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

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.

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.

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.

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.