Henoch-Schönlein purpura (HSP) is the most widespread systemic small-vessel vasculitis of childhood. Limited information exists about the epidemiology, allergen and laboratory bio-markers reflecting HSP disease phases in Northwestern China.
To comprehensively evaluate the epidemiology, allergen and laboratory bio-markers reflecting HSP disease phases for the first time in this region.
We retrospectively evaluated 135 HSP patients and 86 controls aged ≤ 14 years admitted to the Children's Hospital of Gansu Province between January 2016 and December 2017. Epidemiological profiles, clinical characteristics and laboratory biomarkers of both inflammation and activated coagulation were analyzed for each HSP patients and controls. The monocyte-to-lymphocyte ratio (MLR), neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) were calculated based upon the results of routine blood tests performed during hospital stay of the patients.
In total, 77 patients had arthritis, 46 had gastrointestinal involvement and 15 had renal involvement. The most common predisposing factors were upper and lower respiratory tract infections, allergies and seasonal variation. Frequency of renal involvement was significantly higher among patients older than 7 years but lower with a positive rate of allergens. The average levels of C-reactive protein, white blood cells (WBC), neutrophils, platelets, D-dimer, fibrin degradation product (FDP), NLR and PLR among patients were significantly increased compared with the control group. Sensitivity and specificity were highest for neutrophil counts, while the area under the curve (AUC) for platelet count was highest. Patients with gastrointestinal involvement had significantly higher WBC, neutrophil count, D-dimer and FDP levels than those without. Sensitivity, specificity and AUC were highest for neutrophil counts. Increased D-dimer levels were significantly associated with gastrointestinal involvement and renal involvement.
The first report of epidemiologic characteristics of HSP in children in this area enriches the HSP epidemiological data of China. Exposure to allergens should be reduced in patients aged approximately 7 years and renal involvement should be carefully monitored in patients aged > 7 years. WBC count, neutrophil, D-dimer and FDP levels are better than conventional infection markers. Particularly, D-dimer is an independent predictor on HSP patients with gastrointestinal involvement and renal involvement.