Acute graft versus host disease after liver transplantation: patterns of lymphocyte chimerism

Chimerism-Mediated Tolerance in Intestinal Transplantation

In this review, the authors outlined concepts and strategies to achieve immune tolerance through inducing hematopoietic chimerism after solid organ transplantation and introduced challenges and opportunities in harnessing two-way alloresponses to improve outcomes after intestinal transplantation (ITx). Next, the authors discussed the dynamics and phenotypes of peripheral blood and intestinal graft T-cell subset chimerism and their association with outcomes. The authors also summarized studies on other types of immune cells after ITx and their potential participation in chimerism-mediated tolerance. The authors further discussed strategies and future directions to promote chimerism-associated tolerance after ITx to overcome rejection and minimize immunosuppression.

Cellular strategies to induce immune tolerance after liver transplantation: Clinical perspectives

Liver transplantation (LT) has become the most efficient treatment for pediatric and adult end-stage liver disease and the survival time after transplantation is becoming longer due to the development of surgical techniques and perioperative management. However, long-term side-effects of immunosuppressants, like infection, metabolic disorders and malignant tumor are gaining more attention. Immune tolerance is the status in which LT recipients no longer need to take any immunosuppressants, but the liver function and intrahepatic histology maintain normal. The approaches to achieve immune tolerance after transplantation include spontaneous, operational and induced tolerance. The first two means require no specific intervention but withdrawing immunosuppressant gradually during follow-up. No clinical factors or biomarkers so far could accurately predict who are suitable for immunosuppressant withdraw after transplantation. With the understanding to the underlying mechanisms of immune tolerance, many strategies have been developed to induce tolerance in LT recipients. Cellular strategy is one of the most promising methods for immune tolerance induction, including chimerism induced by hematopoietic stem cells and adoptive transfer of regulatory immune cells. The safety and efficacy of various cell products have been evaluated by prospective preclinical and clinical trials, while obstacles still exist before translating into clinical practice. Here, we will summarize the latest perspectives and concerns on the clinical application of cellular strategies in LT recipients.

One-way donor-to-recipient human leukocyte antigen mismatch and graft-versus-host disease in liver transplantation: an observational study of a single-center experience in Korea

Background

Graft-versus-host disease (GVHD) is a rare, but potentially fatal complication of liver transplantation. One-way human leukocyte antigens (HLA) mismatch has emerged as a risk factor for GVHD. However, the risk of mortality associated with HLA-one-way mismatch (OWMM) remains uncertain. We investigated the incidence and characteristics of GVHD.

Methods

In total, 899 patients who underwent liver transplantation at a single center were retrospectively reviewed. The incidence of GVHD and 1- and 5-year survival rates were compared according to whether HLA-OWMM developed.

Results

In the HLA-OWMM group, GVHD developed in two patients (14.3%). Notably, GVHD was only observed in living donor liver transplant (LDLT) recipients in the HLA-OWMM group. The HLA-OWMM group exhibited a lower 1-year patient survival rate than the control (i.e., non-HLA-OWMM) group (78.6% vs. 90.7%, P=0.120). However, the 5-year survival rate in the HLA-OWMM group was similar to that in the control group (78.6% vs. 78.2%, P=0.821). When the HLA-OWMM group was further stratified by the number of mismatched loci, the 5-year survival rate was 83.3% in patients with HLA-OWMM at one to two loci and 75.0% in those with HLA-OWMM at three loci.

Conclusions

Despite the higher incidence of GVHD in LDLT recipients with HLA-OWMM, the 5-year patient survival rates were comparable to those in recipients without HLA-OWMM. The decision to perform LDLT in patients with HLA-OWMM depends on the patient's status and the organ supply of a specific region.

Dual organ transplantation: when heart alone is not enough

PURPOSE OF REVIEW

The number of dual organ transplantations (DOT) are steadily increasing over the past few years. This is both a reflection of increasing complexity and advanced disease process in the patients and greater transplant center experience with performing dual organ transplants. Due to lack of standardization of the process, there remains significant center-based variability in patient selection, perioperative and long-term management of these patients.

RECENT FINDINGS

Overall posttransplant outcomes for DOT have been acceptable with some immunological advantages because of partial tolerance offered by the second organ. These achievements should, however, be balanced with the ethical implications of bypassing the patients who are listed for single organ transplantation because of the preferential allocation of organs for DOT.

SUMMARY

The field of DOT is expanding rapidly, with good long-term outcomes. There is an urgent need for guidelines to standardize the process of patient selection and listing dual organ transplantation.

Immune checkpoint inhibitors in liver transplant: a case series

BACKGROUND

Immune checkpoint inhibitors (ICIs) in the setting of liver transplant (LT) pose a risk of rejection and hold unclear benefit in both the neoadjuvant (pre-transplant) and post-transplant salvage setting. In the pre-transplant setting, neoadjuvant ICIs may serve as a bridge to LT by downstaging disease burden to fit within transplant criteria. Outcomes in this setting include patients who had successful transplants without complications to patients who suffered severe complications, including fatal hepatic necrosis and graft failure requiring re-transplant. Some authors suggest having a period of three months between checkpoint inhibition and transplant may help mitigate adverse effects. In the post-LT setting, there are few treatment options if there is a recurrence of disease, which forces treatment teams to reconsider checkpoint inhibitors. Again, a longer period of time between transplant and checkpoint inhibition may reduce risk of rejection. Case reports of patients treated with ICIs post-transplant utilized either nivolumab or pembrolizumab. As combination atezolizumab/bevacizumab is a relatively new treatment option for unresectable hepatocellular carcinoma (HCC), there are only three reported cases using this combination in the post-LT setting. While there were no cases of rejection, all three cases had progression of disease. As immunotherapy joins transplantation as a mainstay of treatment for HCC, it remains unclear how to best navigate when the treatment course involves both immune activation and immunosuppression.

