Recent advances in vaccination of non-responders to standard dose hepatitis B virus vaccine

Hepatitis B virus(HBV) infection is a global health problem. It is estimated there are more than 2 billion individuals exposed to the virus and 250 million are chronically infected. Hepatitis B is the cause of more than 600000 annual deaths due to cirrhosis and hepatocellular carcinoma. An effective vaccine exists and preventative initiatives center around universal vaccination especially in those at highest risk. Effective vaccination algorithms have led to a significant decline in the development of new infections and its devastating consequences. The vaccine is administered intramuscularly in three doses, with 95% showing long lasting serologic immunity. An additional fourth dose or a repeated higher dose three course regimen is given to those that fail to show immunity. Despite these additional regimens, some remain vulnerable to hepatitis B and are deemed nonresponders. Individuals with chronic disease states such as kidney disease, liver disease, diabetes mellitus, as well as those with a genetic predisposition, and those on immunomodulation therapy, have the highest likelihood of non-response. Various strategies have been developed to elicit an immune response in these individuals. These include increased vaccination dose, intradermal administration, alternative adjuvants, alternative routes of administration, co-administration with other vaccines, and other novel therapies. These alternative strategies can show improved response and lasting immunity. In summary, HBV vaccination is a major advance of modern medicine and all individuals at risk should be sought and vaccinated with subsequent adequate titers demonstrated.

INTRAMUSCULAR VERSUS INTRADERMAL HEPATITIS B REVACCINATIONIN HEALTHY NON-RESPONDER CHILDREN: A 5-YEAR PROSPECTIVE RANDOMIZED STUDY

Objective With the same times of injection to compare low-dose intradermal regimen with routine-dose intramuscular inoculation in revaccination of non-responders to hepatitis B vaccine. Methods 40 healthy non-responder children collected by screening were administrated a three-dose revaccination randomly by intramuscular or intradermal route (10vs 2g per dose), and regularly tested for serologic markers up to five years. By the end of follow-up, a booster dose (5μg) was given to those who had lost anti-HBs of ≥10mIU/mL (seroprotection) and anamnestic response was estimated thereafter. Results All 17 intramuscular and 22 of 23 intradermal children effected seroprotection after revaccination. Intradermal children lost seroprotection over time significantly rapider compared with intramuscular children (Log Rank test, P= 0.029). In year 5, 50% of intramuscular but only 18.2% of intradermal children still maintained seroprotection (P=0.075). 12-14 days after the booster dose, all the eight intramuscular children developed an anamnestic response with anti-HBs titer increasing greater, but two of the 18 intradermal children failed to mount seroprotective level. Conclusion Three-routine-dose intramuscular revaccination was significantly effective than low-dose intradermal one with the same times of injection, especially in long-term immunity. We recommend routine-dose intramuscular protocol in revaccination of non-responders.

Metformin may be a viable adjunctive therapeutic option to potentially enhance immune reconstitution in HIV-positive immunological non-responders

Incomplete immune reconstitution remains a global challenge for human immunodeficiency virus(HIV)treatment in the present era of potent antiretroviral therapy(ART),especially for those individuals referred to as immunological non-responders(INRs),who exhibit dramatically low CD4^(+)T-cell counts despite the use of effective antiretroviral therapy,with long-term inhibition of viral replication.In this review,we provide a critical overview of the concept of ART-treated HIV-positive immunological non-response,and also explain the known mechanisms which could potentially account for the emergence of immunological non-response in some HIV-infected individuals treated with appropriate and effective ART.We found that immune cell exhaustion,combined with chronic inflammation and the HIV-associated dysbiosis syndrome,may represent strategic aspects of the immune response that may be fundamental to incomplete immune recovery.Interestingly,we noted from the literature that metformin exhibits properties and characteristics that may potentially be useful to specifically target immune cell exhaustion,chronic inflammation,and HIV-associated gut dysbiosis syndrome,mechanisms which are now recognized for their critically important complicity in HIV disease-related incomplete immune recovery.In light of evidence discussed in this review,it can be seen that metformin may be of particularly favorable use if utilized as adjunctive treatment in INRs to potentially enhance immune reconstitution.The approach described herein may represent a promising area of therapeutic intervention,aiding in significantly reducing the risk of HIV disease progression and mortality in a particularly vulnerable subgroup of HIV-positive individuals.

