Abstract: SA-PO279
Natural History of IgA Nephropathy and Henoch-Schönlein Purpura Nephritis
Session Information
- Clinical Glomerular Disorders: Vasculitis, C3G, IgAN
November 04, 2017 | Location: Hall H, Morial Convention Center
Abstract Time: 10:00 AM - 10:00 AM
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
| Item | HSPN | IgAN | P |
| Median | |||
| Age at diagnosis (years) | 8.4 | 12.4 | 0.09 |
| eGFR at diagnosis (mL/min) | 106 | 82 | 0.01 |
| eGFR at 1 year (mL/min) | 95 | 101 | 0.61 |
| UPC at diagnosis | 1.8 | 1.1 | 0.58 |
| UPC at 1 year | 0.2 | 0.2 | 0.75 |
| Proportion (%) | |||
| Male | 68.1 | 89.4 | 0.14 |
| Hypertension at diagnosis | 45.5 | 26.3 | 0.33 |
| Hypertension at 1 year | 9.1 | 10.5 | 1.00 |
| Hematuria at diagnosis | 86.4 | 94.7 | 0.61 |
| Hematuria at 1 year | 36.4 | 36.8 | 1.00 |
| Biopsy results (%) | |||
| Mesangial proliferation | 81.0 | 94.7 | 0.35 |
| Endocapillary proliferation | 36.3 | 5.3 | 0.02 |
| Segmental sclerosis | 52.4 | 68.4 | 0.35 |
| Interstitial fibrosis/tubular atrophy | 33.3 | 26.3 | 0.74 |
| Glomerular crescents | 45.5 | 15.8 | 0.05 |