Recurrent deep-vein thrombosis based on homozygous factor V Leiden mutation acquired after liver transplantation

Thrombotic complications post liver transplantation: Etiology and management

Liver transplantation (LT) is the life saving therapeutic option for patients with acute and chronic end stage liver disease. This is a routine procedure with excellent outcomes in terms of patient survival and quality of life post LT. Orthotopic LT (OLT) patients require a critical care as they are prone to variety of post-operative vascular, cardiovascular, biliary, pulmonary and abdominal complications. Thrombotic complications (both arterial and venous) are not uncommon post liver transplant surgery. Such vascular problems lead to increased morbidity and mortality in both donor and graft recipient. Although thromboprophylaxis is recommended in general surgery patients, no such standards exist for liver transplant patients. Drastic advancements of surgical and anesthetic procedures have improvised survival rates of patients post OLT. Despite these, haemostatic imbalance leading to thrombotic events post OLT cause significant graft loss and morbidity and even lead to patient's death. Thus it is extremely important to understand pathophysiology of thrombosis in LT patients and shorten the timing of its diagnosis to avoid morbidity and mortality in both donor and graft recipient. Present review summarizes the current knowledge of vascular complications associated with LT to highlight their impact on short and long-term morbidity and mortality post LT. Also, present report discusses the lacunae existing in the literature regarding the risk factors leading to arterial and venous thrombosis in LT patients.

Thrombophilia Screening: Not So Straightforward

Although inherited thrombophilias are lifelong risk factors for a first thrombotic episode, progression to thrombosis is multifactorial and not all individuals with inherited thrombophilia develop thrombosis in their lifetimes. Consequently, indiscriminate screening in patients with idiopathic thrombosis is not recommended, since presence of a thrombophilia does not necessarily predict recurrence or influence management, and testing should be selective. It follows that a decision to undertake laboratory detection of thrombophilia should be aligned with a concerted effort to identify any significant abnormalities, because it will inform patient management. Deficiencies of antithrombin and protein C are rare and usually determined using phenotypic assays assessing biological activities, whereas protein S deficiency (also rare) is commonly detected with antigenic assays for the free form of protein S since available activity assays are considered to lack specificity. In each case, no single phenotypic assay is capable of detecting every deficiency, because the various mutations express different molecular characteristics, rendering thrombophilia screening repertoires employing one assay per potential deficiency, of limited effectiveness. Activated protein C resistance (APCR) is more common than discrete deficiencies of antithrombin, protein C, and protein S and also often detected initially with phenotypic assays; however, some centres perform only genetic analysis for factor V Leiden, as this is responsible for most cases of hereditary APCR, accepting that acquired APCR and rare F5 mutations conferring APCR will go undetected if only factor V Leiden is evaluated. All phenotypic assays have interferences and limitations, which must be factored into decisions about if, and when, to test, and be given consideration in the laboratory during assay performance and interpretation. This review looks in detail at performance and limitations of routine phenotypic thrombophilia assays.

Donor-derived disorders of hemostasis and thrombosis in liver transplantation: Considerations for deceased donor liver selection

OLT is known to be associated with a precarious perioperative hemostatic state due to dysregulation of procoagulant and anticoagulant factors, endothelial injury, and inflammation. Transmission of inherited bleeding and clotting disorders from the liver donor to the recipient may further complicate hemostasis during and after transplantation. As a result, consideration of congenital coagulation disorders in the liver donor is a practical concern for donor selection. However, there is no clear consensus regarding the selection of donors with known or suspected thrombophilia or bleeding disorders. While multiple case reports and retrospective studies, subject to reporting bias, describe donor-derived thrombophilic and bleeding disorders, there are no large-scale studies in the adult liver transplant literature that examine the frequency of transmission, utility of donor screening, or clinical impact of donor hemostatic disorders. Based on the reported literature, we summarize our approach for donor selection with an aim to balance improved organ utility and optimal post-transplant outcomes.

Pre-Transplant Factors Influencing Rates of Hepatocellular Carcinoma Recurrence in Liver Transplant Recipients

Background

The aim of the study was to determine factors influencing hepatocellular carcinoma (HCC) recurrence in a cohort of patients who underwent liver transplantation (LT) at a large, tertiary-care medical center.

Methods

A total of 132 patients with the diagnosis of HCC at time of transplant were evaluated for HCC recurrence over a 7-year period. Nine patients were found to have HCC recur post-LT.