Initial experiences of maintaining atrioventricular intrinsic conduction during cardiac resynchronization therapy in non-responders

Background Cardiac resynchronization therapy （CRT） is a major breakthrough in therapy for advanced heart failure patients; however, a number of key clinical research questions remain, perhaps most importantly the issue of why apparently suitable patients do not respond to CRT. Methods Seven patients, six males and one female, aged （56.43±6.13） years, all diagnosed with dilated cardiomyopathy, were included in this study. They were all non-responders to CRT who underwent routine optimization postoperatively, and received optimal drug therapy. On the basis of biventricular pacing, titrating various atrioventricular （AV） intervals were performed to get the true fusional QRS complexes composed of biventricular pacing and AV intrinsic conduction. Then, the effects of AV intrinsic conduction during CRT were evaluated. Results On the setting of AV intrinsic conduction during CRT, the true fusional QRS complexes were the narrowest, and all patients showed alleviation of symptoms, improvement of exercise tolerance, life quality and hemodynamic parameters during more than 6 months of follow-up. Conclusions Titrating AV intervals to get the true fusional QRS complexes composed of biventricular pacing and AV intrinsic conduction will be beneficial for non-responders to CRT. Maintaining AV intrinsic conduction during CRT may decrease the rates of non-resoonders to CRT.

Increased early activation of CD56^(dim)CD16^(dim)/-natural killer cells in immunological non-responders correlates with CD4^(+)T-cell recovery

Background:Natural killer(NK)cells play a critical role in suppressing human immunodeficiency virus-1(HIV-1)infection,but knowledge on whether and how NK cells affect immune reconstitution in HIV-1-infected individuals who receive antiretroviral therapy(ART)is limited.Methods:We performed a case-control study with 35 healthy individuals and 66 HIV-1-infected patients including 32 immunological non-responders(INRs)with poor CD4+T-cell recovery(<500 cells/μL after 4 years of ART)and 34 immunological responders(IRs)with improved CD4+T-cell recovery(>500 cells/μL after 4 years of ART).NK cell phenotype,receptor repertoire,and early activation in INRs and IRs were investigated by flow cytometry.Results:A significantly higher proportion of CD56dimCD16dim/-NK cells was observed in INRs than IRs before ART and after 4 years of ART.The number of CD56dimCD16dim/-NK cells was inversely correlated with CD4+T-cell counts in INRs before ART(r=-0.344,P=0.050).The more CD69-expressing NK cells there were,the lower the CD4+T-cell counts andΔCD4,and these correlations were observed in INRs after ART(r=-0.416,P=0.019;r=-0.509,P=0.003,respectively).Additionally,CD69-expressing CD56dimCD16dim/-NK cells were more abundant in INRs than those in IRs(P=0.018)after ART,both of which had an inverse association trend towards significance with CD4+T-cell counts.The expression of the activating receptors NKG2C,NKG2D,and NKp46 on CD56dimCD16dim/-NK cell subsets were higher in IRs than that in INRs after 4 years of ART(all P<0.01).Strong inverse correlations were observed between CD69 expression and NKG2C,NKG2A-NKG2C+,NKG2D,and NKp46 expression on CD56dimCD16dim/-NK cells in INRs after ART(NKG2C:r=-0.491,P=0.004;NKG2A-NKG2C+:r=-0.434,P=0.013;NKG2D:r=-0.405,P=0.021;NKp46:r=-0.457,P=0.008,respectively).Conclusions:INRs had a larger number of CD56dimCD16dim/-NK cells characterized by higher activation levels than did IRs after ART.The increase in the CD56dimCD16dim/-NK cell subset may play an adverse role in immune reconstitution.Further functional studies of CD56dimCD16dim/-NK cells in INRs are urgently needed to inform targeted interventions to optimize immune recovery.

Safety and efficacy of allogeneic natural killer cell immunotherapy on human immunodeficiency virus type 1 immunological non-responders:a brief report

Background:Allogeneic natural killer(NK)cell immunotherapy is recognized as a promising anti-tumor strategy,but whether it plays a role in poor CD4 recovery among human immunodeficiency virus type 1(HIV-1)infected patients is unknown.This study aimed to investigate the safety and effectiveness of allogeneic NK cells immunotherapy on HIV-1 immunological non-responders(INRs)receiving antiretroviral therapy(ART).Methods:From February to April 2018,a prospective,randomized,controlled,open-label clinical trial,which enrolled 20 HIV-1 INRs following specific inclusion criteria,was conducted at Nankai University Second People’s Hospital.Participants were randomly allocated(simple randomization 1:1)to either the combined treatment(NK+ART)group(n=10)or the control(ART)group(n=10).The allogenic highly activated NK cells from killer cell immunoglobulin-like receptor(KIR)/human leukocyte antigen(HLA)-Cw mismatched healthy donor were prepared(108 cells in each injection)and intravenously infused to each recruited patient of NK+ART group in three courses.Key immune parameters(CD4 count,CD8 count,CD4/CD8 ratio),laboratory tests(count of blood cells,biochemistry panel)and symptoms at baseline and at month 1,3,6,9,12,and 24 were measured/collected to analyze the safety and efficacy of the therapy.Comparisons were between the seven time-points of both groups using repeated measurement analysis of variance(ANOVA)test.Generalized estimating equations(GEE)model was performed to evaluate the overall effect of the NK+ART group vs.the ART group.Results:From baseline to 24 months,we noted a mean CD4 count augmentation(139 to 243 cells/μL)in the NK+ART group and(144 to 176 cells/μL)in the ART group(difference,67;95%CI,10 to 124;P=0.024).Our estimations revealed that NK+ART group could improve CD4 level(β=54.59,P=0.006)and CD8 level(β=322.47,P=0.010)on average among the six measurements compared with the ART group.Only two(2/10,20%)participants in the NK+ART group developed a transient mild fever after the first course.Conclusions:This preliminary study informs that HIV-1 INRs,allogenic NK cells immunotherapy is safe and could significantly improve CD4 recovery but not CD4/CD8 ratio.The practical effects,however,need long-term follow-up observations.Further study on the potential underlying mechanism is warranted.Registration info:www.chictr.org.cn/showproj.aspx?proj=34912(No.ChiCTR1900020634).

