Objectives: In this retrospective study, we aimed to determine the most common infectious agents in infants within the first 6 months of liver transplant.
Materials and Methods: Thirty-four infant patients with median age of 8 months (range, 4-12 mo) at the time of liver transplant were retrospectively evaluated. We evaluated causative organisms in bloodstream cultures and in subclavian catheter, urine, and intra-abdominal drainage fluid cultures. We also evaluated Epstein-Barr and cytomegalovirus infections by polymerase chain reaction in all recipients.
Results: The most common isolated bacteria from the bloodstream were Klebsiella pneumoniae, Staphylococcus epidermidis, and Enterococcus faecium. Staphylococcus epidermidis was the most common isolated bacteria from subclavian catheter cultures. Klebsiella pneumoniae was the most common bacteria isolated from intra-abdominal drainage fluid. Only 1 recipient had cytomegalovirus infection during this period.
Conclusions: Our study showed a high incidence of Klebsiella pneumoniae infections in infants after liver transplant. New prophylactic antibiotic strategies can be promoted to prevent Klebsiella pneumoniae infections in infants.
Key words : Bacterial infections, Children, Klebsiella pneumoniae
Infections are a major cause of morbidity and mortality after liver transplant (LT), especially in young children. There are limited studies of infectious complications after LT in infants. We aimed to determine the most common infectious agents in infants within the first 6 months of LT.
Materials and Methods
We conducted a retrospective study at Baskent University (Ankara, Turkey) of infant patients seen between March 2005 and September 2018. This retrospective study was approved by our institutional review board, and parents of study participants provided written informed consent. Thirty-four infant patients with median age of 8 months (range, 4-12 mo) at the time of LT were retrospectively evaluated. Patient characteristics, blood culture results, and clinical outcomes were extracted from electronic medical records. Cases of death within the first 6 months were excluded. The standard immunosuppressive regimen after LT consisted of tacrolimus and mycophenolate mofetil. Methylprednisolone was started intraoperatively (10 mg/kg/dose) and continued with tapering for the first 3 months after LT. The perioperative prophylaxis consisted of ampicillin (200 mg/kg/day) and cefotaxime (150 mg/kg/day), which were administrated intravenously and continued for 72 hours after transplant. Antiviral and antifungal prophylactic regimens consisted of oral valganciclovir and oral fluconazole for the first 3 months after LT. Oral trimethoprim-sulfamethoxazole was initiated for Pneumocystis jiroveci infection prophylaxis. When recipients developed fever suggesting infection, blood cultures and subclavian catheter, urine, and intra-abdominal drainage fluid cultures were collected and analyzed. Subclavian catheter-related bloodstream infections were defined as pathogens that were identified from both catheter and blood cultures. Skin contaminants (such as coagulase-negative staphylococcus, Propionibacterium species) when positive in blood culture were considered as pathogens causing bloodstream infections if the bacteria were isolated from 2 separate blood cultures and accompanied by clinical signs of infection. We evaluated causative organisms in bloodstream culture and in subclavian catheter, urine, and intra-abdominal drainage fluid cultures. We also evaluated Epstein-Barr virus and cytomegalovirus infections with the use of polymerase chain reaction in all recipients.
All statistical calculations were performed with SPSS software (SPSS for Windows, version 21.0; SPSS Inc, Chicago, IL, USA). Logistic regression analysis was used to analyze risk factors. P < .05 was considered statistically significant.
Our analyses included 34 infant patients (20 boys, 14 girls) who underwent LT during the study period. Body weight (mean ± standard deviation) was 6874 ± 1018 g. The underlying diseases were as follows: 26 patients with biliary atresia, 4 patients with neonatal cholestasis, 2 patients with progressive familial intrahepatic cholestasis, and 2 patients with acute liver failure. Pediatric end-stage liver disease score (mean ± standard deviation) was 25.18 ± 10.05.
The first episode of bloodstream infection occurred between 4 and 86 days posttransplant. There were 10 bacteria isolated from blood cultures (n = 19; 55%). The most common isolated bacteria from bloodstream were Klebsiella pneumoniae (n = 4), Staphylococcus epidermidis (n = 4), and Enterococcus faecium (n = 4). The first episode of subclavian catheter infection occurred between 4 and 90 days posttransplant. There were 9 bacteria (n = 12; 35%) isolated from subclavian catheter cultures, with Staphylococcus epidermidis being the most commonly isolated (n = 5). The first episode of urine infection occurred between 7 and 150 days posttransplant. There were 5 bacteria (n = 12; 35%) isolated from the urine, with Klebsiella pneumoniae being the most commonly isolated (n = 5). The first episode of intra-abdominal drainage fluid infection occurred between 6 and 170 days posttransplant. There were 9 bacteria (n = 16; 47%) and 1 fungus (Candida species) (n = 2; 6%) isolated from intra-abdominal drainage fluid cultures within the first 6 months of LT. Klebsiella pneumoniae was also the most common bacterium isolated from intra-abdominal drainage fluid (n = 9). Only 1 recipient had cytomegalovirus infection (20 000 copies/mL) during this period and was treated with intravenous ganciclovir. Risk factors for infections in children are shown in Table 1. We found no significant perioperative risk factors for infections in infants post-LT.
In children, bacterial infection after LT is an important factor in determining morbidity and mortality of recipients. However, studies of infectious com-plications after LT in children are rare, and previous studies had been conducted with limited numbers of patients and age-specific analyses. Immunity in infants is immature compared with that shown in older children; thus, the impact of immunosuppression might be enhanced in infants. Uribe and associates showed that the main cause of death was infection in children weighing less than 10 kg after LT.1
Gram-negative enteric bacteria from the intestine and bile duct are common pathogens related to peritonitis and cholangitis.2,3 In our study, Klebsiella pneumoniae was the most common bacterium isolated from bloodstream, intra-abdominal drainage fluid, and urine cultures. Similarly, Rhee and associates4 found that the most common isolated bacteria in blood cultures were coagulase-negative staphylococcus and Klebsiella pneumoniae in children after LT. Most infections after LT are attributable to perioperative problems. Rhee and associates4 showed that the Kasai operation was a risk factor for bacterial infections in recipients under age of 1 year. However, we found no significant independent risk factor for infections in infants post-LT.
Our analyses showed a high incidence of Klebsiella pneumoniae infections in infants after LT. New prophylactic antibiotic strategies can be promoted to prevent Klebsiella pneumoniae infections in infants.
Volume : 18
Issue : 1
Pages : 93 - 95
DOI : 10.6002/ect.TOND-TDTD2019.P33
From the 1Department of Pediatric Gastroenterology, the 2Department
of Pediatric Infectious Diseases, and the 3Department of
Transplantation, Baskent University Faculty of Medicine, Ankara, Turkey
Acknowledgements: The authors have no sources of funding for this study and have no conflicts of interest to declare.
Corresponding author: Oya Balcı Sezer, Department of Pediatric Gastroenterology, Baskent University, Faculty of Medicine, 06490, Bahcelievler, Ankara, Turkey
Phone: +90 312 203 6868/2932
Table 1. Risk Factors for Infections in 34 Infants After Liver Transplant