**Abstract**

The presence of periodontal pathogens in periodontally healthy children is often overlooked or ignored. Since house dust mite allergy often appears among children with chronic gum disease, it is important to understand the role of lipopolysaccharide—a major immunodominant antigen of *Porphyromonas gingivalis*—in stimulating atopic inflammatory markers of allergies. The aim of the present study is to investigate whether any correlation exists between salivary lipopolysaccharide of *Porphyromonas gingivalis* with circulatory Immunoglobulin-E and Immunoglobulin-G4 in periodontally healthy children with house dust mite allergy. We did an analytic observational study between January and December 2017. We recruited 20 periodontally healthy children (aged 6–16 years) from pediatric allergy-immunology clinic at Dr. Soetomo General Hospital (Indonesia). Lipopolysaccharide of *Porphyromonas gingivalis* was obtained from salivary secretion, while Immunoglobulin-E and Immunoglobulin-G4 were obtained from venous puncture simultaneously. Immunoglobulin analyses were performed by direct-sandwich ELISA, and lipopolysaccharide analyses were performed by limulus amebocyte lysate (LAL) assay. The average of salivary lipopolysaccharide was 7.21 ± 3.06 μg/ml, Immunoglobulin-E was 114.44 ± 26.19 pg/ml, and Immunoglobulin-G4 was 31.02 ± 9.09 ng/ml. There was a strong correlation between salivary lipopolysaccharide and Immunoglobulin-E (r2 = 0.695, *p* < 0.001), and a very strong correlation between salivary lipopolysaccharide and Immunoglobulin-G4 (r2 = 0.796, *p* < 0.001). *Conclusion*: data revealed significant correlations between salivary lipopolysaccharide of *Porphyromonas gingivalis* with circulatory

Immunoglobulin-E and Immunoglobulin-G4 in periodontally healthy children with house dust mite allergy.

**Keywords:** Immunoglobulin-E, Immunoglobulin-G4, lipopolysaccharide, periodontal pathogen, *Porphyromonas gingivalis*
