# Diagnostic Value of Serum Periostin for Cyst Involution in Children with Multicystic Dysplastic Kidney

## TL;DR

This study explores whether serum periostin levels can help diagnose cyst involution in children with a kidney condition called multicystic dysplastic kidney.

## Contribution

The study introduces serum periostin as a potential blood marker for cyst formation in children with multicystic dysplastic kidney.

## Key findings

- Children with MCDK and cysts had significantly higher serum periostin levels than those with cyst involution or healthy children.
- A cut-off value of 133.57 ng/mL for periostin was identified to distinguish patients with renal cysts.
- Periostin levels were lowest in patients with cyst involution, suggesting its potential as a diagnostic marker.

## Abstract

Background: In polycystic kidney diseases, increased periostin levels and disease progression are observed. Multicystic dysplastic kidney (MCDK) is characterized by kidney atrophy. The aim of the study is to assess serum periostin activity in children with MCDK and in patients with MCDK and involution of cysts. Methods: We enrolled in the study 64 children aged 1–5 years (mean age 25 +/− 9 months). Serum periostin (sPOSTN) levels were measured using enzyme-linked immunosorbent assay. We divided children into three groups: group A—patients with MCDK and cysts (n = 34); group B—patients with involution of cysts or after nephrectomy (n = 10), and group C—healthy children (n = 20). Results: Blood samples were obtained from 64 children, including 44 children with MCDK (26 boys, 18 girls). sPOSTN levels were significantly higher in group A, 239.1 ± 168.1 [IQR: 62.4, 385.7] ng/mL, compared to group B, 77.7 ± 82.8 [IQR: 31.7, 117.0] ng/mL (p < 0.05). The median level of periostin in patients with MCDK (groups A and B) was 204.4 ± 168.2 [IQR: 34.9, 363.4] ng/mL and 141.1 ± 129.0 [IQR: 30.3, 276.9] ng/mL in group C, respectively. In patients with the renal cysts, the cut-off value of periostin was 133.57 ng/mL. The lowest level of periostin was observed in patients in group B. There were no significant differences in periostin level between groups B and C. Conclusions: The study shows that a high level of sPOSTN was identified in patients with MCDK and cyst presentation in abdominal ultrasonography. The level of sPOSTN could be a promising blood marker of the cyst’s formation in cystic kidney diseases. However, this study remains preliminary; further studies are needed to confirm our findings.