Low-level viremia (LLV) was defined as persistent or intermittent episodes of detectable hepatitis B virus (HBV) DNA (<2000 IU/mL, detection limit of 10 IU/mL) after 48 weeks of antiviral treatment. Effective antiviral therapies for chronic hepatitis B (CHB) patients, such as entecavir (ETV), tenofovir disoproxil fumarate (TDF), and tenofovir alafenamide (TAF), have been shown to inhibit the replication of HBV DNA and prevent liver-related complications. However, even with long-term antiviral therapy, there are still a number of patients with persistent or intermittent LLV. At present, the research on LLV to address whether adversely affect the clinical outcome is limited, and the follow-up treatment for these patients is open to question. At the same time, the mechanism of LLV is not clear. In this review, we summarize the incidence of LLV, the association between LLV and long-term outcomes, possible mechanisms, and management strategies in these patient populations.
Antiviral Agents/therapeutic use* ; DNA, Viral ; Hepatitis B virus/genetics* ; Hepatitis B, Chronic/drug therapy* ; Humans ; Nucleosides/therapeutic use* ; Tenofovir/therapeutic use* ; Treatment Outcome ; Viremia/drug therapy*

Adult ; Cytomegalovirus ; Cytomegalovirus Infections ; complications ; Drug Hypersensitivity Syndrome ; complications ; virology ; Eosinophilia ; complications ; virology ; Fatal Outcome ; Female ; Gout ; drug therapy ; Hepatitis ; complications ; virology ; Humans ; Liver ; physiopathology ; Viremia

BACKGROUND: Polyomavirus BK (BKV) infection is an important cause of graft loss in kidney transplant patients.PURPOSE: The purpose of this study was to evaluate clinical findings and risk factors for BKV in pediatric patients after kidney transplantation.METHODS: This retrospective single-center study included 31 pediatric kidney transplant recipients from January 2002 to December 2017. Two patients received 2 transplantations during the study period, and each transplant was analyzed independently. Total number of cases is 33 cases with 31 patients. BKV infection was confirmed from blood samples via periodic quantitative polymerase chain reaction.RESULTS: The mean age at kidney transplantation was 11.0±4.7 years, and the male-to-female ratio was 2.7:1. Three patients had a past medical history of high-dose chemotherapy and autologous stem-cell transplantation for solid tumors. Nine patients (27.3%) developed BKV infection. The median period from kidney transplantation to BKV detection in blood was 5.6 months. There was no statistically significant difference in estimated glomerular filtration rate between patients with and those without BKV infection. Among 9 patients with BKV viremia, 7 were treated by reducing their immunosuppressant dose, and BKV was cleared in 6 of these 7 patients. In the other 2 BKV-positive patients, viremia improved without immunosuppressant reduction.CONCLUSION: BKV infection is common in children with kidney transplantation and might not have affected short-term renal function in our patient sample due to early immunosuppressant reduction at the time of BKV detection.
BK Virus ; Child ; Drug Therapy ; Glomerular Filtration Rate ; Humans ; Kidney Transplantation ; Kidney ; Polymerase Chain Reaction ; Polyomavirus ; Retrospective Studies ; Risk Factors ; Transplant Recipients ; Transplants ; Viremia

OBJECTIVETo review the recent literatures related to the factors associated with the size of the HIV reservoir and their clinical significance.

DATA SOURCESLiteratures related to the size of HIV DNA was collected from PubMed published from 1999 to June 2016.

STUDY SELECTIONAll relevant articles on the HIV DNA and reservoir were collected and reviewed, with no limitation of study design.

RESULTSThe composition and development of the HIV-1 DNA reservoir in either treated or untreated patients is determined by integrated mechanism comprising viral characteristics, immune system, and treatment strategies. The HIV DNA reservoir is a combination of latency and activity. The residual viremia from the stochastic activation of the reservoir acts as the fuse, continuing to stimulate the immune system to maintain the activated microenvironment for the rebound of competent virus once treatment with antiretroviral therapy is discontinued.

