The relationship between red cell distribution width and the risk of Henoch-Schönlein purpura nephritis.

INTRODUCTION: Red blood cell distribution width (RDW) is elevated in various inflammatory diseases, but its clinical significance in Henoch-Schönlein purpura nephritis (HSPN) in unknown. The aim of this study was to determine the value of RDW as a risk factor or marker for HSPN in children.

METHODS: This was a case-control study of 105 Henoch-Schönlein purpura (HSP) patients, 120 HSPN patients and 192 healthy controls. The relationship between RDW-coefficient of variation (RDW-CV) and the clinical characteristics of HSPN patients was determined by a multiple logistic regression analysis (MVLRA). Receiver operating characteristic (ROC) curves were applied to compare the diagnostic potential of the RDW-CV, a panel of routine markers and combinations of these indices.

RESULTS: The RDW-CV values were significantly higher in the HSPN group than the HSP group and controls (P < 0.001). Significant correlations were found between RDW-CV and ESR (P = 0.001). A combination of RDW-CV and ESR in a ROC curve showed 80% sensitivity and 84.9% specificity in the HSP patients, and 85.8% sensitivity and 93.8% specificity in the HSPN patients. The MVLRA revealed that RDW-CV (OR 1.69, 95% CI 1.16-2.48, P = 0.007) was an independent predictor of HSPN.

CONCLUSIONS: The RDW levels were highest in the HPSN group, suggesting that RDW, especially the combination of RDW and ESR, may have value when assessing the risk of HSPN.