Late allograft fibrosis in pediatric liver transplant recipients: Assessed by histology and transient elastography

Late allograft fibrosis in LT recipients can cause graft dysfunction and may result in re‐transplantation. TE is a non‐invasive tool for the assessment of liver fibrosis. We aimed to evaluate the prevalence of allograft fibrosis in pediatric LT recipients, identify factors associated with allograft fibrosis, and determine the diagnostic value of TE, compared to histology. All children who underwent LT for ≥3 years were included. TE was performed for LSM in all patients. LSM of ≥7.5 kPa was considered as abnormal and suggestive of allograft fibrosis. Percutaneous liver biopsy was performed when patients had abnormal LSM and/or abnormal LFTs. Histological fibrosis was diagnosed when METAVIR score ≥F1 or LAF scores ≥1. TE was performed in 43 patients and 14 (32.5%) had abnormal LSM suggestive of allograft fibrosis. Histological fibrosis was identified in 10 of the 15 patients (66.7%) who underwent percutaneous liver biopsy and associated findings included chronic active HBV infection (n = 3), and late acute rejection (n = 3). Multivariate analysis showed that graft age was significantly associated with allograft fibrosis (OR = 1.22, 95% CI: 1.05‐1.41, P = 0.01). In conclusion, late allograft fibrosis is common in children undergoing LT for ≥3 years and associated with graft age. HBV infection and late acute rejection are common associated findings. Abnormal TE and/or LFTs may guide physicians to consider liver biopsy for the detection of late allograft fibrosis in LT children.     

The use of transient elastography and non‐invasive serum markers of fibrosis in pediatric liver transplant recipients

The use of non‐invasive markers to diagnose liver allograft fibrosis is not well established in children after LTx. TE, FT, and ELF score were performed in 117 liver‐transplanted children (60M, 8.9 [0.5–18.5] yr) and 336 healthy controls. Liver biopsy was available in 36 children. Results of histology and non‐invasive markers were compared using correlation coefficient or Mann–Whitney U‐test as appropriate. TE correlated best with histological degree of fibrosis (r = 0.85 vs. r = 0.04 [FT] or r = ?0.38 [ELF]). Liver stiffness values for transplanted children without fibrosis were significantly higher than those of healthy controls (7.55 [5.4–20.4] kPa vs. 4.5 [2.5–8.9] kPa). Presence of rejection was a potent confounder for the performance of TE. Both TE and FT reflected clinical changes (acute rejection, cholestasis, increasing fibrosis) in a total of 16 patients who underwent serial measurements. TE correlates better with histological degree of fibrosis in liver‐transplanted children than FT or ELF, but an individual baseline value needs to be determined for each patient. Normal or cutoff values for pathological degrees of fibrosis cannot be transferred from non‐transplanted children. Follow‐up studies, preferably with protocol biopsies, might help to improve the diagnostic quality of TE.     

Transient elastography for non‐invasive evaluation of post‐transplant liver graft fibrosis in children

As graft survival in pediatric LT is often affected by progressive fibrosis, numerous centers carry out protocol liver biopsies. Follow‐up biopsy protocols differ from center to center, but all biopsies are progressively spaced out, as time from transplant increases. Therefore, there is a need for non‐invasive techniques to evaluate graft fibrosis progression in those children who have no clinical or serological signs of liver damage. Indirect markers, such as the APRI, should be relied on with caution because their sensitivity in predicting fibrosis can be strongly influenced by the etiology of liver disease, severity of fibrosis, and patient age. A valid alternative could be TE, a non‐invasive technique already validated in adults, which estimates the stiffness of the cylindrical volume of liver tissue, 100‐fold the size of a standard needle biopsy sample. The aims of this study were to evaluate the reliability of TE in children after LT and to compare both the TE and the APRI index results with the histological scores of fibrosis on liver biopsies. A total of 36 pediatric LT recipients were studied. All patients underwent both TE and biopsy within a year (median interval ‐0.012 months) at an interval from LT of 0.36 to 19.47 years (median 3.02 years). Fibrosis was assessed on the biopsy specimens at histology and staged according to METAVIR. There was a statistically significant correlation between TE stiffness values and METAVIR scores (P = .005). The diagnostic accuracy of TE for the diagnosis of significant fibrosis (F ≥ 2) was measured as the area under the curve (AUROC = 0.865), and it demonstrated that the method had a good diagnostic performance. APRI was not so accurate in assessing graft fibrosis when compared to METAVIR (AUROC = 0.592). A liver stiffness cutoff value of 5.6 kPa at TE was identified as the best predictor for a significant graft fibrosis (METAVIR F ≥ 2) on liver biopsy, with a 75% sensitivity, a 95.8% specificity, a 90% positive predictive value, and an 88.5% negative predictive value. These data suggest that TE may represent a non‐invasive, reliable tool for the assessment of graft fibrosis in the follow‐up of LT children, alerting the clinicians to the indication for a liver biopsy, with the aim of reducing the number of protocol liver biopsies.     

