Elevated human epididymis protein 4 concentrations in chronic kidney disease

Background: Human epididymis protein 4 (HE4) has recently become an available tumour biomarker for detecting ovarian cancer along with the standard cancer antigen 125 (CA125). However, it is unknown if the levels of HE4 and CA125 may be altered in subjects who have impaired renal function with no ovarian disorders. Methods: In 113 female patients at different stages of chronic kidney disease (CKD) with no ovarian and lung cancer and 68 subjects with normal renal and ovarian function, HE4 and CA125 concentrations were analysed by using chemiluminescent microparticle immunoassay (Architect (R), Abbott) and electrochemiluminescent immunoassay (Modular E170 (R), Roche), respectively. Renal function was evaluated by measuring serum creatinine and urea concentrations (Cobas Integra-800 (R), Roche). Estimated glomerular filtration rate (eGFR in mL/min/1.73 m(2)) was calculated by the 4v-MDRD formula. Results: Significantly increased HE4 concentrations (P < 0.0001) were found in individuals with differently decreased eGFR values (<90 mL/min/1.73 m(2)) compared with clinical controls. CA125 serum concentration was higher than normal in subjects with CKD3 (eGFR = 30-59 mL/min/1.73 m(2)), but significant elevation (P = 0.006) in CA125 concentrations was seen only in those who had severe renal failure (CKD4-5; eGFR <30 mL/min/1.73 m(2)). These tendencies were independent of age in our study cohort, and seemed to be more evident among women in premenopausal status. Conclusions: HE4 concentrations may be elevated in CKD patients with no ovarian and lung cancer. Thus, HE4 results should be interpreted cautiously in women with renal disorders.