Society of pediatric liver transplantation: Current registry status 2011-2018

BACKGROUND

SPLIT was founded in 1995 in order to collect comprehensive prospective data on pediatric liver transplantation, including waiting list data, transplant, and early and late outcomes. Since 2011, data collection of the current registry has been refined to focus on prospective data and outcomes only after transplant to serve as a foundation for the future development of targeted clinical studies.

OBJECTIVE

To report the outcomes of the SPLIT registry from 2011 to 2018.

METHODS

This is a multicenter, cross-sectional analysis characterizing patients transplanted and enrolled in the SPLIT registry between 2011 and 2018. All patients, <18 years of age, received a first liver-only, a combined liver-kidney, or a combined liver-pancreas transplant during this study period.

RESULTS

A total of 1911 recipients from 39 participating centers in North America were registered. Indications included biliary atresia (38.5%), metabolic disease (19.1%), tumors (11.7%), and fulminant liver failure (11.5%). Greater than 50% of recipients were transplanted as either Status 1A/1B or with a MELD/PELD exception score. Incompatible transplants were performed in 4.1%. Kaplan-Meier estimates of 1-year patient and graft survival were 97.3% and 96.6%. First 30 days of surgical complications included reoperation (31.7%), hepatic artery thrombosis (6.3%), and portal vein thrombosis (3.2%). In the first 90 days, biliary tract complications were reported in 13.6%. Acute cellular rejection during first year was 34.7%. At 1 and 2 years of follow-up, 39.2% and 50.6% had normal liver tests on monotherapy (tacrolimus or sirolimus). Further surgical, survival, allograft function, and complications are detailed.

Liver transplant for metastatic pancreatoblastoma: 7-year event-free survival after chemotherapy, pancreatectomy, complete hepatectomy, and liver transplant

Pancreatoblastoma is a rare malignant tumor in children. Surgical resection of the tumor is necessary for cure; however, due to its aggressive nature, it is often unresectable at presentation due to tumor size, local invasion, and/or metastasis. Because it is a rare tumor, there is currently no standard treatment regimen. We report a case of a 4-year-old boy who presented with metastatic pancreatoblastoma with multiple large metastases involving all four sectors of the liver. We began treatment with chemotherapy (cisplatin, 5FU, vincristine, and doxorubicin), which significantly reduced the tumor burden in both the pancreas and liver. We then performed a staged subtotal pancreatectomy, complete hepatectomy, and living donor left lateral segment liver transplant. This was followed by postoperative adjuvant chemotherapy. Our patient is alive and healthy and has now been tumor-free for 7 years with no tumor relapse.

Plasmapheresis treatment of antibody-mediated rejection in an A2 donor to O pediatric liver transplant recipient

It is safe to transplant kidneys from blood group A2 donors into O recipients if the latter have low titers of anti-A antibodies. However, in liver transplantation, O and B recipients of A2 donor livers are not routinely screened for anti-blood group antibodies because of the immuno-absorptive capacity of the liver and the low incidence of antibody-mediated rejection. Herein, we report a rare case of combined cell and antibody-mediated rejection in a pediatric blood group O recipient of an A2 donor liver, and rescue of the allograft using PP and IVIG.

Genome-wide linkage analysis of 160 North American families with celiac disease

Celiac disease (CD) is a common autoimmune disease caused by exposure to the protein gliadin in wheat, and related prolamins in barley and rye. The prevalence of the disease in the US is 1:133. The aim of this study was to identify non-human leukocyte antigen (HLA) loci that predispose to CD. A genome-wide search of 405 microsatellite markers was performed on DNA samples from 160 families with a minimum of two cases of CD. Multipoint, parametric and non-parametric linkage (NPL) analyses were performed. Locations on chromosomes 1q, 3q, 6p, 6q, 7q, 9q and 10q showed linkage statistics (NPL scores or heterogeneity logarithm of the odds (HLOD) scores) of approximately 2.0 or larger. The greatest evidence for linkage outside of chromosome 6 was on 7q and 9q. An NPL score of 2.60 occurred at position 151.0 on 7q and a HLOD score of 2.47 occurred at position 144.8 on 9q under a recessive model. As expected, there was highly significant linkage to the HLA region on 6p, with NPL and HLOD scores exceeding 5.50. In conclusion, this genome-wide linkage analysis represents one of the largest such studies of CD. The most promising region is a putative locus on 7q, a region reported independently in previous genome-wide searches.

Linkage analysis of HLA and candidate genes for celiac disease in a North American family-based study

BACKGROUND

Celiac disease has a strong genetic association with HLA. However, this association only explains approximately half of the sibling risk for celiac disease. Therefore, other genes must be involved in susceptibility to celiac disease. We tested for linkage to genes or loci that could play a role in pathogenesis of celiac disease.

