Pteridines (May 1998)

Neopterin, Serum Amyloid A, and Cytokine Monitoring After Renal Transplantation

  • Neumann M. Christine,
  • Sprenger Hans,
  • Grebe Scott O.,
  • Gemsa Dietmar,
  • Reibnegger Gilbert,
  • Lange Harald,
  • Müller Thomas F.

DOI
https://doi.org/10.1515/pteridines.1998.9.2.113
Journal volume & issue
Vol. 9, no. 2
pp. 113 – 121

Abstract

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A reliable and early diagnosis of viral infections and rejection episodes is a major goal of immunologic monitoring in transplantation. Soluble markers like the cytokines, neopterin or serum amyloid A are frequently recommended as diagnostic parameters. However they are not often used routinely in transplant medicine. The study investigates the diagnostic value of plasma (P), serum (S), and urine (U) levels of neopterin (S-/U-NEOP), serum amyloid A (SAA), tumor necrosis factor-α, (P-/U-TNF-α), soluble interleukin-2 receptor (P-/U -sIL-2R), and interleukin-6 (U -IL-6) in transplant monitoring and describes an approach for their use in the clinical routine decision making. In 29 renal transplant patients blood and urine samples were collected daily during the posttransplant course on ward. The cytokines were measured by ELISAs, neopterin by RIA, and SAA by immunonephelometry. Descriptive statistics, sensitivity and specificity, day of first significant parameter increase/decrease, receiver operating characteristic curves, and post-test probabilities were calculated for each parameter. 12 acute rejection episodes were diagnosed. As rejection markers, S-NEOP and P-TNF-α had the highest sensitivity, U-IL-6 the highest specificity. 8 viral infections occurred. U-NEOP showed values higher than 1000 μmol/moICrea. It did not exceed this threshold in case of rejection episodes. SAA and U-IL-6 showed peak. levels during rejections but not during episodes of viral infections. Using the calculated likelihood ratio formulas the probability for the occurrence of an acute rejection could be estimated for the individual, daily parameter measurement. Adding the physician IS rating for rejection posttest probabilities were computed. Immunologic monitoring is possible in transplant medicine. Using daily measurements of serum amyloid A and neopterin facilitates the differential diagnosis of acute rejection episodes and viral infections. The likelihood ratio approach permits an application of the parameter monitoring in the clinical routine.

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