Transient elastography assessment of liver allograft fibrosis in pediatric transplant recipients

TE measures liver stiffness to assess fibrosis. Its use in post‐transplant patients was reported in few small pediatric studies. We evaluated TE ability to predict liver graft fibrosis in a large cohort while comparing it to the performance of APRI and FIB‐4. We also investigated the effect of graft type on LSMs. Patients at Boston Children's Hospital who underwent LT and LSM ≤ 1 year from biopsy (2007‐2018) were eligible. Ninety‐four patients (45%M) aged 1‐21 years (89% < 18 years; 13% < 2 years) were eligible. Median time between transplant/biopsy and LSM was 5.1 years and 52 days, respectively. Thirty‐nine percent received whole‐liver grafts, 54% TV grafts, and 6% as part of MV. At LSM, median ALT was 25 [IQR 16‐33] IU/L. Twenty‐one percent had METAVIR ≥ F2. LSM was statistically higher among those with significant fibrosis (METAVIR ≥ F2) compared to those with METAVIR F0/F1 (median [IQR] 7.5 [4.6, 13.6] vs 5.1 [4.0, 6.4] kPa, respectively) (P = .005 by Wilcoxon rank‐sum test). APRI and FIB‐4 distributions were not different across METAVIR stages. The AUROC for LSM was 0.71 (95% CI 0.56‐0.85) with an optimal cut‐point of 6.5 kPa. Graft type had no influence on the AUROC for LSM. TE is useful for assessing significant graft fibrosis in children and young adult LT recipients and performs better than APRI and FIB‐4. TV grafts demonstrate similar correlation with histology as whole‐liver grafts.     

The histological quantification of alpha‐smooth muscle actin predicts future graft fibrosis in pediatric liver transplant recipients

Activated hepatic stellate cells express cytoplasmic ASMA prior to secreting collagen and consequent liver fibrosis. We hypothesized that quantifying ASMA could predict severity of future fibrosis after LT. For this, 32 pairs of protocol biopsies, that is, “baseline” and “follow‐up” biopsies taken at 1‐ to 2‐year intervals from 18 stable pediatric LT recipients, transplanted between 2006 and 2012 were selected. Morphometric quantification of “ASMA‐positive area percentage” was performed on the baseline biopsy. Histological and fibrosis assessment using Metavir and LAFSc was performed on all biopsies. The difference of fibrosis severity between the “baseline” and “follow‐up” was termed “prospective change in fibrosis.” Significant association was seen between extent of ASMA positivity on baseline biopsy and “prospective change in fibrosis” using Metavir (P=.02), cumulative LAFSc (P=.02), and portal LAFSc (P=.01) values. ASMA‐positive area percentage >1.05 predicted increased fibrosis on next biopsy with 90.0% specificity. Additionally, an association was observed between extent of ASMA positivity and concomitant ductular reaction (P=.06), but not with histological inflammation in the portal tract or lobular area. Hence, ASMA quantification can predict the future course of fibrosis.     

