Identification and characterization of a G-quadruplex structure in the pre-core promoter region of hepatitis B virus covalently closed circular DNA.

Approximately 250 million people worldwide are chronically infected with the hepatitis B virus (HBV) and are at increased risk of developing cirrhosis and hepatocellular carcinoma. The HBV genome persists as covalently closed circular DNA (cccDNA), which serves as the template for all HBV mRNA transcripts. Current nucleos(t)ide analogs used to treat HBV do not directly target the HBV cccDNA genome and thus cannot eradicate HBV infection. Here, we report the discovery of a unique G-quadruplex structure in the pre-core promoter region of the HBV genome that is conserved among nearly all genotypes. This region is central to critical steps in the viral life cycle, including the generation of pregenomic RNA, synthesis of core and polymerase proteins, and genome encapsidation; thus, an increased understanding of the HBV pre-core region may lead to the identification of novel anti-HBV cccDNA targets. We utilized biophysical methods (circular dichroism and small-angle X-ray scattering) to characterize the HBV G-quadruplex and the effect of three distinct G to A mutants. We also used microscale thermophoresis to quantify the binding affinity of G-quadruplex and its mutants with a known quadruplex-binding protein (DHX36). To investigate the physiological relevance of HBV G-quadruplex, we employed assays using DHX36 to pull-down cccDNA and compared HBV infection in HepG2 cells transfected with wild-type and mutant HBV plasmids by monitoring the levels of genomic DNA, pregenomic RNA, and antigens. Further evaluation of this critical host-protein interaction site in the HBV cccDNA genome may facilitate the development of novel anti-HBV therapeutics against the resilient cccDNA template.

Prognostic Value of Controlled Attenuation Parameter by Transient Elastography.

OBJECTIVES: Liver stiffness measurement (LSM) by transient elastography (TE) has been shown to predict outcomes in patients with liver disease. While controlled attenuation parameter (CAP) measurement can accurately quantify hepatic steatosis, its prognostic value is unknown. We aim to determine if CAP is predictive for liver-related events (LRE), non-hepatocellular carcinoma (HCC) cancers, and cardiovascular events (CVE). METHODS: Consecutive patients with both a reliable LSM and ≥10 successful CAP measurements by TE from August 2012 to March 2016 were included in the analysis. LRE were defined as HCC or hepatic decompensation. CVE were defined as acute coronary syndrome (ACS), cerebrovascular accident (CVA), or coronary intervention (stenting or bypass). RESULTS: Of the 5,848 patients that were examined, 4,282 (56.7% male, median age 57 years) had adequate follow-up, reliable LSM (median 6.1 kPa), and ≥10 CAP measurements (median 250 dB/m). Indications for TE were: suspected non-alcoholic fatty liver disease (NAFLD) (40.7%), hepatitis B (HBV) (37.0%), hepatitis C (2.9%), and others (19.4%). During 8,540 patient-years of follow-up, there were 45 patients with LRE (34 HCC, 33 decompensations), 73 with newly diagnosed non-HCC cancers, and 65 with CVE (27 ACS, 25 CVA, and 35 coronary interventions). CAP did not predict LRE, non-HCC cancer, or CVE on univariate analysis. On multivariate analysis, LSM, male sex, platelet count, serum albumin, and HBV etiology independently predicted LRE; age was the only independent predictor of non-HCC cancer; while age, fasting blood glucose, total cholesterol, and creatinine predicted for CVE. Subgroup analyses of viral hepatitis and NAFLD patients revealed similar results. CONCLUSION: Neither the presence nor the severity of hepatic steatosis as measured by CAP predict LRE, cancer, or CVE in the short term.

Effects of acute exercise on markers of inflammation in pediatric chronic kidney disease: a pilot study.

