Blood routine examination: a simple way for differential diagnosis of immunoglobulin A vasculitis with abdominal involvement and appendicitis in children.

To explore the value of blood routine examination indexes in the differential diagnosis of immunoglobulin A vasculitis (IgAV) with abdominal involvement and appendicitis in children. Forty-seven patients with IgAV and abdominal involvement, 95 cases with appendicitis, and 48 healthy children were enrolled in this study. Demographic and laboratory data were retrospectively recorded from medical files. The levels of serum percentage of lymphocytes (LYM%), percentage of eosinophils (E%), red cell volume distribution width (RDW) and platelet (PLT) count were higher, while blood cells (WBC) count, percentage of neutrophils (N%), percentage of monocytes (M%), mean platelet volume (MPV), platelet distribution width and C-reactive protein were lower in the group of IgAV with abdominal involvement compared to appendicitis group (P < 0.05). Multivariate logistic regression analysis showed LYM% (odds ratio (OR) = 1.34, P = 0.001) and RDW (OR = 2.96, P = 0.045) were independent risk factors for IgAV with abdominal involvement. N% (OR = 1.270, P = 0.006) and MPV (OR = 51.15, P = 0.042) were independently associated with appendicitis. Using receiver operating characteristic analysis, the optimal cut-off values (sensitivity and specificity) respectively were 42.17% (95.7%, 100.0%) for LYM%, 12.65% (83.0%, 83.2%) for RDW, 61.5% (91.6%, 97.9%) for NE% and 10.1fL (78.9%, 75.4%) for MPV, with the AUC values of 0.989, 0.881, 0.985, 0.810, respectively. Blood routine examination indices, especially the N%, LYM%, RDW, and MPV, can be used for simple differential diagnosis of IgAV with abdominal involvement and appendicitis.