Table 1.

Threshold values of concentration

Normal (mg/L)Uremia (mg/L)Comments
IS (molecular weight 212)
 IStotal maximum236.04Highest individual value
 IStotal high0.52044.520Highest mean
 ISfree highLess than LOD4.520Highest mean
PCS (molecular weight 188)
 PCStotal maximum105.078Highest individual value
 PCStotal high2.97743.078Highest mean
 PCSfree high0.1202.620Highest mean
  • Highest individual value is the highest single value per patient ever reported; highest mean is the highest mean for a patient group ever reported. Current average values observed in an average dialysis population as reported in the most recent review of the European Uremic Toxin Group are 23.1 mg/L for IStotal and 20.9 mg/L for PCStotal.20 IS, indoxyl sulfate; LOD, limit of detection; PCS, p-cresyl sulfate.