title: Risk Factors Associated with Renal Involvement in Childhood Henoch-Schönlein Purpura: A Meta-Analysis.
abstract: OBJECTIVE
  Henoch-Schönlein purpura (HSP) is an important cause of chronic kidney disease in children. This meta-analysis identified risk factors associated with renal involvement in childhood HSP.
  
  
  METHODS
  PubMed, Embase, and Web of Science were searched. The quality of all eligible studies was assessed using the Newcastle-Ottawa scale criteria. An analysis of possible risk factors was conducted to report the odds ratio (OR) and weighted mean difference (WMD).
  
  
  RESULTS
  Thirteen studies (2398 children) revealed 20 possible and 13 significant risk factors associated with renal involvement in HSP, with the following meta-analysis estimates of OR and WMD, with 95% confidence intervals: older age (0.90, 0.61-1.19); age > 10 y (3.13, 1.39-7.07); male gender (1.36, 1.07-1.74); abdominal pain (1.94,1.24-3.04); gastrointestinal bleeding (1.86, 1.30-2.65); severe bowel angina (3.38, 1.17-9.80); persistent purpura (4.02, 1.22-13.25); relapse (4.70, 2.42-9.14); WBC > 15 × 109/L (2.42, 1.39-4.22); platelets > 500 × 109/L (2.98, 1.22-7.25); elevated antistreptolysin O (ASO) (2.17, 1.29-3.64); and decreased complement component 3 (C3) (3.13, 1.62-6.05). Factors not significantly associated with renal involvement were: blood pressure; orchitis; elevated C-reactive protein; elevated erythrocyte sedimentation rate (ESR); and elevated serum IgA/IgE or IgG. Arthritis/arthralgia may be a risk factor according to the criteria of the American College of Rheumatology (1.41, 1.01-1.96).
  
  
  CONCLUSIONS
  The following are associated with renal involvement in pediatric HSP: male gender; > 10 y old; severe gastrointestinal symptoms (abdominal pain, gastrointestinal bleeding, and severe bowel angina); arthritis/arthralgia; persistent purpura or relapse; WBC > 15 × 109/L; platelets > 500 × 109/L; elevated ASO; and low C3. Relevant clinical interventions for these risk factors may exert positive effects on the prevention of kidney disease during the early stages of HSP. However, the results should be interpreted cautiously due to the limitations of the studies.
authors.affiliation: Department of Nephrology, Key Laboratory of the Ministry of Education, Children's Hospital of Chongqing Medical University, Chongqing, People's Republic of China.
authors.forename: Han
authors.initials: H
authors.lastname: Chan
authors.affiliation: Department of Nephrology, Key Laboratory of the Ministry of Education, Children's Hospital of Chongqing Medical University, Chongqing, People's Republic of China.
authors.forename: Yan-Ling
authors.initials: YL
authors.lastname: Tang
authors.affiliation: Department of Nephrology, Key Laboratory of the Ministry of Education, Children's Hospital of Chongqing Medical University, Chongqing, People's Republic of China.
authors.forename: Xiao-Hang
authors.initials: XH
authors.lastname: Lv
authors.affiliation: Department of Nephrology, Key Laboratory of the Ministry of Education, Children's Hospital of Chongqing Medical University, Chongqing, People's Republic of China.
authors.forename: Gao-Fu
authors.initials: GF
authors.lastname: Zhang
authors.affiliation: Department of Nephrology, Key Laboratory of the Ministry of Education, Children's Hospital of Chongqing Medical University, Chongqing, People's Republic of China.
authors.forename: Mo
authors.initials: M
authors.lastname: Wang
authors.affiliation: Department of Nephrology, Key Laboratory of the Ministry of Education, Children's Hospital of Chongqing Medical University, Chongqing, People's Republic of China.
authors.forename: Hai-Ping
authors.initials: HP
authors.lastname: Yang
authors.affiliation: Department of Nephrology, Key Laboratory of the Ministry of Education, Children's Hospital of Chongqing Medical University, Chongqing, People's Republic of China.
authors.forename: Qiu
authors.initials: Q
authors.lastname: Li
mesh_terms: D002648:Child; D006801:Humans; D011695:IgA Vasculitis / Q000453:epidemiology*; D007668:Kidney; D012307:Risk Factors