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Abstract: TH-PO845

Identification of PR3-ANCA MPA and MPO-ANCA GPA as Different Subsets of ANCA Disease

Session Information

Category: Glomerular Diseases

  • 1202 Glomerular Diseases: Immunology and Inflammation

Authors

  • Alba, Marco A., University of North Carolina at Chapel Hill, Chapel hill, North Carolina, United States
  • Hu, Yichun, UNC Kidney Center, Chapel Hill, North Carolina, United States
  • Poulton, Caroline J., UNC Kidney Center, Chapel Hill, North Carolina, United States
  • Blazek, Lauren N., UNC Kidney Center, Chapel Hill, North Carolina, United States
  • Jennette, J. Charles, University of North Carolina at Chapel Hill, Chapel hill, North Carolina, United States
  • Falk, Ronald J., UNC Kidney Center, Chapel Hill, North Carolina, United States
  • Hogan, Susan L., UNC Kidney Center, Chapel Hill, North Carolina, United States
Background

Granulomatosis with polyangiitis (GPA) and microscopic polyangiitis (MPA) are two major clinicopathologic variants of ANCA vasculitis. Typically, MPA and GPA have been associated with MPO-ANCA and PR3-ANCA, respectively. In this study, we detailed the characteristics of the less common subsets PR3-ANCA MPA and MPO-ANCA GPA.


Methods

Patients from the Glomerular Disease Collaborative Network (GDCN) inception cohort were analyzed. Clinicopathologic phenotype was established according to the Chapel Hill Consensus Conference nomenclature. Baseline manifestations, relapses, ESRD, and survival were studied. Fisher’s exact test and Wilcoxon rank sum test were used for comparisons. Proportional hazards models were used to evaluate multivariable time to relapse, ESRD, and death for specificity controlling for age, sex, lung and ear, nose, and throat (ENT) involvement, creatinine at diagnosis and induction with cyclophosphamide. Because the GDCN is primarily composed of nephrologist thus resulting in a cohort where biopsy-proven renal involvement was present in almost all patients, prevalence of kidney disease was not compared between groups.

Results

See Table 1. MPO-ANCA MPA vs PR3-ANCA MPA: MPA patients with MPO-positivity were older and had lower prevalence of ENT and musculoskeletal manifestations. MPO-ANCA GPA vs PR3-ANCA GPA: Patients with MPO-ANCA were older, more likely female, and had lower prevalence of ENT and nervous system involvement. In the proportional hazards models, ANCA serotype was not predictive of relapse, ESRD, or death neither in MPA nor in GPA (Table 1).

Conclusion

PR3-ANCA MPA and MPO-ANCA GPA represent particular subsets of ANCA disease with distinct organ involvement. The impact of these differences on the clinical management warrants further evaluation.

Funding

  • Other NIH Support