Supplementary Material for: Differences in the Clinical Manifestations and Mortality of Systemic Lupus Erythematosus Onset in Children and Adults: A Systematic Review and Meta-Analysis

<b><i>Introduction:</i></b> The aim of this study was to assess the differences between childhood-onset and adult-onset systemic lupus erythematosus (cSLE and aSLE) for clinical manifestations and mortality using a meta-analytic approach. <b><i>Methods:</i></b> The PubMed, EMBASE, and the Cochrane library were searched for eligible studies published between January 1982 and March 2021. The odds ratio (OR) with 95% confidence interval was used to calculate the pooled effect estimates using the random-effects model. <b><i>Results:</i></b> Thirty-four studies involving 21,946 SLE patients were included. cSLE was associated with an increased risk of malar rash (OR: 1.64; <i>p</i> &lt; 0.001), ulcers/mucocutaneous involvement (OR: 1.22; <i>p</i> = 0.039), general neurological involvement (OR: 1.52; <i>p</i> &lt; 0.001), seizures (OR: 1.92; <i>p</i> &lt; 0.001), general renal involvement (OR: 2.08; <i>p</i> &lt; 0.001), proteinuria (OR: 1.35; <i>p</i> = 0.015), urinary cellular casts (OR: 1.67; <i>p</i> = 0.047), fever (OR: 2.31; <i>p</i> &lt; 0.001), anemia (OR: 1.91; <i>p</i> &lt; 0.001), thrombocytopenia (OR: 1.41; <i>p</i> &lt; 0.001), leucopenia (OR: 1.57; <i>p</i> = 0.017), lymphadenopathy (OR: 2.40; <i>p</i> &lt; 0.001), and cutaneous vasculitis (OR: 1.72; <i>p</i> = 0.001) as compared with aSLE. Moreover, cSLE versus aSLE was associated with a reduced risk of articular manifestations (OR: 0.63; <i>p</i> = 0.001), pulmonary involvement (OR: 0.54; <i>p</i> = 0.001), and pleuritis (OR: 0.61; <i>p</i> &lt; 0.001). There were no significant differences between cSLE and aSLE for mortality risk (OR: 1.20; <i>p</i> = 0.203). <b><i>Conclusion:</i></b> We found that certain clinical manifestations of SLE are different in cSLE and aSLE. Moreover, the mortality risk of cSLE and aSLE was not significantly different.