Review article: management of hepatic disease following haematopoietic cell transplant

Profile of Hepatobiliary Dysfunction in Hematopoietic Stem Cell Transplant Recipients - An Indian Perspective

BACKGROUND/AIMS

Hematopoietic stem cell transplantation (HSCT) is an established curative modality for various hematological malignancies and other diseases. Hepatobiliary dysfunction and subsequent sequelae constitute a common cause of morbidity and mortality in post-transplant scenario. However, data among Indian HSCT recipients is lacking.

METHODS

One hundred and one HSCT recipients (37 prospective and 64 retrospective) were followed up for hepatobiliary dysfunction in the post-transplant period. The causes for hepatobiliary dysfunction were categorized as sinusoidal obstruction syndrome (SOS), formerly known as veno-occlusive disease (VOD); acute and chronic graft-versus- host disease (GVHD); drug-induced liver injury (DILI); viral infections and miscellaneous causes including bacterial, fungal and unknown causes based on clinical and laboratory evidence.

RESULTS

Among the 101 transplants, 56.44% (n = 57) were allogenic transplants, and 43.56% (n = 44) were autologous transplants. Hepatobiliary dysfunction was observed among 71 (70.30%) patients in first 30 days and overall, among 78 (77.23%) patients. Incidence of hepatobiliary dysfunction was higher among allogenic transplant patients compared to autologous transplants (91.23% vs. 59.09%, p < 0.001). The most common cause of hepatobiliary dysfunction reported was Drug-induced liver injury (DILI). In most cases, however, hepatobiliary dysfunction was multifactorial. Sinusoidal obstruction syndrome (15.79%), acute liver GVHD (31.58%), chronic liver GVHD (33.33%) and viral infection/reactivation (26.32%) were reported only in allogenic transplant patients. 15 (14.85%) patients died of which 14 patients had hepatobiliary dysfunction, commonest cause being infections.

CONCLUSION

Our study reported a higher incidence of hepatobiliary dysfunction among Indian population post HSCT and was associated with significant mortality. In majority of the cases, the cause is multifactorial and pose a diagnostic dilemma and challenges in therapy.

HLA haploidentical peripheral blood stem cell transplantation using reduced dose of posttransplantation cyclophosphamide for poor-prognosis or refractory leukemia and myelodysplastic syndrome

Nonmyeloablative, human leukocyte antigen (HLA) haploidentical, T-cell-replete bone marrow transplantation followed by high-dose posttransplantation cyclophosphamide (PT/Cy) has recently been developed. This transplantation milieu has resulted in favorable outcomes with low transplantation-related mortality, owing to a low incidence of graft-versus-host disease (GVHD), without increased infectious complications. However, the high relapse rate remains a major concern. We therefore performed a prospective pilot study of HLA haploidentical peripheral blood stem cell transplantation (PBSCT) with intensified conditioning, followed by two lower doses of PT/Cy. A total of 20 patients with refractory or poor-prognosis myelodysplastic syndrome (MDS) and leukemia were enrolled in the study. A trend toward a lower incidence of grade III-IV acute GVHD at day 100 in the group receiving 25 mg/kg × 2 doses of PT/Cy, compared with the group receiving 25 mg/kg of PT/Cy (9.1% vs. 33%, p = 0.20), was noted. However, the cumulative incidence of chronic GVHD was low, at 10% irrespective of PT/Cy dose. The number of infused CD34(+) cells significantly correlated with the grade of acute GVHD (p = 0.004). In addition, the occurrence of BK virus hemorrhagic cystitis was significantly more common in the double-dose PT/Cy group (25% vs. 0%, p = 0.043), especially when combined with busulfan. The probability of overall survival at 1 year in the double-dose group tended to be better compared with that in the single-dose group (64% vs. 44%, respectively; p = 0.20). In conclusion, HLA haploidentical, T-cell-replete PBSCT with 25 mg/kg × 2 doses of PT/Cy might be a feasible option for treating high-risk leukemia and MDS.