METHODS

DNA samples, from members of 62 families with a minimum of two cases of celiac disease, were genotyped at HLA and at 13 candidate gene regions, including CD4, CTLA4, four T-cell receptor regions, and 7 insulin-dependent diabetes regions. Two-point and multipoint heterogeneity LOD (HLOD) scores were examined.

RESULTS

The highest two-point and multipoint HLOD scores were obtained in the HLA region, with a two-point HLOD of 3.1 and a multipoint HLOD of 5.0. For the candidate genes, we found no evidence for linkage.

CONCLUSIONS

Our significant evidence of linkage to HLA replicates the known linkage and association of HLA with CD. In our families, likely candidate genes did not explain the susceptibility to celiac disease.

Prevalence and clinical characteristics of celiac disease in Downs syndrome in a US study

Celiac disease is an autoimmune gastrointestinal disorder characterized by mucosal atrophy of the jejunum on exposure to gluten, a protein found in grains. The purpose of our study was to determine the prevalence of celiac disease in children with Downs syndrome in a U.S.-based Caucasian population. The 97 Downs syndrome children were screened for celiac disease using serum IgA-anti-endomysial antibody testing, which is highly specific and sensitive for the disorder. Children with titers greater than 1:5 (using the IgA endomysial antibody [EMA] test; EMA+) were considered affected. Ten children (10.3%) were EMA+. We examined their HLA DQA1 DQB1 genotype, karyotype, clinical characteristics, and the prevalence of celiac disease in their first-degree relatives. The nine available karyotypes were trisomy 21. Downs syndrome-specific mean height percentile was 64%+/-26% (range <5-99%) and weight percentile was 43%+/-28% (range 5-95%). Presence of diarrhea, constipation, vomiting, and abdominal pain was similar for children with and without celiac disease. Only bloating symptoms were significantly more frequent in those with celiac disease (EMA+). Seven of eight (88%) genotyped EMA+ children had the celiac disease-associated high-risk HLA DQA1*0501 DQB1*0201 genotype as compared with 13/ 80 (16%) of EMA- children. Five of 48 (10%) first-degree relatives of the celiac disease (EMA+) children were EMA+. In conclusion, celiac disease, as diagnosed by positive endomysial antibody tests, has an increased prevalence in children with Downs syndrome in the U.S. as compared with the general population (1/250). Clinical and growth characteristics do not distinguish between children with and without celiac disease. Based on these observations, it is recommended that children with Downs syndrome be screened for celiac disease.

Postpericardiotomy syndrome: no evidence for a viral etiology

BACKGROUND

Postpericardiotomy syndrome has been considered a disorder induced by viral infection. This conclusion is based on serologic criterions, but these may be unreliable following either cardiopulmonary bypass or transfusion therapy. Previous studies have not verified the proposed etiology either by isolation of viruses, or by detection of their genome. We sought, therefore, to clarify the role, if any, of viruses in this syndrome.

METHODS AND RESULTS

We studied prospectively 149 children aged from 6 months to 16 years who were undergoing open heart surgery. Blood samples were collected from all prior to operation, and again 7 to 10 days post-operatively, and 47 were sampled at the time of development of symptoms of pericardial involvement. Serums were analyzed for the presence of IgM and IgG antibodies to cytomegalovirus, herpes simplex virus, and Epstein-Barr virus. The polymerase chain reaction was used for amplification when assessing the genome of the enteroviruses. Cultures for viruses were established on samples of stool, urine, and throat swabs collected 7 days post-operatively, and at the time of postpericardial symptoms. Pericardial fluid obtained from 5 patients with the syndrome was cultured for viruses, and tested for enterovirus genome. On the basis of clinical and echocardiographic findings, 34 children were determined to have definite evidence of the syndrome, 13 were considered to have possible evidence, and the results from these patients were compared to those from patients with no pericardial symptoms, the latter being matched for age and transfusion status. We isolated viruses from one or more sites in five patients with definite evidence (16%), from one (9%) of those with possible evidence, and from seven (19%) of the controls. All serums and pericardial samples were negative for enterovirus genome. IgM antibodies were found in only 5 patients, three with symptoms of pericardial involvement and two without. Rates of seroconversion to IgG for the viruses were lower in the patients with symptoms of pericardial involvement compared to controls, but were strongly influenced by transfusion status.

CONCLUSION

Our study has provided no evidence to support a viral etiology for the postpericardiotomy syndrome.

Celiac disease and human leukocyte antigen genotype: accuracy of diagnosis in self-diagnosed individuals, dosage effect, and sibling risk

BACKGROUND

Celiac disease is an autoimmune disorder of the small intestine characterized by intolerance to gluten. Traditionally, diagnosis is made by intestinal biopsy. Testing for immunoglobulin (Ig) A endomysial antibodies in the serum also is used for diagnosis. Biopsy and serology revert to normal with adherence to a gluten-free diet. Often, after an index case is diagnosed, siblings with symptoms adhere to a gluten-free diet without biopsy or serologic confirmation. More than 90% of patients with celiac disease have the human leukocyte antigen (HLA) DQA1*0501-DQB1*0201 genotype. Non-HLA genes also have been implicated.