CONCLUSIONThe size of the HIV-1 DNA pool and its composition has great significance in clinical treatment and disease progression.

Anti-HIV Agents ; therapeutic use ; DNA, Viral ; genetics ; Female ; HIV Infections ; drug therapy ; genetics ; HIV-1 ; drug effects ; genetics ; pathogenicity ; Humans ; Male ; Viral Load ; drug effects ; genetics ; Viremia ; drug therapy ; genetics

BACKGROUNDFew studies have examined the properties of human immunodeficiency virus type 1 (HIV-1) epitope-specific cytotoxic T lymphocyte (CTL) responses in children. To address this issue, we characterized epitope-specific CTL responses and analyzed the determinants that may affect CTL responses before and after highly active antiretroviral therapy (HAART) in children with HIV-1 infection.

METHODSA total of 22 HIV-1-infected children and 23 uninfected healthy children as control were enrolled in the study. Circulating CD4 T cells and HIV-1 RNA load in plasma were routinely measured. Peripheral HIV-1-specific CTL frequency and HIV-1 epitope-specific, interferon-gamma (IFN-gamma)-producing T lymphocytes were measured using tetramer staining and enzyme-linked immunospot (ELISPOT) assay, respectively. Circulating dendritic cell (DC) subsets were monitored with FACS analysis.

RESULTSMore than 80% of the children with HIV-1 infection exhibited a positive HIV-1-epitope-specific CTL response at baseline, but HIV-specific CTLs and IFN-gamma-producing lymphocytes decreased in patients who responded to HAART in comparison with non-responders and HAART-naive children. The duration of virus suppression resulted from HAART was inversely correlated with CTL frequency. While in HAART-naive children, HIV-1-specific CTL frequency was positively correlated with myeloid DC (mDC) frequency, although the cause and effect relationship between the DCs and CTLs remains unknown.

CONCLUSIONSHIV-1-epitope-specific CTL responses are dependent on antigenic stimulation. The impaired DC subsets in blood might result in a defect in DC-mediated T cell responses. These findings may provide insight into understanding the factors and related mechanisms that influence the outcome of HIV-1 carriers to HAART or future antiviral therapies.

Adolescent ; Antiretroviral Therapy, Highly Active ; CD8-Positive T-Lymphocytes ; immunology ; Child ; Epitopes ; immunology ; Female ; HIV Infections ; drug therapy ; immunology ; HIV-1 ; immunology ; Humans ; Male ; T-Lymphocytes, Cytotoxic ; immunology ; Viremia ; drug therapy

BACKGROUNDDespite its widespread use in the management of HIV-related cytomegalovirus (CMV) infection, there have been surprisingly few reports of the use of valganciclovir (VGC) in the post-allotransplant setting. So far, no multi-center, non-crossover trial data have been available with the use of this drug as the primary pre-emptive. The present study evaluated the efficacy and safety of VGC for preemptive therapy of CMV infection after allogeneic hematopoietic stem cell transplantation (HSCT).

METHODSFrom January to April 2007, VGC was adopted in eleven centers in mainland China for pre-emptive therapy of CMV infection in consecutive patients undergoing allogeneic HSCT. Allogeneic HSCT recipients were followed weekly via CMV pp65 antigenemia assay or real-time quantitative polymerase chain reaction (PCR) for detection of CMV-DNA. Patients with a positive assay were treated with VGC, 900 mg P.O. twice a day for 14 days followed by 900 mg P.O. once a day for 14 days after a negative result or the CMV-DNA load was lower.

RESULTSA total of 54 patients (15 siblings, 28 mismatched related donors, 11 unrelated donors) had a positive assay treated with oral VGC. The seroconversion rate was 89% (48/54) as confirmed by a negative assay; six patients failed oral VGC. No significant toxicity was encountered. No case of CMV disease was diagnosed in the responding patients with a median follow-up of 5.3 months after the drug administration.

CONCLUSIONPre-emptive therapy of CMV viraemia with oral VGC is safe and effective in allogeneic HSCT.

