Abstract: TH-PO180

Dual-Positive Anti-Myeloperoxidase and Anti-Glomerular Basement Membrane Antibody Vasculitis

Session Information

Category: Nephrology Education

  • 1302 Fellows and Residents Case Reports

Authors

  • Afzal, Muhammad, OU Tulsa, Tulsa, Oklahoma, United States
  • Baradhi, Krishna M., OU Tulsa, Tulsa, Oklahoma, United States
Background

Vasculitis secondary to the combination of anti-glomerular basement membrane (GBM) antibody and antineutrophil cytoplasmic antibodies (ANCA) is not common occuring up to 14% in patients with primary ANCA vasculitis and in up to 38% of patients with primary anti-GBM disease and moreover ANCA is usually directed against myeloperoxidase (MPO). Histologically, both are characterised by crescentic necrotizing glomerulonephritis. Immunofluorescence in anti-GBM disease reveals linear IgG staining, while ANCA vasculitis is pauci-immune.

Methods

69 yr-old-male presented with abdominal pain & diarrhea and found to have acute oliguric renal failure. Labs showed BUN of 80 mg/dl and creatinine 8.34 mg/dl with associated hematuria and proteinuria. Serology revealed elevated MPO-ANCA (116.9 AU/ml) as well as anti-GBM antibodies (101 U). Renal biopsy showed diffuse necrotizing and crescentic glomerulonephritis with 1+ linear Ig G staining. Patient was started on plasmapheresis concurrently with hemodialysis and immunosuppressive therapy (cyclophosphamide and pulse steroids). Plasmapheresis was continued until Anti-GBM titers were < 20 U. Unfortunately his renal function did not recover and was discharged on tapering steroids, while continuing hemodialysis.

Conclusion

This is a unique case of rapidly progressive nephritis due to dual MPO-ANCA antibodies and anti-GBM antibodies (DAV). Clinical presentation of DAV may vary from isolated ANCA related vasculitis and mortality usually tends to be higher. Renal survival in dual-positive patients is not better than that in anti-GBM-positive patients and is inferior compared to patients with MPO-ANCA only. Relapse with Dual-antibody vasculitis is higher than in anti-GBM disease,hence clinical vigilance is necessary to detect relapse . Treatment of DAV is similar to anti-GBM disease with plasmapheresis, cyclophosphamide, and steroids. Patients with either ANCA-related disease or anti-GBM disease, whether diagnosed serologically or histologically, should be tested for the second antibody. This dual serological approach provides better prognostication and dictates appropriate management, as goal is to limit further immunosupression in dialysis dependent patients.