Ichiro Morioka

Polymorphisms in TLR-2 are associated with congenital cytomegalovirus (CMV) infection but not with congenital CMV disease

BACKGROUND Cytomegalovirus (CMV) is the most common cause of congenital virus infection. However, the risk factors for infection in utero and for progression to a severe clinical outcome remain uncertain. Recent studies have identified associations of specific single nucleotide polymorphisms (SNPs) in Toll-like receptor (TLR) genes with susceptibility to infections of some viruses and with their clinical outcome. METHODS Genetic polymorphisms in the TLR-2, TLR-4, and TLR-9 genes were analyzed in 87 children with congenital CMV infections by the TaqMan allelic discrimination assay. The frequencies of genotypes in the general Japanese population were obtained from the National Center for Biotechnology Information (NCBI) databases. Associations between the analyzed SNPs and congenital CMV infection or disease were evaluated. RESULTS The CC genotype at SNP rs3804100 in the TLR-2 gene was significantly associated with congenital CMV infection but not with congenital CMV disease. Furthermore, the AG genotype at SNP rs1898830 in the TLR-2 gene tended to be identified less frequently in children with congenital CMV infection. There were no statistically significant associations between SNPs in the TLR-4 and TLR-9 genes and congenital CMV infection or disease. CONCLUSION TLR-2 polymorphisms may have some association with congenital CMV infection, although the mechanism underlying this effect remains to be clarified.

A Novel Diagnostic Tool for Detecting Neonatal Infections Using Multiplex Polymerase Chain Reaction

Background: In newborns with infections, it is necessary to detect various pathogens rapidly and accurately, because the infections are often fatal when diagnosis is delayed. However, no diagnostic tools that rapidly detect pathogens causing neonatal infectious diseases are available. Objectives: To establish a rapid diagnostic tool using multiplex polymerase chain reaction (PCR) to detect 8 major pathogens that often cause neonatal infections, including Group B Streptococcus, Escherichia coli, Pseudomonas aeruginosa, methicillin-resistant Staphylococcus aureus, Ureaplasma urealyticum, herpes simplex virus, Cytomegalovirus, and Candida albicans, and to validate this tool in the neonatal intensive care unit (NICU). Methods: One hundred and thirty clinical samples were obtained from newborns with any infectious signs or histories. DNA was extracted from these samples and multiplex PCR was performed with a mixture of 8 primer pairs, all designed to amplify pathogenic DNA and produce different sizes of amplicons. Seventy-seven samples with suspicion of bacterial infections were also examined by bacterial culture to evaluate the accuracy of the multiplex PCR results. Results: Six of the 8 pathogens could be rapidly detected by our multiplex PCR method, within 3.5–4.5 h. These positive results led us to immediately diagnose and select proper drugs against each pathogen. In comparison with culture results, our test characteristics were as follows: specificity: 93%, negative predictive value: 96%, and concordance rate: 90%. Conclusions: We have established and validated a rapid diagnostic tool for detecting pathogens using multiplex PCR, which may be useful for the confirmed diagnosis of neonatal infections in the NICU.