CASE DESCRIPTION

Patients who had an LT and were treated with ICIs (pre or post LT) at the University of Cincinnati were included in this retrospective chart review.

CONCLUSIONS

Fatal rejection remains a significant risk even 4 years after LT. Neoadjuvant ICIs also pose a risk for acute cellular rejection; however, this may not always be clinically significant. Graft versus host disease (GVHD) may be an additional, previously unreported risk of ICIs in the setting of LT. Prospective studies are needed to understand benefits and risks of checkpoint inhibitors in the LT setting.

Acute Graft Versus Host Disease Following Liver Transplantation: Case Report With Review of Current Literature

Graft verus host disease (GVHD) following Liver transplantation is rare life threatening complication with very high mortality rate around 85%. Due to increased recognition of this condition management approach is rapidly evolving due to newer diagnostic methods and drugs. Etiology, risk factors, pathogenesis, preventive strategies, management approach and newer drugs are discussed. We present our experience of 2 cases from a large cohort of 1052 Liver transplant operations over a decade.

Graft-versus-host disease after pediatric liver transplantation: A diagnostic challenge

BACKGROUND

Graft-versus-host disease (GVHD) is a rare but serious complication after pediatric liver transplantation (LTx). Early diagnosis is difficult due to nonspecific presenting symptoms and non-pathognomonic skin histopathological features. The aim of this article was to describe a case of pediatric GVHD after LTx and to review available data on pediatric GVHD highlighting the diagnostic difficulty. We also propose a diagnostic algorithm to improve the diagnostic capability and increase clinical awareness about this potentially fatal condition.

METHODS

We did a comprehensive literatures review on studies on GvHD following pediatric LTx between 1990 and February 2021, chimerism study by short tandem repeat (STR), HLA typing by sequence-specific oligonucleotide (SSO) method, and flowcytometry crossmatch.

RESULTS

Our search yielded 23 case reports. The most common clinical manifestations were fever and rash (91%) followed by diarrhea. Mortality rate was 36.8% mainly due to sepsis and organ failure. Diagnosis was challenging and chimerism study to confirm donor engraftment was performed on only half of the cases. Prevalence of "donor dominant HLA one-way matching" typically occurs in homozygous parents-to-child transplantation was 75% in cases with HLA testing.

CONCLUSION

So far, there are no available standard diagnostic criteria for GVHD following pediatric LTx. Recognition of multiple risk factors through proper laboratory assessment can predict the occurrence, and early chimerism study can confirm suggestive clinical manifestation. The strong likelihood of developing GVHD in "donor one-way HLA match" and the severe problems imposed by this complication may justify avoidance of HLA homozygous parent's donation.

Acute Graft-Versus-Host Disease After Orthotopic Liver Transplantation: Predicting This Rare Complication Using Machine Learning

Acute graft-versus-host disease (GVHD) is a rare complication after orthotopic liver transplantation (OLT) that carries high mortality. We hypothesized that machine-learning algorithms to predict rare events would identify patients at high risk for developing GVHD. To develop a predictive model, we retrospectively evaluated the clinical features of 1938 donor-recipient pairs at the time they underwent OLT at our center; 19 (1.0%) of these recipients developed GVHD. This population was divided into training (70%) and test (30%) sets. A total of 7 machine-learning classification algorithms were built based on the training data set to identify patients at high risk for GVHD. The C5.0, heterogeneous ensemble, and generalized gradient boosting machine (GGBM) algorithms predicted that 21% to 28% of the recipients in the test data set were at high risk for developing GVHD, with an area under the receiver operating characteristic curve (AUROC) of 0.83 to 0.86. The 7 algorithms were then evaluated in a validation data set of 75 more recent donor-recipient pairs who underwent OLT at our center; 2 of these recipients developed GVHD. The logistic regression, heterogeneous ensemble, and GGBM algorithms predicted that 9% to 11% of the validation recipients were at high risk for developing GVHD, with an AUROC of 0.93 to 0.96 that included the 2 recipients who developed GVHD. In conclusion, we present a practical model that can identify patients at high risk for GVHD who may warrant additional monitoring with peripheral blood chimerism testing.

Graft-versus-host disease after liver transplantation is associated with bone marrow failure, hemophagocytosis, and DNMT3A mutations

Graft-versus-host disease after liver transplantation (LT-GVHD) is rare, frequently fatal, and associated with bone marrow failure (BMF), cytopenias, and hyperferritinemia. Given hyperferritinemia and cytopenias are present in hemophagocytic lymphohistiocytosis (HLH), and somatic mutations in hematopoietic cells are associated with hyperinflammatory responses (clonal hematopoiesis of indeterminate potential, CHIP), we identified the frequency of hemophagocytosis and CHIP mutations in LT-GVHD. We reviewed bone marrow aspirates and biopsies, quantified blood/marrow chimerism, and performed next-generation sequencing (NGS) with a targeted panel of genes relevant to myeloid malignancies, CHIP, and BMF. In all, 12 marrows were reviewed from 9 LT-GVHD patients. In all, 10 aspirates were evaluable for hemophagocytosis; 7 had adequate DNA for NGS. NGS was also performed on marrow from an LT cohort (n = 6) without GVHD. Nine of 10 aspirates in LT-GVHD patients showed increased hemophagocytosis. Five (71%) of 7 with LT-GVHD had DNMT3A mutations; only 1 of 6 in the non-GVHD LT cohort demonstrated DNMT3A mutation (p = .04). Only 1 LT-GVHD patient survived. BMF with HLH features was associated with poor hematopoietic recovery, and DNMT3A mutations were over-represented, in LT-GVHD patients. Identification of HLH features may guide prognosis and therapeutics. Further studies are needed to clarify the origin and impact of CHIP mutations on the hyperinflammatory state.

