We describe a case of a 60-year-old patient with decompensated liver cirrhosis (Child-Pugh C; model of end-stage liver disease [MELD] score 40) with hepatorenal syndrome requiring hemodialysis, who underwent liver transplantation (LTx) using a graft from a 49-year-old donor with hemolysis, elevated liver enzymes, low platelets (HELLP) syndrome during a twin pregnancy, leading to intracerebral mass bleeding 2 days after cesarean section with subsequent brain death. Donor blood analyses (at organ harvesting: alanine aminotransferase, 470 U/L; aspartate aminotransferase [AST], 680 U/L; platelets, 138 cells/nL, cytomegalovirus [CMV]+) and liver histology were typical for HELLP syndrome. The LTx surgery was uneventful.
Immunosuppression consisted of induction therapy with basiliximab and methyl-prednisolone. Mycophenolate mofetil was added immediately after LTx. Tacrolimus was started on postoperative day (POD) 5 after LTx. In parallel, methyl-prednisolone was gradually reduced and discontinued on POD 15. Because of persistent renal dysfunction requiring intermittent hemodialysis, tacrolimus whole-blood concentrations were initially kept below the therapeutic range. The postoperative course was complicated by cytomegalovirus infection, multiple bacterial infections, as well as a fall on POD 19, which resulted in fractures of several ribs and skull with concomitant left hemisphere subdural hematoma, and a large subcapsular liver hematoma. Immunosuppression was switched to everolimus as the main immunosuppressant beginning on POD 84, supplemented with low-dose tacrolimus. The patient was discharged on POD 103 and is currently well 12 months after LTx.
After obtaining informed consent, repeated serum graft-derived cell-free DNA (GcfDNA) measurements were performed retrospectively as part of an institutional review board-approved, multicenter prospective study and therefore not used to make therapeutic decisions. Initial subtherapeutic tacrolimus levels resulted in a substantial increase in GcfDNA, which normalized after tacrolimus concentrations reached the therapeutic range. The CMV infection, traumatic liver hematoma, as well as an acute rejection episode during immunosuppressive regime changes, resulted in increased GcfDNA of up to 90%, which normalized after treatment of the respective clinical problem (Fig. 1).
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FIGURE 1: Laboratory data after transplantation. The upper panel shows the tacrolimus-everolimus concentrations in whole blood and GcfDNA values for the first 180 days after LTx. The lower panel shows serum AST, bilirubin, and γGT concentrations. GcfDNA, graft-derived cell-free DNA; AST, aspartate aminotransferase; LTx, liver transplantation.
Liver transplantation is the only effective treatment of end-stage liver diseases. Organ shortage is still a major problem, leading to the increased use of marginal donor organs. The potential usefulness of GcfDNA as a biomarker for organ integrity after solid organ transplantation (1) has been improved by a recently described, more rapid, and cost-effective digital droplet polymerase chain reaction method (2). This novel GcfDNA method was compared to conventional serum markers as a way to assess graft integrity after transplantation of a HELLP syndrome donor liver.
In this case, which was complicated by recurrent CMV reinfection, liver trauma, and difficulties establishing stable, effective, tolerable immunosuppression, GcfDNA was found retrospectively to be a useful and rapidly responding biomarker of organ damage. The GcfDNA peaked at approximately 90% immediately after transplantation representing HELLP-associated damage, as well as preservation and ischemia-reperfusion injury, but rapidly decreased to below 10% on POD 8, suggesting a good recovery because earlier studies suggest that GcfDNA less than 10% indicate a lack of graft damage (2). When tacrolimus trough levels fell below the therapeutic range, GcfDNA again increased up to 66%, suggesting beginning graft rejection injury. Once tacrolimus concentrations became therapeutic, GcfDNA values dropped below 5%. Classical liver injury markers (transaminases, bilirubin, γ-glutamyltransferase [γGT]) are not sensitive for the assessment of acute rejections (3). During periods of under-immunosuppression, GcfDNA elevations were greater than that of AST (GcfDNA was 6.7 and 9.9 times the upper limit of the reference range vs. 3.9 and 3.0 for AST, respectively). The γGT showed elevations to 13.0 and 6.8 times normal, but this was delayed compared to GcfDNA (Fig. 1). After liver trauma, a hematoma led to hepatocellular damage from probable graft ischemia, and GcfDNA increased to 90%, indicating severe liver damage.
In conclusion, this new “liquid biopsy” allows direct assessment of organ integrity using only a blood sample. Compared to conventional injury markers, GcfDNA has been shown (1, 4), and exemplified here, to be more sensitive and more rapid in its dynamics, and therefore could allow for earlier recognition of graft injury. This could enable timelier initiation of interventions to prevent severe graft injury or even graft loss. Furthermore, the method offers an effective assessment of individual responses to immunosuppressive therapy (4), allowing for reduction of immunosuppressive dosages and subsequent side effects. This method is also suitable to monitor marginal donor organ injury as shown in this case of a HELLP syndrome donor. The clinical benefit of routine GcfDNA monitoring as a liquid biopsy after LTx is currently being evaluated in a prospective multicenter trial that has already enrolled over 60 LTx subjects.
Philipp Kanzow
1
Otto Kollmar2
Ekkehard Schütz3
Michael Oellerich1
Jessica Schmitz1,3
Julia Beck3
Philip D. Walson1
Jan E. Slotta2
1 Department of Clinical Chemistry
University Medical Center Goettingen
Goettingen, Germany
2 Department of General, Visceral and
Pediatric Surgery, University Medical Center
Goettingen, Goettingen, Germany
3 Chronix Biomedical, Goetheallee
Goettingen, Germany
REFERENCES
1. Lo YM. Transplantation monitoring by plasma DNA sequencing.
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2. Beck J, Bierau S, Balzer S, et al. Digital droplet PCR for rapid quantification of donor DNA in the circulation of transplant recipients as a potential universal biomarker of graft injury.
Clin Chem 2013; 59: 1732.
3. Rodríguez-Perálvarez M, Germani G, Papastergiou V, et al. Early tacrolimus exposure after liver transplantation: relationship with moderate/severe acute rejection and long-term outcome.
J Hepatol 2013; 58: 262.
4. Oellerich M, Schütz E, Kanzow P, et al. Use of graft-derived cell-free DNA as an organ integrity biomarker to reexamine effective tacrolimus trough concentrations after liver transplantation.
Ther Drug Monit 2014; 36: 136.