Does thrombocytopenia contribute to patent ductus arteriosus

nature medicine volume 17 | number 1 | january 2011 29 addition, they showed in a retrospective clinical study that thrombocytopenia increases the risk for PDA in German premature newborns2. To test whether thrombocytopenia generally increases the risk for PDA, we investigated the association between PDA and thrombocytopenia in Japanese premature newborns with a retrospective study at Kobe University Hospital in Japan using the same experimental design as described by Echtler et al.2. We diagnosed DA closure as the absence the definition of osteoarthritis is a major limitation for human genetic studies of osteoarthritis research worldwide, as the KL grading system is limited in its reproducibility and sensitivity as a result of the subjective judgment of individual observers and the categorical classification into only five grade scales. More importantly, in human genetic studies on common diseases such as osteoarthritis with a high prevalence, selection of appropriate and disease-free controls is essential to avoid potential bias resulting from contamination of the control group with affected subjects. The Nakajima et al.6 control group may not be an appropriately disease-free group, again resulting in a decrease of the detection power. According to their references9–15, subjects that are diagnosed to be free of disease by radiographs (KL = 0 or 1) are apparently limited to small cohorts and are very low in number, so that the majority are those without radiographic diagnosis, including the ‘healthy’ population and the subjects with other diseases or trauma. The abovementioned ROAD epidemiologic study has shown a high prevalence of knee osteoarthritis in the Japanese population (KL ≥ 2, 61.9%; KL ≥ 3, 20.6%)8. Furthermore, the ROAD study has also revealed that the prevalence of pain-free subjects is 67.2% and that prevalence of people with KL grades 0 or 1 is 38.1%, indicating that a considerable number of asymptomatic individuals with osteoarthritis are included in the so-called healthy population. Hence, a substantial percentage of the control group used by Nakajima et al.6 may actually be undiagnosed cases. Because the MAF of their case group (KL = 2, 3 or 4; 12.8%) is lower than that of our control group (KL = 0 or 1; 15.2%), supporting an inverse correlation between MAF and KL scores, the discrepancy between our results and theirs may largely result from the inclusion criteria of their control group. Owing to the abovementioned limitations of conventional genetic approaches, the study by Nakajima et al.6 results in very small statistical powers of detecting susceptibility in all populations: 0.13, 0.29, 0.16 and 0.03 for Japanese, Chinese, European and Australian populations, respectively, calculated on the basis of their respective allele frequencies, as compared with the statistical power of 0.71 in our study2. Their statement that “the power of the association study is >80% for our Japanese cohort alone,” may be scientifically inaccurate, as this number may be calculated on the basis of our allele frequency using case and control groups with more stringent selection criteria than were used in their study, as mentioned above. The minimum number of subjects required for the statistical power of >0.8, as they claim, should be 11.7, 4.2, 8.4 and ~3 × 106 times larger for their Japanese, Chinese, European and Australian populations, respectively. This is also owing to very low MAFs in European and Australian populations. Hence, an association analysis of the rs17039192 SNP in their populations, as well as including them in the meta-analysis, is not easily achieved, although studies on different SNPs of the EPAS1 gene with higher MAFs, if any should exist in these populations, might be of interest. Overall, we disagree with the assertions by Nakajima et al.6, as their study possibly compares a case group with ambiguous definition to a control group that may contain affected subjects. Furthermore, although the P value for rs17039192 and its association with osteoarthritis in our study2 is not very striking, our luciferase assay nonetheless shows that a single rs17039192 mutation causes a significant change of the EPAS1 promoter activity in cultured human chondrocytes2, supporting that this is a strong functional SNP.

Neurological outcomes in symptomatic congenital cytomegalovirus-infected infants after introduction of newborn urine screening and antiviral treatment

BACKGROUND Newborn screening for urinary cytomegalovirus (CMV) and early introduction of antiviral treatment are expected to improve neurological outcomes in symptomatic congenital CMV-infected infants. This cohort study prospectively evaluated neurological outcomes in symptomatic congenital CMV-infected infants following the introduction of hospital-based newborn urinary CMV screening and antiviral treatment. SUBJECTS/METHODS Following institutional review board approval and written informed consent from their parents, newborns were prospectively screened from 2009 to 2014 for urinary CMV-DNA by PCR within 1 week after birth at Kobe University Hospital and affiliated hospitals. CMV-positive newborns were further examined at Kobe University Hospital, and those diagnosed as symptomatic were treated with valganciclovir for 6 weeks plus immunoglobulin. Clinical neurological outcomes were evaluated at age ⩾12 months and categorized by the presence and severity of neurologic sequelae. RESULTS Urine samples of 6348 newborns were screened, with 32 (0.50%) positive for CMV. Of these, 16 were diagnosed with symptomatic infection and 12 received antiviral treatment. Four infants developed severe impairment (33%), three developed mild impairment (25%), and five developed normally (42%). CONCLUSIONS This is the first Japanese report of neurological assessments in infants with symptomatic congenital CMV infection who received early diagnosis and antiviral treatment. Urinary screening, resulting in early diagnosis and treatment, may yield better neurological outcomes in symptomatic congenital CMV-infected infants.

