Intra-laboratory analytical variability of biochemical markers of fibrosis (Fibrotest) and activity (Actitest) and reference ranges in healthy blood donors.
Combinations of tests comprising alpha2-macroglobulin, haptoglobin, apolipoprotein Al, gamma-glutamyltransferase, total bilirubin (Fibrotest) and alanine aminotransferase (Actitest) are being developed as alternatives to liver biopsy in patients with chronic hepatitis C. The aim of this study was to assess in the same laboratory the impact of parameter assay variations on Fibrotest and Actitest results and intra-patient reproducibility of the two tests. The stability of the samples for each test was studied after storage at -80 degrees C and -20 degrees C. Within-run, between-run and total imprecision for each parameter assay, and for Fibrotest and Actitest results, were determined. Transferability of assay results between different analyzers was studied. Intra-patient reproducibility was assessed in 55 hospitalized patients. Fibrotest and Actitest reference ranges were determined in 300 blood donors (reference group). The stability of the parameters was affected by serum storage at -20 degrees C only. The impact of parameter analytical variability on Fibrotest and Actitest results was less than 10% and intra-patient reproducibility was acceptable (p > 0.05). The transferability between different analyzers of results of assays performed under the same standardized and calibration conditions was excellent. Fibrotest and Actitest reference ranges in blood donors were (mean+/-SE) 0.075+/-0.004 and 0.068+/-0.004, respectively. The low intra-laboratory and intra-patient variability in Fibrotest and Actitest results confirm Fibrotest and Actitest reliability.
Imbert-Bismut
Françoise
F
Service of Biochemistry, Hôpital La Pitie-Salpétrière, Paris, France. Fimbis@aol.com
Messous
Djamila
D
Thibault
Vincent
V
Thibaut
Vincent
V
Myers
Rob B
RB
Piton
Annie
A
Thabut
Dominique
D
Devers
Laure
L
Hainque
Bernard
B
Mercadier
Anne
A
Poynard
Thierry
T
D000367:Age Factors; D000410:Alanine Transaminase / Q000097:blood; D000704:Analysis of Variance; D016632:Apolipoprotein A-I / Q000097:blood / Q000737:chemistry; D001663:Bilirubin / Q000097:blood / Q000737:chemistry; D015415:Biomarkers / Q000097:blood; D001782:Blood Donors; D015992:Body Mass Index; D019963:Clinical Chemistry Tests / Q000295:instrumentation / Q000592:standards / Q000706:statistics & numerical data*; D016001:Confidence Intervals; D003955:Diagnostic Tests, Routine / Q000295:instrumentation / Q000592:standards / Q000706:statistics & numerical data; D004795:Enzyme Stability; D005355:Fibrosis; D005615:Freezing; D006242:Haptoglobins / Q000032:analysis / Q000737:chemistry; D019698:Hepatitis C, Chronic / Q000097:blood*; D006801:Humans; D012016:Reference Values; D015203:Reproducibility of Results; D012737:Sex Factors; D013696:Temperature; D000511:alpha-Macroglobulins / Q000032:analysis / Q000737:chemistry; D005723:gamma-Glutamyltransferase / Q000097:blood / Q000737:chemistry
D016632:Apolipoprotein A-I; D015415:Biomarkers; D006242:Haptoglobins; D000511:alpha-Macroglobulins; D005723:gamma-Glutamyltransferase; D000410:Alanine Transaminase; D001663:Bilirubin