Neural Epidermal Growth Factor–Like 1 Protein is a novel target antigen in membranous lupus nephritis of Chinese patients

Abstract Neural Epidermal Growth Factor–Like 1（NELL-1）Protein may be the second most common target antigen of membranous nephropathy after PLA2R and more likely expressed in patients with secondary membranous nephropathy（sMN) . However, there are no relevant studies on the clinical characteristics of NELL-1 positive sMN in Chinese individuals,which is the focus of this study.A total of 100 patients with sMN were enrolled in our study.Immunofluorescence staining for PLA2R, THSD7A and NELL-1 were performed in their renal tissue samples. There are 13 cases of PLA2R-MN, 5 cases of NELL-1 association MN, and 82 cases of triple antigen-negative MN.The median age of NELL-1 associated sMN was 41 years, 80% are women,median urine protein 5.73 g/24 h ,median eGFR 42 mL/min/1.73 m2.It is noteworthy that all NELL-1 positive sMN patients in our cohort had a history of systemic lupus erythematosus(SLE), which accounted for 8.9% of SLE patient.there are four of five NELL-1 associated sMN patients pathologically manifested as IV/V lupus nephritis,and two patients entered ESRD within 1 year. So we supposed that NELL-1 related MN may be a special subgroup of membranous lupus nephritis(LMN) which may have a poor renal prognosis.