Culture-Proven Neonatal Sepsis in Japanese Neonatal Care Units in 2006–2008

Background: Recent Japanese epidemiology of neonatal sepsis and its predominant pathogens has not been reported. It is also unknown whether there are center differences in the incidence of neonatal sepsis, including early-onset sepsis (EOS) and late-onset sepsis (LOS) in Japan. Objectives: To investigate the morbidity and characteristics of neonatal sepsis in recent years and the differences in the incidence of sepsis among Japanese neonatal care units. Methods: We retrospectively collected the data of newborn infants with culture-proven sepsis that occurred in five Japanese centers of perinatal care from 2006 to 2008. The incidence of sepsis was calculated, including EOS and LOS, and compared among centers. Results: Morbidity from sepsis occurred in 51/6,894 (0.74%) infants. The incidence of EOS and LOS was 0.13 and 0.61%, respectively. The incidence of total sepsis and LOS in infants <1,000 g of birth weight was significantly higher than that in infants who weighed >1,000 g at birth, whereas there were no significant differences in the incidence of EOS between the different birth weights. Methicillin-resistant Staphylococcus aureus was the most common pathogen involved in morbidity and mortality of neonatal sepsis. Significant center differences were observed in the incidence of LOS, but not EOS. Conclusions: The majority of culture-proven neonatal sepsis is LOS, which differs among centers, especially in infants who weigh <1,000 g at birth in Japan. We consider that it is important to control nosocomial infection in newborn care units to further reduce the morbidity of neonatal sepsis in Japan.

A polymorphic mutation, c.-3279T > G, in the UGT1A1 promoter is a risk factor for neonatal jaundice in the Malay population.

The uridine diphosphoglucuronate-glucuronosyltransferase 1A1 (UGT1A1) gene encodes the enzyme responsible for bilirubin glucuronidation. To evaluate the contribution of UGT1A1 promoter mutations to neonatal jaundice, we determined the genotypes of c.-3279T>G, c.-3156G>A, and A(TA)7TAA in Malay infants with neonatal jaundice (patients) and in infants without neonatal jaundice (controls). In our population study, only c.-3279T>G was associated with neonatal jaundice. The genotype distributions between both groups were significantly different (p = 0.003): the frequency of homozygosity for c.-3279G was much higher in patients than those in controls. Allele frequency of c.-3279G was significantly higher in patients than those in controls (p = 0.006). We then investigated changes in transcriptional activity because of c.-3279T>G. Luciferase reporter assay in HepG2 cells demonstrated that transcriptional activity of the c.-3279G allele was significantly lower than that of the c.-3279T allele in both the absence and presence of bilirubin. Luciferase reporter assay in COS-7 cells elucidated that c.-3279T>G modified the synergistic effects of the nuclear factors associated with transcriptional machinery. In conclusion, the c.-3279T>G mutation in the UGT1A1 promoter is a genetic risk factor for neonatal jaundice.

Mechanistic aspects of the formation of α-dystroglycan and therapeutic research for the treatment of α-dystroglycanopathy: A review.

α-Dystroglycanopathy, an autosomal recessive disease, is associated with the development of a variety of diseases, including muscular dystrophy. In humans, α-dystroglycanopathy includes various types of congenital muscular dystrophy such as Fukuyama type congenital muscular dystrophy (FCMD), muscle eye brain disease (MEB), and the Walker Warburg syndrome (WWS), and types of limb girdle muscular dystrophy 2I (LGMD2I). α-Dystroglycanopathy share a common etiology, since it is invariably caused by gene mutations that are associated with the O-mannose glycosylation pathway of α-dystroglycan (α-DG). α-DG is a central member of the dystrophin glycoprotein complex (DGC) family in peripheral membranes, and the proper glycosylation of α-DG is essential for it to bind to extracellular matrix proteins, such as laminin, to cell components. The disruption of this ligand-binding is thought to result in damage to cell membrane integration, leading to the development of muscular dystrophy. Clinical manifestations of α-dystroglycanopathy frequently include mild to severe alterations in the central nervous system and optical manifestations in addition to muscular dystrophy. Eighteen causative genes for α-dystroglycanopathy have been identified to date, and it is likely that more will be reported in the near future. These findings have stimulated extensive and energetic investigations in this research field, and novel glycosylation pathways have been implicated in the process. At the same time, the use of gene therapy, antisense therapy, and enzymatic supplementation have been evaluated as therapeutic possibilities for some types of α-dystroglycanopathy. Here we review the molecular and clinical findings associated with α-dystroglycanopathy and the development of therapeutic approaches, by comparing the approaches with the development of Duchenne muscular dystrophy.