Preparative regimen dosing for hematopoietic stem cell transplantation in patients with chronic hepatic impairment: analysis of the literature and recommendations

Hematopoietic stem cell transplantation (HSCT) is a potentially life-saving therapy for patients with malignant and nonmalignant disease states. Transplant has been associated with high treatment-related morbidity and mortality, therefore limiting its usefulness in patients with baseline liver dysfunction. In the event that a patient with hepatic insufficiency is selected for HSCT, dosage adjustments may be considered; however, no reliable endogenous biomarkers can serve as a guide for adjustments. There is no clear standard or guideline for how to approach these patients, and most adjustments are made empirically on the basis of expert opinion. This article offers practical advice and outlines our personal approaches to provide dosing recommendations for commonly-used preparative agents in the setting of hepatic impairment with the aim to optimize dosing for this patient population.

Immunoproteomic analysis of potentially severe non-graft-versus-host disease hepatitis after allogenic bone marrow transplantation

The development of potentially severe non-graft-versus-host disease (GVHD) hepatitis resembling autoimmune hepatitis (AIH) has been reported after bone marrow transplantation (BMT). The aim of this study was to better characterize this form of hepatitis, particularly through the identification of autoantigens recognized by patient sera. Five patients who received an allogeneic BMT for the treatment of hematological diseases developed liver dysfunction with histological features suggestive of AIH. Before and during the onset of hepatic dysfunction, sera were tested on immunoblottings performed with cytosolic, microsomal, mitochondrial, and nuclear proteins from rat liver homogenate and resolved by two-dimensional electrophoresis. Antigenic targets were identified by mass spectrometry. During the year that followed BMT, all patients presented with GVHD. Acute hepatitis then occurred after the withdrawal, or during the tapering, of immunosuppressive therapy. At that time, no patients had a history of liver toxic drug absorption, patent viral infection, or any histopathological findings consistent with GVHD. Immunoreactive spots stained by sera collected at the time of hepatic dysfunction were more numerous and more intensely expressed than those stained by sera collected before. Considerable patient-dependent pattern heterogeneity was observed. Among the 259 spots stained exclusively by sera collected at the time of hepatitis, a total of 240 spots were identified, corresponding to 103 different proteins. Twelve of them were recognized by sera from 3 patients.

CONCLUSIONS

This is the first immunological description of potentially severe non-GVHD hepatitis occurring after BMT, determined using a proteomic approach and enabling a discussion of the mechanisms that transform an alloimmune reaction into an autoimmune response. Any decision to withdraw immunosuppression after allogeneic BMT should be made with caution.

Role of pharmacogenetics in busulfan/cyclophosphamide conditioning therapy prior to hematopoietic stem cell transplantation

Hematopoietic stem cell transplantation (HSCT) is a curative treatment for several malignant and nonmalignant disorders. Busulfan (Bu) and cyclophosphamide (Cy) are the most commonly used alkylators in high-dose pretransplant conditioning for HSCT; a treatment that is correlated with drug-related toxicity and relapse. Pharmacogenetic investigations have shown that CYP450, as well as aldehyde dehydrogenase, are clearly involved with Cy metabolism and are associated with altered treatment response, Cy metabolism and the unique stem-cell sparing capacity. Moreover, glutathione-S-transferase isoenzymes have been associated with cellular outward transport of various alkylating agents, including Cy metabolites, melphalan, Bu and chlorambucil. A shift from genetic-based studies to whole-genome-based investigations of Cy- and Bu-associated markers may contribute to personalizing the conditioning therapy and enhancing the clinical outcome of HSCT.

How can we reduce hepatic veno-occlusive disease-related deaths after allogeneic stem cell transplantation?