Results

No significant demographic values were found to indicate recurrence. Pre-LT factors potentially influencing HCC recurrence rates included number of days between HCC diagnosis and date of LT (P = 0.015), caudate lobe involvement (P = 0.019), increased use of radiation therapies pre-LT (P = 0.011), and total number of locoregional therapies (LRT) pre-LT (P < 0.001). Post-transplant outcomes demonstrated a significant difference in deep venous thrombosis (DVT) in the recurrent vs. non-recurrent groups (P = 0.035).

Conclusions

The prevalence of HCC recurrence in this study was lower than the national average, yet difficulty still exists in predicting pre-LT factors which may influence HCC recurrence rates.

Perioperative hemostatic management in the cirrhotic patient: a position paper on behalf of the Liver Intensive Care Group of Europe (LICAGE)

Recent data demonstrated that amongst patients undergoing elective surgery the prevalence of cirrhosis is 0.8% equating to approximately 25 million cirrhotic patients undergoing surgery each year worldwide. Overall, the presence of cirrhosis is independently associated with 47% increased risk of postoperative complications and over two and a half-increased risk of in-hospital mortality in patients undergoing elective surgery. In particular, perioperative patients with chronic liver disease have long been assumed to have a major bleeding risk on the basis of abnormal results for standard tests of hemostasis. However, recent evidence outlined significant changes to traditional knowledge and beliefs and, nowadays, with more sophisticated laboratory tests, it has been shown that patients with chronic liver disease may be in hemostatic balance as a result of concomitant changes in both pro- and antihemostatic pathways. The aim of this paper endorsed by the Liver Intensive Care Group of Europe was to provide an up-to-date overview of coagulation management in perioperative patients with chronic liver disease focusing on patient blood management, monitoring of hemostasis, and current role of hemostatic agents.

Cardiovascular disease risk in patients receiving organ transplantation: a national cohort study

Although organ transplantation is the definitive treatment for end-stage organ failure, the post-transplant outcomes can be substantially influenced by cardiovascular complications. A national cohort study was performed to estimate risks of cardiovascular diseases in those with heart, lung, kidney, and liver transplantation. This cohort study consisted of 5978 solid organ transplantations identified using the Taiwan National Health Insurance Database. Cardiovascular and mortality risks in transplant recipients were evaluated using standardized incidence ratios, excess absolute risks, and standardized mortality ratios as compared to those in the general population. In heart, kidney, and liver recipients, the standardized incidence ratios of overall cardiovascular diseases were 9.41 (7.75-11.44), 3.32 (2.29-3.77), and 1.4 (1.15-1.7) and the overall standardized mortality ratios were 5.23 (4.54-6.03), 1.48 (1.34-1.63), and 3.95 (3.64-4.28), respectively. Except for heart organ recipients who were at highest risk for coronary artery disease with a standardized incidence ratio of 13.12 (10.57-16.29), kidney and liver organ recipients had a ninefold increased risk in developing deep vein thrombosis post-transplant. In conclusion, solid organ transplant patients are at risk of cardiovascular disease, in particular, deep vein thrombosis, which may warrant early identification of high-risk patients in addition to prompt and adequate thromboprophylaxis perioperatively.

Genetic, hematological, and immunological disorders transmissible with liver transplantation

It is well recognized that solid organ transplantation can transmit bacterial infection and chronic viral hepatitis as well as certain cancers. As indications for liver transplantation (LT) have expanded, it has been used to treat and even cure certain genetic cholestatic disorders, urea cycle defects, and coagulation abnormalities; many of these conditions are potentially transmissible with LT as well. It is important for clinicians and transplant patients to be aware of these potentially transmissible conditions as unexplained post-LT complications can sometimes be related to donor transmission of disease and thus should prompt a thorough exploration of the donor allograft history. Herein, we will review the reported genetic, metabolic, hematologic, and immunological disorders that are transmissible with LT and describe clinical scenarios in which these cases have occurred, such as in inadvertent or recognized transplantation of a diseased organ, domino transplantation, and with living related liver donation. Liver Transplantation 23 663-678 2017 AASLD.

