[Show abstract][Hide abstract] ABSTRACT: Chronic granulomatous disease (CGD) is a rare immunodeficiency disease, which is characterized by the lack of a functional nicotinamide adenine dinucleotide phosphate (NADPH) oxidase in phagocytes. The disease presents leukocytosis, anemia, hypergammaglobulinemia, and granuloma formation of the skin, lung, or lymph nodes. The mutation of the CYBB gene encoding gp91phox, located on chromosome Xp21.1 is one of the causes of CGD. We report a patient with X-linked CGD who carried a novel mutation, a c.1133A>G (paAsp378Gly) missense mutation, in the CYBB gene.
[Show abstract][Hide abstract] ABSTRACT: Background:QuantiFERON-TB Gold In-Tube (QFT-G IT; Cellestis Inc., Valencia, CA, USA) is one of the Interferon-gamma Release Assays (IGRAs) that are promising tools for diagnosing active or latent Mycobacterium tuberculosis infection. We investigated the clinical and laboratory factors that affect the rate of indeterminate QFT-G IT test results. We also suggest the workflow strategy to achieve optimized test results using QFT-G IT for the diagnosis of active TB or LTBI.Methods:We performed statistical analysis using data from review of medical records, retrospectively. The first phase included 683 QFT-G IT test results from 676 patients tested from January 2008 to May 2008, and the second phase included additional 663 QFT-G IT test results from 653 patients tested from January 2008 to December 2008 at Samsung Medical Center, a tertiary care hospital in South Korea.Results:Immunosuppressive drug therapy, underlying diseases, bed-ridden status, and hypoalbuminemia were significantly associated with an indeterminate QFT-G IT test result. With the reduction in incubation delay from an average of 9.82 hours to an average of 2.70 hours during the test procedure by making changes in the workflow, the frequency of indeterminate QFT-G IT test results was significantly reduced from 11.4% to 2.7%. However, if there was a more than 6 hours of incubation delay, the frequency of indeterminate QFT-G IT test results was increased in a statistically significant manner.Conclusion:This study demonstrates that not only the clinicopathological factors, but also the laboratory factor such as incubation delay affects significantly on the rate of indeterminate QFT-G IT test results, and hence optimization of the test procedure may contribute to the reduction in the rate of indeterminate QFT-G IT test results that delay the diagnosis of TB.
Journal of clinical microbiology 10/2013; · 4.16 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: We describe three children with urinary tract abnormalities and large numbers of S. pneumoniae in their urine, along with a brief review of previously reported cases. These findings strongly suggest that S. pneumoniae is a uropathogen, especially in children with urinary tract abnormalities.
The Pediatric Infectious Disease Journal 08/2013; · 3.57 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Fluoroquinolones are an important class of antibiotics that are widely used in adult patients because of their broad spectrum of activity, good tissue penetration, and oral bioavailability. However, fluoroquinolone use in children is limited because juvenile animals developed arthropathy in previous experiments on fluoroquinolone use. Indications for fluoroquinolone use in patients younger than 18 years, as stated by the U.S. Food and Drug Administration, include treatment of complicated urinary tract infections and postexposure treatment for inhalation anthrax. In Korea, the systemic use of fluoroquinolones has not been approved in children younger than 18 years. Although concerns remain regarding the adverse musculoskeletal effects of fluoroquinolones in children, their use in the pediatric population has increased in many circumstances. While pediatricians should be aware of the indications and adverse effects of fluoroquinolones, recent studies have shown that the risk for musculoskeletal complications in children did not significantly increase following fluoroquinolone treatment. In addition, fluoroquinolones may be particularly helpful in treating multidrug-resistant infections that have not responded to standard antibiotic therapy in immunocompromised patients. In the present article, we provide an updated review on the safety and current recommendations for using fluoroquinolones in children.
Korean Journal of Pediatrics 05/2013; 56(5):196-201.