Diagnosis and treatment of acute graft-versus-host disease after liver transplantation: Report of six cases

BACKGROUND

Graft-versus-host disease (GVHD) following liver transplantation (LT) is an unpredictable complication with poor outcome. However, consensus regarding the diagnosis and therapeutic regimen for the disease is yet lacking. The present study summarized the clinical experience on the diagnosis and treatment of acute GVHD (aGVHD) following LT and reviewed the pertinent literature.

CASE SUMMARY

Between January 1^st, 2000 and December 31^st, 2020, a total of 1053 LT were performed in the First Affiliated Hospital of Xi’an Jiaotong University. Six recipients developed aGVHD with clinical symptoms of fever, rash, diarrhea, and pancytopenia. The incidence of aGVHD was 0.57%. The median time from LT to the clinical presentation of aGVHD was 22.17 d. The median time from the beginning of the clinical symptom to histopathological diagnosis was 7.5 d. All six cases underwent treatment of immunosuppressant adjustment, corticosteroids, human normal immunoglobulin, and antithymocyte globulin/IL-2 antagonists. Despite intensive treatment strategies, 4 patients were deceased due to sepsis, multiple organ failure, and cerebral hemorrhage. The remaining two cases were discharged as treatment successfully. However, one died because of tuberculosis infection on the 6th month of follow-up, the other one was alive healthy during 30 mo of follow-up.

CONCLUSION

The rapid diagnosis of aGVHD is mainly based on the time from the first symptom, histopathological features, and the donor T-lymphocyte chimerism. Our cases report highlights massive corticosteroid therapy and age difference between donors and recipients could accelerate to aGVHD. Moreover, gut microbial interventions and donor-targeted serotherapy may provide novel therapeutics.

Chronic graft-versus-host disease in pancreas after kidney transplant recipients - An unrecognized entity

Graft-versus-host disease (GVHD), a common complication after peripheral blood stem cell or bone marrow transplantation, rarely occurs in kidney and pancreas transplant recipients. The true incidence may be confounded by the rarity of the disorder, with a resultant lack of appreciation of the diagnosis as a potential cause of common clinical manifestations such as cytopenias and immune dysfunction. Reports of GVHD in kidney and pancreas transplant recipients almost uniformly describe patients in the early posttransplant period (days to months) with the typical manifestations of acute GVHD involving the skin, liver, and intestines. In contrast, reports of solid organ transplant recipients with clinical features more consistent with chronic GVHD (cGVHD) are lacking, raising concern of underrecognition of this severe complication. Occurrence later after transplant may be even more likely to result in lack of recognition. We report 2 cases of possible cGVHD occurring in recipients of pancreas after kidney transplantation, which were diagnosed at 5.5 and 42 months after pancreas transplant. Both patients presented with severe pancytopenia, multiple opportunistic infections, and features suggestive of cGVHD. Transplant professionals should be aware of the possibility of acute and cGVHD in pancreas after kidney transplant recipients and be able to recognize the clinical manifestations.

The Immunological Basis of Liver Allograft Rejection

Liver allograft rejection remains a significant cause of morbidity and graft failure in liver transplant recipients. Rejection is caused by the recognition of non-self donor alloantigens by recipient T-cells. Antigen recognition results in proliferation and activation of T-cells in lymphoid tissue before migration to the allograft. Activated T-cells have a variety of effector mechanisms including direct T-cell mediated damage to bile ducts, endothelium and hepatocytes and indirect effects through cytokine production and recruitment of tissue-destructive inflammatory cells. These effects explain the histological appearances of typical acute T-cell mediated rejection. In addition, donor specific antibodies, most typically against HLA antigens, may give rise to antibody-mediated rejection causing damage to the allograft primarily through endothelial injury. However, as an immune-privileged site there are several mechanisms in the liver capable of overcoming rejection and promoting tolerance to the graft, particularly in the context of recruitment of regulatory T-cells and promotors of an immunosuppressive environment. Indeed, around 20% of transplant recipients can be successfully weaned from immunosuppression. Hence, the host immunological response to the liver allograft is best regarded as a balance between rejection-promoting and tolerance-promoting factors. Understanding this balance provides insight into potential mechanisms for novel anti-rejection therapies.

Graft-vs-Host Disease Colitis After Lung Transplant

Graft-vs-host disease, characteristically a major complication of allogenic hematopoietic stem cell transplantation, is rare after solid organ transplantation. We report a 50-year-old man who presented with abdominal pain, vomiting, and diarrhea shortly after bilateral lung transplantation. Colonoscopy with biopsy revealed diffuse severe active colitis with ulceration and crypt apoptosis consistent with graft-vs-host disease colitis. The diagnosis was confirmed by the presence of donor lymphocytes in the peripheral blood. His symptoms were refractory to corticosteroids but responded to the addition of infliximab and extracorporeal photophoresis. He remained in remission 17 months later.