Association of post‐transplant donor‐specific HLA antibody with liver graft fibrosis during long‐term follow‐up after pediatric liver transplantation

The aim of this study was to evaluate the significance of post‐transplant DSA as a predictor of liver fibrosis during long‐term follow‐up after pediatric LT. We evaluated the histological findings in 18 LT recipients who underwent liver biopsy after DSA screening. Liver fibrosis was scored based on the METAVIR fibrosis staging. Patients were divided into 2 groups based on histological findings, and clinical characteristics among patients with liver fibrosis were assessed. Of 18 patients, 7 were included in the fibrosis group. No significant between‐group differences were found regarding peritransplant characteristics, including age, sex, primary disease, ABO incompatibility, and immunosuppressive regimen. Episodes of acute rejection and non‐adherence to immunosuppressive drugs were comparable between both groups. The MFI for anti‐DR DSA and positive rate were significantly higher in the fibrosis group (1655 vs 216; P = .019, 86% vs 27%; P = .012, respectively). MFI for anti‐DQ DSA was higher in the fibrosis group, but non‐significantly (2052 vs 384; P = .46). Post‐transplant anti‐DR DSA is associated with graft fibrosis during long‐term follow‐up. This finding seems useful for the implementation of valid histological examinations of liver grafts for patients with higher MFI, especially for anti‐DR DSA, after pediatric LT.     

Unique clinical conditions associated with different acinar regions of fibrosis in long‐term surviving pediatric liver grafts

In the majority of long‐term survivors after PLTx, graft fibrosis has been identified. Recently, subtypes of graft fibrosis have been described based on their predominant acinar localization. We aimed to evaluate whether the development of portal, perisinusoidal, and centrilobular distribution of graft fibrosis is related to patient or transplantation‐related parameters. We reviewed the histological features in protocol liver biopsies taken at 1 and 5 years after PLTx of 47 children on a tacrolimus‐based immunosuppressive regimen. Fibrosis was assessed according to the LAFSc. The prevalence of portal fibrosis increased from 31% to 62%, sinusoidal from 68% to 79%, and centrilobular from 76% to 85%. The presence of portal fibrosis was associated with total bilirubin and γGT levels (each P<.02) and tended to be associated with biliary complications (P=.06). Sinusoidal fibrosis was associated with prior rejection episodes (P<.02) and centrilobular fibrosis with the presence of HLA mismatches (P=.02). In conclusion, using the LAFSc, we found a high incidence of progressive fibrosis in the 1‐year and 5‐year protocol biopsies after PLTx. Progression of fibrosis was observed in all acinar compartments, and each of the three locations is associated with different clinical conditions.     

Lipid profile and cardiovascular risk factors in pediatric liver transplant recipients

Cardiovascular diseases induce long‐term morbidity and mortality of adult LT recipients. The aim of this retrospective study was to assess CVRF, lipid abnormalities, and atherosclerosis (appraised by c‐IMT), more than 10 yr after pediatric LT. Thirty‐one children who underwent LT between December 1990 and December 2000 were included. Median age at LT was 14 months (range 4–64), and median follow‐up after LT was 11.9 yr (range 9.0–17.3). In our cohort, obesity (9.7%) and treated hypertension (9.7%) were rare. None of the patients was smoker or diabetic. High TC and TG were both observed in 6.5% of the patients. The mean c‐IMT for male patients was 1.22 ± 1.55 and 1.58 ± 1.23 mm in female patients. Seven patients (22%) had a mean c‐IMT above +2 s.d. Values below the 5th percentile were noted for LDL‐cholesterol (58.1%), HDL‐cholesterol (25.8%), apolipoprotein B (40%), and apolipoprotein A1 (20%). LDL‐cholesterol and apolipoprotein B levels were significantly lower in patients treated by tacrolimus in comparison with CsA (p < 0.05). In conclusion, our results suggest that pediatric LT patients do not present significant CVRF; moreover, instead of hyperlipidemia, hypocholesterolemia (LDL‐C) is frequent and immunosuppressive therapy is probably the cause.     

Growth of liver allografts over time in pediatric transplant recipients

The liver's capacity to grow in response to metabolic need is well known. However, long‐term growth of liver allografts in pediatric recipients has not been characterized. A retrospective review of pediatric recipients at a single institution identified patients who had cross‐sectional imaging at 1, 5, and 10 years post‐transplant. Using volumetric calculations, liver allograft size was calculated and percent SLV were compared across the different time points; 18 patients ranging from 0.3 to 17.7 years old were identified that had imaging at 2 or more time points. Measured liver volumes increased by 59% after 5 years and 170% after 10 years. The measured liver volumes compared to calculated %SLV for these patients were 123 ± 37%, 97 ± 19%, and 118 ± 27% at 1, 5, and 10 years after transplant, respectively. Our data suggest that liver allografts in pediatric recipients increase along with overall growth, and reach SLVs for height and weight by 5 years post‐transplantation. Additionally, as pediatric recipients grow, the livers appear to maintain appropriate SLV.     

