Post-transplant lymphoproliferative disorder in pediatric intestinal transplant recipients: A literature review

Gut and liver involvement in pediatric hematolymphoid malignancies

Hematolymphoid malignancies are common neoplasms in childhood. The involvement of the gastrointestinal (GI) tract, liver, biliary system, pancreas, and peritoneum are closely interlinked and commonly encountered. In leukemias, lymphomas, and Langerhans cell histiocytosis (LCH), the manifestations result from infiltration, compression, overwhelmed immune system, and chemotherapy-induced drug toxicities. In acute leukemias, major manifestations are infiltrative hepatitis, drug induced gastritis, neutropenic typhlitis and chemotherapy related pancreatitis. Chronic leukemias are rare. Additional presentation in lymphomas is cholestasis due to infiltration or biliary obstruction by lymph nodal masses. Presence of ascites needs a thorough workup for the underlying pathophysiology that may modify the therapy and affect the outcome. Uncommon hematolymphoid malignancies are primary hepatic, hepatosplenic, and GI lymphomas which have strict definitions. In advanced diseases with extensive spread, it may be impossible to distinguish these diseases from the primary site of origin. LCH produces biliary strictures that mimic as sclerosing cholangitis. Liver infiltration is associated with poor liver recovery even after chemotherapy. The heterogeneity of gut and liver manifestations in hematolymphoid malignancies has a clinical impact on their management. Though chemotherapy is the mainstay of therapy in all hematolymphoid malignancies, debulking surgery and radiotherapy have an adjuvant role in specific clinical scenarios. Rare situations presenting as liver failure or end-stage liver disease require liver transplantation. At their initial presentation to a primary care physician, given the ambiguity in clinical manifestations and the prognostic difference with time-bound management, it is vital to recognize them early for optimal outcomes. Pooled data from robust registries across the world is required for better understanding of these complications.

Course of renal allograft function after diagnosis and treatment of post-transplant lymphoproliferative disorders in pediatric kidney transplant recipients

BACKGROUND

Post-transplant lymphoproliferative disease (PTLD) is a life-threatening complication in renal transplant recipients. Immunomodulatory and chemotherapeutic treatment potentially affect allograft function. The aim of this study was to evaluate graft function of pediatric kidney transplant recipients following diagnosis and standardized treatment of PTLD.

METHODS

Patients were identified from the German Ped-PTLD registry, and data on renal function were retrospectively retrieved from patient charts. For PTLD treatment, immunosuppressive therapy was reduced and all children received rituximab (375 mg/m² ) for up to six doses. Two patients required additional low-dose chemotherapy. Renal allograft function was monitored by consecutive measurements of estimated glomerular filtration rate (eGFR) at defined time points. Follow-up was up to 60 months after PTLD.

RESULTS

Twenty patients were included in this cohort analysis. Median time from transplantation to PTLD was 2.4 years. Histopathology showed monomorphic lesions in 16 and polymorphic in 4 patients. Two patients experienced PTLD relapse after 2 and 14 months. Range-based analysis of variance showed stable allograft function in 17 of 20 patients (85%). Mean eGFR increased during early treatment phase. One patient experienced graft rejection 5.3 years after diagnosis of PTLD. Another patient developed recurrence of primary renal disease (focal-segmental glomerulosclerosis) and lost his renal allograft 3.8 years post-transplant (2.0 years after PTLD diagnosis).

CONCLUSION

Treatment of PTLD with rituximab with or without low-dose chemotherapy in combination with reduced immunosuppression, mostly comprising of an mTOR inhibitor-based, calcineurin inhibitor-free regimen, is associated with stable graft function and favorable graft survival in pediatric renal transplant patients.

Current Practices on Diagnosis, Prevention and Treatment of Post-Transplant Lymphoproliferative Disorder in Pediatric Patients after Solid Organ Transplantation: Results of ERN TransplantChild Healthcare Working Group Survey

(1) Background: Post-transplant lymphoproliferative disease (PTLD) is a significant complication of solid organ transplantation (SOT). However, there is lack of consensus in PTLD management. Our aim was to establish a present benchmark for comparison between international centers and between various organ transplant systems and modalities; (2) Methods: A cross-sectional questionnaire of relevant PTLD practices in pediatric transplantation was sent to multidisciplinary teams from 17 European center members of ERN TransplantChild to evaluate the centers’ approach strategies for diagnosis and treatment and how current practices impact a cross-sectional series of PTLD cases; (3) Results: A total of 34 SOT programs from 13 European centers participated. The decision to start preemptive treatment and its guidance was based on both EBV viremia monitoring plus additional laboratory methods and clinical assessment (61%). Among treatment modalities the most common initial practice at diagnosis was to reduce the immunosuppression (61%). A total of 126 PTLD cases were reported during the period 2012–2016. According to their histopathological classification, monomorphic lesions were the most frequent (46%). Graft rejection after PTLD remission was 33%. Of the total cases diagnosed with PTLD, 88% survived; (4) Conclusions: There is still no consensus on prevention and treatment of PTLD, which implies the need to generate evidence. This might successively allow the development of clinical guidelines.