Graft-Versus-Host Disease After Liver Transplantation

http://aasldpubs.onlinelibrary.wiley.com/hub/journal/10.1002/(ISSN)2046-2484/video/15-2-reading-wood a video presentation of this article http://aasldpubs.onlinelibrary.wiley.com/hub/journal/10.1002/(ISSN)2046-2484/video/15-2-interview-lindenmeyer an interview with the author.

Are donor lymphocytes a barrier to transplantation tolerance?

PURPOSE OF REVIEW

Following solid organ transplantation (SOT), populations of donor lymphocytes are frequently found in the recipient circulation. Their impact on host alloimmunity has long been debated but remains unclear, and it has been suggested that transferred donor lymphocytes may either promote tolerance to the graft or hasten its rejection. We discuss possible mechanisms by which the interaction of donor passenger lymphocytes with recipient immune cells may either augment the host alloimmune response or inhibit it.

RECENT FINDINGS

Recent work has highlighted that donor T lymphocytes are the most numerous of the donor leukocyte populations within a SOT and that these may be transferred to the recipient after transplantation. Surprisingly, graft-versus-host recognition of major histocompatibility complex class II on host B cells by transferred donor CD4 T cells can result in marked augmentation of host humoral alloimmunity and lead to early graft failure. Killing of donor CD4 T cells by host natural killer cells is critical in preventing this augmentation.

SUMMARY

The ability of passenger donor CD4 T cells to effect long-term augmentation of the host humoral alloimmune response raises the possibility that ex-vivo treatment or modification of the donor organ prior to implantation may improve long-term transplant outcomes.

Improved survival after LTx-associated acute GVHD with mAb therapy targeting IL2RAb and soluble TNFAb: Single-center experience and systematic review

Acute graft-versus-host disease (GVHD) after liver transplant (LTx) is a rare complication with a high mortality rate. Recently, monoclonal antibody (mAb) treatment, specifically with anti-interleukin 2 receptor antibodies (IL2RAb) and anti-tumor necrosis factor-α antibodies (TNFAb), has gained increasing interest. However, evidence is mostly limited to case reports and the efficacy remains unclear. Here, we describe 5 patients with LTx-associated GVHD from our center and provide the results of our systematic literature review to evaluate the potential therapeutic benefit of IL2RAb/TNFAb treatment. Of the combined population of 155 patients (5 in our center and 150 through systematic search), 24 were given mAb (15.5%)-4 with TNFAb (2.6%) and 17 with IL2RAb (11%) ("mAb group")-and compared with patients who received other treatments (referred to as "no-mAb group"). Two-sided Fisher exact tests revealed a better survival when comparing treatment with mAb versus no-mAb (11/24 vs 27/131; P = .018), TNFAb versus no-mAb (3/4 vs 27/131; P = .034), and IL2RAb versus no-mAb (8/17 vs 27/131; P = .029). This systematic review suggests a beneficial effect of mAb treatment and a promising role for TNFAb and IL2RAb as a first-line strategy to treat LTx-associated acute GVHD.

Graft Versus Host Disease After Liver Transplantation in Adults: A Case series, Review of Literature, and an Approach to Management

BACKGROUND

Graft-versus-host-disease (GVHD) after liver transplantation (LT) is a deadly complication with very limited data on risk factors, diagnosis and management. We report a case series and a comprehensive review of the literature.

METHODS

Data were systematically extracted from reports of GVHD after LT, and from the United Network for Organ Sharing database. Group comparisons were performed.

RESULTS

One hundred fifty-six adult patients with GVHD after LT have been reported. Median time to GVHD onset was 28 days. Clinical features were skin rash (92%), pancytopenia (78%), and diarrhea (65%). Six-month mortality with GVHD after LT was 73%. Sepsis was the most common cause of death (60%). Enterobacter bacteremia, invasive aspergillosis, and disseminated Candida infections were frequently reported. Recipient age over 50 years is a risk factor for GVHD after LT. Hepatocellular carcinoma was overrepresented, whereas chronic hepatitis C was underrepresented, in reported United States GVHD cases relative to all United Network for Organ Sharing database LT cases. Mortality rate with treatment of GVHD after LT was 84% with high-dose steroids alone, 75% to 100% with regimens using dose increases of calcineurin inhibitors, and 55% with IL-2 antagonists. Mortality was 25% in small case series using the CD2-blocker alefacept or TNF-α antagonists.

CONCLUSIONS

Age older than 50 years and hepatocellular carcinoma appear to be risk factors for GVHD. Hepatitis C may be protective. High-dose steroids and calcineurin inhibitors are ineffective in the treatment of GVHD after LT. CD2-blockers and TNF-α antagonists appear promising. We propose a diagnostic algorithm to assist clinicians in managing adults with GVHD after LT.