Adolescent ; Adult ; Antiviral Agents ; therapeutic use ; China ; Cytomegalovirus Infections ; drug therapy ; Female ; Ganciclovir ; analogs & derivatives ; therapeutic use ; Hematopoietic Stem Cell Transplantation ; Humans ; Male ; Middle Aged ; Viremia ; drug therapy ; virology ; Young Adult

BACKGROUNDTo determine the relationship between diversity of hepatitis C virus quasispecies and viremia, activity of liver disease and response to interferon therapy.

METHODSHCV quasispecies heterogeneity in 68 patients with chronic hepatitis C were detected by single stranded conformational polymorphism (SSCP) analysis of the HCV E2 hypervaribale region 1 (HVR1); of these, 48 were subsequently treated with interferon-alpha for 6 months.

RESULTSHVR1 was amplified in 61 patients. The average number of SSCP bands was 6.2+/-2.4. Quasispecies heterogeneity significantly correlated with serum HCV RNA levels (P<0.01), but not with serum ALT, AST levels and histological activity index (P>0.05). Of the patients who received interferon therapy, 43 were HVR1 positive. Patients who gained sustained response (n=11) had lower pre-treatement quasispecies heterogeneity (3.3+/-1.2) compared to those who had complete end-of-treatment response (ETR) with relapse (6.3+/-2.2, n=12, P<0.5) or no response (8.0+/-3.3, n=20, P<0.01). At the end of treatment, HVR1 could still be detected in 16 patients. The number of quasispecies heterogeneity in these patients decreased to 3.4+/-1.2, which was significantly lower than that in the patients who didn't receive interferon therapy (6.8+/-2.5, P<0.01). Of these 16 patients, 10 had change in quasispecies patterns.

CONCLUSIONSIncreased quasispecies heterogeneity can cause high HCV viremia, but it is not related to severity of liver disease. Quasispecies heterogeneity is another marker to predict the response to interferon-alpha in patients with chronic hepatitis C.

Adolescent ; Adult ; Antiviral Agents ; therapeutic use ; Female ; Genetic Heterogeneity ; Hepacivirus ; drug effects ; genetics ; Hepatitis C, Chronic ; drug therapy ; virology ; Humans ; Interferon-alpha ; therapeutic use ; Male ; Middle Aged ; Polymorphism, Single-Stranded Conformational ; RNA, Viral ; blood ; Viremia ; virology

Varicella-zoster virus infection can lead to severe illness in immunocompromised patients. Further the mortality rate of disseminated varicella infection is extremely high particularly in immunocompromised children. We report a case of disseminated varicella infection in a child with acute lymphoblastic leukemia who was receiving chemotherapy, but was initially admitted with only for acute abdominal pain. The patient rapidly developed severe complications, including acute respiratory distress syndrome, acute hepatitis, disseminated intravascular coagulation, and encephalopathy. Acyclovir is a highly potent inhibitor of varicella-zoster virus infection. However, owing to rapid disease progression, it might not be sufficient to control a disseminated varicella infection, especially in immunocompromised patients. Immunoglobulin neutralize virus invasion and suppress viremia, acting synergistically with acyclovir. In this case, early administration of acyclovir and a high-dose of immunoglobulin, combined with mechanical respiratory support, proved adequate for treatment of this severe illness.
Abdominal Pain ; Acyclovir ; Chickenpox* ; Child* ; Disease Progression ; Disseminated Intravascular Coagulation ; Drug Therapy ; Hepatitis ; Herpesvirus 3, Human ; Humans ; Immunocompromised Host ; Immunoglobulins* ; Mortality ; Precursor Cell Lymphoblastic Leukemia-Lymphoma ; Respiratory Distress Syndrome, Adult ; Viremia

