Expression of the Interleukin-10 Signaling Pathway Genes in Individuals With Down Syndrome and Periodontitis Lı ´cia Bezerra Cavalcante,* Marcia Hiromi Tanaka,* Juliana Rico Pires, † Luciano Henrique Apponi, ‡ Elisa Maria Aparecida Giro,* Sandro Roberto Valentini, ‡ Denise M. Palomari Spolido ´ rio, § Marisa Veiga Capela, i Carlos Rossa Jr., ¶ and Raquel M. Scarel-Caminaga # Background: Individuals with Down syndrome (DS) have a higher prevalence and severity of periodontal disease, which cannot be explained by poor oral hygiene alone and is related to changes in the immune response. The aim of this study is to evaluate whether DS was associated with differential modula- tion of expression of genes associated with proinflammatory and anti-inflammatory responses in periodontal disease. Methods: A total of 51 individuals were evaluated: 19 individ- uals with DS and periodontal disease (group 1), 20 euploid indi- viduals with periodontal disease (group 2; positive control), and 12 euploid individuals without periodontal disease (group 3; negative control). Clinical periodontal evaluation and gingival biopsies were performed. Quantitative reverse transcription- polymerase chain reaction was used to determine expression levels of interleukin-10 (IL-10), the receptors IL-10RA and IL- 10RB, intracellular adhesion molecule 1 (ICAM-1), interferon- g-inducible protein 10 (IP-10), and the signaling intermediates Janus kinase 1, signal transducer and activator of transcription 3 (STAT-3), and suppressor of cytokine signaling 3 (SOCS-3). Results: Expression of IL10, SOCS3, IP10, and ICAM1 mRNA in DS patients was significantly lower compared to euploid indi- viduals with periodontal disease, whereas IL-10RB and STAT-3 mRNA levels were higher in individuals with DS. Conclusion: Reduced expression of IL-10 coupled with a pos- sible increase of STAT3 activation (increase of STAT3 and reduc- tion of SOCS3 mRNA) indicates an important modulation of the immune response, with attenuation of anti-inflammatory and in- crease of proinflammatory mediators. This modulation may be related to the increased prevalence and severity of periodontitis in individuals with DS. J Periodontol 2012;83:926-935. KEY WORDS Cytokines; Down syndrome; gene expression; inflammation; periodontitis. D own syndrome (DS) is a chromo- somal disorder caused by an error in cell division that results in the presence of a third chromosome 21 or ‘‘trisomy 21.’’ 1 The first observa- tion that the oral conditions in young children with DS are markedly different from those in normal children was re- ported by Jones. 2 Since then, there have been at least two literature reviews examining the oral conditions of individ- uals with DS. 3,4 Periodontal diseases, such as chronic periodontitis and aggressive periodonti- tis, are characterized by a progressive gingival inflammatory response to bacte- rial dental plaque, leading to destruction of the periodontium and eventually tooth loss. 5 Orner 6 observed an increased prevalence of periodontal disease in 89% of DS children compared to their age-matched and chromosomally nor- mal siblings (58%). For individuals with DS who lived in institutions, a periodon- tal disease prevalence of 90% was ob- served in those ranging from 1 to 39 years, whereas 36% of DS children <6 years of age had periodontal pocket formation. 7 Swallow 8 studied DS and mentally re- tarded (MR) patients in three different environments: institutions, day training centers, and special schools, and found that within these environments, the prev- alence of periodontitis was higher in DS * Department of Orthodontics and Pediatric Dentistry, School of Dentistry at Araraquara, Sa ˜o Paulo State University, Araraquara, Sa ˜o Paulo, Brazil. † Department of Periodontics and Implantology, University Center of Educational Foundation of Barretos, Barretos, Sa ˜o Paulo, Brazil. ‡ Department of Biological Sciences, School of Pharmaceutical Sciences, Sa ˜o Paulo State University. § Department of Physiology and Pathology, School of Dentistry at Araraquara, Sa ˜o Paulo State University. i Department of Physical Chemistry, Institute of Chemistry at Araraquara, Sa ˜o Paulo State University. ¶ Department of Oral Diagnosis and Surgery, School of Dentistry at Araraquara, Sa ˜o Paulo State University. # Department of Morphology, School of Dentistry at Araraquara, Sa ˜o Paulo State University. doi: 10.1902/jop.2011.110056 Volume 83 • Number 7 926