Outcomes of pediatric identical living-donor liver and hematopoietic stem cell transplantation

Chronic IS is associated with significant morbidity in transplant recipients. Moreover, IS does not prevent chronic graft failure frequently. Allograft immune tolerance in LT can be induced by complete donor chimerism through allogenic HSCT combined with identical LDLT. This approach may exempt patients from chronic lifelong IS. However, it is unclear whether its benefits justify its risks. Here, we present three cases from our institution and analyze seven additional reports of children treated with HSCT/LDLT, all receiving HSCT due to hemato-oncological indications. In eight of 10 cases, donor macrochimerism resulted in allograft tolerance. Nine patients survived. One patient died due to fulminant ADV infection. Further complications were GvHD (n = 3) and bone marrow failure (n = 2). In conclusion, donor-specific allograft tolerance can be achieved by identical-donor HSCT/LDLT. However, at present, this approach should generally be limited to selected indications due to a potentially unfavorable risk-benefit ratio. Novel toxicity-reduced conditioning protocols for HSCT/LDLT in the absence of malignant or non-hepatic disease may prove to be a sufficiently safe approach for inducing graft tolerance in children receiving a LDLT in the future. This concept may reduce the burden of lifelong IS.

Immunological basis for treatment of graft versus host disease after liver transplant

Graft versus host disease (GVHD) after liver transplant, although a rare disease, has a very high mortality rate. GVHD occurs due to immunoreactions caused by donor T lymphocytes and host cell surface antigens resulting in proliferation and clonal expansion of T lymphocyte. Migration of effector cells, including macrophages, NK cells and cytotoxic T lymphocyte, to the target organs such as skin, intestine and bone marrow results in skin rashes, diarrhea and bone marrow depression. GVHD is diagnosed by clinical symptoms, histopathological findings and by the presence of chimerism. The delayed diagnosis, opportunistic infections and lack of definitive treatment of post orthotopic liver transplant (OLT)-GVHD results in sepsis and multi-organ failure leading to very low survival rates. In this review, we have focused on early diagnosis and critically discuss novel treatment modalities to decrease the incidence of GVHD.

Extracorporeal photopheresis in solid organ transplant-associated acute graft-versus-host disease

BACKGROUND

Extracorporeal photopheresis (ECP) culls pathogenic T lymphocytes, be these the clones of cutaneous T-cell lymphoma, or mediators of chronic graft-versus-host disease (GVHD) after allogeneic bone marrow transplantation (BMT-GVHD). Whether or not ECP may have an effect in the rarer instances of solid organ transplantation-associated GVHD (SOT-GVHD) is unclear. Mortality rates in SOT-GVHD rival those of transfusion-associated GVHD, with fatalities preceded by pancytopenia and peripheral blood chimerism (PBC) levels exceeding 20%. ECP has been described in two SOT-GVHD cases to date, with one surviving.

STUDY DESIGN AND METHODS

Clinicolaboratory features (including HLA relationships) in a case of multivisceral transplantation were reviewed from the time of surgery to the onset and progression of SOT-GVHD. ECP, which was introduced as a less immunosuppressive and more selective intervention, was assessed for its effect on serial PBC (as measured by short-tandem-repeat analysis) and clinical outcome.

RESULTS

Multivisceral SOT-GVHD manifested with erythroderma, neutropenic sepsis, and PBC increasing from 6% on Posttransplant Day (PTD) 38 to 78% by PTD 60 (at a doubling time of 6 days despite corticosteroids). ECP was administered on PTDs 62 and 67 and was associated with the first evidence of PBC decay to 67% on PTD 69. Death nevertheless ensued on the last day of salvage antithymocyte globulin (PTDs 69-73) despite further PBC reduction to 41%.

CONCLUSION

Further study is needed to determine if the sooner or more frequent application of ECP might attenuate the high case fatality rates of SOT-GVHD.

Macrochimerism in Intestinal Transplantation: Association With Lower Rejection Rates and Multivisceral Transplants, Without GVHD

Blood chimerism has been reported sporadically among visceral transplant recipients, mostly in association with graft-vs-host disease (GVHD). We hypothesized that a higher degree of mixed chimerism would be observed in multivisceral (MVTx) than in isolated intestinal (iITx) and isolated liver transplant (iLTx) recipients, regardless of GVHD. We performed a longitudinal prospective study investigating multilineage blood chimerism with flow cytometry in 5 iITx and 4 MVTx recipients up to one year posttransplant. Although only one iITx patient experienced GVHD, T cell mixed chimerism was detected in 8 out of 9 iITx/MVTx recipients. Chimerism was significantly lower in the four subjects who displayed early moderate to severe rejection. Pre-formed high-titer donor-specific antibodies, bound in vivo to the circulating donor cells, were associated with an accelerated decline in chimerism. Blood chimerism was also studied in 10 iLTx controls. Among nonsensitized patients, MVTx recipients exhibited greater T and B cell chimerism than either iITx or iLTx recipients. Myeloid lineage chimerism was present exclusively among iLTx and MVTx (6/13) recipients, suggesting that its presence required the hepatic allograft. Our study demonstrates, for the first time, frequent T cell chimerism without GVHD following visceral transplantation and a possible relationship with reduced rejection rate in MVTx recipients.

Bone marrow engraftment and associated dermatologic sequelae in a three-yr-old after liver transplantation

We present a case of a three-yr-old child with a history of multisystem Langerhans cell histiocytosis treated with systemic chemotherapy, who developed progressive liver failure and received an orthotopic split liver transplant while continuing on chemotherapy. One month following transplant, he developed acute graft-vs.-host disease of the skin and gastrointestinal tract. Peripheral blood chimerism studies post-transplant demonstrated an increasing predominance of donor lymphocytes and granulocytes. Shortly after, the patient developed vitiligo, and two yr after transplantation, the patient developed skin manifestations of psoriasis. We discuss and review the current literature, which demonstrates that chimerism following liver transplantation is rare and in our patient may be related to his profound immunosuppression around the time of liver transplant as well the development of acute graft-versus-host disease. While autoimmune disease can occur after solid organ and stem cell transplant, our patient developed skin manifestations of autoimmunity after liver transplantation, which is also rarely described.

