Abstract: SA-PO288

IgA Nephropathy with Positive Anti-Neutrophil Cytoplasm Antibody – A Case Series

Session Information

Category: Glomerular

  • 1005 Clinical Glomerular Disorders

Authors

  • Kang, Amy, Imperial College Renal and Transplant Centre, London, United Kingdom
  • Cook, H. Terence, Imperial College of London, London, United Kingdom
  • Pusey, Charles D., Imperial College London, London, United Kingdom
Background

IgA nephropathy (IgAN) with positive anti-neutrophil cytoplasm antibody (ANCA) is rare and may have different clinical characteristics from isolated IgAN.

Methods

We describe seven biopsy-proven IgAN patients (3% of our cohort) with positive ANCA (age 25 -66 years, 5 male and 2 female, median Cr 57mmol/L, eGFR 51mL/min/1.73m2).Two initially ANCA negative patients developed worsening renal function and ANCA seropositivity. One recovered renal function with immunosuppression; the other was not immunosuppressed and progressed to dialysis. Five patients were ANCA positive from presentation. Two patients, with features of systemic vasculitis, received immunosuppression; one recovered renal function and the other progressed to dialysis. Two out of three patients with renal-limited disease had stable renal function on mycophenolate mofetil, and one was lost to follow-up.

On biopsy, three out of the seven patients had segmental necrosis and crescents on a background of IgAN. Of the remaining four patients, one had features of endocapillary proliferation and the other three did not. IgAN can be associated with both PR3 and MPO – ANCA, but MPO-ANCA was more frequent in our cases (5 out of 7).

Conclusion

ANCA status can change in patients with IgAN and should be considered as a cause of rapid deterioration in renal function, as shown here. The patients in this series received a variety of treatment regimens. Four out of five patients who were selected to receive immunosuppressive therapy had improved or stable renal function at the end of follow up. IgAN with positive ANCA may represent an overlap syndrome between IgAN and ANCA vasculitis, and hence be more responsive to immunosuppressive treatment. We suggest that ANCA are tested in patients with IgAN, especially if renal function deteriorates rapidly, and that immunosuppressive treatment is considered if ANCA is detected.