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.

Health status in young adults two decades after pediatric liver transplantation

We conducted a cross-sectional study of patients who underwent pediatric liver transplant (LT) between 1988 and 1992 to evaluate long-term health status. Survivors completed socio-demographic, medical and Health-Related Quality of Life (HRQOL) surveys by mail including the SF-36v2, PedsQL™4.0 Generic Core Scale, PedsQL™ Cognitive Functioning Scale and PedsQL™3.0 Transplant Module. SF-36 scores were converted to SF6D-based utilities and risk factors for lower outcomes were assessed. Eighty-five of 171 patients had survived. Fifty-six were contacted with a response rate of 66%. Median age at LT was 0.86 years (IQR 0.58-3.0) and 64.3% had biliary atresia. Mean age at survey was 23.0 ± 4.4 years: 62% attended college, 68% lived with parents and 80% of those over 23 were employed. Patient health utilities were lower than norms (0.75 ± 0.12 vs. 0.82 ± 0.18, p < 0.01) and correlated with unemployment (p < 0.042), hospitalizations (p < 0.005) and lower education level (p < 0.016). Lower PedsQL™3.0 Transplant Module and PedsQL™ 4.0 Generic Core Scale scores correlated with unemployment (p = 0.006, p = 0.009) and hospitalizations (p = 0.006, p = 0.02). Pediatric transplant recipients who survive to adulthood have lower physical HRQOL, measurable transplant-related disability and lower health utility. Transplantation is life saving; however, physical and psychological sequelae continue to affect health status up to two decades later.

Phase I study of sapacitabine, an oral nucleoside analogue, in patients with advanced leukemias or myelodysplastic syndromes

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Background: Sapacitabine, a 2′-deoxycytidine nucleoside analogue with unique ability to induce G2 cell cycle arrest and cause irreparable single-strand DNA breaks, is undergoing clinical evaluation for the treatment of cancer. The recommended Phase II dose (RD) in patients with advanced solid tumors was 75 mg b.i.d.×7 days orally every 21 days. The major DLT was myelosuppression. Here, we present the initial results of a Phase I study of sapacitabine in patients with advanced leukemias or MDS. The primary objective was to define the MTD of the above dosing schedule and the secondary objectives were to characterize the PK/PD effects of sapacitabine and its major metabolite CNDAC. Methods: Eligible patients had relapsed/refractory leukemias or MDS, or untreated disease if not willing to proceed with conventional systemic chemotherapy, adequate organ functions and performance status of 0–2. At least 3 patients were enrolled at each dose level. The MTD was the highest dose level at which =2/6 patients experienced a DLT during the first treatment cycle. Results: Twenty- nine patients received sapacitabine. Median age was 64 (range: 36 - 91). The majority of patients had AML (n=24) or MDS (n=4). Median number of prior chemotherapies was 2 (range: 0 - 6). MTD was reached at the dose level of 375 mg b.i.d. with 2/7 patients experienced the DLT of small bowel obstruction (n=1) or neutropenic colitis (n=1). One patient died from complications of neutropenic colitis. Common non-hematologic adverse events (all grades, regardless of causality) included nausea, vomiting, diarrhea, anorexia, alopecia, and fatigue, most of which were mild to moderate in intensity. PK and PD data are being analyzed. To date, 7 patients (5 AML, 2 MDS) had a reduction in bone marrow blast counts to = 5% including 1 CR in refractory AML with incomplete platelet recovery and 1 CR in relapsed MDS. In addition, 2 AML patients with relapsed leukemia cutis had a significant reduction in leukemia infiltrates in skin. Conclusion: The RD of sapacitabine for the b.i.d.×7 days every 21 days schedule is 325 mg b.i.d. The DLT is gastrointestinal toxicity. Sapacitabine is well tolerated and has promising antileukemic activity in patients with relapsed or refractory AML and MDS.

No significant financial relationships to disclose.

