Potential role of Human Epididymis Protein 4 (HE4) as biomarker for IgA Nephropathy|Potenziale ruolo dell'Human Epididymis Protein 4 come biomarcatore nella nefropatia mesangiale a depositi di IgA

Human Epididymis Secretory Protein 4 (HE4) serum concentrations have been widely investigated in patients with ovarian cancer. However, high levels of HE4 can be also found in other tumors and in renal fibrosis. The aim of this study was to assess serum HE4 levels in a cohort of patients with IgA Nephropathy (IgAN) and the correlation of this potential biomarker with the degree of fibrosis.Methods: the study included 63 Italian patients with histological diagnosis of IgAN (41 males and 22 females) where HE4 was measured at the time of renal biopsy using a chemiluminescent assay (Abbott Laboratories, Wiesbaden, Germany). The biopsy was scored according to the current Oxford classification using MEST score. The relationship between HE4 and each of the MEST parameters was analyzed by a non-parametric method. A ROC curve analysis was performed to assess the diagnostic accuracy of HE4 in identifying the presence of fibrosis.Results: serum HE4 concentrations were significantly increased across the progressive degrees of fibrosis related T parameter (p <0.0001) [(median; interquartile range (IQR): T0 = 57.5 pmo/L (43.7-100.7); T1 = 106.0 pmo/L (78.0-149.0); T2 = 210.5 pmo/L (148.2-320.2)]. The ROC curve analysis, after adjusting for age and sex, showed that HE4 is diagnostic for the presence of fibrosis with an Area Under the Curve of 0.79 (95%CI: 0.68-0.91).Conclusions: the relationship between serum level of HE4 and the degree of interstitial fibrosis suggests the potential role of HE4 as useful biomarker in IgAN