Absence of peripheral blood chimerism in graft-vs-host disease following orthotopic liver transplantation: case report and review of the literature

BACKGROUND

Graft-vs-host disease (GVHD) is a rare and often fatal complication of orthotopic liver transplantation (OLT). The skin is frequently involved early in disease progression, but clinical and histopathological features may be nonspecific, presenting a diagnostic challenge. While the detection of peripheral blood chimerism has been proposed as a diagnostic criterion for post-OLT GVHD, it is not known whether peripheral blood chimerism is an absolute requirement for the diagnosis.

MATERIALS AND METHODS

We report a case of a 57-year-old man who developed post-OLT GVHD with cutaneous, enteric, and bone marrow involvement. We also review the epidemiology, pathogenesis, clinical presentation, histopathology, molecular diagnostic techniques, and treatment of GVHD following liver transplantation.

RESULTS

In our patient, analysis of the peripheral blood by short-tandem repeat polymerase chain reaction did not detect circulating donor lymphocytes. Donor lymphocytes were detected in the buccal mucosa, however, confirming the diagnosis. A review of chimerism patterns in 63 previously published cases of post-OLT GVHD reveals that this is the first reported case in which chimerism was absent in the peripheral blood but present in another site.

CONCLUSIONS

Peripheral blood chimerism may be absent in cases of post-OLT GVHD. A combination of clinical, histopathological, and molecular features is therefore required to make this challenging diagnosis.

Effect of reverse chimerism on rejection in clinical transplantation

Chimerism may enable allografts to survive when immunosuppressive therapy is administered at low levels or is even absent. Reverse chimerism (RC) is focused on intragraft chimerism that repopulates the allograft with cells of recipient origin. We aimed to identify and analyze current clinical evidence on RC and the presence of endothelial RC and tissue-specific RC. A total of 33 clinical reports on cardiac, kidney, liver, and lung transplants published between 1972 and 2012 that focused on RC were included in a systematic review. Liver allografts presented with the highest percentage of endothelial RC and lung allografts by far the lowest. Tissue-specific RC was present in most of the recipients, but at very low levels. There were also cardiac and kidney allografts with chimerism, but the functionality of the cells of recipient origin was questionable. We were unable to determine whether RC was a trigger for or a result of acute rejection. Further clinical research should focus on outcomes to evaluate the clinical relevance of this form of chimerism in transplantation.

Treatment of liver transplant graft-versus-host disease with antibodies against tumor necrosis factor-α

Acute graft-versus-host disease is uncommon after liver transplant. We recently treated a 60-year-old man with liver transplant for hepatocellular carcinoma. After the primary liver transplant graft did not function, revision liver transplant resulted in excellent function. Subsequently, the patient developed watery diarrhea, systemic inflammatory response syndrome, a skin rash on his limbs and trunk, and palmar erythema. Skin biopsy suggested viral exanthems consistent with cytomegalovirus. Despite treatment for cytomegalovirus, intestinal symptoms worsened. Analysis of peripheral blood with fluorescence-activated cell sorting showed a high proportion of T lymphocytes, with 5% to 10% T cells specific to the second donor, suggestive of graft-versus-host disease. Within 48 hours after beginning therapy with antibodies against tumor necrosis factor-α (infliximab), the skin rash disappeared and endoscopy showed slight improvement of the mucosal regeneration. However, despite antifungal prophylaxis with caspofungin, the patient developed angioinvasive pulmonary aspergillosis and multiple organ failure, and he died. In conclusion, typical clinical symptoms of graft-versus-host disease after liver transplant may include skin rash and gastrointestinal symptoms, and diagnosis may be confirmed by histologic examination and testing for blood chimerism. A consensus for the treatment of graft-versus-host disease still is lacking, but tumor necrosis factor-α is an encouraging target for therapy to decrease the symptoms of graft-versus-host disease and enable mucosal regeneration.

Relevance of HLA compatibility in living donor liver transplantation: the double-edged sword associated with the patient outcome

HLA compatibility in living donor liver transplantation (LDLT) seems relevant to the acceptability of graft livers because LDLT recipients often share most or some part of HLAs with the respective donors. This study retrospectively investigated whether HLA compatibility affected the outcome of LDLT. Three hundred ninety LDLTs were performed in this hospital, and 346 pairs of HLAs (HLA-A, B, DR) were retrieved from the medical record between October 1996 and March 2011. The dates of the deaths were censored when a recipient apparently died of or was retransplanted by other causes than graft failure because of host-versus-graft (HVG) response to purely analyze the outcomes of LDLT in view of HVG response. The relationship between HLA compatibility and graft-versus-host disease (GVHD) was also analyzed. No recipients with recipient-against-donor HLA mismatch (R→D MM) 0 experienced graft failure by HVG response. On the other hand, three of five recipients with "R→D MM 0" together with "donor-against-recipient MM 3" died of fatal GVHD. HLA compatibility in LDLT not only affected the long-term acceptance of graft livers but also the risk of fatal GVHD.