N-Acetyltransferase 2 Acetylation Polymorphism: Prevalence of Slow Acetylators Does Not Differ between Atopic Dermatitis Patients and Healthy Subjects

The genetic polymorphism of human N-acetyltransferase 2 (NAT2) divides the human population into groups with rapid, intermediate and slow acetylator status. Slow acetylator status has been considered a predisposing factor for allergic diseases, lupus erythematosus, toxic epidermal necrolysis or Stevens-Johnson syndrome. The aim of this study was to investigate whether Caucasian patients suffering from atopic dermatitis differed from healthy individuals with regard to the genotype and phenotype of NAT2. Twenty unrelated healthy Caucasian volunteers (9 females and 11 males, aged from 22 to 59 years) and twenty unrelated Caucasian patients suffering from atopic dermatitis (9 females and 11 males, aged between 20 and 54 years) participated in this study. For each one, the NAT2 genotype was determined by polymerase chain reaction with DNA extracted from peripheral blood, using specific primers for the wild-type allele (wt) and the 3 most frequent mutated alleles of NAT2 (C481-->T, G590-->A and G857-->A). The NAT2 phenotype was evaluated with dapsone as a test substrate using high-pressure liquid chromatography. Statistical analysis was performed using the chi(2) test. Phenotype and genotype were distributed as follows: (1) of the healthy subjects, 60% were rapid acetylators (RA) and 40% were slow acetylators (SA); 10% of the RA and 15% of the SA were homozygous, 50% of the RA and 25% of the SA were heterozygous; (2) of the patients, 55% were RA, 40% were SA and 5% were intermediate acetylators (IA); 10% of the RA and 10% of the SA were homozygous, 45% of the RA and 35% of the SA were heterozygous. No significant statistical difference was found between the two groups for genotypes (p = 0.75) or phenotypes (p = 0.60). The phenotyping and genotyping results of healthy subjects were comparable to those found in previous studies. The absence of a significant statistical difference between healthy subjects and atopic dermatitis patients is in contrast to the results of previous studies. Some authors considered that allergic patients are mostly SAs. This could be explained by the fact that we only considered patients suffering from atopic dermatitis whereas, in other studies, patients suffered from different (one or several associated) allergic diseases. NAT2 polymorphism does not differ between patients suffering from atopic dermatitis and healthy subjects. The importance attributed to the SA status, which was previously considered a predisposing factor for allergic diseases such as atopic dermatitis, should be reviewed.

Treatment of fracture-dislocation of the proximal interphalangeal joint using the Suzuki external fixator

We describe a simple technique for fracture-dislocations of the proximal interphalangeal joint. Eight fingers with a fracture-dislocation were treated with a self-manufactured dynamic external fixator, allowing early mobilization. The fixator consists of pins and rubbers. The clinical and radiographic outcome was evaluated and recorded. A near-normal function was obtained in four patients. The average total active motion was 82 degrees. Radiographic reduction was maintained. This external fixator is an inexpensive and simple technique for these difficult fracture-dislocations. Early intervention (before two weeks post-trauma) is recommended.

The relationship between malaria and HIV

OBJECTIVE

To determine if there is an association between HIV and malaria infection.

DESIGN

A cross sectional survey.

SETTING

Sanyati Rural District, a malarious endemic area of Zimbabwe.

SUBJECTS

338 volunteers aged 15 months to 76 years.

MAIN OUTCOME MEASURES

Prevalence of Malaria and HIV.

RESULTS

The prevalence of malaria and HIV was 26.6% and 26.3% respectively. There was no association between prevalence of HIV and malaria.

CONCLUSION

There is no association between malaria and HIV.

Complications in 100 living-liver donors

OBJECTIVE

A review of 100 living-liver donors was performed to evaluate the perisurgical complications of the procedure and thus to help quantify the risks to the donor.

SUMMARY BACKGROUND DATA

Despite the advantages of living-donor liver transplantation (LDLT), the procedure has received criticism for the risk it imposes on healthy persons. A paucity of data exists regarding the complications and relative safety of the procedure.

METHODS

One hundred LDLTs performed between November 1989 and November 1996 were reviewed. Donor data were obtained by chart review, anesthesia records, and the computerized hospital data base. Patient variables were compared by Fisher's exact test and the Student's t test.