[Show abstract][Hide abstract] ABSTRACT: We compared the 16S rRNA gene sequencing results analyzed with the GenBank, EzTaxon, and BIBI databases for blood culture specimens for which identifications were incomplete, conflicting, or unidentifiable using conventional methods. Analyses performed using GenBank combined with EzTaxon (kappa = 0.79) were more discriminative than those using other databases alone or in combination with a second database.
Journal of clinical microbiology 03/2012; 50(5):1792-5. · 4.16 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Respiratory viruses (RVs) are a known cause of morbidity and mortality after hematopoietic stem cell transplantation (HSCT). In this retrospective study, we focused on the first 28 d after transplantation in pediatric HSCT recipients and showed that a multiplex PCR assay significantly increased RV detection compared with a viral culture method. Among 176 pediatric HSCT recipients, 84 with respiratory symptoms within one yr after HSCT were tested by viral culture or multiplex PCR. Within 28 d after HSCT, nine patients were infected with RVs; the incidence of a first episode of RV infection within 28 d after HSCT was 5.1%. Eight patients recovered without complications. However, one patient died of adenovirus (AdV) pneumonia with pulmonary hemorrhage; the mortality rate of RV infection within 28 d after HSCT was 0.57%. In the nine patients with RV infection, five different types of RV were identified, either alone or with another RV. These were corona virus (CoV), rhinovirus (RhV) and respiratory syncytial virus combined with CoV; AdV combined with RhV; and parainfluenza virus. Viral culture detected only one case of RV infection, while multiplex PCR detected eight, suggesting that screening of respiratory infections using multiplex PCR is better than the conventional culture method.
[Show abstract][Hide abstract] ABSTRACT: This study was performed in order to evaluate the incidence and characteristics of cytomegalovirus (CMV) infection in children with acute leukemia according to donor source and graft type.
We retrospectively identified children with acute leukemia who had received allogeneic hematopoietic cell transplantation at Samsung Medical Center in Korea from October 1998 to December 2009.
In total, 134 recipients were identified. The patients were classified into the following three groups: unrelated cord blood (CB, n=36), related bone marrow or peripheral blood stem cells (RD, n=41), and unrelated bone marrow or peripheral blood stem cells (UD, n=57). The 365-day cumulative incidence of CMV antigenemia was not significantly different among the three groups (CB 67% vs. RD 49% vs. UD 65%, p=0.17). However, CB recipients had the highest median value of peak antigenemia (CB 160/2×10⁵ leukocytes vs. RD 7/2×10⁵ leukocytes vs. UD 19/2×10⁵ leukocytes, p<0.01) and the longest duration of CMV antigenemia than the other stem cell source recipients (CB 87 days vs. RD 17 days vs. UD 28 days, p<0.01). In addition, the 730-day cumulative incidence of CMV disease was the highest in the CB recipients (CB 36% vs. RD 2% vs. UD 5%, p<0.01). Thirteen CB recipients developed CMV disease, in which five of them had more than one organ involvement. Two patients, who were CB recipients, died of CMV pneumonia.
This study suggests that CB recipients had both longer and higher cumulative incidences of CMV infection. Therefore, a more aggressive and effective strategy of CMV management should be considered in CB recipients.
Yonsei medical journal 03/2012; 53(2):393-400. · 0.77 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Respiratory virus (RV) infection can cause significant morbidity and mortality in pediatric cancer patients. Parainfluenza virus (PIV) is a common pathogen in childhood among the respiratory viruses. The objective of this study is to evaluate the impact of parainfluenza virus infection in pediatric cancer patients.
A retrospective review of medical records of 1,554 children diagnosed with cancer from January 2000 through July 2008 was analyzed at Samsung Medical Center.
