CD38 and systemic lupus erythematosus: Assess for underlying autoimmune or autoinflammatory condition in consultation with Rheumatology:- Disease specific evaluation by history/exam (e.g. for sJIA, SLE, JDM)- IL-18, CXCL9- May pursue genetic testing if history of immune dysregulation suggestive of an IEI-Cycling lymphocytes (CD38+/HLA-DR+ by FC)