BACKGROUND: Children and adolescents with chronic kidney disease (CKD) are chronically exposed to high levels of inflammation, placing them at an increased risk of secondary health complications. Regular exercise may represent an effective therapy to reduce inflammation. The aims of this pilot study were to determine the effects of acute exercise on inflammation and immune cell counts in CKD. METHODS: Nine children and adolescents (4 males) with CKD stages III-V performed a graded exercise test to determine peak oxygen uptake (VO2peak). Following a 10-min break, participants cycled for 20 min at 50 % of VO2peak. Blood samples were collected before and after the exercise period for the determination of complete blood counts, natural killer cells (NK(bright), NK(dim)) and circulating progenitor cell (CPC) counts, as well as interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α) concentrations. RESULTS: Complete blood counts and NK(dim) cell and CPC counts were unchanged with exercise. Following exercise, NK(bright) cell counts increased (7.4 ± 4.3 vs. 12.2 ± 8.3 × 10(6) cells/L; p = 0.02), while trends were observed for an increase in IL-6 (2.1 ± 2.2 vs. 2.7 ± 2.6 pg/mL; p = 0.08), decrease in TNF-α (4.5 ± 1.2 vs. 4.2 ± 1.0 pg/mL; p = 0.08) and an increase in the IL-6:TNF-α ratio (0.6 ± 0.7 vs. 0.8 ± 0.8; p = 0.07). CONCLUSIONS: Our findings suggest that acute exercise may create an anti-inflammatory environment in children and adolescents with CKD stages III-V.

Survey of chronic haemodialysis in children between 2007 and 2012 in China.

AIM: The prevalence of chronic kidney disease (CKD) in children has been on the rise in China and more and more paediatric patients are now relying on chronic renal replacement therapies to sustain their lives. However, there is still a lack of literature in China about their outcomes, thus making it difficult, if not impossible for the paediatric nephrology community to develop strategies to guide future developments and to better serve this group of sick children. METHODS: Our institution has recently conducted a nation-wide survey to obtain data of children with end-stage renal disease (ESRD) between the years 2007 to 2012. Questionnaires were distributed to 39 member hospitals of the Chinese Paediatric Nephrology Association. Only 28 of our member hospitals were actively providing dialysis services to children and their responses were included in this study. RESULTS: There were a total of 1033 children with ESRD and within this cohort, 474 patients (45.9%) received chronic dialysis and 380 patients (80.2%) preferred haemodialysis. CONCLUSION: Haemodialysis is far more commonly used than peritoneal dialysis in China and the outcomes were similar to the experiences in North America. The data we gained through this survey provides the foundation for future planning and development of the paediatric dialysis services in China.

Severe Ethanol Poisoning Among United States College Fraternity Pledges.

Hazing is a longstanding tradition in university and college fraternities. This practice often uses alcohol as a penalty during hazing rituals, resulting in severe ethanol poisoning and even death among pledges. Typically, the serum ethanol levels in these poisoned students are extremely high. Preventing severe ethanol poisoning is crucial, and can be achieved through education about the harms of these hazing activities. Hemodialysis is an effective treatment for severe ethanol poisoning as it removes the excess alcohol in a timely manner.

A lack of living donor renal transplantation for Asian children represents an opportunity to improve pediatric healthcare.

INTRODUCTION: The relationship between pediatric primary care practitioners and families provides an early opportunity to address ethnic/racial pediatric subspecialty health care disparities. Living donor pediatric renal transplantation is safe and more effective than deceased donor renal transplantation. The purpose of this study is to identify groups of children who may be less likely to receive living donor renal transplantation, as the first step in assisting pediatric clinicians to increase living donor renal transplantation. METHOD: We employed a retrospective cohort design. We analyzed data from the medical records of 80 children receiving renal transplantation over 20 years in a large pediatric medical center. RESULTS: The proportions of children receiving a living donor renal allograft differed by ethnicity/race (P = .04). Specifically, children of Asian ethnicity/ race were significantly less likely than children of White ethnicity/race to receive a living donor renal allograft (P = .01). There were no significant differences in age at transplantation or wait time for deceased donor transplantation. DISCUSSION: We discuss the possible reasons for the discrepancy and potential directions for family-centered pediatric practice, policy, and research to address this potential pediatric healthcare disparity.

Immune-Based Therapy for Hospitalized Patients With COVID-19 and Risk of Secondary Infections: A Systematic Review and Meta-analysis.

