Potential of Serum and Urinary Matrix Metalloproteinase-9 Levels for the Early Detection of Renal Involvement in Children With Henoch-Schönlein Purpura

Matrix metalloproteinase-9 (MMP-9) is an enzyme implicated in the pathogenesis of renal diseases. Renal involvement is the principal cause of morbidity and mortality in children with Henoch-Schönlein purpura (HSP).
The aim of this study was to evaluate whether serum and urinary MMP-9 levels are associated with renal involvement in HSP
Patients and We evaluated 40 children with HSP (patient group) and 27 healthy volunteer children (control group). The patient group was divided into two subgroups based on the presence or absence of nephritis. Nephritis was defined as the existence of hematuria and/or proteinuria. All anthropometric data, physical examination findings, blood pressure, and laboratory parameters were recorded. The serum and urine samples were analyzed to determine the MMP-9 levels three days after the initial phase of the disease.
The mean age was 7.65 ± 3.41 (range 2 - 16) years in the patient group and 9.52 ± 3.91 (range 2 - 16) years in the control group. Henoch-Schonlein purpura nephritis (HSPN) was identified in eight patients. There was no significant difference in the serum MMP-9 levels between the HSPN subgroup and the controls (P > 0.05). However, there were significant differences in the urinary MMP-9 levels between the HSP subgroup and the control group (P The levels of MMP-9 in the urine were remarkably high in patients with HSPN. This non-invasive marker may therefore be an important indicator for the early diagnosis of nephritis in children with HSP.