Salivary proteomics: A new adjuvant approach to the early diagnosis of familial juvenile systemic lupus erythematosus

Abstract

Systemic lupus erythematosus (SLE) is a chronic multisystemic disease characterized by autoimmune inflammatory disturbance. Pleomorphic manifestations are present and a potentially progressive and debilitating course can be detected. SLE rarely manifests before age 5, and its onset peaks is around puberty. Although clinical manifestations, immunological alterations and treatment do not differ between juvenile and adult SLE, children tend to present with a more aggressive disease course than adults. Hence, autoimmune rheumatic diseases are the most common cause of morbidity and mortality in pediatric populations. Blood serum analysis plays an especially important role in the detection and monitoring of autoantibodies in SLE. However, since blood sampling is an uncomfortable procedure, especially in children, novel less invasive techniques and approaches are of utmost importance to evaluate pediatric subjects. In this regard, saliva samples have several advantages, such as: easy access, fast collection, painless and riskless procedure. Saliva has antimicrobial, immunomodulatory and anti-inflammatory properties, as well as several other relevant features. The whole saliva is a complex mixture of major and minor salivary gland secretion, gingival crevicular fluid, transudates plasma protein, keratinocyte products and oral microbiota. This biological fluid reflects the physiological state of the body, including the emotional condition, and endocrine, nutritional and metabolic changes. Therefore, salivary proteomics is becoming increasingly used for the early diagnosis of several diseases such as breast cancer, oral cancer, Sjögren's syndrome, diffuse systemic sclerosis, rheumatoid arthritis, among others. Considering the detection of some potential markers related to SLE in serum and urine, this study aims to conduct an initial evaluation of the possible presence of such biomarkers in saliva. Furthermore, it is expected to track down new salivary proteins that could be correlated with the disease. As such, it is important to evaluate whether the analysis of the salivary proteome of children whose mothers have SLE may help identify biomarkers for the early detection and monitoring of the condition.