Background: Immune-based therapies are standard-of-care treatment for coronavirus disease 2019 (COVID-19) patients requiring hospitalization. However, safety concerns related to the potential risk of secondary infections may limit their use. Methods: We searched OVID Medline, Ovid EMBASE, SCOPUS, Cochrane Library, clinicaltrials.gov, and PROSPERO in October 2020 and updated the search in November 2021. We included randomized controlled trials (RCTs). Pairs of reviewers screened abstracts and full studies and extracted data in an independent manner. We used RevMan to conduct a meta-analysis using random-effects models to calculate the pooled risk ratio (RR) and 95% CI for the incidence of infection. Statistical heterogeneity was determined using the I 2 statistic. We assessed risk of bias for all studies and rated the certainty of evidence using the Grading of Recommendations Assessment, Development, and Evaluation methodology. We conducted a meta-regression using the R package to meta-explore whether age, sex, and invasive mechanical ventilation modified risk of infection with immune-based therapies. The protocol is registered with PROSPERO (CRD42021229406). Results: This was a meta-analysis of 37 RCTs including 32 621 participants (mean age, 60 years; 64% male). The use of immune-based therapy for COVID-19 conferred mild protection for the occurrence of secondary infections (711/15 721, 4.5%, vs 616/16 900, 3.6%; RR, 0.82; 95% CI, 0.71-0.95; P = .008; I 2 = 28%). A subgroup analysis did not identify any subgroup effect by type of immune-based therapies (P = .85). A meta-regression revealed no impact of age, sex, or mechanical ventilation on the effect of immune-based therapies on risk of infection. Conclusions: We identified moderate-certainty evidence that the use of immune-based therapies in COVID-19 requiring hospitalization does not increase the risk of secondary infections.

Association of IgG co-deposition with serum levels of galactose-deficient IgA1 in pediatric IgA nephropathy.

OBJECTIVE: To determine whether the absence of mesangial IgG deposits is associated with the absence of elevated blood levels of galactose-deficient IgA1 (Gd-IgA1) in pediatric patients with IgA nephropathy (IgAN). DESIGN AND METHODS: Serum Gd-IgA1 levels were determined by ELISA using an N-acetylgalactosamine-specific lectin from Helix aspersa. Levels of Gd-IgA1 above the 90th percentile for healthy pediatric controls were considered to be elevated. Renal biopsy samples were examined by immunofluorescence for presence and intensity of staining for IgA, IgG, IgM, C3 and C1q and by light microscopy for histological changes. Findings were graded by a single pathologist (L. Gaber) at UTHSC until 2007 and by NephropathTM (Little Rock, AR, USA) thereafter. Staining for the mesangial deposits was considered negative when intensity was trace or less, and positive at greater intensity. Fisher's exact test was used to determine significance of 2 × 2 tables. RESULTS: Serum samples were obtained from 30 patients with IgAN diagnosed before age 18 years. Male:female ratio was 2.3:1. Twenty were Caucasian and 10 were African-American. Blood was obtained within 3 months of biopsy (incident cases) for 12, while 18 provided blood > 3 months after biopsy (prevalent cases). Serum Gd-IgA1 level was elevated in 23 (77%) of cases and 20 (67%) had a biopsy positive for IgG. Of those 20 patients, 18 (90%) had an elevated serum Gd-IgA1 level, whereas 5 (50%) of patients with biopsies without IgG had a normal serum Gd-IgA1 level (p = 0.026). SUMMARY: In this small study we found a weak association between the absence of IgG in the biopsy and normal serum Gd-IgA1 level.

The dangers of substance abuse in adolescents with chronic kidney disease: a review of the literature.

Although there exist no specific data on the prevalence of substance abuse among children and adolescents with chronic kidney diseases (CKD), the magnitude of this problem should not be underestimated, as almost half of twelfth-graders in the U.S. admit to a history of using illegal drugs at least once when asked (National Institute on Drug Abuse, 2011). According to the 2010 Canadian Alcohol and Drug Use Monitoring Survey (Health Canada, n.d.), the prevalence of drug abuse among Canadian youths and young adults aged 15 to 24 remains higher than in adults older than 25 years of age, and the rates of drug use (excluding cannabis) in the past years were 7.9% and 0.8%, respectively, illustrating an almost 10 times higher rate in the younger age group (Health Canada, n.d.). Drug abuse can lead to numerous medical problems, including renal injury, and it is clearly a major public health concern, especially in patients with subnormal kidney function (Vupputuri et al., 2004). As most of the children and adolescents that suffer from CKD have long-term and trustful relationships with the nephrology team, we have the obligation and are in an excellent position to address this particular health issue (Finkelstein & Finkelstein, 2000; Kimmel, 2002; Kimmel, Cohen, & Peterson, 2008). This review summarizes the available data on the nephrotoxic effects of various commonly abused drugs with special emphasis on the additional damage that occurs in patients with pre-existing CKD. These data were obtained from a thorough search of the available primary literature, specifically using the PubMed database. The purpose is to provide health professionals with a resource to properly educate their CKD patients on the dangers of these drugs.