Hepatic veno-occlusive disease (VOD) is a common and potentially devastating complication of hematopoietic stem cell transplantation. Confirmative diagnosis of this disorder can prove difficult early post hematopoietic stem cell transplantation, as a broad differential diagnosis exists and no definitive diagnostic test is available. Incidence of VOD has decreased in recent years, with especially dramatic declines in severe and fatal VOD. This improvement is attributed to less toxic and reduced-intensity conditioning regimens, and more appropriate patient selection. When severe VOD does occur, current treatments have been largely ineffective. Prevention remains the primary tool in the clinician's arsenal for managing VOD. Our institution pursues aggressive preventative measures for VOD, including appropriate conditioning regimen selection, avoiding hepatotoxic drugs, early prophylactic use of ursodiol, and aggressive fluid management. With appropriate management steps, we believe the incidence of VOD and related deaths can be further decreased.

Iron overload in patients undergoing hematopoietic stem cell transplantation

Recipients of hematopoietic stem cell transplantation (HSCT) frequently have iron overload resulting from chronic transfusion therapy for anemia. In some cases, for example, in patients with myelodysplastic syndromes and thalassemia, this can be further exacerbated by increased absorption of iron from the gut as a result of ineffective erythropoiesis. Accumulating evidence has established the negative impact of elevated pretransplantation serum ferritin, a surrogate marker of iron overload, on overall survival and nonrelapse mortality after HSCT. Complications of HSCT associated with iron overload include increased bacterial and fungal infections as well as sinusoidal obstruction syndrome and possibly other regimen-related toxicities. Based on current evidence, particular attention should be paid to prevention and management of iron overload in allogeneic HSCT candidates, especially in patients with thalassemia and myelodysplastic syndromes. The pathophysiology of iron overload in the HSCT patient and optimum strategies to deal with iron overload during and after HSCT require further study.

Severe hepatocellular injury after hematopoietic cell transplant: incidence, etiology and outcome

Hepatic complications of transplant are a common cause of mortality. Although mild elevations of serum aminotransferase enzymes (aspartate and alanine (AST, ALT)) do not carry an adverse prognosis, this is not the case with severe hepatocellular injury. We reviewed 6225 consecutive recipients to determine the incidence and outcomes of severe hepatocellular injury (AST >1500 U/l) before day 100, which occurred in 88 patients. Causes were sinusoidal obstruction syndrome (SOS) (n = 46), hypoxic hepatitis (n = 33), varicella zoster virus (VZV) hepatitis (n = 4), drug-liver injury (n = 2) and unknown (n = 3). The incidence declined from 1.9% in the 1990s to 1.1% recently (owing to a fivefold decline in SOS and disappearance of VZV hepatitis). In hypoxic hepatitis, peak serum AST was 3545 U/l (range, 1380-25 246) within days of shock or prolonged hypoxemia; case fatality rate was 88%. In SOS, AST increases occurred 2-6 weeks after diagnosis; peak AST was 2252 U/l (range, 1437-8281); case fatality rate was 76%, with only serum bilirubin able to distinguish survivors (2.7 vs 11.3 mg/100 ml, P=0.0009). We conclude that circulatory insults (sinusoidal injury, hypotension and hypoxemia), and not infection, are the most common cause of severe hepatocellular injury, the frequency of which has declined because of a falling incidence of SOS and VZV hepatitis.

Personalized dosing of cyclophosphamide in the total body irradiation-cyclophosphamide conditioning regimen: a phase II trial in patients with hematologic malignancy

This study investigates the efficacy and safety of personalized cyclophosphamide (CY) dosing in 50 patients receiving CY along with total body irradiation (TBI). Participants received CY 45 mg/kg with subsequent therapeutic drug monitoring using Bayesian parameter estimation to personalize the second CY dose to a target area under the curve (AUC) for carboxyethylphosphoramide mustard (CEPM) (a reporter molecule for CY-derived toxins) and for hydroxycyclophosphamide (to ensure engraftment). The mean second CY dose was 66 mg/kg; the total dose ranged from 45 to 145 mg/kg. After completion of this phase II study, we compared participants' clinical outcomes with those of concurrent controls (n = 100) who received TBI along with standard CY doses of 120 mg/kg. Patients receiving personalized CY dosing had significantly lower postconditioning peak total serum bilirubin (P = 0.03); a 38% reduction in the hazard of acute kidney injury (AKI) (P = 0.03); and nonrelapse and overall survival rates similar to those in the controls (P = 0.70 and 0.63, respectively) despite the lower doses of CY administered to most of the patients in the personalized dosage group.

