Pediatric respiratory tract illness is one of the most common reasons for physician visits and hospitalization and is associated with significant morbidity and mortality. Respiratory illness (RI), mainly involving the upper airways, is common in children and their recurrence constitutes a demanding challenge for the pediatricians.

A child with recurrent respiratory infections presents a difficult diagnostic challenge. It is necessary to discriminate between those with simply-managed causes for their symptoms such as recurrent viral infections or asthma, from the children with more serious underlying pathology such as bronchiectasis or immune dysfunction.

Recurrent infectious rhinitis is usually defined as more than five episodes per year and recurrent pharyngitis or tonsillitis more than three episodes within 12 months. It is evident, that only a few appropriate tests are enough helpful to discriminate between a “well-being” child and a patient with immune dysfunction.

Asthma is a chronic inflammatory disorder of the airways involving many cells and cellular elements. The inflammation causes swelling and narrowing of the airway restricting the capability of air to pass through to the lung tissue. The swelling and narrowing of the airways cause recurrent episodes of coughing, wheezing, breathlessness, and chest tightness [1-3].

IgE is the least abundant of the human immunoglobulin classes and was accordingly the last to be discovered in the late 1960s. The concentration of IgE in normal human sera is between 10 and 400 ng/ml)⁷. Furthermore, at least in humans, the turnover rate of IgE is much more rapid than that of another immunoglobulin. The half-life of IgE in the circulation is estimated at 2-2.5 days. Sometimes the immune system reacts unnecessarily vigorously against otherwise harmless environmental agents, allergens.

These overreactions are termed hypersensitivity reactions and fall into four subgroups, type’s I-IV, depending upon the mechanism behind the action. The type I hypersensitivity reactions are mediated by allergen-specific IgE and are responsible for the clinical manifestation of atopic allergies, such as hay fever, food allergies, eczema, asthma, and anaphylaxis, parasitic infections [4-7].

After incubation, unbound enzyme anti-IgE is washed away and the bound complex is then incubated with a developing agent. After stopping the reaction, the fluorescence of the eluate is measured. The fluorescence is directly proportional to the concentration of IgE in the sample. To evaluate the test results, the response for the patient samples is compared directly to the response for the calibrators.

Reagents: UniCAP/Pharmacia CAP System™ Washing Solution Product No. 10-9202-01, 2 bottles (400 ml each) of Concentrate, 2 bottles (86 ml each) of additive. The additive contains Surfactant and 5.8 % Kathon CG. The concentrate contains Phosphate buffer and 0.05 % Kathon CG. Store concentrate and additive at 2-8°C until the expiration date. Reconstitute using 5 liters of distilled water, 1 bottle Concentrate, and 1 bottle Additive. Mix thoroughly.

Storage: Allow the samples to thaw in the refrigerator at 2-8º C temperature. Bring the number of samples to be tested to room temperature. Maintain the samples at room temperature during the testing process. Store the sample box back in the refrigerator at 2-8 until the testing is completed on all the samples in the box.

Calculation: The IDM software uses Red bard 5 parameter calculations to graph the calibrator concentrations as a log-log graph. The software then plots the sample response on the calibration curve to calculate the concentration into kU/L, or IU/ml.

Statistical analysis: Continuous data were entered into an excel sheet and analyzed using SPSS (trial version) software. A Chi-square test was used to find an association between elevated serum IgE levels and other variables. The significance level was set at less than 0.05.

The present study was undertaken to determine the correlation of serum IgE levels with recurrent respiratory tract illness. A total of 99 children were included in this study. Elevated serum IgE levels were found in 48.48% of children with recurrent respiratory tract illnesses. Male to Female ratio in recurrent respiratory tract illness with elevated serum IgE levels was 3.4:1 This study showed an increasing number of children with recurrent respiratory tract illness and serum IgE levels with increasing age.

A child with recurrent respiratory infections presents a difficult diagnostic challenge. It is necessary to discriminate between those with simply-managed causes for their symptoms such as recurrent viral infections or asthma, from the children with more serious underlying pathology such as bronchiectasis or immune dysfunction.

The present study was undertaken to determine the correlation of serum IgE levels with recurrent respiratory tract illness. A total of 99 children were included in this study.

Studies by Satwani et al and Dhar S et al showed that clinical activity of the disease as recorded by the "SCORAD" index can be used as an indicator of the hematological abnormalities as well as to some extent as a prognostic indicator.

In the current study number of boys with elevated serum IgE was more than girls, which is statistically significant (p=0.0003) Similar results were seen in the studies done by Satwani et al (65%) and Borish L et al (66.5%) The factor responsible for this result could be that, the boys are more exposed to the outdoor activities, hence, increased chances of getting exposed to respiratory infections and allergens [8,12-13].

Petridou ET et al did an investigation that suggests an IgE-mediated allergic response among women with BC in comparison to their controls. The finding needs confirmation by immuno-epidemiological investigation to clarify the directionality of this association and whether laboratory-ascertained atopy can be considered as a risk-marker of susceptibility in the development of BC Johnsson V et al studied that Serum IgE level was determined in 76 monozygous and 81 dizygous like-sexed twin pairs representing adult twins living in the Helsinki area. Monozygous twin pairs were frequently concordant concerning elevated IgE levels, although some pairs were strikingly discordant, indicating that there is a wide range of phenotypic expression for each genotype [14,15]. In the current study, the number of children with elevated serum IgE levels significantly increased with increasing age with a p-value of 0.01. This is by the study conducted on Greek children, by Petridou et al, in children aged 1 month to 14 years, total IgE levels increased by almost 80% per year until 5 years of age. Similarly in a study by Johnsson et al (USA), a 60% increase in IgE levels was observed from birth to 4 years of age. Hamid Habib et al too had significantly increased serum IgE levels with increasing age with p-value 0.001 [14-16].

In the current study, serum IgE levels are significantly elevated (78.04%) in children who were weaned off earlier (before 6 months of age) with a p-value of 0.01 Similar results 60% of elevation of serum IgE levels with early weaning was seen in the study by Satwani H et al with p-value <0.01 and little less, 50% elevation of serum IgE with early weaning were seen in A L Wright et al with p-value <0.005.In the current study, children born as preterm were less likely to have elevated serum IgE levels as compared to those who were born at term gestation. These values are near the study by Siltanen et al in the study “Preterm birth reduces the atopy in adults” showing 69% elevation of serum IgE levels in children born at term gestation [8,15,16,17].

This study showed an increasing number of children with recurrent respiratory tract illness and serum IgE levels with increasing age. Males, preterm and bottle-fed babies are more prone. There was a significant role in a family history of recurrent respiratory tract illness in children with elevated serum IgE levels. The majority of studies are following the present study, however, some studies results are contrary to what was inferred. Therefore more studies with a large sample size are needed to derive a conclusion.

An increasing number of children with recurrent respiratory tract illness and serum IgE levels with increasing age. Males, preterm and bottle-fed babies are more prone. There was a significant role in a family history of recurrent respiratory tract illness in children with elevated serum IgE levels. More studies with a large sample size are needed to derive a conclusion

Dr. Rashmi Vishwakarma: Concept and data collection, Dr. Anita Sharan: Data collection and statistical analysis, Dr. Priti Reddy: Data collection and references, Dr. K. Satyanarayana: Discussion and guidance