Late graft loss after intestinal transplantation

PURPOSE OF REVIEW

Despite improvement in short-term outcomes after intestinal transplantation in the last 20 years, long-term rates of graft attrition and patient survival remain unchanged, with worse outcomes compared with other solid organ transplants. This review investigates the multiple causes of late graft loss, including chronic rejection, infection, graft-versus-host disease, posttransplant lymphoproliferative disorder and postsurgical complications.

RECENT FINDINGS

New insights into immunology of the intestine and evolution of immunosuppression, as well as review of current persistent causes of late graft loss, shed light on findings that may help improve long-term intestinal allograft survival.

SUMMARY

Although intestinal transplantation remains a life-saving intervention with significant advancements since its inception, further understanding of mechanisms of injury is needed to improve long-term outcomes and prevent late intestinal graft loss.

Factors Associated With 5- and 10-Year Survival After Intestinal Transplantation in Infants and Children

OBJECTIVES

Intestinal transplantation is an option for permanent intestinal failure with parenteral nutrition intolerance. We sought to determine long-term intestinal graft survival in pediatric patients at our center and to identify factors influencing survival.

METHODS

Retrospective chart review of 86 patients transplanted between 2003 and 2013, targeting potential explanatory variables related to demographics, perioperative factors, and postoperative complications.

RESULTS

Intestinal graft survival was 71% and 65% after 5 and 10 years, respectively. Five-year graft survival was attained in 79% of patients with a history of anatomic intestinal failure compared with 45% with functional intestinal failure (P = 0.0055). Compared with nonsurvival, 5-year graft survival was also associated with reduced incidences of graft-versus-host disease (2% vs 16%, P = 0.0237), post-transplant lymphoproliferative disorder (3% vs 24%, P = 0.0067), and de novo donor-specific antibodies (19% vs 57%, P = 0.0451) plus a lower donor-recipient weight ratio (median 0.727 vs 0.923, P = 0.0316). Factors not associated with 5-year intestinal graft survival included graft rejection of any severity and inclusion of a liver graft. Factors associated with graft survival at 10 years were similar to those at 5 years.

CONCLUSIONS

In our experience, outcomes in pediatric intestinal transplantation have improved substantially for anatomic but not functional intestinal failure. Graft survival depends on avoidance of severe infectious and immunological complications including GVHD, whereas inclusion of a liver graft provides no obvious survival benefit. Reduced success with functional intestinal failure may reflect inherently increased susceptibility to complications in this group.

Hematologic malignancies of the gastrointestinal luminal tract

Hematologic malignancies include several lymphoproliferative and myeloproliferative disorders, many of which are frequently encountered in current health care settings. These malignancies frequently affect the gastrointestinal (GI) tract, either by secondary extranodal or extramedullary extension to the GI tract, or as a primary process arising in the GI tract. In fact, the GI tract may represent the most common extranodal site of involvement in many of them, such as lymphoma. Furthermore, in the current era of improved cancer treatment and advanced transplant procedures with increased survival, it has been quite common to encounter GI involvement by these malignancies through the disease course. Post-transplant lymphoproliferative disorder following kidney transplantation, for example, very commonly involves the GI tract. Other conditions that can involve the GI tract include multiple myeloma, plasmacytoma, myeloid sarcoma, mastocytosis, and Castleman disease. Imaging diagnosis of these malignancies can be challenging, since they are much less common than primary GI cancers and both share many common imaging features as well. However, certain imaging features, particularly in combination with a matching clinical scenario, play a pivotal role in diagnosing these conditions and directing further evaluation. In this article, we review common and rare hematologic malignancies of the GI tract and discuss their pathophysiologic, clinical, and imaging features.

Donor helper innate lymphoid cells are replaced earlier than lineage positive cells and persist long-term in human intestinal grafts - a descriptive study

Intestinal grafts carry large donor lymphoid load that is replaced by recipient cells. The dynamics of this process may influence the tolerance, rejection or graft-versus-host disease. We analysed distribution and turnover of T and B (Lin+) lymphocytes, natural killer (NK) and helper innate lymphoid cells (hILC) in intestinal epithelium (IEp) and lamina propia (LP) from a long-term cohort of eight intestinal recipients and from a single patient monitored deeply during the first 8 months post-transplant (posTx). Long-term intestinal grafts showed significantly higher %hILC than native bowels in IEp and LP until 10 years posTx and recovery to normal levels was observed afterwards. We also observed an imbalance between hILC subsets in IEp [increase of type 1 (ILC1) and decrease in type 3 (ILC3) innate lymphoid cells] that persisted along posTx time even when %hILC was similar to native bowels. Regarding hILC origin, we still detected the presence of donor cells at 13 years posTx. However, this chimerism was significantly lower than in Lin+ and NK populations. According to these findings, observation from the patient monitored in early posTx period showed that recipient hILC repopulate earlier and faster than Lin+ cells, with increase in ILC1 related to rejection and infection episodes.