Epidemiology of invasive group B streptococcal disease in infants from urban area of South China, 2011-2014.

BACKGROUND: Group B Streptococcus (GBS) is a leading cause of morbidity and mortality in infants in both developed and developing countries. To our knowledge, only a few studies have been reported the clinical features, treatment and outcomes of the GBS disease in China. The severity of neonatal GBS disease in China remains unclear. Population-based surveillance in China is therefore required. METHODS: We retrospectively collected data of <3 months old infants with culture-positive GBS in sterile samples from three large urban tertiary hospitals in South China from Jan 2011 to Dec 2014. The GBS isolates and their antibiotic susceptibility were routinely identified in clinical laboratories in participating hospitals. Serotyping and multi-locus sequence typing (MLST) were also conducted for further analysis of the neonatal GBS disease. RESULTS: Total 70 cases of culture-confirmed invasive GBS infection were identified from 127,206 live births born in studying hospitals, giving an overall incidence of 0.55 per 1000 live births (95% confidence interval [CI] 0.44-0.69). They consisted of 49 with early-onset disease (EOD, 0.39 per 1000 live births (95% CI 0.29-0.51)) and 21 with late-onset disease (LOD, 0.17 per 1000 live births (95% CI 0.11-0.25)). The incidence of EOD increased significantly over the studying period. Five infants (4 EOD and 1 LOD) died before discharge giving a mortality rate of 7.1% and five infants (7.1%, 2 EOD and 3 LOD) had neurological sequelae. Within 68 GBS isolates from GBS cases who born in the studying hospitals or elsewhere, serotype III accounted for 77.9%, followed by Ib (14.7%), V (4.4%), and Ia (2.9%). MLST analysis revealed the presence of 13 different sequence types among the 68 GBS isolates and ST-17 was the most frequent sequence type (63.2%). All isolates were susceptible to penicillin, ceftriaxone, vancomycin and linezolid, while 57.4% and 51.5% were resistant to erythromycin and clindamycin, respectively. CONCLUSIONS: This study gains the insight into the spectrum of GBS infection in south China which will facilitate the development of the guidance for reasonable antibiotics usage and will provide evidence for the implementation of potential GBS vaccines in the future.

Identification of Circulating MicroRNAs in Biliary Atresia by Next-Generation Sequencing.

OBJECTIVES: Biliary atresia (BA) is an idiopathic neonatal liver disease, characterized by inflammatory and fibrotic obliteration of extrahepatic bile ducts. Therefore, reliable methods for noninvasive diagnosis are needed. The present study aimed to analyze circulating microRNAs (miRNAs) in patients with BA using next-generation sequencing for identifying novel diagnostic biomarkers. METHODS: An initial screening of miRNAs in plasma from patients with BA and healthy controls (HCs) was performed on an Illumina next-generation sequencing platform. Differential miRNAs were validated by quantitative real-time polymerase chain reaction (qPCR). Target genes and related signal transduction pathways of differential miRNAs were predicted by online software. RESULTS: In total, 146 differential miRNAs were identified by deep sequencing. Fifteen miRNAs with read counts >1000, that included 7 upregulated and 8 downregulated miRNAs, were predicted to be associated with liver fibrosis, biliary differentiation, and bile duct development. Of these, 6 miRNAs with read counts >5000 were analyzed by qPCR on an independent sample set comprising 44 patients with BA, 20 cholestatic disease controls, and 20 HCs. Two upregulated miRNAs (miR-122-5p, miR-100-5p) and 2 downregulated miRNAs (miR-140-3p, miR-126-3p) were confirmed by individual qPCR. Only miR-140-3p was significantly different from controls (P < 0.05), yielding an area under receiver operating characteristic curve of 0.75 with sensitivity of 66.7% and specificity of 79.1% at optimal threshold. CONCLUSIONS: Our findings indicate that patients with BA exhibit a distinct profile of circulating miRNAs and that plasma miR-140-3p may be a promising diagnostic biomarker for this disease.

[Deep sequencing of the T cell receptor Vb CDR3 repertoire of peripheral CD4+T cells in primary biliary cirrhosis].

OBJECTIVE: To determine the immune repertoires of peripheral CD4+T cell receptor (TCR) Vb CDR3 in primary biliary cirrhosis (PBC) and analyze TCR diversity and preferred usage at sequence-level resolution. METHODS: ARM-PCR and high-throughput sequencing were used to obtain millions of TCR Vb CDR3 sequences from peripheral CD4+T cells isolated from 7 patients with PBC and healthy volunteers. All sequencing data were analyzed, together with corresponding clinical information, by bioinformatic software. The Mann-Whitney U test was used for statistical analysis. RESULTS: The PBC patients showed a lower level of diversity among the peripheral CD4+TCR Vb CDR3 than the healthy volunteers, and patients with higher level progression of the disease showed a greater lack of diversity. In addition, 4 specific preferred-usage amino acid sequences were discovered for the PBC patients: ASSFTGGPVEQY, ASSLISSGNNEQF, ATSRDTLAGGPGDTQY, and SASLEGNTEAF; these sequences were also found in higher frequencies in patients with later stages of PBC. CONCLUSIONS: Decreased TCR Vb CDR3 diversities and specific preferred usage of TCR CDR3 sequences in peripheral CD4+T lymphocytes in PBC suggest that clonal expansion of a large number of CD4+T cells may be an important factor for PBC progression. These data provide a better understanding about the general characteristics of CD4+T cells in PBC patients and related to pathogenesis of the disease, and may provide useful insights into potential targets for immunotherapy.