Clinical consequences of human herpesvirus‐6 DNAemia in peripheral blood in pediatric liver transplant recipients

The significance of HHV6 DNAemia after solid organ transplantation has not been fully determined. Our objectives were to determine the prevalence of HHV6 DNAemia in pediatric liver transplant recipients and to describe the associated clinical characteristics and outcomes. This was a retrospective case–control study. Eligible liver transplant patients aged ≤ 18 yr with HHV6 DNAemia were matched with two subjects without HHV6 DNAemia. Matching was by age ± 6 months. Among 154 subjects, 25 patients (16%) had HHV6 DNAemia detected by PCR in whole blood or plasma (M:F ratio = 0.9:1). While 28% of subjects with DNAemia (7/25) had symptoms consistent with HHV6 infection, active infection was detected in only four subjects (2.6% of liver transplant patients). The major symptoms/signs were fever, vomiting, lethargy, splenomegaly, bone marrow suppression, and elevated transaminases. The prevalence of DNAemia due to other herpesviruses in cases vs. controls was EBV 56% vs. 60%, CMV 12% vs. 12%, HHV7 20% vs. 12%; p value is not significant for all pairwise comparisons. HHV6 DNAemia in pediatric liver transplant patients is not an uncommon entity. While the clinical relevance is still not entirely established, active HHV6 infection and attributable symptoms are relatively rare.     

First experience with basiliximab in pediatric liver graft recipients

Several studies have shown a significant reduction of acute cellular graft rejection in adult liver and kidney graft recipients treated with monoclonal anti-interleukin-2 (IL-2)-receptor antibodies. The mechanism was inhibition of activated T-helper cells by blocking the alpha-chain (CD25) of the IL-2 receptor. The pilot study described here evaluated the use of basiliximab in pediatric liver transplantation (LTx), which is the first report on its use in children. Fifty-two liver-transplanted children were analyzed in this study. A matched-pair historical control group (n = 26) received cyclosporin A (CsA) and prednisolone, and patients in the basiliximab group (n = 26) were treated with low-dose CsA and basiliximab (after reperfusion and on day 4 post-transplant). The incidences were compared of acute graft rejections, infectious complications, and the adverse effects of immunosuppressive medication within the first 6 months post-transplant. The incidence of acute rejection was significantly higher in the control group (61.5% vs. 11.5%, p = 0.0004). The frequency of infectious complications was similar (46.1% vs. 53.8%). Patients in the basiliximab group showed less arterial hypertension; however, the differences were not statistically significant (30.7% vs. 7.7%, p = 0.07). Nephrotoxicity, hepatotoxicity or neurotoxicity were only seen in the control group (7.7%; 3.8%; 3.8%, respectively). Hence, the use of basiliximab in combination with CsA and steroids in pediatric liver transplant recipients is safe and reduces the incidence of acute graft rejection. Further studies are needed to confirm our preliminary results and to analyze long-term effects on post-transplant lymphoproliferative disease, chronic rejection, and patient survival.     

Epstein‐Barr viral load monitoring for diagnosing post‐transplant lymphoproliferative disorder in pediatric liver transplant recipients

This study aimed to investigate the incidence of PTLD in pediatric liver transplant recipients and the risk factors for the development of PTLD. We also determined clinically useful quantitative EBV PCR parameters for aiding in the diagnosis of EBV‐associated PTLD in the pediatric liver transplant recipients at our institute. We reviewed children < 18 years old who had undergone liver transplantations and quantitative analysis of whole blood EBV load at our institute from January 2006 to March 2015. A total of 142 liver transplant recipients were included, and their median age was 1.5 years. Clinically significant high‐level EBV DNAemia ≥ 10 000 copies/mL at least twice was observed in 53.5% and PTLD occurred in 9.9%. Among PTLD group, graft failure and mortality rate were as high as 21.4% and 14.3%, respectively. Deceased donor, presence of high‐level EBV DNAemia, and primary CMV infection following transplant were associated with an increased risk for PTLD in the multivariate analysis. The peak titer at 10 875 copies/mL could be used as a cutoff value with a sensitivity of 92.9% and a specificity of 37.9%; the rate of increase in EBV load suggested a sensitivity of 64.3% and a specificity of 70.9% at the cutoff value of 44 000 copies/mL/week. In conclusion, the incidence of PTLD following liver transplant in children was as high as 10%. PTLD is associated with significant morbidity and mortality. Close monitoring of EBV DNAemia is crucial for the early diagnosis and proper treatment of PTLD in pediatric liver transplant recipients.     

