Clinical features and expression of PLA(2)R in renal tissue with idiopathic membranous nephropathy in children

Objective To explore the clinical features and expression of PLA2R in renal tissue of children with idiopathic membranous nephropathy. Methods Retrospective study was performed in patients with membranous nephropathy diagnosed through renal biopsy and the follow-up time was at least half a year in Shanghai Children's Hospital from January 2010 to February 2017. We compared their clinicopathological and pathological findings of IMN. Indirect immunofluorescence assay was used to detect glomerular PLA2R expression. We analyzed the differences of clinical features between the PLA2R negative and positive groups. T test, rank-sum test and Fisher exact test were used. Results Eleven cases had hematuria and proteinuria, 9 cases presented with nephrotic syndrome, and 2 cases showed isolated proteinuria. Of the 22 cases of children with IMN, 16 patients had complete remission (complete remission rate was 72.8%), and 22 patients had partial remission. The renal function of all cases was normal and in all cases the estimated glomerular filtration rate was > 90 ml/(min·1.73m2). Of 22 cases with IMN, 7 cases were PLA2R-positive in renal tissue and 15 cases were PLA2R-negative. The age of positive group (10 years old) was older than the negative group (6 years old)(Z=-2.483, P<0.05) and the time of positive group (6 months) for urine protein to return to negative was longer than the negative group (2.5 months) through treatment. These differences were significantly different (Z=-2.072, P<0.05). Conclusions Hematuria and proteinuria can be found in most children with idiopathic primary membranous nephropathy. Prednisone combined with immunosuppressant was effective. The positive rate of PLA2R in renal tissue of children with IMN was about 32%. The age of PLA2R positive group was older than the negative group. And the time of urine protein turning to negative in positive group was longer than that in the negative group. Key words: Idiopathic membranous nephropathy; Remission; Immunosuppressive agents; M Type phospholipase A2 receptor; Child