Autoimmune liver disease-related autoantibodies in patients with biliary atresia.

AIM: To investigate the prevalence and clinical significance of autoimmune liver disease (ALD)-related autoantibodies in patients with biliary atresia (BA). METHODS: Sera of 124 BA patients and 140 age-matched non-BA controls were assayed for detection of the following autoantibodies: ALD profile and specific anti-nuclear antibodies (ANAs), by line-blot assay; ANA and anti-neutrophil cytoplasmic antibody (ANCA), by indirect immunofluorescence assay; specific ANCAs and anti-M2-3E, by enzyme linked immunosorbent assay. Associations of these autoantibodies with the clinical features of BA (i.e., cytomegalovirus infection, degree of liver fibrosis, and short-term prognosis of Kasai procedure) were evaluated by Spearman's correlation coefficient. RESULTS: The overall positive rate of serum autoantibodies in preoperative BA patients was 56.5%. ALD profile assay showed that the positive reaction to primary biliary cholangitis-related autoantibodies in BA patients was higher than that to autoimmune hepatitis-related autoantibodies. Among these autoantibodies, anti-BPO was detected more frequently in the BA patients than in the controls (14.8% vs 2.2%, P < 0.05). Accordingly, 32 (25.8%) of the 124 BA patients also showed a high positive reaction for anti-M2-3E. By comparison, the controls had a remarkably lower frequency of anti-M2-3E (P < 0.05), with 6/92 (8.6%) of patients with other liver diseases and 2/48 (4.2%) of healthy controls. The prevalence of ANA in BA patients was 11.3%, which was higher than that in disease controls (3.3%, P < 0.05), but the reactivity to specific ANAs was only 8.2%. The prevalence of ANCAs (ANCA or specific ANCAs) in BA patients was also remarkably higher than that in the healthy controls (37.9% vs 6.3%, P < 0.05), but showed no difference from that in patients with other cholestasis. ANCA positivity was closely associated with the occurrence of postoperative cholangitis (r = 0.61, P < 0.05), whereas none of the autoantibodies showed a correlation to cytomegalovirus infection or the stages of liver fibrosis. CONCLUSION: High prevalence of autoantibodies in the BA developmental process strongly reveals the autoimmune-mediated pathogenesis. Serological ANCA positivity may be a useful predictive biomarker of postoperative cholangitis.

Validation of aspartate aminotransferase to platelet ratio for diagnosis of liver fibrosis and prediction of postoperative prognosis in infants with biliary atresia.

AIM: To validate the value of aspartate aminotransferase to platelet ratio index (APRI) in assessment of liver fibrosis and prediction of postoperative prognosis of biliary atresia (BA) infants from Mainland China. METHODS: Medical records of 153 BA infants who were hospitalized from January 2010 to June 2013 were reviewed. The efficacy of APRI for diagnosis of liver fibrosis was assessed using the receiver operator characteristic (ROC) curve compared to the pathological Metavir fibrosis score of the liver wedge specimens of 91 BA infants. The prognostic value of preoperative APRI for jaundice persistence, liver injury, and occurrence of cholangitis within 6 mo after KP was studied based on the follow-up data of 48 BA infants. RESULTS: APRI was significantly correlated with Metavir scores (rs = 0.433; P < 0.05). The mean APRI value was 0.76 in no/mild fibrosis group (Metavir score F0-F1), 1.29 in significant fibrosis group (F2-F3), and 2.51 in cirrhosis group (F4) (P < 0.001). The area under the ROC curve (AUC) of APRI for diagnosing significant fibrosis and cirrhosis was 0.75 (P < 0.001) and 0.81 (P = 0.001), respectively. The APRI cut-off of 0.95 was 60.6% sensitive and 76.0% specific for significant fibrosis diagnosis, and a threshold of 1.66 was 70.6% sensitive and 82.7% specific for cirrhosis. The preoperative APRI in infants who maintained jaundice around 6 mo after KP was higher than that in those who did not (1.86 ± 2.13 vs 0.87 ± 0.48, P < 0.05). The AUC of APRI for prediction of postoperative jaundice occurrence was 0.67. A cut-off value of 0.60 showed a sensitivity of 66.7% and a specificity of 83.3% for the prediction of jaundice persistence. Preoperative APRI had no significant association with later liver injury or occurrence of cholangitis. CONCLUSION: Our study demonstrated that APRI could diagnose significant liver fibrosis, especially cirrhosis in BA infants, and the elevated preoperative APRI predicts jaundice persistence after KP.