Evaluating non-adherence to immunosuppressant medications in pediatric liver transplant recipients

Abstract:  Non-adherence with recommended immunosuppressant medications is common post-pediatric liver transplant and is the most important reason for organ rejection in long-term survivors. However, there is currently no validated, standard method to measure adherence, with a well-defined threshold, making it extremely difficult to evaluate interventions to improve adherence. Previous studies have suggested that the degree of fluctuation of medication blood levels over time can provide an idea about how regularly the medication is being taken. The present study, conducted at UCLA medical center, sought to identify a specific threshold value of the s.d. of individual tacrolimus blood levels in pediatric liver transplant recipients which would be associated with rejection episodes in these patients. A threshold of 3.0 has been identified in other studies, and was supported by the analysis of retrospective data from 96 subjects. However, further analysis found that a s.d. of 2.5 appeared to have a better fit with the data. These findings suggest the utility of monitoring the s.d. of routine tacrolimus blood levels in pediatric liver transplant recipients for detecting non-adherence to immunosuppressant medication prior to clinical rejection, allowing earlier interventions.     

Presentation of atopic disease in a large cohort of pediatric liver transplant recipients

Atopic disease occurs in solid organ transplant recipients with an increasingly recognized frequency. The time course for the development of these atopic diseases in liver transplantation has not been described. The objective was to characterize the atopic manifestations of children receiving chronic immunosuppression after orthotopic liver transplantation (OLT). Chart review and follow-up questionnaire were utilized for 176 OLT pediatric recipients at a single institution for manifestations of allergic disease. Atopic disease was present in 25 (14.2%) patients. Median age at transplant was 16 months with a median follow-up of 63 months. Food allergy and non-food related atopic symptoms presented at a median of 11.5 (IQR, 6-28) and 19 (IQR, 5-41) months post-transplantation, respectively. The median age at transplant of the non-atopic children was 72 months, higher than patients with atopy (p < 0.001). Food allergy and atopic skin disease symptoms were present in 40% and 56% of cases, respectively. Asthma, allergic rhinitis, or both were found in 66% of cases. The onset of symptoms of food allergy and eczema (median, 12 months post-transplantation) preceded symptoms of allergic rhinitis and asthma. (median of 27 and 30 months post-transplantation, respectively). Atopy occurs in ～14% of pediatric liver transplant recipients, with manifestations including food allergy, eczema, allergic rhinitis, and asthma.     

Outcome of pediatric liver transplant recipients in Turkey: single center experience

To summarize the evolution of the pediatric liver transplant program in a developing country. Between April 1997, and September 2003, 32 cadaveric (CD) and 35 living donor (LD) liver transplantations were performed on 61 children (median age 3.8 yr, range 0.5-16) at Ege University Organ Transplantation and Research Center. The patient's charts were reviewed retrospectively. The outcome of patient and graft survival was analyzed and the incidence of graft loss, complications and rejections was calculated. Indications for liver transplantation were metabolic liver disease (n = 17), biliary atresia (n = 14), viral hepatitis (n = 4), autoimmune hepatitis (n = 6), cryptogenic cirrhosis (n = 11), fulminant liver failure (n = 5) and others (n = 5). Seven of 61 children with chronic liver disease had hepatocellular carcinoma concomitantly. Median pediatric end-stage liver disease score was 23 (range 1-54). Seven children (11.4%) were UNOS status I, 44 (72%) were UNOS status II and 10 (16.6%) were UNOS status III. The median follow-up of the study population was 3.6 yr (range 0.5-6). Actuarial patient survival rates at 1, 2, 3 and 4 yr were 86, 86, 71.3 and 65% in the CD group vs. 80, 76, 67 and 67% in the LR group, respectively (p = NS). Patients listed as UNOS status 1 had lower survival rates than patients listed as UNOS status 2 and 3 (p < 0.05). The mortality rate was 26.2%. Graft survival rates were 81, 81, 75 and 64% at 1, 2, 3 and 4-yr respectively. Six patients (9%) underwent retransplantation. The main complications were infections (64.7%) and surgical complications (43.2%) (including biliary complication, vascular problems, postoperative bleeding, small for size and large for size). The incidence of acute cellular rejection was 39.3%, whereas chronic rejection was 7.4%. The result of liver transplantation in Turkish children was slightly inferior to those reported for North American and European children. However, an important characteristic of these patients that distinguishes them from Europe and North America is that most were UNOS status IIa and UNOS status I (44%). Despite technical and medical progress, infectious and biliary problems have continued to be an important cause of mortality in these patients.     

