Hitachi Hemolytic Index correlates with HBOC-201 concentrations: Impact on suppression of analyte results

ObjectivesTo determine the feasibility of laboratories to use an instrument's Hemolytic Index (HI) to determine if a test result would be accurate in the presence of hemoglobin-based oxygen carrier HBOC-201.Design and methodsHI values from the Roche Hitachi Modular P800 for samples containing HBOC-201 were determined. HI limits for 24 tests determined by addition of RBC lysate hemoglobin to serum and the instrument manufacturer's HI limits were compared to HI limits for reporting the same tests determined by adding HBOC-201 to plasma.ResultsThere is a linear relationship (R2 = 0.99) between the HI value on the Modular P800 and HBOC-201 concentrations. Twenty-one of 24 HI limits for reporting results as determined by the manufacturer or adding RBC lysate to serum were more conservative or equal to the limit determined by HBOC-201 interference testing. HBOC-201 interference testing was more conservative for albumin, creatinine, and uric acid.ConclusionFor most analytes, the Modular P800 HI provides an accurate, conservative and automated method to determine whether laboratory results should be reported or suppressed when samples contain HBOC-201.