Genetic, Clinical, and Pathologic Backgrounds of Patients with Autosomal Dominant Alport Syndrome

BACKGROUND AND OBJECTIVES Alport syndrome comprises a group of inherited heterogeneous disorders involving CKD, hearing loss, and ocular abnormalities. Autosomal dominant Alport syndrome caused by heterozygous mutations in collagen 4A3 and/or collagen 4A4 accounts for <5% of patients. However, the clinical, genetic, and pathologic backgrounds of patients with autosomal dominant Alport syndrome remain unclear. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS We conducted a retrospective analysis of 25 patients with genetically proven autosomal dominant Alport syndrome and their family members (a total of 72 patients) from 16 unrelated families. Patients with suspected Alport syndrome after pathologic examination who were referred from anywhere in Japan for genetic analysis from 2006 to 2015 were included in this study. Clinical, laboratory, and pathologic data were collected from medical records at the point of registration for genetic diagnosis. Genetic analysis was performed by targeted resequencing of 27 podocyte-related genes, including Alport-related collagen genes, to make a diagnosis of autosomal dominant Alport syndrome and identify modifier genes or double mutations. Clinical data were obtained from medical records. RESULTS The median renal survival time was 70 years, and the median age at first detection of proteinuria was 17 years old. There was one patient with hearing loss and one patient with ocular lesion. Among 16 patients who underwent kidney biopsy, three showed FSGS, and seven showed thinning without lamellation of the glomerular basement membrane. Five of 13 detected mutations were reported to be causative mutations for autosomal recessive Alport syndrome in previous studies. Two families possessed double mutations in both collagen 4A3 and collagen 4A4, but no modifier genes were detected among the other podocyte-related genes. CONCLUSIONS The renal phenotype of autosomal dominant Alport syndrome was much milder than that of autosomal recessive Alport syndrome or X-linked Alport syndrome in men. It may, thus, be difficult to make an accurate diagnosis of autosomal dominant Alport syndrome on the basis of clinical or pathologic findings. No modifier genes were identified among the known podocyte-related genes.

Serum unbound bilirubin as a predictor for clinical kernicterus in extremely low birth weight infants at a late age in the neonatal intensive care unit

BACKGROUND This study aimed to evaluate peak serum total bilirubin (TB) and unbound bilirubin (UB) levels in preterm infants with clinical kernicterus (KI) who were diagnosed by clinical findings during infancy. DESIGN/SUBJECTS For this multicenter retrospective study, 18 Japanese extremely low birth weight (ELBW) infants with clinical KI were included. Clinical KI was diagnosed based on the presence of motor developmental impairment with/without athetosis, and abnormal magnetic resonance imaging or brainstem auditory evoked potential findings during infancy. High and low TB or UB levels were defined as serum TB levels ⩾ and <15 mg/dL or serum UB levels ⩾ and <0.8 μg/dL, respectively. The clinical characteristics of KI preterm infants were analyzed. The proportion of infants with high or low serum TB levels and with high or low serum UB levels was then investigated. Sensitivity and specificity were calculated. RESULTS In 18 KI infants, the median age when serum TB levels peaked was 28 days after birth. In eight KI infants with low serum TB levels, 88% of them had high serum UB levels. For comparison of the number of infants who had high or low serum TB and UB levels, the sensitivity was 90% and specificity was 13%. CONCLUSIONS Serum TB and UB levels peak at a later age than expected. Chronic serum UB monitoring may be helpful for identifying ELBW infants at risk for developing KI, even when they do not have high serum TB levels.

Hypoalbuminemia following Abdominal Surgery Leads to High Serum Unbound Bilirubin Concentrations in Newborns Soon after Birth

Background: The serum concentration of unbound bilirubin (UB), which is bilirubin not bound to albumin (Alb), is a better index than total bilirubin concentration (TB) for identifying infants at risk for developing bilirubin neurotoxicity. The degree to which the hypoalbuminemia following abdominal surgery in jaundiced newborns affects bilirubin binding is unknown. Objective: To determine whether lower Alb occurring in newborns undergoing abdominal surgery shortly after birth results in significantly higher UB in serum versus nonsurgical patients at comparable serum TB. Methods: A matched case-control study was conducted with term and late-preterm newborns. The surgery group included 15 newborns who underwent abdominal operation within 3 days after birth. Clinical and laboratory data (serum UB, TB, and Alb concentrations, UB/TB ratio, and binding constant) in the surgery group were collected and compared with those of 30 control newborns who did not undergo abdominal surgery (control group). Results: Serum UB and the UB/TB ratio in the surgery group were significantly higher than those in the control group (p < 0.02, p < 0.001, respectively), whereas there were no significant differences in serum TB and binding constant between the groups. Serum Alb concentrations in the surgery group were significantly lower than those in the control group (p < 0.001). When pre- and postoperative serum Alb concentrations were compared, there was a significant decrease from 3.4 to 2.7 g/dl (p < 0.001). Conclusions: Our study suggests that hypoalbuminemia following abdominal surgery causes a higher serum UB at comparable serum TB in newborns.