Comparison of immune thrombocytopenic purpura between patients with juvenile and adult systemic Lupus erythematosus

Abstract

Hematologic abnormalities are often the initial manifestation of systemic lupus erythematosus (SLE) and thrombocytopenia associated with the disease is almost always immune mediated. Its prevalence has been estimated between 10% and 40% in the adult population, and the medical literature shows a higher frequency of this manifestation in juvenile SLE (JSLE) versus adult SLE (aSLE). The lack of research evaluating the initial clinical and laboratory differences in immune thrombocytopenic purpura (ITP) in patients with JSLE and aSLE in a large population of a single university hospital, led to the development of this relevant multicenter study.Objectives: To assess the initial clinical and laboratory differences of ITP between patients with JSLE and aSLE.Methods: The study population will include samples of JSLE and aSLE patients followed in two Rheumatology Services of the Hospital das Clinicas, FMUSP, since the creation of each of the services. The diagnosis will be carried out according to the American College of Rheumatology classification criteria, with disease onset before 18 years of age for JSLE. The study will be a historical cohort, with a retrospective analysis by reviewing the charts of all patients with JSLE and damages, according to a standardized clinical protocol using items that address demographic data, clinical manifestations and laboratory characteristics, activity and cumulative damage of the disease and treatment. This information will be collected in an extensive database. Thrombocytopenia will be defined as platelet count less than 100,000/mm³ in the absence of drugs to justify this change and severe thrombocytopenia as a platelet count less than 50,000/mm³ in the absence of drugs to justify this change. The following clinical and laboratory manifestations will also be evaluated: presence of hemorrhage, arterial or venous thrombosis, need for blood transfusion, use of anticoagulants and myelogram. Results will be presented as median (range) or mean±standard deviation for continuous variables and number (%) for categorical variables. The data will be compared using the Mann-Whitney test or t test for continuous variables to evaluate initial clinical and laboratory differences between patients with JSLE and aSLE. For categorical variables, the differences will be evaluated by Fisher's exact test or chi-square test. In all statistical tests the level of significance of the independent variable will be set at 5% (p <0.05).