Distinctive clinical features of pediatric systemic lupus erythematosus in three different age classes

It is estimated that around 20% of patients with systemic lupus erythematosus (SLE) have their onset in childhood but there have been conflicting data about the prevalence and severity of the clinical features in different age classes. We conducted this study to analyse the clinical features of patients with pediatric SLE (pSLE) with onset in infancy, prepubertal and postpubertal age. The charts of patients followed at the Department of Pediatrics, University of Padua, who met the criteria for SLE diagnosis, were reviewed. Patients were divided into three groups based on age at disease onset: group A, patients < or =2 years old, group B patients aged between 2 and 10 years, group C patients between 11 and 16 years of age. The clinical and laboratory characteristics of each group were compared. Forty-two patients with pSLE entered the study: 2 were diagnosed before the age of 2 years, 11 between 2 and 10 years and 29 between 10 and 16 years. Eleven more patients with infantile (onset <2 years) SLE (iSLE) were found by a systematic literature search on PubMed and EmBASE and added for analysis to the group A. The female preponderance was significant only in postpubertal patients (F:M = 6.3: 1) whereas the other two groups presented a similar F:M ratio (1.2: 1). In comparison with the other two groups, iSLE showed a significantly higher prevalence of cardiovascular and pulmonary involvement, anemia and thrombocytopenia and a shorter disease duration at time of diagnosis. The postpubertal group showed a higher frequency of musculoskeletal involvement and leukopenia. In prepubertal patients there was no female preponderance and the frequency of clinical features was intermediate between infantile and postpubertal patients. Complement fractions level, antinuclear antibodies (ANA), anti-dsDNA, anti-cardiolipin antibodies and lupus anti-coagulant autoantibodies were not significantly different in the three groups. In general, the prevalence of internal organs involvement in pSLE seems to decrease with age. In infants, SLE is more severe than in the following ages. Postpubertal patients have a strong female preponderance and more specific signs of disease at onset. Prepubertal patients have an intermediate disease severity and no gender predilection.