The role of liver biopsy in the workup of liver dysfunction late after SCT: is the role of iron overload underestimated?

Abnormalities in liver function tests are common in hematopoietic SCT (HSCT) recipients. We retrospectively investigated the role of liver biopsy in determining the cause of elevated liver enzymes and its impact on the management of patients in the post-HSCT setting. A total of 24 consecutive liver biopsies were obtained from 20 patients from September 2003 to December 2007. A definite histopathologic diagnosis was obtained in 91.7% of the biopsies. Iron overload (IO) was found in 75% and GVHD in 54.2% of the patients. The initial clinical diagnosis of GVHD was confirmed in 56.5% and refuted in 43.5% of the allogeneic HSCT recipients. The median number of post transplant transfusions, percent transferrin saturation and ferritin levels were found to be higher in patients who had histologically proven hepatic IO (p1=0.007, p2=0.003 and p3=0.009, respectively). Regression analysis showed a significant correlation between serum ferritin levels and histological grade of iron in the hepatocytes. Our data suggest that hepatic IO is a frequent finding in the post-HSCT setting, which contributes to hepatic dysfunction and it should be considered in the differential diagnosis, particularly in patients with high serum ferritin levels.

Allogeneic hematopoietic cell transplant in HCV-infected patients

Hepatitis C virus (HCV) is a major cause of liver disease worldwide. After allogeneic Hematopoietic Cell Transplant (HCT), HCV is known to be associated with transient hepatitis in the immediate post-transplant period, and a potential risk factor of veno-occlusive disease (SOS). Very recently, HCV-infected HCT recipients have been shown to be at higher risk of earlier cirrhosis, leading to greater morbidity and mortality. Long-term survivors after HCT are thus at a high risk for HCV-related complications and, as a consequence, the treatment of HCV infection becomes critical. We describe here the potential clinical complications in HCV-infected recipients, in the short, but also the long-term follow-up after HCT. The pathophysiology of liver fibrosis is discussed as well as the present recommended therapy in this particular population.

Acute graft versus host disease

Acute graft-versus-host disease (GVHD) occurs after allogeneic hematopoietic stem cell transplant and is a reaction of donor immune cells against host tissues. Activated donor T cells damage host epithelial cells after an inflammatory cascade that begins with the preparative regimen. About 35%-50% of hematopoietic stem cell transplant (HSCT) recipients will develop acute GVHD. The exact risk is dependent on the stem cell source, age of the patient, conditioning, and GVHD prophylaxis used. Given the number of transplants performed, we can expect about 5500 patients/year to develop acute GVHD. Patients can have involvement of three organs: skin (rash/dermatitis), liver (hepatitis/jaundice), and gastrointestinal tract (abdominal pain/diarrhea). One or more organs may be involved. GVHD is a clinical diagnosis that may be supported with appropriate biopsies. The reason to pursue a tissue biopsy is to help differentiate from other diagnoses which may mimic GVHD, such as viral infection (hepatitis, colitis) or drug reaction (causing skin rash). Acute GVHD is staged and graded (grade 0-IV) by the number and extent of organ involvement. Patients with grade III/IV acute GVHD tend to have a poor outcome. Generally the patient is treated by optimizing their immunosuppression and adding methylprednisolone. About 50% of patients will have a solid response to methylprednisolone. If patients progress after 3 days or are not improved after 7 days, they will get salvage (second-line) immunosuppressive therapy for which there is currently no standard-of-care. Well-organized clinical trials are imperative to better define second-line therapies for this disease. Additional management issues are attention to wound infections in skin GVHD and fluid/nutrition management in gastrointestinal GVHD. About 50% of patients with acute GVHD will eventually have manifestations of chronic GVHD.