A total of 6.4% (137/1,554) had respiratory virus infection and 54% (74/137) of patients with RV infection had PIV infection. PIV type 3 was the predominant subtype. Among patients with PIV infection, 59 children (79.7%) had upper respiratory tract infection (URI) whereas 15 children (20.3%) had lower respiratory tract infection (LRI) at initial presentation. Among patients with URI, 12 (20.3%) progressed to pneumonia with the median interval of 4 days from URI to LRI. Mortality associated with PIV infection was 18.5% (5/27) in patients with LRI. Among patients with PIV infection, 80% (59/74) had nosocomial infection, which shows the difficulty and importance of infection control at pediatric cancer ward.
PIV infection was most commonly diagnosed among pediatric cancer patients with RV infection and PIV infection led to significant pulmonary complications and direct mortality in immunocompromised children. Since there are no effective antiviral agents for PIV infection, precautionary infection control and early diagnosis are the only methods available to prevent the infection spread.
Pediatric Blood & Cancer 11/2011; 59(4):708-10. · 2.35 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: A 3-year-old girl with acute respiratory distress syndrome due to a H1N1 2009 influenza virus infection was complicated by necrotizing pneumonia was successfully treated with extracorporeal membrane oxygenation (ECMO). This is the first reported case in which a pediatric patient was rescued with ECMO during the H1N1 influenza epidemic in Korea in 2009.
Korean Journal of Pediatrics 08/2011; 54(8):345-9.
[Show abstract][Hide abstract] ABSTRACT: The risk of invasive fungal infection is greater for allogeneic hematopoietic stem cell transplantation (HSCT) than for autologous transplantation. Therefore, many transplantation centers use antifungal prophylaxis for allogeneic HSCT, however, there exists no standard guidelines or consensus regarding autologous HSCT.
A prospective double-blind randomized study was conducted in autologous HSCT recipients who were divided into prophylaxis and empirical treatment groups, and we investigated the efficacy of itraconazole prophylaxis in pediatric autologous HSCT.
Total 87 autologous HSCT episodes in 55 children with high-risk solid tumors were studied. No invasive fungal infections occurred in either group. However, patients in the prophylaxis group had a significantly shorter duration of fever (p < 0.05) and received antibacterial treatment of shorter duration (p < 0.05) with fewer numbers of antibiotics (p < 0.05 for the use of second line antibiotics) than those in the empirical group. No significant additional adverse events were found with itraconazole prophylaxis.
Although beneficial effects such as a shorter duration of fever and reduced need for antibiotic use were observed in the prophylaxis group, the results were not sufficient to draw a definite recommendation about the routine use of antifungal prophylaxis in pediatric autologous HSCT recipients with high-risk solid tumors (Trial registration: NCT00336531).
Yonsei medical journal 03/2011; 52(2):293-300. · 0.77 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Pneumatosis intestinalis (PI) in children is associated with immunosuppression, mucosal disruption from trauma, obstructive pulmonary disease, congenital heart disease, and gastrointestinal infections. Our study is the first report of norovirus infection-associated PI.
A retrospective review was performed in pediatric patients (older than 30 days) with PI from March 2005 to April 2009. Since December 2008, in addition to routine stool examinations, reverse-transcriptase polymerase chain reaction testing for calicivirus (norovirus and sapovirus), adenovirus, astrovirus, and enterovirus has been performed.
Twenty-seven patients with PI were identified. The median age was 1.4 (range 0.2-14.8 years). Seventeen patients (63.0%) were immunocompromised hosts. Pathogens were identified in 5 immunocompromised patients (5/27 and 5/8 since December 2008). Of note, norovirus was identified in 4 patients (80%, 4/5) during the cold weather season. The genotype of noroviruses in these patients was GII-4. Among 27 patients with PI, 10 patients (37.0%) developed PI in the spring and 11 (40.7%) in the winter. Twenty-four patients survived (88.9%, 24/27). None of the patients with norovirus or rotavirus infection died.
Our data suggest that norovirus infection may contribute to the development of PI in immunocompromised hosts.
Journal of pediatric gastroenterology and nutrition 03/2011; 52(3):314-8. · 2.18 Impact Factor