Abstract: TH-PO958
Anti-GBM Disease: A Case Report of an Atypical Presentation
Session Information
- Glomerular Trainee Case Reports
November 07, 2019 | Location: Exhibit Hall, Walter E. Washington Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Trainee Case Report
- 1202 Glomerular Diseases: Immunology and Inflammation
Authors
- Al Shami, Feras, Brown University /Rhode Island Hospital Nephrology Fellowship Program, West Warwick, Rhode Island, United States
- Bautista, Josef, Hypertension & Nephrology Inc., Providence, Rhode Island, United States
- Birkenbach, Mark, Rhode Island Hospital, Providence, Rhode Island, United States
- Nizami, Tarek, Rhode Island Hospital, Providence, Rhode Island, United States
Introduction
Anti GMB disease is a rarely encountered, but well known entity. It can present with nephritic syndrome, alveolar hemorrhage, or both. It is typically associated with positive circulating anti GBM antibodies. We are repotting a case of seronegative anti GBM antibody disease presenting with RPGN picture.
Case Description
A 59 year old female with a history of hemochromatosis presented with complaints of night sweats and fevers. She was sent to the hospital by her PCP with abnormal labs and hypertension. Her physical exam was unremarkable. Her labs were remarkable for creatinine of 3.05 mg/dl, BUN of 32 mg/dl, eGFR of 23 ml/min/1.73 m and CRP of 113. Dipstick urinalysis was positive for blood and protein. Urine sediment exam showed dysmorphic RBCs. Measured urine microalbuminuria was 299 mg/g of creatinine. Extensive serological workup, including testing for anti GBM antibodies, was negative. Light microscopy exam of a kidney biopsy showed focal granulomatous and crescentic glomerulonephritis as well as focal interstitial granulomatous inflammation with giant cells. The immunofluorescence studies revealed findings consistent with IgG type anti-glomerular basement membrane disease. After pulse methylprednisolone was started, the creatinime started to trend down. The patient was eventually treated with prednisone tapper and rituximab with continuous improvement in her GFR.
Discussion
Anti GBM disease is frequently associated circulating IgG antibodies that commonly target cryptic, conformational epitopes within the NC1 domain of the alpha 3 chain of Type IV Collagen. These antibodies are usually detected in sera using different conventional serological methods. Seronegativity in anti GBM disease is extremely rare. We identified less than 10 cases describing this atypical presentation in the literature. In one case, anti GBM detection was variable with each relapse. Sero negative anti GMB disease has also been described to recur in renal allografts. Anti GBM antibodies are known to be heterogeneous with respect to collagen type IV domain reactivity in the sera of patients with anti-GBM antibody disease. This could explain the seronegativity of anti GBM disease when conventional serological methods are used. Cases with sero negative anti-GBM disease present challenges not only for diagnosis but also management, since anti GBM titers cannot be used to monitor these patients.