[1] Univ Penn, Div Rheumatol, Rheumatol, Philadelphia, PA 19104 USA
[2] Childrens Hosp Philadelphia, Div Gastroenterol Hepatol & Nutr, Philadelphia, PA 19104 USA
[3] Univ Penn, Div Nephrol & Hypertens, Philadelphia, PA 19104 USA
[4] Univ Penn, Dept Biostat Epidemiol & Informat, Philadelphia, PA 19104 USA
[5] Univ Penn, Div Gastroenterol, Philadelphia, PA 19104 USA
[6] Univ Penn, Div Rheumatol, Philadelphia, PA 19104 USA