[Management of children after renal transplantation: highlights for general pediatricians].

The number of children undergoing successful renal transplantations has been increasing steadily and as a result, general pediatricians are now more likely to encounter children with a kidney allograft in their practice. Although the medical care immediately after transplantation is mostly provided by transplant teams, more and more outpatient care will eventually be performed at the patient's local community. Medical care from general pediatricians is particularly important, especially for children who are residing far from transplant centers. As these children require prolong immunosuppressive therapies and are susceptible to various specific clinical problems, it is imperative for their primary care providers and pediatricians to be knowledgeable about their specific needs and be competent in providing care. This article highlights the roles and common practice related issues that pertain to general pediatricians in the care of pediatric renal allograft recipients.

Thrombotic thrombocytopenic purpura in pediatric patients.

Although thrombotic thrombocytopenic purpura (TTP) is rarely seen in pediatric patients, failure to recognize this condition often leads to severe consequences and poor outcomes. Classic features of TTP include thrombocytopenia, microangiopathic hemolytic anemia, acute kidney injury, fever, and central nervous system involvement. However, patients suffering from this condition may not present with all of the symptoms simultaneously. Therefore, it is of utmost importance for healthcare providers to have a high index of suspicion. Laboratory investigations may reveal the presence of schistocytes on peripheral blood smear, negative Coombs test, high lactate dehydrogenase levels and severely low platelet counts. The etiology of TTP is mainly due to insufficient cleavage of the large multimers of von Willebrand factor (vWF) secondary to decreased activity of ADAMTS13 (a disintegrin and metalloprotease with Thrombospondin type 1 repeats, member 13). TTP can be broadly classified into familial TTP (Upshaw Schulman syndrome) and non-familial TTP. Familial TTP is due to a congenital deficiency of ADAMTS13. Its mainstay of therapy is initiation of plasmapheresis during the acute phase, followed by regular fresh frozen plasma (FFP) infusions. Alternatively, non-familial TTP is due to a decrease in ADAMTS13 activity secondary to the presence of anti-ADAMTS13 antibodies. Once again, the primary treatment is plasmapheresis; however, recent anecdotal data also supports the use of rituximab in select cases.

Pediatric en bloc kidney transplantation into pediatric recipients.

As a result of the ongoing shortage in organ supply, en bloc renal transplantation from small donors has become more common for adult recipients with ESRD. However, because of concern for higher complication rates and sub-optimal outcomes, it is not being performed in every center, and data describing its use in pediatric recipients are even more limited. We retrospectively studied three patients who have undergone en bloc renal transplantation at our center. Median age at transplantation was 16.7 yr with a median follow-up of 1.2 yr. Donor age ranged from nine to 49 months with weight ranging from 10 to 22 kg. There were no post-operative thrombotic complications. All grafts showed increased renal size at follow-up by ultrasound. There was no clinical or histological rejection at last follow-up. To the best of our knowledge, this is the first report on the outcomes of en bloc kidney transplantation from pediatric donors into pediatric recipients. Based on our experience, albeit very limited, we feel that en bloc renal transplantation from young donors is an acceptable and safe procedure with low complication rates in pediatric recipients and should be given consideration to minimize wait times on the wait list and to improve quality of life.

Extended experience with a steroid minimization immunosuppression protocol in pediatric renal transplant recipients.

PURPOSE: To determine the safety and efficacy of a novel steroid minimization protocol after renal transplantation at a single Northern California center. INTRODUCTION: We have previously reported our experience on the short-term outcomes in eight children using our steroid minimization protocol. Herein, we present our ongoing experience in using this regimen in 20 children. METHODS: Children receiving immunosuppression with a steroid minimization protocol at our center from 1/04-12/08 (Group 2) were retrospectively compared with 20 controls (Group 1). RESULTS: At one-month follow-up, Group 2 was observed to have lower eGFR, hemoglobin, white cell count, and cholesterol. The incidence of adverse events during the first yr was comparable. Three patients in Group 1 displayed histological evidence of acute rejection, one patient in Group 2 developed humoral rejection; another patient in Group 2 had sub-clinical rejection. Surgical complications were observed in 20% of patients in both groups. While 10% of patients in Group 1 developed diabetes mellitus, none was observed in Group 2. Thirty and 40% of patients in Groups 1 and 2, respectively, suffered from infectious complications during the first yr. CONCLUSIONS: Our novel steroid minimization immunosuppression is safe in children and associated with no increased risk of rejection and infection.

