Table 1.

Clinical features of patients with IgA nephropathy obtained by questionnaire surveys in Europe and Japan

FeatureEuropeJapan
Numbers437470
Age, yrs43.540.1
Sex, male/female, %67/3341/59
Ethnicity93% White, others from Asian, American and AfricanAll Japanese
History and persistent macrohematuria, %2329
Time between first detection of hematuria and renal biopsy (<1 year), %5434
History of single detection of proteinuria (>1 g/day), %2211
History of proteinuria (>300 mg/day) in twice detections greater than 3 months apart before renal biopsy, %4072
Nephrotic syndrome before renal biopsy, %214
Time between first detection of proteinuria and renal biopsy (<1 year), %7240
Detection of increase of serum creatinine before renal biopsy, %2113
eGFR at the time of renal biopsy (> 60 ml/min per 1.73m2), %5571
Significant (>20%) decrease in GFR at time of biopsy over the previous months, %208
Elevated serum IgA at the renal biopsy, %1134
Family history of kidney disease / family history of IgAn, %7 / (IgAn: 2)16 / (IgAn: 2)
Renal abnormalities were discovered as part of a systematic screening program, %1074
  • IgAn, IgA nephropathy.