The tool evaluates the severity of IgA vasculitis nephritis by analyzing three critical clinical indicators: glomerular filtration rate (GFR), proteinuria levels, and the proportion of crescents detected in a renal biopsy. Each parameter has distinct options to choose from, aiding in determining the severity level of nephritis.

For glomerular filtration rate:
- Select between "Normal" which is greater than 80 mL/min/1.73 m², or "Impaired" which is lower.

Proteinuria is assessed by the urine protein/creatinine ratio:
- "Mild or Moderate" covers ratios below 100 mg/mmol or between 100-250 mg/mmol.
- "Severe persistent" encompasses a ratio above 250 mg/mmol for 4 weeks, over 100 mg/mmol for 3 weeks, or more than 50 mg/mmol for 6 weeks.

The crescent component requires examining biopsy results to note if crescents appear in:
- Less than 50% of glomeruli.
- More than 50% of glomeruli.

The severity is interpreted as follows based on your selections:

- Mild IgA vasculitis nephritis is identified when the GFR is normal and proteinuria is either mild or moderate.
- Moderate IgAV nephritis is considered if either the GFR is impaired or proteinuria is severe, with less than 50% crescents present.
- The case is regarded as severe IgAV nephritis when either the GFR is impaired or proteinuria is severe persistent, alongside more than 50% crescents.

This comprehensive evaluation ensures an accurate assessment of nephritis severity, essential for guiding clinical decisions and management strategies effectively.

The severity grading for IgA vasculitis nephritis is a clinical tool designed to stratify patients with IgA vasculitis nephritis into mild, moderate, or severe categories. This stratification aids in guiding treatment decisions and providing prognostic information.

The primary components of this grading system are glomerular filtration rate (GFR), proteinuria, and the presence of crescents on renal biopsy. GFR is categorized as either normal (> 80 mL/min/1.73 m**2) or impaired (< 80 mL/min/1.73 m**2). Proteinuria is classified as mild (urine protein/creatinine ratio < 100 mg/mmol), moderate (urine protein/creatinine ratio 100-250 mg/mmol), or severe persistent (urine protein/creatinine ratio > 250 mg/mmol for 4 weeks or > 100 mg/mmol for 3 weeks or > 50 mg/mmol for 6 weeks). The presence of crescents on renal biopsy is divided into two categories: less than 50% or more than 50%.

The severity of IgA vasculitis nephritis is determined by a combination of these factors. Mild IgAV nephritis is defined by normal GFR and mild proteinuria. Moderate IgAV nephritis is characterized by either impaired GFR or severe persistent proteinuria, along with less than 50% crescents on renal biopsy. Severe IgAV nephritis is identified by either impaired GFR or severe persistent proteinuria, in conjunction with more than 50% crescents on renal biopsy.

Severity grading for IgA vasculitis nephritis