Pathogenesis of Henoch-Schönlein purpura nephritis.

The severity of renal involvement is the major factor determining the long-term outcome of children with Henoch-Schönlein purpura (HSP) nephritis (HSPN). Approximately 40% children with HSP develop nephritis, usually within 4 to 6 weeks after the initial onset of the typical purpuric rashes. Although the pathogenetic mechanisms are still not fully delineated, several studies suggest that galactose-deficient IgA1 (Gd-IgA1) is recognized by anti-glycan antibodies, leading to the formation of the circulating immune complexes and their mesangial deposition that induce renal injury in HSPN.

Impact of Hepatitis B Virus Genetic Variation, Integration, and Lymphotropism in Antiviral Treatment and Oncogenesis.

Chronic Hepatitis B Virus (HBV) infection poses a significant global health burden. Although, effective treatment and vaccinations against HBV are available, challenges still exist, particularly in the development of curative therapies. The dynamic nature and unique features of HBV such as viral variants, integration of HBV DNA into host chromosomes, and extrahepatic reservoirs are considerations towards understanding the virus biology and developing improved anti-HBV treatments. In this review, we highlight the importance of these viral characteristics in the context of treatment and oncogenesis. Viral genotype and genetic variants can serve as important predictive factors for therapeutic response and outcomes in addition to oncogenic risk. HBV integration, particularly in coding genes, is implicated in the development of hepatocellular carcinoma. Furthermore, we will discuss emerging research that has identified various HBV nucleic acids and infection markers within extrahepatic sites (lymphoid cells). Intriguingly, the presence of hepatocellular carcinoma (HCC)-associated HBV variants and viral integration within the lymphoid cells may contribute towards the development of extrahepatic malignancies. Improved understanding of these HBV characteristics will enhance the development of a cure for chronic HBV infection.

Molecular mechanisms of viral hepatitis induced hepatocellular carcinoma.

Chronic infection with viral hepatitis affects half a billion individuals worldwide and can lead to cirrhosis, cancer, and liver failure. Liver cancer is the third leading cause of cancer-associated mortality, of which hepatocellular carcinoma (HCC) represents 90% of all primary liver cancers. Solid tumors like HCC are complex and have heterogeneous tumor genomic profiles contributing to complexity in diagnosis and management. Chronic infection with hepatitis B virus (HBV), hepatitis delta virus (HDV), and hepatitis C virus (HCV) are the greatest etiological risk factors for HCC. Due to the significant role of chronic viral infection in HCC development, it is important to investigate direct (viral associated) and indirect (immune-associated) mechanisms involved in the pathogenesis of HCC. Common mechanisms used by HBV, HCV, and HDV that drive hepatocarcinogenesis include persistent liver inflammation with an impaired antiviral immune response, immune and viral protein-mediated oxidative stress, and deregulation of cellular signaling pathways by viral proteins. DNA integration to promote genome instability is a feature of HBV infection, and metabolic reprogramming leading to steatosis is driven by HCV infection. The current review aims to provide a brief overview of HBV, HCV and HDV molecular biology, and highlight specific viral-associated oncogenic mechanisms and common molecular pathways deregulated in HCC, and current as well as emerging treatments for HCC.

Identification of a novel mutation in the MAFB gene in a pediatric patient with multicentric carpotarsal osteolysis syndrome using next-generation sequencing.

Multicentric carpotarsal osteolysis syndrome (MCTO) is a rare form of skeletal dysplasia characterized by progressive bone resorption, in the carpal and tarsal bones. Patients may develop chronic kidney disease, which eventually advances to end-stage renal disease (ESRD). Both sporadic and familial cases of autosomal-dominant inheritance are reported in literature. Here, we report a case of a 10.5-year-old boy who presented with CKD stage V, and who suffered from bone deformities and difficulty in walking at a younger age. He was diagnosed with MCTO and subjected to genetic analysis. We identified a novel mutation (NM_005461.5:c.173C > G) in the exon 1 of MAFB using next-generation sequencing. However, the mutation was not detected in his asymptomatic parents or siblings. This novel heterozygous mutation has not been reported previously. Our results show that the new mutation broadens the spectrum of disease phenotypes. This mutation may be helpful to confirm the potential cases of MCTO, which although can be identified through radiographic findings, stand a high chance of being misdiagnosed as rheumatological disease or as a metabolic bone disease secondary to CKD.