Hematopoietic chimerism in liver transplantation patients and hematopoietic stem/progenitor cells in adult human liver

Liver transplantation (LT) is a cure for many liver diseases. Blood chimerism of donor origin can develop after LT, which raises the possibility of the existence of hematopoietic stem/progenitor cells (HSPCs) in the liver. We characterized the blood chimerism in a large cohort of 249 LT patients and analyzed putative HSPCs in adult human livers. The overall incidence of chimerism was 6.43%, of which 11.11% was among short-term (1 day to 6 months) and 3.77% was among long-term (6 months to 8 years) LT patients. Hematopoietic Lin(-) CD34(+) CD38(-) CD90(+) populations have been demonstrated to generate long-term lymphomyeloid grafts in transplantations. In human adult livers, we detected Lin(-) CD34(+) CD38(-) CD90(+) populations accounting for 0.03% ± 0.017% of the total single liver cells and for 0.05% ± 0.012% of CD45(+) liver cells. Both Lin(-) CD34(+) and Lin(-) CD45(+) liver cells, from extensively perfused human liver grafts, were capable of forming hematopoietic myeloid-lineage and erythroid-lineage methylcellulose colonies. More importantly, Lin(-) CD45(+) or CD45(+) liver cells could be engrafted into hematopoietic cells in an immunodeficient mouse model. These results are the first evidence of the presence of putative HSPC populations in the adult human liver, where the liver is a good ectopic niche. The discovery of the existence of HSPCs in the adult liver have implications for the understanding of extramarrow hematopoiesis, liver regeneration, mechanisms of tolerance in organ transplantation, and de novo cancer recurrence in LT patients.

CONCLUSION

The human adult liver contains a small population of HSPCs. In LT patients, there are two types of chimerisms: transient chimerism, resulting from mature leucocytes, and long-term chimerism, derived from putative HSPCs in the liver graft.

Acute graft versus host disease after orthotopic liver transplantation

Graft versus host disease (GVHD) is an uncommon complication after orthotopic liver transplantation (OLT) with an incidence of 0.1–2%, but an 80–100% mortality rate. Patients can present with skin rashes, diarrhea, and bone marrow aplasia between two to eight weeks after OLT. Diagnosis of GVHD is made based on clinical and histologic evidence, supported by chimerism studies showing donor HLA alleles in the recipient bone marrow or blood. Several therapeutic approaches have been used for the management of GVHD after OLT including increased immunosuppression, decreased immunosuppression, and cellular therapies. However, success rates have been low, and new approaches are needed.

Chronic graft-versus-host disease after liver transplantation: a case report

Graft-versus-host disease (GVHD) after orthotopic liver transplantation (OLT) is a rare but significant complication, occurring in 1%-2% of cases with a mortality rate of 85%- 90%. It occurs when donor passenger lymphocytes mount an alloreactive response against the host's histocompatibility antigens. It presents as fever, rash, and diarrhea with or without pancytopenia. Between March 2002 and September 2011, among 656 OLT patients 1 (0.15%) had acute GVHD. A biopsy at the 7th posttransplantation month revealed chronic GVHD. Consequently, in the cases that had fever, rash, and/or desquamation of the any part of body after liver transplantation, GVHD must be considered and skin biopsies must be planned for the diagnosis.

Unsuccessful treatment of four patients with acute graft-vs-host disease after liver transplantation

AIM: To investigate appropriate therapeutic strategies for graft-vs-host disease (GVHD) following liver transplantation.

METHODS: Four patients who developed GVHD after liver transplantation in West China Hospital were included in this study. Therapeutic strategies with augmentation or withdrawal of immunosuppressants combined with supportive therapy were investigated in these patients. In addition, a literature review of patients who developed GVHD after liver transplantation was performed.

RESULTS: Although a transient response to initial treatment was detected, all four patients died of complications from GVHD: one from sepsis with multiple organ failure, one from gastrointestinal bleeding, and the other two from sepsis with gastrointestinal bleeding. Few consensuses for the treatment of GVHD after liver transplantation have been reached.

CONCLUSION: New and effective treatments are required for GVHD after liver transplantation to improve the prognosis of patients with this diagnosis.

Correlation of Chimerism with Acute Graft-versus-Host Disease in Rats following Liver Transplantation

The accurate diagnosis of acute graft-versus-host disease following liver transplantation (LTx-aGVHD) has been hampered. Chimerism appears in the majority of recipients after LT and its significance in the diagnosis of LTx-aGVHD has not been clearly established. To demonstrate the significance of chimerism on the diagnosis of LTx-aGVHD, we compared the change of chimerism in syngeneic LT recipients, semiallogeneic LT recipients, and LTx-aGVHD induced recipients. Chimerism in PBMCs following sex-mismatched LT was identified by real-time PCR based on a rat Y-chromosome-specific primer. All recipients in semiallogeneic group grew in a normal pattern. However, when 4 × 10(8) donor splenocytes were transferred simultaneously during LT, the morbidity of lethal aGVHD was 100%. The chimerism appeared slightly higher in the semiallogeneic group than in the syngeneic LT group, but the difference was not significant. However, when the recipients developed lethal aGVHD after LT, chimerism in the PBMCs increased progressively, and even at an early time, a significant increase in chimerism was observed. In conclusion, high level chimerism correlated well with LTx-aGVHD, and detection of chimerism soon after transplantation may be of value in the diagnosis of LTx-aGVHD prior to the onset of symptoms.

