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.

Viral enteritis in intestinal transplant recipients

Intestinal transplant recipients (ITR) are at high risk for infections due to the high level of immunosuppression required to prevent rejection. There are limited data regarding viral enteritis post-intestinal transplantation. We retrospectively reviewed ITR transplanted between January 2008 and December 2016. Descriptive statistics, including mean (standard deviation) and median (range), were performed. Sixty-one (43.9%) of the 139 transplanted patients had viral enteritis: 26% norovirus, 25% adenovirus, and 9% each rotavirus and sapovirus. The median age of pediatric patients was 1.6 years (0.4-16.9) and for adults 36.3 years (27.1-48.2). Fifty-seven (58%) of 99 pediatric ITR had viral enteritis compared to 4 (10%) of 40 adult ITR. Median time-to-clinical resolution of enteritis for all patients was 5 days (1-92). Standard of care therapies administered: anti-motility agents (10%), anti-emetics agents (14%), and intravenous fluids (42%). There was a higher incidence of viral enteritis in pediatric compared to adults ITR. The majority of viral enteritis episodes resolved within 1 week and were treated with supportive therapy.

Life of patients 10 years after a successful pediatric intestinal transplantation in Europe

A multicenter Europe-wide single-point study in intestinal transplantation (ITx) centers was conducted to identify and describe patients surviving for more than 10 years after ITx in childhood. The health and nutritional status, care requirements and psychosocial status were recorded. Among 120 transplanted before 2005, 38 patients with a functioning graft were included. Thirty (79%) had an exclusive oral diet, seven (18%) complimentary enteral nutrition for eating disorders, and one a combination of parenteral and enteral nutrition. They received a median of five drugs daily and five had a stoma. We did not observe any catch-up growth during the 10 years of follow-up. In the previous five years, 22 patients needed unplanned hospitalization with a median in-patient stay of six days. Eleven needed ongoing psychiatric follow-ups, and nine needed other specialist follow-ups. An increasing independency from parents was seen after the age of 18, with three having a stable employment and 31 pursuing education. Despite a good graft function, growth may not catch up. The burden of medical care remains high in the long term. This has to be closely followed in a multidisciplinary setting to improve long-term quality of life in these patients.

Infectious Complications Following Small Bowel Transplantation

Microbiological spectrum and outcome of infectious complications following small bowel transplantation (SBT) have not been thoroughly characterized. We performed a retrospective analysis of all patients undergoing SBT from 2004 to 2013 in Spain. Sixty-nine patients underwent a total of 87 SBT procedures (65 pediatric, 22 adult). The median follow-up was 867 days. Overall, 81 transplant patients (93.1%) developed 263 episodes of infection (incidence rate: 2.81 episodes per 1000 transplant-days), with no significant differences between adult and pediatric populations. Most infections were bacterial (47.5%). Despite universal prophylaxis, 22 transplant patients (25.3%) developed cytomegalovirus disease, mainly in the form of enteritis. Specifically, 54 episodes of opportunistic infection (OI) occurred in 35 transplant patients. Infection was the major cause of mortality (17 of 24 deaths). Multivariate analysis identified retransplantation (hazard ratio [HR]: 2.21; 95% confidence interval [CI]: 1.02-4.80; p = 0.046) and posttransplant renal replacement therapy (RRT; HR: 4.19; 95% CI: 1.40-12.60; p = 0.011) as risk factors for OI. RRT was also a risk factor for invasive fungal disease (IFD; HR: 24.90; 95% CI: 5.35-115.91; p < 0.001). In conclusion, infection is the most frequent complication and the leading cause of death following SBT. Posttransplant RRT and retransplantation identify those recipients at high risk for developing OI and IFD.

The current state of intestine transplantation: indications, techniques, outcomes and challenges

Intestine transplantation is the least common form of organ transplantation in the United States and often deemed one of the most difficult. Patient and graft survival have historically trailed well behind other organ transplants. Over the past 5-10 years registry reports and single center series have demonstrated improvements to patient survival after intestinal transplantation that now match patient survival for those without life-threatening complications on parenteral nutrition. For various reasons including improvements in medical care of patients with intestinal failure and difficulty accessing transplant care, the actual number of intestine transplants has declined by 25% over the past 6 years. In light of the small numbers of intestine transplants, many physicians and the lay public are often unaware that this is a therapeutic option. The aim of this review is to describe the current indications, outcomes and advances in the field of intestine transplantation and to explore concerns over future access to this important and life-saving therapy.

Adenovirus: current epidemiology and emerging approaches to prevention and treatment

Infections caused by adenoviruses are associated with significant morbidity and mortality in both hematopoietic stem cell and solid organ transplant recipients. The risk seems to be highest in allogeneic hematopoietic stem cell transplant recipients as well as heart, lung and small-bowel transplant recipients. Management of these infections may be difficult and includes reduction of immunosuppression whenever possible combined sometimes with antiviral therapy (mainly cidofovir). The currently available antiviral therapy is limited by the need for intravenous administration, potentially significant renal and hematologic toxicities. New emerging therapies such as brincidofovir and transfusion of adenovirus-specific T-lymphocytes may increase the available armamentarium for these potentially life-threatening infections.