Perioperative thrombotic complications in liver transplantation

Although the perioperative bleeding complications and the major side effects of blood transfusion have always been the primary concern in liver transplantation (OLT), the possible cohesion of an underestimated intrinsic hypercoagulative state during and after the transplant procedure may pose a major threat to both patient and graft survival. Thromboembolism during OLT is characterized not only by a complex aetiology, but also by unpredictable onset and evolution of the disease. The initiation of a procoagulant process may be triggered by various factors, such as inflammation, venous stasis, ischemia-reperfusion injury, vascular clamping, anatomical and technical abnormalities, genetic factors, deficiency of profibrinolytic activity, and platelet activation. The involvement of the arterial system, intracardiac thrombosis, pulmonary emboli, portal vein thrombosis, and deep vein thrombosis, are among the most serious thrombotic events in the perioperative period. The rapid detection of occlusive vascular events is of paramount importance as it heavily influences the prognosis, particularly when these events occur intraoperatively or early after OLT. Regardless of the lack of studies and guidelines on anticoagulant prophylaxis in this setting, many institutions recommend such an approach especially in the subset of patients at high risk. However, the decision of when, how and in what doses to use the various chemical anticoagulants is still a difficult task, since there is no common consensus, even for high-risk cases. The risk of postoperative thromboembolism causing severe hemodynamic events, or even loss of graft function, must be weighed and compared with the risk of an important bleeding. In this article we briefly review the risk factors and the possible predictors of major thrombotic complications occurring in the perioperative period, as well as their incidence and clinical features. Moreover, the indications to pharmacological prophylaxis and the current treatment strategies are also summarized.

Liver transplantation using grafts with rare metabolic disorders

Metabolic diseases that involve the liver represent a heterogeneous group of disorders. Apart from the metabolic defect, the subject's liver functions may be normal. With the increasing need for organs, livers from donors with metabolic diseases other than familial amyloid polyneuropathy might be possibly used for transplantation. However, whether such livers qualify as grafts and how they might impact recipient outcome are still unanswered questions. This review of the literature summarizes current experience in the use of such grafts in the context of cadaveric, domino, and living-related liver transplantation.

An improved algorithm for activated protein C resistance and factor V Leiden screening

OBJECTIVES

To evaluate the performance of a Russell viper venom-based activated protein C resistance (APCR) screening test relative to DNA analysis for the factor V Leiden mutation.

METHODS

We evaluated the concordance between Pefakit APCR screening results and DNA analysis for 435 patients homozygous (n = 11), heterozygous (n = 310), or wild-type (n =114) for the G1691A allele.

RESULTS

Using receiver operating characteristic analysis, we found that a cutoff of 1.89 for the APCR ratio yields a sensitivity and specificity of 99.1%. In patients with discrepant genotype-phenotype correlation, their APCR may provide a more clinically relevant result.

CONCLUSIONS

We compared several strategies for employing reflex testing and found that performing initial APCR screening followed by confirmatory molecular analysis on a subset of cases in the borderline regions between the diagnostic groups can reduce unnecessary testing by approximately 80% without compromising diagnostic accuracy.

Predictive genetic testing of a bone marrow recipient-ethical issues involving unexpected results, gender issues, test accuracy, and implications for the donor

We present a case where an apparently straightforward Lynch syndrome predictive genetic test of DNA from a blood sample from a woman yielded an unexpected result of X/Y chromosome imbalance. Furthermore, it demonstrates the complexities of genetic testing in people who have had bone marrow transplants. This highlights the potential for multiple ethical and counselling challenges, including the inadvertent testing of the donor. Good communication between clinics and laboratories is essential to overcome such challenges and to minimise the provision of false results.

Acquired antithrombin type IIb deficiency after liver transplantation: a case report

A 3-year-old girl with multifocal hepatoblastoma was referred to our clinic for living-donor liver transplantation, the patient's father being the donor. Pretransplant evaluation revealed that the father presented partial asymptomatic antithrombin (AT) deficiency, with no inherited AT deficiency found in the girl. The genetic testing showed an AT type IIb deficiency responsible for a defect in the heparin-binding region of AT which is less thrombogenic but more common than the other AT qualitative defects. Her mother was ABO incompatible. Despite the thrombophilia on the father's side, transplantation was successfully performed under replacement therapy with intravenous AT concentrate and low-molecular-weight heparin thromboprophylaxis given to both the recipient and the donor. No thrombotic complications occurred. In the posttransplantation course, acquired partial AT deficiency was detected in the recipient, who received adjuvant chemotherapy without thrombotic complications. This case report highlights the relevance of full thrombophilic work-up before liver transplantation from a living donor, while illustrating that the procedure can be successfully performed in the case of AT deficiency on the donor's side provided that appropriate AT supplementation and thromboprophylaxis are administered to both the recipient and the donor.