RESULTS

There were 57 women and 43 men with a median age of 29. Donors were divided into two groups: group A (first 50 donors), and group B (last 50 donors). There were 91 left lateral segments and 9 left lobes. There were no deaths. Fourteen major complications occurred in 13 patients; 9 occurred in group A and 5 in group B. Biliary complications consisted of five bile duct injuries (group A = 4, group B = 1) and two cut edge bile leaks. Complications were more common in left lobe resections (55%) than in left lateral segment grafts (10%). Minor complications occurred in 20% of patients. A significant reduction in overall complications (major and minor) was observed between the groups (group A, n = 24 [45%] vs. group B, n = 10 [20%]). In addition, surgical time and hospital stay were both significantly reduced.

CONCLUSIONS

Although the procedure is safe, many LDLT donors have a perisurgical complication. Surgical experience and technical modifications have resulted in a significant reduction in these complications, however. To minimize the risks for these healthy donors, LDLT should be performed at institutions with extensive experience.

Short report: severe malaria associated with blood group

The ABO blood groups are not linked to the incidence of simple malaria infection but have been associated with rosette formation. In an effort to see if clinically severe malaria is associated with blood group, 489 patients were studied in Zimbabwe. Patients with malaria and group A blood had lower hemoglobin levels and more risk of coma than did infected patients with other blood groups. In this population, severe malaria is associated with blood group.

An additional allelic variant of the CYP2D6 gene causing impaired metabolism of sparteine

The identification of a novel CYP2D6 allele from a healthy Caucasian poor metabolizer was achieved by using a previously described polymerase chain reaction/single-strand conformation polymorphism strategy. Among the four point mutations that this allele carries, a missense mutation in exon 1 (212 G-->A or D6-H) seems to be responsible for the loss of CYP2D6 function. Although the mutation D6-H has a low prevalence in a randomly selected population of healthy Caucasians, its identification should further increase the phenotype prediction rate by genotyping.

An efficient strategy for detection of known and new mutations of the CYP2D6 gene using single strand conformation polymorphism analysis

To detect mutations in the cytochrome P450 CYP2D6 gene (CYP2D6), we developed a strategy based on single-strand conformation polymorphism (SSCP) analysis of the gene amplified by polymerase chain reaction (PCR). The efficiency of the method was evaluated by analysing DNA samples from extensive metabolizers (EM) and poor metabolizers (PM) of debrisoquine. Haplotypes, alleles and mutations of CYP2D6 had previously been characterized in each individual using PCR assays, Xba I restriction fragment length polymorphism (RFLP) and sequencing. PCR-SSCP results were in complete agreement with those obtained using established methods. All previously characterized mutations were associated with particular shifts in the electrophoretic mobility of DNA fragments allowing their identification. We further tested the efficiency of PCR-SSCP for detecting new CYP2D6 mutations. DNA from a PM subject presumed to carry an unknown non-functional mutant allele of CYP2D6 was amplified and bands with aberrant migration patterns were observed on SSCP gels. Sequence analysis of the corresponding DNA fragments revealed the causative mutations. In this way, a novel non-functional allele of the gene, carrying three previously reported mutations and a new mutation in the third exon which results in a premature termination codon, was characterized. Finally, CYP2D6 SSCP analysis was performed on DNA amplified with fluorescent primers and an automated DNA sequencer was used for SSCP analysis of products. We conclude that the PCR-SSCP approach is a powerful method of identifying simultaneously known and new mutations of the CYP2D6 gene.

A nonsense mutation in the cytochrome P450 CYP2D6 gene identified in a Caucasian with an enzyme deficiency

A novel mutation that generates a stop codon in the third exon of the gene encoding the cytochrome P-450 CYP2D6 was identified in a Caucasian having a deficiency of the isozyme, by means of single strand conformation polymorphism analysis of DNA fragments amplified by the polymerase chain reaction, followed by selective sequencing.

A novel CYP2D6 allele with an abolished splice recognition site associated with the poor metabolizer phenotype

A novel loss-of function allele of the CYP2D6 gene was characterized in a PM individual using exon-by-exon PCR-SSCP analysis. This allele, we termed CYP2D6(F), harbours four mutations including a new mutation (D6-F) which abolishes the splice acceptor site of the 1st intron and results in a premature stop codon. DNA samples from a large population of healthy unrelated volunteers were tested for D6-F using a PCR-assay we developed for the specific identification of the mutation in genomic DNA. The prevalence of D6-F was very low. However, its identification combined with that of the previously reported gene inactivating mutations would further increase the phenotype prediction rate by genotyping.

