Noninvasive diagnosis of primary membranous nephropathy using phospholipase A2 receptor antibodies.

Kidney biopsy is the gold standard to diagnose membranous nephropathy (MN). Approximately 70%-80% of patients with primary MN have anti-phospholipase A2 receptor (PLA2R) antibodies. We hypothesized that PLA2R antibody testing without kidney biopsy may be a valid strategy to make a non-invasive diagnosis of MN in patients with a negative work-up for secondary causes. The medical records of all Mayo Clinic patients in Minnesota, Florida, and Arizona with serum PLA2R antibody tests between January 2015 and June 2018 were reviewed. PLA2R antibody testing was performed in 838 unique patients, with 143 testing positive. In 132 of these patients, a native kidney biopsy was performed. The primary diagnosis in all biopsies was MN. Potential secondary causes were identified in 35 cases, with the most common being malignancy and autoimmunity. Ninety-seven patients had a negative work-up for secondary causes of MN. Sixty of those 97 patients had an estimated glomerular filtration rate (eGFR) >60 ml/min/1.73m2. In these patients, the kidney biopsy did not provide significant information that altered management; one patient had a superimposed diabetic nephropathy and a second patient had a superimposed focal segmental glomerulosclerosis (FSGS) lesion. Among the 37 patients with primary MN and eGFR <60 ml/min/1.73m2, additional findings included acute interstitial nephritis, diabetic nephropathy, and cellular crescents in one case each. Thus, among patients with preserved kidney function and no evidence of secondary causes, a positive PLA2R antibody test highly predicts a tissue diagnosis of PLA2R-associated MN. Further validation in a prospective study is warranted to determine whether PLA2R antibody testing be used as a non-invasive diagnostic test to guide therapy.

Bobart SA ，De Vriese AS ，Pawar AS ，Zand L ，Sethi S ，Giesen C ，Lieske JC ，Fervenza FC ... -  《-》

Circulating antibodies to α-enolase and phospholipase A(2) receptor and composition of glomerular deposits in Japanese patients with primary or secondary membranous nephropathy.

Kimura Y ，Miura N ，Debiec H ，Morita H ，Yamada H ，Banno S ，Ronco P ，Imai H ... -  《-》

The Sensitivity and Specificity of Serum Phospholipase A2 Receptor Antibodies in Diagnosing Primary Membranous Nephropathy in Patients with Adult Nephrotic Syndrome and its Correlation with Serum Phospholipase A2 Receptor Staining in Kidney Biopsies.

Membranous nephropathy (MN) is one of the most common causes of nephrotic syndrome (NS) in nondiabetic adults, with about 70%-80% of cases of MN being primary MN (pMN). Many studies have shown that serum phospholipase A2 receptor (PLA2R) antibodies are a diagnostic and prognostic biomarker for pMN, with a pooled diagnostic sensitivity and specificity of 54%-82% and 89%-100%, respectively, resulting in PLA2R staining and serum PLA2R antibodies being incorporated in the management algorithms of MN. We studied the sensitivity and specificity of serum PLA2R antibodies for diagnosing pMN and its correlation with PLA2R staining in kidney biopsies in a prospective observational study of 58 adult NS subjects undergoing a kidney biopsy. Serum PLA2R antibodies were determined by indirect immunofluorescence (IF) before the biopsy. Kidney biopsies were sent for light microscopy and IF examinations. Biopsy samples with MN histology were stained for PLA2R antigens. Out of the 58 adult NS subjects, 28 were diagnosed with pMN and one with secondary MN. Serum PLA2R antibodies were positive in 12 subjects with pMN, and one had focal segmental glomerulosclerosis not otherwise specified, giving a sensitivity of 42.8% and specificity of 96.7% for diagnosing pMN. There was a significant association between glomerular staining for PLA2R (24 of 28 subjects) and a diagnosis of pMN by kidney biopsy, with a sensitivity of 82.8%. Cohen's kappa agreement between glomerular staining for PLA2R and a diagnosis of MN was 0.83 (0.57-1.08).

Vellakampadi D ，Bonu R ，Siddini V ，Vankalakunti M ... -  《-》

Enhanced expression of the M-type phospholipase A2 receptor in glomeruli correlates with serum receptor antibodies in primary membranous nephropathy.

Hoxha E ，Kneißler U ，Stege G ，Zahner G ，Thiele I ，Panzer U ，Harendza S ，Helmchen UM ，Stahl RA ... -  《-》

Prevalence, diagnostic value and clinical characteristics associated with the presence of circulating levels and renal deposits of antibodies against the M-type phospholipase A2 receptor in idiopathic membranous nephropathy.

Segarra-Medrano A ，Jatem-Escalante E ，Quiles-Pérez MT ，Salcedo MT ，Arbós-Via MA ，Ostos H ，Valtierra N ，Carnicer-Cáceres C ，Agraz-Pamplona I ... -  《-》