METHODS

One hundred ninety-five individuals with confirmed or suspected celiac disease were identified in 73 families affected by the disease. IgA endomysial antibody testing was performed for all symptomatic family members who did not have biopsy-confirmed diagnoses. DNA samples were genotyped at D6S276 and the HLA class II loci DQA and DQB.

RESULTS

At the time sampling was begun in families, 88 of 177 (49.7%) individuals were self-diagnosed and adhering to a gluten-free diet. Ninety percent (91/101) of confirmed cases (biopsy or serology) had at least 1 copy of the DQA1*0501-DQB1*0201 genotype, whereas only 67% (46/69) of cases self-diagnosed (adherence to gluten-free diet without confirmation) had at least 1 copy. Of confirmed cases, 61% carried two copies of DQB*0201. It is estimated that the HLA association and other unlinked genes contribute approximately equally to the sibling risk of celiac disease.

CONCLUSIONS

A dosage effect of DQB1*0201 may be associated with an increased risk of celiac disease. Self-diagnosis of celiac disease is as common as confirmed diagnosis in families in the United States. Diagnosis of celiac disease on the basis of clinical response to gluten restriction is inaccurate. With long-term adherence to a gluten-free diet, serologic test results are likely to be negative. Based on HLA genotype, approximately one third of self-diagnosed individuals are unlikely to have celiac disease. However, it is not possible to determine which individuals consuming a gluten-free diet have the disease. Therefore, before starting a gluten-free diet, serologic screening and biopsy confirmation are necessary.

Treatment of pediatric autoimmune enteropathy with tacrolimus (FK506)

Autoimmune enteropathy is characterized by chronic secretory diarrhea, villous atrophy, associated autoantibodies, and a partial response to immunosuppression. Currently available therapy (including steroids and cyclosporine) has resulted in remission only in a subset of patients. We evaluated the effects of tacrolimus (FK506) in patients with autoimmune enteropathy refractory to steroids and cyclosporine. Three patients with diagnosed autoimmune enteropathy who continued to have intractable diarrhea despite treatment with steroids and/or cyclosporine were treated with oral tacrolimus. Despite documented histological villous atrophy and poor absorption of oral cyclosporine, therapeutic tacrolimus levels were easily achieved in all 3 patients. All patients showed clinical improvement as documented by decreased stool output and ability to be weaned off parenteral nutrition; response time ranged from 1 to 4 months after tacrolimus was begun. Histological improvement was noted in all patients, and the small bowel biopsy specimens of 2 of the 3 patients showed a return to normal. All patients have been followed up for at least 6 months and are in clinical remission; 1 has received a bone marrow transplant for underlying immunodeficiency. Tacrolimus is a useful drug in the treatment of autoimmune enteropathy, even in patients who have not responded to steroids or cyclosporine. No long-term follow-up of patients with autoimmune enteropathy treated with tacrolimus is currently available.

The utility of latex agglutination assays in the diagnosis of pediatric viral gastroenteritis

To design a rapid and efficient protocol for processing pediatric stool specimens, the authors used 434 specimens to evaluate two commercial latex assays to detect rotavirus (Meritec-Rotavirus and Rotalex) and one to detect adenovirus (Adenolex). Rotavirus latex assay results were compared with electron microscopic examination and adenovirus latex assay results with virus culture. Ninety-two specimens (21%) were positive for rotavirus and 28 (6.5%) for adenovirus; 5 (1%) had both viruses. The sensitivity, specificity, positive predictive values, and negative predictive values for the three assays were, respectively, as follows: Meritec-Rotavirus (97%, 99%, 97%, 99%), Rotalex (91%, 99%, 94%, 98%), and Adenolex (46%, 99%, 77%, 97%). For primary rotavirus screening, the Meritec-Rotavirus and Rotalex latex assays offer a good alternative to electron microscopic examination. For primary adenovirus screening, the low sensitivity of the Adenolex latex assay precludes its use as a routine screen. Its excellent specificity, however, makes it a useful tool for culture confirmation.

Serum alpha fetoprotein (AFP) levels in normal infants

Serum alpha-fetoprotein (AFP) levels were monitored in 32 normal babies consecutively from 2 to 3 days, 2 wk, and 2 and 4 months after birth. In addition, serum AFP concentration was also measured in 116 random specimens from infants with normal liver enzymes and 10 infants born immaturely. Results were combined to establish normal AFP levels for infants at various ages. Serum AFP disappeared rapidly after birth. We found that it was not until 8 months of age that the normal AFP level in infants approached adult level. The half-lives of AFP degradation were estimated to be 5.5 days between birth and 2 wk, 11 days between 2 wk to 2 months, and 33 days between 2 and 4 months of age. In contrast to earlier belief, we felt that some AFP synthesis still exists after birth; however, the rate of synthesis may also decrease with age.