Abstract: SA-PO279

Natural History of IgA Nephropathy and Henoch-Schönlein Purpura Nephritis

Session Information

Category: Glomerular

  • 1005 Clinical Glomerular Disorders

Authors

  • Spector, Benjamin L., University of Iowa, Iowa City, Iowa, United States
  • Misurac, Jason, University of Iowa, Iowa City, Iowa, United States
Background

Though histopathologically identical, Henoch-Schönlein purpura nephritis (HSPN) and IgA nephropathy (IgAN) are thought to follow markedly different courses. Despite their relatively high prevalence, limited data exist describing their natural histories.

Methods

This retrospective analysis examines all biopsy-confirmed cases of HSPN (n=22) and IgAN (n=19) at our institution from January 1989 to May 2016 through 1-year of follow-up. Inclusion criteria were diagnosis before age 18 years, minimum 1-year of follow-up, and absence of pre-existing renal disease. We compared demographics, clinical biomarkers, and treatments.

Results

Both cohorts show male predominance. In HSPN, age at diagnosis was younger and renal biopsies showed higher rates of glomerular crescents and endocapillary proliferation. The IgAN cohort presented more often with gross hematuria (31.8% vs 63.2%, p= 0.06), hypertension (HTN), and lower estimated glomerular filtration rate (eGFR). Urine protein/creatinine ratio (UPC) and overall hematuria rates were equivalent between groups. At 1-year follow-up, there were no differences in clinical features or immunosuppressant use.

Conclusion

In HSPN, patients had younger presentation and higher prevalence of crescents and endocapillary proliferation on biopsy. IgAN was more likely to present with HTN, gross hematuria, and lower eGFR. There were no significant differences in clinical biomarkers at 1-year follow-up.

Demographics and clinical features
ItemHSPNIgANP
Median   
Age at diagnosis (years)8.412.40.09
eGFR at diagnosis (mL/min)106820.01
eGFR at 1 year (mL/min)951010.61
UPC at diagnosis1.81.10.58
UPC at 1 year0.20.20.75
Proportion (%)   
Male68.189.40.14
Hypertension at diagnosis45.526.30.33
Hypertension at 1 year9.110.51.00
Hematuria at diagnosis86.494.70.61
Hematuria at 1 year36.436.81.00
Biopsy results (%)   
Mesangial proliferation81.094.70.35
Endocapillary proliferation36.35.30.02
Segmental sclerosis52.468.40.35
Interstitial fibrosis/tubular atrophy33.326.30.74
Glomerular crescents45.515.80.05