Idiopathic Membranous Nephropathy: Clinical And Pathological Manifestation, Diagnosis And Treatment

Objective: To introduce idiopathic membranous nephropathy (IMN) by three aspects:clinical and pathological manifestations, diagnosis and treatment, for a bettercomprehension and therapy for this disease.Methods:1) We collect475biopsy-proven IMN patients during Jan2009to Oct2013andanalyze their clinical and pathological data. We also collect their profession to investigatethe job characters.2) We conduct a study of212biopsy-proven IMN patients and28patients of membranous lupus nephritis (MLN) from Mar2010to Sep2012. We examineand compare their glomerular IgG subclasses staining.3) We analyze retrospectively68biopsy-proven IMN patients diagnosed between Apr2008and Feb2013, treated bydifferent immunosuppression regimes (corticosteroid plus CsA or CTX), with a follow-upof at least12months. We compare the efficacy and side effects during the treatment.Results:1) IMN incidence is rising during the past5years. IMN patients have a sex ratio(M/F) of1.11:1, and an average age of53.0±14.9years old. With the age gose up, IMNpatients have a higher cardiovascular risk such as decrease of hemoglobin, elevation offasting glucose, systolic and diastolic blood pressure (P<0.01). The majorimmunofluorescence staining is IgG (97.2%) and C3(73.6%). Stage I (25.3%) and II (58.3%)are most common, stage III (15.6%) and atege IV (0.8%) are not predominant.2) There isno difference of the IgG subclasses deposition percentage between the different stage ofIMN, all of them are IgG4predominant (stage I100%, stage II93.8%, stage III85.7%). Theaverage intensities of deposit florescence of IgG3(P=0.013) and IgG4(P=0.02) innon-NS group are higher than those in NS group. The glomerular stainings in MLN arenon-IgG4predominant. Their average intensities of deposit florescence of all IgGsubclasses are significantly different from those of IMN patients (P <0.001).3) Bothregimes can reduce urinary protein and raise albumin in IMN patients. CsA group has arelatively higher remission rate at3months but there is no difference in remission rate at 12months (85.2%vs75.0%，P=0212). CsA group has a decline in eGFR at12months(104.1±31.7vs82.9±26.8ml/min/1.73m2，P<0.001).5patients turned out to haveglucose intolerance or diabetes during follow-up in CsA group;1patient got glucoseintolerance in CTX group, and two patients got severe pulmonary infection, one of themgot acute pyelonephritis as well.Conclusion: IMN is a common glomerulonephritis which occurs mainly in elderlypeople with a predominant of male. It has a high incidence in some kind of profession.IMN patients with different ages have their own clinical characters; IgG4is the main IgGsubclass staining in glomerular in IMN patients while for MLN is non-IgG4. Theexamination of glomerular IgG subclasses helps to differ IMN from MLN pathologically,which could be extended as a method to the clinical application; two regimes(corticosteroids plus CsA or CTX) can both relieve NS in IMN patients. CsA may causedecline in renal function while CTX may cause more infection events, and these sideeffects should be noticed by clinician.