); IgE (102.0mg/dL+3.6) and IFN- (73.1pg/ml+12.0) were significantly higher and MES IgA (85.40mg/dL+13.64) was significantly lower than resolved ASOM (203.4mg/dL+7.9, 60.4mg/dL+6.1, 27.2pg/ml+4.1 and 228.30mg/dL +16.22 respectively). There were no significant differences in levels of MES IgM, serum IgM, IgA and IgE, IFN- and zinc between the two groups. Reduced levels of neonatal retinol, zinc and IFN- were associated with the development of early suppurative otitis media. Reduced middle ear secretion of IgA and IgG; and serum IgG and retinol were determinants of chronicity in acute suppurative otitis media. Immunoglobulins and retinol may be used in monitoring the progression from acute to chronic suppurative otitis media. Keywords: Suppurative otitis media, Immunoglobulins, Cytokines Word Count: 493