Intra-individual variation of analytes in serum from patients with chronic liver diseases.

The average biological intra-individual CV in 20 patients with chronic liver diseases (CLD), estimated for 14 analytes during a stationary phase, significantly exceeded that for a normal group in the cases of Na+, K+, Cl-, total protein, albumin, cholinesterase, hemoglobin, and alpha-amylase; it did not differ significantly from the normal group for cholesterol, alkaline phosphatase, aspartate aminotransferase, and alanine aminopeptidase; and it was significantly lower than in the normal group for alanine aminotransferase and gamma-glutamyltransferase. There were no significant sex-related differences in mean intra-individual variation in CLD patients. Individual values were gaussian-distributed for all analytes, including enzymes. The estimated biological component of intra-individual variation and the analytical variation as determined for each laboratory can be used to derive decision-making criteria in monitoring CLD.