title: Lupus-like membranous nephropathy: Is it lupus or not?
abstract: BACKGROUND
  Membranous glomerulonephritis is typically classified as idiopathic or secondary to systemic lupus erythematosus (SLE), hepatitis B, drugs, toxins, other infections, or malignancy. Not infrequently in some patients without a definite diagnosis of SLE, pathologic features of secondary membranous nephropathy are seen e.g., mesangial and/or subendothelial deposits, tubuloreticular inclusions, and full house immunofluorescence. In these patients, there is uncertainty about the etiology, response to therapy, and prognosis of membranous GN.
  
  
  METHODS
  We retrospectively reviewed the charts of 98 patients with membranous GN at San Francisco General Hospital and John Stroger Hospital of Cook County over a 10-year period. Data were collected and analyzed using SPSS.18.
  
  
  RESULTS
  Thirty-nine (40 %) had idiopathic membranous GN (Group 1), thirty-six (37 %) had lupus membranous GN (Group 2) and twenty-three (23 %) had some pathological features of secondary membranous GN, but no definite etiology of membranous GN (Group 3). At baseline (at time of renal biopsy) and after mean follow-up of 3.5 years, the average serum creatinine (in mg/dL) in Group 1 was (1.6 ± 1.0 versus 1.6 ± 1.7), Group 2 was (1.8 ± 2.5 versus 1.2 ± 0.9) and Group 3 was (1.1 ± 0.4 versus 1.27 ± 0.83), respectively. For the same time points, the average urine protein to creatinine ratio (g/g) in Group 1 was (9.8 ± 7.1 versus 5.7 ± 6.7), Group 2 was (4.2 ± 3.9 versus 1.7 ± 2.2), and Group 3 was (7.4 ± 5.7 versus 3.1 ± 3.8). In addition, during the follow-up period, eleven of 39 (28 %) in Group 1, two of 36 (6 %) in Group 2, and three of 23 (13 %) in Group 3 progressed to end-stage renal disease and were started on dialysis.
  
  
  CONCLUSIONS
  It appears that patients with lupus membranous GN have better renal prognosis than patients with idiopathic membranous GN. The renal prognosis for patients with pathological features of lupus membranous but no diagnosis of systemic lupus (lupus-like membranous GN) falls in between. Further studies are needed to determine if Group 3 patients can (a) definitively be classified as true idiopathic membranous GN or lupus membranous GN or (b) they have a separate disease from either M-type phospholipase A2 receptor membranous nephropathy or systemic lupus-induced membranous nephropathy.
authors.affiliation: Division of Nephrology, San Francisco General Hospital and the University of California, 1001 Potrero Ave, Building 100, Rm 342, San Francisco, CA, 94110-1341, USA. Samr@medsfgh.ucsf.edu.
authors.forename: Ramin
authors.initials: R
authors.lastname: Sam
authors.affiliation: Division of Nephrology, Stroger Hospital of Cook County, Chicago, IL, USA.
authors.forename: Amit
authors.initials: A
authors.lastname: Joshi
authors.affiliation: Division of Nephrology, San Francisco General Hospital and the University of California, 1001 Potrero Ave, Building 100, Rm 342, San Francisco, CA, 94110-1341, USA.
authors.forename: Sam
authors.initials: S
authors.lastname: James
authors.affiliation: Department of Pathology, University of California, San Francisco, CA, USA.
authors.forename: Kuang-Yu
authors.initials: KY
authors.lastname: Jen
authors.affiliation: Department of Biostatistics, Ardabil University of Medical Sciences, Ardabil, Iran.
authors.forename: Firouz
authors.initials: F
authors.lastname: Amani
authors.affiliation: Division of Nephrology, Stroger Hospital of Cook County, Chicago, IL, USA.
authors.forename: Peter
authors.initials: P
authors.lastname: Hart
authors.affiliation: Department of Pathology, Rush Medical College, Chicago, IL, USA.
authors.forename: Melvin M
authors.initials: MM
authors.lastname: Schwartz
mesh_terms: D000328:Adult; D000367:Age Factors; D000974:Antibodies, Antinuclear / Q000097:blood; D002784:Cholesterol / Q000097:blood; D003404:Creatinine / Q000097:blood / Q000652:urine; D018450:Disease Progression; D005260:Female; D015433:Glomerulonephritis, Membranous / Q000209:etiology* / Q000378:metabolism / Q000473:pathology*; D006801:Humans; D007676:Kidney Failure, Chronic / Q000209:etiology / Q000628:therapy; D008181:Lupus Nephritis / Q000150:complications / Q000378:metabolism / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D011507:Proteinuria / Q000209:etiology; D012189:Retrospective Studies; D012709:Serum Albumin / Q000378:metabolism; D012737:Sex Factors
chemical_list: D000974:Antibodies, Antinuclear; D012709:Serum Albumin; D002784:Cholesterol; D003404:Creatinine
keywords: Idiopathic membranous; Membranous GN; Pathological features of lupus membranous; Systemic lupus