Ektachem bilirubin fraction Bc as a predictor of liver transplant rejection

Bilirubin fractions Be and DELTA, not routinely available prior to the EKTACHEM Chemistry Analyzer and its slide methodology, were studied in an outpatient population of liver transplant recipients. A preliminary evaluation by the authors has shown that direct bilirubin (DBILI) levels in the normal range consist almost exclusively of DELTA (protein-bound conjugated bilirubin), while at elevated DBILI levels, an increasing amount of Be (non-protein-bound conjugated bilirubin) is measured as well. The present study evaluated the clinical significance of Be in the serum of 80 liver transplant recipients as a means of identifying episodes of rejection. Each patient was classified into rejection or nonrejection categories based on clinical status, liver biopsy results, and/or response to therapy. Eighteen patients were classified as experiencing an episode of rejection during the period of this study. Fourteen of these (77.8%) had Be levels that ranged from 0.1 to 6.8 mg/ dl. Sixty two patients were classified in the nonrejection category. Fourteen (22.6%) of these patients had Be levels that ranged from 0.1 to 0.6 mg/dl. In our outpatient liver transplant recipients with Be ≥0.1 mg/dl, the relative risk of rejection (% of rejection patients with Bc/% of nonrejection patients with Be) was 3.44. This value indicates that Be determination may be a helpful adjunct in the assessment of rejection.