Liver allograft pathology in healthy pediatric liver transplant recipients

Liver transplantation offers excellent results for children with end‐stage liver disease, and efforts should be directed toward maintaining long‐term graft health. We evaluate graft pathology in healthy pediatric transplant recipients with low‐maintenance immunosuppressive medications to assess whether protocol biopsies are helpful for adapting immunosuppression and protecting long‐term graft function. Liver biopsies were performed on 60 healthy pediatric liver transplant recipients, and histological findings were correlated with laboratory, serological, and radiological results. Fourteen patients (23%) were diagnosed with acute or early chronic rejection, and immunosuppressive medications were increased in these children. Liver function tests did not correlate with histological findings. The incidence of fibrosis was 36% in transplant recipients five or more years after liver transplantation. We observed an unexpectedly high prevalence of rejection and fibrosis in children with no laboratory abnormalities, which led to changes in their immunosuppressive medications. Scheduled biopsies appear to be useful in pediatric transplant recipients with low immunosuppressive medications for early detection of morphological changes in liver transplants. Further studies are needed to evaluate whether adaption of immunosuppression helps to reduce tissue damage and the incidence of allograft dysfunction in the long term.     

Early post‐operative intravenous tacrolimus in pediatric liver transplant recipients is not superior to oral tacrolimus

We aimed to compare the early results of i.v. with p.o. TAC as a primary immunosuppressant in pediatric patients undergoing LT. This retrospective study enrolled 75 children who underwent LT and received TAC‐steroid regimens as a primary immunosuppressant between September 2011 and October 2015 at our institution. Thirty‐five recipients received TAC i.v. and 40 received TAC p.o. Early results were evaluated and compared, including ACR, EBV, or CMV infection; renal adverse effects; and hospital stay. Comparisons of 90‐day post‐transplant results showed that the rates of overall viral (74% vs 40% P < 0.002), EBV (46% vs 17.5% P < 0.008), and CMV (51% vs 30% P = 0.05) infections were significantly higher in the i.v. than in the p.o. group. Neither regimen has any adverse effects on renal function. There were no between‐group differences in ACR incidence and severity, serum creatinine concentration, and hospital stay. Patient and graft survival rates at 3 months and 1 year did not differ significantly between the two groups. Compared with p.o. treatment, i.v. administration of high TAC concentration did not have beneficial post‐transplant effects on ACR incidence and severity, while increasing the incidence of viral infections in pediatric LT.     

Tacrolimus-associated eosinophilic gastroenterocolitis in pediatric liver transplant recipients: role of potential food allergies in pathogenesis

Tacrolimus is a macrolide agent that is now the primary immunosuppressant used in prevention of graft rejection in transplant recipients. It has been found to be superior to cyclosporine (CSA) for rescue therapy as well as for earlier weaning of steroids. Both tacrolimus and CSA share similar toxicity profiles; however, their gastrointestinal side effects have received little attention. We report three cases of eosinophilic colitis in liver transplant recipients, maintained on tacrolimus as immunosuppressive medication post-liver transplantation. These patients also had high serum immunoglobulin (Ig)E levels, eosinophilia and IgE-positive radioallergosorbent test for milk proteins. The colitis appeared to be mediated by food allergies. Each patient had symptomatic improvement following reduced immunosuppression and an appropriately restricted diet. We conclude that tacrolimus may play a role in the initiation of food allergies, leading to eosinophilic colitis. More studies are needed in a controlled setting to identify the prevalence of similar findings among other pediatric liver transplant recipients.     

