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

Meltem Erol; Ozgul Yigit; Mehmet Tasdemir; Ozlem Bostan Gayret; Ovgu Buke; Aysegul Gunes; Sahin Hamilcikan; Ozgur Kasapcopur

doi:10.5812/ijp.6129

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

Iran J Pediatr. 2016 Jun 5;26(4):e6129. doi: 10.5812/ijp.6129. eCollection 2016 Aug.

Authors

Meltem Erol¹, Ozgul Yigit¹, Mehmet Tasdemir², Ozlem Bostan Gayret¹, Ovgu Buke¹, Aysegul Gunes³, Sahin Hamilcikan¹, Ozgur Kasapcopur⁴

Affiliations

¹ Department of Pediatrics, Bagcilar Training and Research Hospital, Istanbul, Turkey.
² Department of Pediatric Nephology, Koc University Hospital, Istanbul, Turkey.
³ Department of Biochemistry, Bagcilar Training and Research Hospital, Istanbul, Turkey.
⁴ Department of Pediatric Rheumatology, Cerrahpasa Medical Faculty, Istanbul University, Istanbul, Turkey.

Abstract

Background: 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).

Objectives: The aim of this study was to evaluate whether serum and urinary MMP-9 levels are associated with renal involvement in HSP.

Patients and methods: 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.

Results: 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 < 0.05), with the urinary MMP-9 levels being significantly higher in patients in the HSP subgroup (P = 0.001). Further, the urinary MMP-9 levels were significantly higher in the patients with nephritis than in the patients without nephritis (P = 0.001) and the controls (P = 0.001). The optimal cut-off point (sensitivity; specificity) of the urinary MMP-9 level for the diagnosis of HSPN was 94.7 pg/mL.

Conclusions: 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.

Keywords: Henoch-Schönlein Purpura; Henoch-Schönlein Purpura Nephritis; Matrix Metalloproteinase-9.