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Abstract: TH-PO686

Pulmonary Renal Syndrome Caused by Seronegative Anti-Glomerular Basement Membrane (GBM) Disease

Session Information

Category: Glomerular Diseases

  • 1402 Glomerular Diseases: Clinical, Outcomes, and Trials

Authors

  • Abidian, Mohamed Modar, Emory University, Atlanta, Georgia, United States
  • Bavi, Santhoshi Rupa, Ascension Saint Joseph - Chicago, Chicago, Illinois, United States
  • Chachar, Atiya, Tanner Health System, Villa Rica, Georgia, United States
  • Bilal, Anum, Emory University, Atlanta, Georgia, United States
Introduction

Anti-GBM disease is a common cause of crescentic RPGN with or without pulmonary hemorrhage. We present an unusual case of pulmonary renal syndrome caused by biopsy proven anti-GBM disease without serum anti-GBM antibodies (Ab).

Case Description

A 50 YO F with history of asthma and suspected PE on apixaban presented with dyspnea and found to have hypoxia with bilateral lung opacities and AKI (SCr 1.7, baseline 0.6) Urinalysis showed hematuria and nephrotic-range proteinuria of 3.8 gm/gm. Initial serologic workup for infectious and autoimmune etiologies was negative, particularly ANCA <1:20 and anti-GBM Ab 0.5 units (normal range: 0.0-0.9). A renal biopsy showed diffuse necrotizing crescentic GN involving 50% of glomeruli with linear IgG deposits along the GBM. Prompt treatment with high dose steroids, cyclophosphamide and plasmapheresis was initiated along with supportive care. Clinical course was complicated by severe hemoptysis leading to hypoxia and cardiac arrest that necessitated VV ECMO support and CRRT after ROSC. Bronchoscopy showed blood in the airway but no active hemorrhage and repeated anti-GBM Ab remained within reference range. Given severe hypoxemia,13 additional TPE sessions were done along with CYC and steroids. Later on, pulmonary function improved significantly allowing for ECMO decannulation. However, RRT-requiring AKI persisted without renal recovery.

Discussion

We present a rare case of pulmonary renal syndrome caused by seronegative anti-GBM disease occur in only 2-3% of cases. The diagnosis relies on the detection of anti-GBM Ab along with biopsy-proven crescentic necrotizing GN and/or alveolitis but serum Ab can be negative in rare cases due to low test sensitivity, antibodies to atypical GBM epitopes, or non-IgG anti-GBM Ab. The absence of alveolar hemorrhage on initial presentation with negative serology makes the diagnosis challenging, thus kidney biopsy becomes critical for early diagnosis and salvage treatment. Given the rarity of seronegative anti-GBM disease, there is no data on management and prognosis and the renal outcome of this case is undetermined.

Biopsy