Value of D-dimer to immunoglobulin A ratio in evaluating renal impairment in acute phase in Henoch-Schönlein purpura children complicated with gastrointestinal involvement at initial diagnosis

Objective To investigate the relationships of D-dimer (D-D), immunoglobulin A (IgA) and D-D to IgA ratio (D-D/IgA) with renal impairment in acute phase in Henoch-Schönlein purpura (HSP) children complicated with gastrointestinal involvement at initial diagnosis.

Methods A total of 148 children with HSP at initial diagnosis were analyzed retrospectively, and they were divided into no gastrointestinal involvement group with 78 cases and gastrointestinal involvement group with 70 cases according to clinical manifestation. According to condition of renal impairment in acute phase, the children in the gastrointestinal involvement group were divided into renal impairment group with 20 cases and no renal impairment group with 50 cases. The differences of clinical parameters were compared between different groups, and multivariate Logistic regression model was used to analyze the influencing factors of renal impairment in acute phase in HSP children with gastrointestinal involvement at initial diagnosis.

Results There were significant differences in age, sex distribution, D-D level, fibrinogen level, IgA, D-D/IgA, leukocyte count, neutrophil count, neutrophil-to-lymphocyte ratio (NLR), platelet count, platelet-to-lymphocyte ratio (PLR) between the gastrointestinal involvement group and the no gastrointestinal involvement group (P < 0.05 or P < 0.01). In the gastrointestinal involvement group, 20 children had renal impairment in acute phase, and the median time from diagnosis to occurrence of renal impairment was 7 days. Age, IgA level and D-D/IgA in the renal impairment group were significantly lower than those in the no renal impairment group, while the D-D level was significantly higher than that in the no renal impairment group (P < 0.01). The result of multivariate Logistic regression model showed that D-D/IgA (OR=1.999, 95%CI, 1.245 to 3.349; P=0.005) was the only relevant factor for renal impairment in acute phase in HSP children complicated with gastrointestinal involvement at initial diagnosis.

Conclusion The levels of D-D, IgA and D-D/IgA increase in HSP children with gastrointestinal involvement at initial diagnosis. D-D/IgA is the only relevant factor for renal impairment in acute phase in HSP children complicated with gastrointestinal involvement at initial diagnosis.