BACKGROUNDS/AIMS: The ultimate goal of antiviral therapy using interferon/pegylated interferon combined with ribavirin in chronic C-viral hepatitis is to achieve a sustained virologic response (SVR). Several studies have shown that the reappearance rate of hepatitis C virus (HCV) RNA in serum after the achievement of an SVR is less than 1%; the durability of an SVR in Korean patients is not known. The aim of this study was to determine the durability of the virologic response in chronic hepatitis C patients with an SVR to antiviral therapy. METHODS: A total of 156 patients who were treated successfully with interferon/peginterferon and ribavirin were evaluated retrospectively. Patients received either subcutaneous conventional interferon alpha 3x10(6) units three times a week or subcutaneous pegylated interferon (alpha-2a: 180 microgram, alpha-2b: 80-100 microgram) once a week in combination with ribavirin at 600-1,200 mg daily (depending on body weight). Patients with HCV genotype 1 were treated for 48 weeks, whereas those with non-genotype 1 were treated for 24 weeks. RESULTS: Eighty-two patients underwent treatment with conventional interferon and ribavirin, whereas 74 patients were treated with pegylated interferon and ribavirin. An SVR was achieved in 73 patients (73/156, 46.8%). HCV RNA reappeared in eight patients (8/73, 11.0%; detected by qualitative PCR), including one patient with persistent viremia (1/73, 1.4%). CONCLUSIONS: Reappearance of HCV RNA after earlier achievement of an SVR might appear more frequently than previously reported. Close follow-up of these patients is recommended and the implication of temporary viremia should be determined in the future.
Adult ; Antiviral Agents/*therapeutic use ; Drug Therapy, Combination ; Female ; Genotype ; Hepatitis C, Chronic/*drug therapy ; Humans ; Interferon Alfa-2a/*therapeutic use ; Interferon-alpha/*therapeutic use ; Male ; Middle Aged ; Polyethylene Glycols/*therapeutic use ; RNA, Viral/metabolism ; Recurrence ; Retrospective Studies ; Ribavirin/*therapeutic use ; Viremia/drug therapy

OBJECTIVETo develop a standard duck hepatitis B virus (DHBV) animal model using a local Hubei species of duck, Ma Ya, and use it as an in vivo experimental system to study antiviral strategies against hepatitis B.

METHODSTwo-day-old Ma Ya ducklings were experimentally infected via intraperitoneal injection with the DHBV inocula which was collected from the transfected culture supernatant of 1.5-fold-overlength genome recombinant plasmid. Blood samples were taken twice or thrice a week during post-inoculation for 50 days. Viremia was quantified by serum real-time PCR to show the peak. Antiviral treatment of the DHBV-infected ducklings was started 3 d post-inoculation. The animals received oral administration of lamivudine (3TC) at a dose of 25 mg/kg/d for 5 d, followed by a maintenance therapy thrice weekly for 3 more weeks. Serum was quantified to show the viremia peak and liver biopsy specimens were analysed by Southern blotting and in-situ hybridization at the end of antiviral drug treatment.

RESULTSThe experimental infection rate of 2-day-old ducklings was 87.5%. Viremia started to be detectable on day 7 and reached a peak on day 11 post-inoculation, followed by a decrease and fluctuations. Four weeks of oral administration of 3TC led to a significant decrease in viremia peak during. This effect was not sustained, as a rebound in viremia was observed after drug withdrawal. Similarly, the analysis of liver biopsies at the end of 3TC treatment showed a marked decrease in DHBV DNA. However, after drug withdrawal a rebound of intrahepatic DHBV DNA was observed in duck livers.

CONCLUSIONThe Hubei duck model with experimental DHBV infection of transfected supernatant is more suitable for the hepadnavirus biologic research due to its stability and practicability.

Animals ; Animals, Newborn ; DNA, Viral ; genetics ; metabolism ; Disease Models, Animal ; Ducks ; Hepadnaviridae Infections ; blood ; drug therapy ; virology ; Hepatitis B Virus, Duck ; drug effects ; genetics ; growth & development ; Hepatitis, Viral, Animal ; blood ; drug therapy ; virology ; Lamivudine ; pharmacology ; Liver ; drug effects ; pathology ; virology ; Reverse Transcriptase Inhibitors ; pharmacology ; Viremia ; blood