Solid organ transplant-associated acute graft-versus-host disease

Solid organ transplant-associated graft-versus-host disease is an infrequent and potentially lethal complication. The incidence of this complication varies according to the type of organ transplant with higher rates associated with liver and small bowel transplants. The clinical presentation typically includes fever and skin rash, and most cases quickly advance to become a multisystem disease affecting the bone marrow and other nontransplanted solid organs. The diagnosis is based on the clinical symptoms, pathologic changes in biopsied tissues, and systemic lymphoid chimerism. The mortality of this disease can exceed 75% after liver transplant and most patients die from infections or hemorrhage due to bone marrow failure. There is no standard treatment strategy for this complication, and the management mainly consists of both prophylaxis and immediate treatment without delay. This short review summarizes the current pathogenesis, diagnosis, and treatment of this entity.

Should microchimerism turn into rejection prophylactics?

Non-self cells can circulate in the body of an individual after any sort of contact with an allogeneic source of cells, thus creating a situation of chimerism that can be transient or prolonged over time. This situation may appear after stem cell transplantation, pregnancy, transfusion or transplantation. Concerning transplantation, many hypotheses have been formulated regarding the existence, persistence and role of these circulating cells in the host. We will review the principal hypotheses that have been formulated for years since the first description of non-self circulating cells in mammals to the utilization of artificially induced chimerism protocols for the achievement of tolerance.

Avoiding pitfalls: what an endoscopist should know in liver transplantation--part II

Over the last decade the number of patients undergoing transplantation has increased. At the same time, effective peri- and postoperative care and better surgical techniques have resulted in greater numbers of recipients achieving long-term survival. Identification and effective management in the form of adequate treatment is essential, since any delay in diagnosis or treatment may result in graft loss or serious threat to patient's life. Various aspects of endoscopic findings that can be commonly encountered among liver transplant recipients are discussed herein. Topics include: persistent and/or recurrent esophageal varices, reflux, Candida or cytomegalovirus (CMV) esophagitis, esophageal neoplasms, posttransplant peptic ulcer, biliary complications, posttransplant lymphoproliferative disorder (PTLD), Kaposi's sarcoma, CMV colitis and inflammatory bowel disease, colonic neoplasms, Clostridium difficile infection, and graft versus host disease (GVHD).

Infliximab treatment for steroid-refractory acute graft-versus-host disease after orthotopic liver transplantation: a case report

Acute graft-versus-host disease (GVHD) following orthotopic liver transplantation is a rare but severe disease with a 75% death rate in adults. Various therapeutic strategies have been proposed for steroid-refractory GVHD, but there is still no consensus. Tumor necrosis factor-alpha is a key inflammatory cytokine involved in acute GVHD physiopathology, and infliximab has shown encouraging results for the treatment of acute GVHD following hematopoietic stem cell transplantation. We report the first case of acute GVHD following liver transplantation that was refractory to steroids and anti-lymphocyte globulin but was successfully treated with infliximab.

FISH diagnosis of acute graft-versus-host disease following living-related liver transplant

Acute graft-versus-host disease (GVHD) is an uncommon but often fatal complication following liver transplant. We describe a GVHD case in which a female patient with primary biliary cirrhosis underwent a living-related liver transplant from her son. The human leukocyte antigen typing of the donor was homozygous at all loci. The recipient's human leukocyte antigen type was haplo-identical to that of the donor. A bone marrow aspirate performed for pancytopenia revealed a severely hypoplastic marrow. Fluorescent in situ hybridization (FISH) using X- and Y-chromosome probes demonstrated that 80% of marrow cells were of donor origin. Comparison of Giemsa-stained cell morphology and FISH showed that the erythroid precursor cells were predominantly of male pattern (XY). This report is one of only a few studies that prove the migration of a donor's hematopoietic stem cells to a recipient's bone marrow. We demonstrated that FISH analysis using sex chromosome probes is useful to confirm a diagnosis of GVHD following organ transplantation from a donor of the opposite sex. We also showed that donor hematopoietic stem cells in a liver graft can migrate to the recipient's bone marrow. We suggest that FISH is a rapid and reliable test for confirming the diagnosis of GVHD in a peripheral blood or skin biopsy sample.

Acute graft-versus-host disease after liver transplant: novel use of etanercept and the role of tumor necrosis factor alpha inhibitors

Acute graft-versus-host disease following orthotopic liver transplantation is a rare but feared complication arising in 1% to 2% of cases with a dismal prognosis. It most often presents as fever, rash, and diarrhea with or without pancytopenia. Patients die from complications of marrow failure such as sepsis or bleeding. Because of its low incidence, there is no clear treatment protocol for this complication. Both increasing and withdrawing immunosuppression have been attempted with variable success. Although anti-tumor necrosis factor alpha therapy has been widely used for the treatment of steroid-resistant acute graft-versus-host disease in the hematopoietic stem cell transplant setting, there previously have been no reported cases of its use in liver transplantation. The aim of this report is to review a case of acute graft-versus-host disease and the use of etanercept to manage this complication. Etanercept has never previously been used in liver transplantation complicated by acute graft-versus-host disease. In the hematology literature, the success of its use is offset by significant rates of serious infectious (especially fungal) complications. However, preliminary results are encouraging and offer insight into its use as a potentially viable therapeutic option. We report the first successful use of etanercept in liver transplantation-associated graft-versus-host disease, albeit complicated by invasive aspergillosis, and recommend concurrent antifungal prophylaxis when the drug is used in this setting.