Acquired pseudoxanthoma elasticum presenting after liver transplantation

BACKGROUND

Pseudoxanthoma elasticum (PXE) is thought to be a metabolic disorder resulting from mutations in the gene encoding the cellular transporter, ABCC6, which is primarily expressed in liver and kidney. We encountered 3 patients who developed clinical and histopathological evidence of PXE after liver transplantation, suggesting that PXE could have been acquired from the transplanted organ.

OBJECTIVE

We sought to delineate the clinical features and screen each patient and samples of donor liver for mutations in the ABCC6 gene.

METHODS

Each patient underwent full clinical examination, skin biopsy, and ophthalmologic examination, and whole genome sequencing using standard techniques. Fixed samples of donor liver tissue were available for mutation analysis in two patients and of donor kidney tissue in one.

RESULTS

All 3 patients had unequivocal clinical and histopathologic evidence of PXE. No patient (or family member available for screening) had evidence of mutations in ABCC6. Neither liver specimen nor the single available kidney specimen showed evidence of mutations in ABCC6.

LIMITATIONS

Liver tissue was not available from one patient and DNA was of poor quality in another, resulting in limited screening. Genetic testing does not detect ABCC6 mutations in 10% of patients with confirmed PXE.

CONCLUSION

Although we were unable to demonstrate ABCC6 mutations in limited screening of fixed donor livers, the absence of any PXE mutations in the affected patients, the timing of onset of PXE, and the known acquisition of other metabolic disorders and coagulopathies from donor livers suggest that PXE was likely acquired via liver transplantation.

Thrombotic events after pediatric liver transplantation

TE may contribute to morbidity and mortality after LT. The objectives were to determine the incidence of early TE post-pediatric LT and compare differences between children with and without TE. A retrospective review of 88 transplanted children (January 2002-October 2007) was performed to determine the incidence of Doppler-confirmed DVT and ATE in the first month post-LT. Fourteen (16%) patients developed TE: DVT in seven (8%) and ATE in seven (8%) patients. Six of 88 (6.8%) developed symptomatic CVL-related DVT. Median (range) time post-LT to DVT and ATE were 7 (4-18) and 8 (1-31) days, respectively. There was no significant difference in age/body weight at LT between patients with or without DVT and ATE. There was no significant difference between patients with or without HAT in age and weight at LT, cold ischemic time, duration of surgery, hematocrit levels, whole-organ graft type, intraoperative FFP, high-risk CMV status, or early acute cellular rejection. In conclusion, the incidence of early TE post-pediatric LT was 16%, including DVT in 8%. Prospective studies are necessary to evaluate the role of prophylactic anticoagulation and potential modifiable risk factors post-pediatric LT.

Living donor liver transplantation: usefulness of hemostatic and prothrombotic screening in potential donors

Bleeding and thrombosis are serious complications of living donor liver transplantation (LDLT). The aim of this paper was to describe the results of a screening for coagulation disorders, including for thrombophilic factors, in potential living liver graft donors and to evaluate thrombotic and bleeding events in donors and recipients, during and after the procedure. From January 2001 to January 2007, 41 LDLTs were performed at our institution. We performed systematic screening for bleeding or prothrombotic states among 188 potential donors, 38 (20.2%) of whom showed at least one abnormality. We rejected potential donors with factor V Leiden, prothrombin mutation G20210A, and deficiencies in anticoagulant proteins (protein C, protein S, and antithrombin) or coagulation factors. Bleeding and thrombotic events in donors and recipients of the 41 LDLTs were evaluated during 7 days to 70 months follow-up. No major bleeding events were detected in the donors. Neither donor nor recipient experienced venous thrombosis or pulmonary embolism. Among all recipients, six suffered hepatic artery thrombosis including five in the first month probably related to surgery. Deep venous thrombosis and pulmonary embolism are well-known complications of hepatic surgery; Prothrombotic abnormalities in the donor can be transmitted to the recipient, leading to increased risk of serious postoperative events. Although the cost-effectiveness is not definitely established, we recommend systematic screening for hemostatic and prothrombotic disorders to prevent more morbidity of a procedure that already has high risks of bleeding and thrombosis.

Activated protein C resistance acquired through liver transplantation

Coagulation factors are produced by the liver. It is well recognized that liver transplantation can cure haemophilia. We described a case of thrombophilia acquired due to liver transplantation from a donor with heritable thrombophilia.