Synthesis and characterization of adducts of alachlor and 2-chloro-N-(2,6-diethylphenyl)acetamide with 2'-deoxyguanosine, thymidine, and their 3'-monophosphates

Adducts of the preemergence herbicide 2-chloro-N-(methoxymethyl)-N-(2,6-diethylphenyl)-acetamide (alachlor) and 2-chloro-N-(2,6-diethylphenyl)acetamide (CDEPA) with 2'-deoxyguanosine, thymidine, 2'-deoxyguanosine 3'-monophosphate, and thymidine 3'-monophosphate have been synthesized and characterized. Under mildly basic conditions alachlor and CDEPA form N-1 adducts with 2'-deoxyguanosine and N-3 adducts with thymidine as a result of chlorine displacement. In addition, alachlor formed an N-7 adduct with 2'-deoxyguanosine, 7-[[(N-(methoxymethyl)-N-(2,6-diethylphenyl)carbamoyl]methyl]guani ne. N-1 adducts of alachlor and CDEPA with 2'-deoxyguanosine 3'-monophosphate and N-3 adducts with thymidine 3'-monophosphate are also described. In addition to spectroscopic data, structural proof included the dephosphorylation of each nucleotide adduct to its corresponding nucleoside adduct by nuclease P1. Alachlor and alachlor adducts but not CDEPA and CDEPA adducts exhibited rotational isomerism as evidenced by proton and 13C NMR studies. These rotamers were attributed to hindered rotation about the shortened N-carbonyl bond. Computational methods employing molecular mechanics and quantum mechanics were used to characterize the structures and energies of these rotamers to account for the patterns of duplicate NMR resonances observed.

Liver transplantation: living-related donations

The LRLT procedure appears to be a promising alternative and adjunct to conventional liver transplantation. The advantages to this technique are a donor for each recipient, an improved quality of graft, and a reduction in pretransplant mortality in children. The procedure is not without risks, but the overall benefits seem to outweigh these risks, and only future experience will tell otherwise. Will there continue to be a need for such a procedure? We believe there will be, because the number of candidates needing transplantation will continue to grow and the demand for cadaveric organs will never be met. However, the procedure is extremely labor and resource intensive, and it is our belief that only a handful of large major medical centers will be able to adopt a live-donor program.

Performance of 133 compounds in the lambda prophage induction endpoint of the Microscreen assay and a comparison with S. typhimurium mutagenicity and rodent carcinogenicity assays

The Microscreen assay was developed as a means of testing very small samples, as in complex mixture fractionation. It is a multi-endpoint assay which utilizes E. coli WP2s(lambda). Exposure takes place to serial dilutions of the test compound in microtitre wells (250 microliters) followed by sampling from wells in which growth has occurred ('non-toxic wells'). Although a number of different endpoints can be measured, only the prophage induction endpoint (the first one developed) has been extensively tested. Results with 133 compounds are presented. These include 111 compounds which have been tested in the S. typhimurium assay and 66 compounds for which both rodent bioassay and S. typhimurium assay data exists. The concordance for the Microscreen assay and the S. typhimurium assay was 71%. For this group of compounds, the sensitivity of the Microscreen assay in detecting carcinogens was 76% compared with 58% for the S. typhimurium assay. However, the S. typhimurium assay was somewhat more specific (69%) compared with the Microscreen (56%). The overall association between carcinogenicity and Microscreen results was statistically significant (p = 0.029), whereas for the S. typhimurium assay the association with carcinogenicity was non-significant (p = 0.086). The Microscreen assay was able to detect halogenated compounds better than the S. typhimurium assay. The Microscreen assay should prove useful in complex mixture fractionation, or in other situations where sample size is limiting.

Indications for liver transplantation in pediatric patients

Orthotopic liver transplantation has become a widely accepted therapy for children with end-stage liver disease. Several factors need to be kept in mind when advocating this procedure in pediatric patients. These include the following: (1) Liver transplantation is a high-risk procedure with a 10-15% mortality in the best of circumstances. (2) Recipients require long-term drug administration and have a potential for chronic disability. (3) The procedure is extremely expensive. (4) The long-term survival remains unknown. (5) Newer techniques and procedures need to be carefully evaluated. These factors, and the indications and contraindications for this procedure are discussed in this overview.