Clinicopathological Analysis Of248Cases Of Idiopathic Membranous Nephropathy And Detection Of Serum Anti-PLA₂R Antibody In A Single Center

Object:1. To analyze the clinical manifestations, pathological findings andauxiliary examination of248adult patients diagnosed with Idiopathic membranousnephropathy (IMN) from the single center in North of China, and to summarize thegeneral onset features, clinicopathologic characteristics and clinicopathologicrelationship of these patients.2. To discuss the role of serum anti-M-phospholipaseA2receptor (anti-PLA2R) antibody in the diagnosis and evaluate prognosis for IMNcombining our data with several published articles.Methods:248IMN cases were involved proven by renal biopsy from January2010to Dec2014in the Second Hospital of Jilin University. Clinical and pathologicaldata were collected from all the enrolled patients, including gender, age, livingareas,serum urea nitrogen, serum creatinine, serum albumin, blood lipids, bloodpressure, and24-hour urinary protein etc. The data were analyzed by SPSS statisticalmethod. In addition, morning fasting serum samples were collected from20caseswith nephrotic syndrom selected from June2014to Dec2014. Anti-PLA2R antibodyin serum was tested by Western blotting. The positive rate of PLA2R-Ab and itscorrelation with proteinuria, disease activity and prognosis were analyzed.Results:1. Among248cases of IMN, there were177males and71females(male to female ratio was2.5:1). The age of onset ranged from17to85years old,mean age was52.18±12.68years old. The main patients with IMN were elderlies.Urban and rural patients ratio was0.7:1, the majority of rural patients. The proteinuriaranged from0.17g/24h~14.34g/24h,75％patients had proteinuria＞3.5g/24h. Thelevels of serum albumin were fluctuating between9.1g/L and49.6g/L, which lessthan30g/L in177cases (71.4%). All patients had different degree of proteinuria,177cases had nephrotic syndrome (71.4%),101had hematuria (40.7%) demonstrating microscopic hematuria,110had hypertension(44.4%) and renal insufficiency in23cases(9.3%). Compared with the female patients, male patients had more severeclinical manifestations, such as nephrotic syndrome and renal insufficiency was morecommon(the differences was statically significant), female with hematuria wassignificantly more (the differences was statically significant), there was no statisticalsignificance among age, anemia, blood lipid and hypertension. Eelderly patientscompared with the young group, the former had longer pre-biopsy course and moresevere anemia, renal insufficiency, hypertension, etc. With the increase ofproteinuria,clinical manifestations was more severe. Pathological stage II was thedominant pathologic pattern(59.7%), stage I and II of IMN accounted for95.6%.Stage III or above in patients pre-biopsy course was lengthened apparently,BUN,serum creatinine, anemia, renal dysfunction increased obviously (the differenceswas statically significant), but the ratio of nephrotic syndrome reduced. In this study,membranous nephropathy associated with other pathological findings were not rare.In32cases,17cases of membranous nephropathy with renal arteriolar sclerosis,4cases combined with diabetic nephropathy,6cases with subacuterenaltubulointerstitial injury,4cases combined with IgA nephropathy and1caseconcomitant with obesity related glomerulopathy.2. In20cases of IMN, who clinical manifestations as nephrotic syndrome,positive rate of PLA2R-Ab antibody was80%(16cases).The serum PLA2R-Ab levelsin IMN patients was positively correlated with24-hour urinary protein, wasnegatively correlated with serum albumin.The positive rate of IgG4staining was90%(18cases).Conclusion:1. Generally speaking, through the single center research of northern China, theproportion of IMN patients in all of the renal biopsy showed an increasing tendencyduring the past five years.2. Nephrotic syndrome is the most common clinical manifestations of IMN,Hematuria in IMN is not unusual, more performance for microscopic hematuria.When the patients of male gender, old age or grave proteinuria, the clinical manifestations are more severe, pathological stage is higher and relatively poorprognosis, so renal biopsy should be actively recommended to these patients.3. In idiopathic membranous nephropathy, stage II was the most common type.The clinical manifestation and pathological findings were not completelycorresponding.4. In this study, positive rate of serum anti-PLA2R antibody was80%. The serumlevels of PLA2R-Ab in IMN patients was positively correlated with24-hour urinaryprotein, was negatively correlated with serum albumin.5. In IMN,the deposition of glomerular immune complex was mainly IgG4.