Utility of liver biopsy culture in pediatric liver transplant recipients

Abstract: The purpose of our study was to determine the utility of the practice of culturing percutaneous liver biopsy specimens obtained from pediatric LT recipients for evaluation of fever and/or elevated serum aminotransferases. Accordingly, a retrospective analysis was done of the 101 liver biopsies obtained during an eight-year period which had been submitted for bacterial, fungal and/or viral culture (out of a total of 174 biopsies in 38 patients). The purpose of the analysis was to ask three questions. (1) What organisms were cultured? (2) Were there clinical profiles that were characteristic of the type of organism? (3) Was the practice cost-effective? The analysis indicated that 34/86 biopsy cultures were positive for bacteria, 4/75 for fungus and 2/81 for virus. Clinical and laboratory data for children with cultures positive for enteric flora (n = 9) were compared to those with cultures positive for Gram-positive organisms (n = 17), laboratory contaminants (n = 8), and those with negative cultures (n = 52). Children with biopsies positive for enteric flora had a ‘cholestatic profile’: mean direct bilirubin 7 mg/dl, ALT 78 IU/l, direct bilirubin/ALT 0.09, in comparison to children with biopsies positive for Gram-positive flora. These children had a ‘hepatocellular profile’: mean direct bilirubin 4 mg/dl, ALT 332 IU/l, direct bilirubin/ALT 0.01 (p = 0.04 versus the enteric flora values) and a high percentage of polymorphonuclear leukocytes (mean 69% versus 38% for those with negative cultures, p = 0.001.) The charge for performing each bacterial culture was $28 (total $28 × 86 = $2408: $268 per enteric flora-positive biopsy; $93 per biopsy positive for either enteric flora or Gram-positive flora). The charge for each fungal culture was also $28 (total $28 × 75 = $2100: $525 per positive culture), while the cost for each viral culture was $140 (total $140 × 81 = $11 340: $5670 per positive culture). Thus, discounting the eight cultures positive for laboratory contaminants, a total of $15 848 was spent for 32 positive cultures. Given the high cost of liver transplantation, this information suggests that discretion should be used in submission of liver biopsy samples for culture in pediatric transplant patients. We recommend that when liver biopsies are performed for evaluation of elevated serum aminotransferases and/or fever, culture of biopsy specimens for bacteria should be considered in children with a ‘cholestatic profile’: direct bilirubin ≥ 7 mg/dl and direct bilirubin/ALT > 0.08, or a ‘hepatocellular profile’: direct bilirubin ≤ 4 mg/dl and direct bilirubin/ALT < 0.05, together with polymorphonuclear leukocytes > 70%. Following these guidelines might provide valuable information pertinent to patient management (especially since Gram-negative organisms can sometimes be cultured from the liver and not from blood) while reducing costs. Fungal cultures should be restricted to critically ill children. However, our data suggest that the practice of obtaining fungal and viral cultures of the liver in most pediatric transplant patients has an unacceptably high cost/benefit ratio, particularly since recovery of the organism from the peripheral blood is likely.     

Outcome of pediatric liver transplant in grafts with multiple arteries

Abstract:  Young age, small diameter of the hepatic artery, presence of multiple arteries, and the selected technique are risk factors for hepatic arterial complications. We report the outcomes of pediatric liver transplant (LT) patients who had received a liver graft with multiple arteries. Since April 2001, 89 pediatric LTs have been performed at our center. Twenty-six liver grafts (29.2%) that had multiple hepatic arteries were analyzed retrospectively. Twenty-five grafts had 2, and 1 graft had 3, hepatic arteries. In 17 grafts with double arteries, and in 1 graft with 3 arteries, the adjacent edges of the hepatic arteries were sutured together at the back table to create a single opening, and the recipient's common hepatic artery was then anastomosed to that orifice. In 8 grafts with double arteries, 2 separate anastomoses were performed between the graft hepatic arteries and the recipient's hepatic artery branches. The mean age of the recipients was 7.9 ± 5.4 years (range, 0.6–17 years). During the early postoperative period, hepatic arterial thromboses occurred in 3 recipients. Two of these 3 recipients were treated with transcatheter arterial thrombolysis using streptokinase or recombinant plasminogen and intraluminal stent placement, and the remaining recipient was treated with a re-anastomosis using a polytetrafluoroethylene graft. Three recipients died during follow-up, which ranged from 1 to 71 months. In conclusion, multiple graft arteries did not increase the incidence of hepatic arterial complications in our series.