Wenshen Jianpi recipe(温肾健脾方) induced immune reconstruction and redistribution of natural killer cell subsets in immunological non-responders of human immunodeficiency virus/acquired immune deficiency syndrome:a randomized controlled trial

OBJECTIVE:To evaluate the effects of the Wenshen Jianpi recipe(温肾健脾方,WJR)on immune reconstruction and natural killer(NK)cells in immunological non-responders(INRs)of people living with human immunodeficiency virus(HIV)(PLWH)and propose new therapeutic strategies for HIV.METHODS:Based on Traditional Chinese Medicine treatment principle“invigorating Qi and warming Yang in the spleen and kidneys”,WJR combined with antiretroviral therapy(ART)therapy was performed in a randomized,double-blind,placebo-controlled study of 60 patients with non-responders.The randomized process was executed by the Clinical Evaluation Center of China Academy of Chinese Medical Sciences.Sixty patients who met the inclusion criteria obtained random numbers(that is the drug number)was randomly divided into a treatment group and a placebo control group according to a 1∶1 ratio.CD4+T cell counts and natural killer(NK)cells counts were evaluated at baseline and 12-week,24-week follow-ups.RESULTS:Four participants received random numbers and did not enter the group due to the patient’s own reasons.A total of 56 patients were enrolled,including 28 in the treatment group and 28 in the control group.CD4+T cell counts in the treatment group were significantly increased at week 24(P=0.01<0.05),which were significantly higher than those in the control group(P=0.01<0.05).Although no significant differences were observed between two groups,the CD56bri CD16-NK cell counts in the treatment group were significantly increased after duration.and CD56dim CD16+NK cell counts in the treatment group were significantly higher than those in the control group after 24 weeks of treatment(P=0.025<0.05).As compared with the control group,the treatment group had significantly lower CD56neg CD16+NK cell counts after 24 weeks of treatment(P=0.023<0.05).CONCLUSIONS:WJR promotes the immune reconstruction of INRs and redistribution of NK cell subsets,notably decreasing CD56neg CD16+NK cell counts in INRs.However,the redistribution of NK cell subsets is not beneficial for immune reconstruction in INRs.Further large-scale RCTs are required to evaluate the effect of WJR on immune recovery in INRs and decipher the underlying mechanism.

Treatment of hepatitis C virus infection

Acute and chronic hepatitis C virus (HCV) infection remains a serious health problem worldwide, however, there has been advancement in the treatment of HCV infection due to standard treatment using pegylated interferon and ribavirin. The literature indicates that therapy for HCV is becoming more individualized. In addition to considering genotype and viral RNA levels before treatment, achievement of an early virologic response (EVR) and a rapid virologic response (RVR) is now possible during therapy. Moreover, problem patients, such as non-responders, relapsers, HIV or HBV co- infected patients, patients with liver cirrhosis, and pre- or post-liver transplantation patients are an increasing fraction of the patients requiring treatment. This article reviews the literature regarding standard treatments and problem patients with acute and chronic HCV infection. It also includes discussion on contraindications and side effects of treatment with interferon and ribavirin, as well as new drug development.

Combination of pegylated interferon and lamivudine for patients with chronic hepatitis B who have failed treatment

BACKGROUND: Treatment of chronic hepatitis B (CHB) alone with interferon or lamivudine alone or in combination is effective in only a small proportion of patients. Treatment of patients in whom antiviral therapy fails is challenging. This study was made to determine the efficacy of combined pegylated interferon alpha (peg-IFN) and lamivudine in patients with CHB who had failed to respond to antiviral treatment. METHODS: Twenty patients with CHB proven by liver biopsy, with ALT levels >1.5×ULN,HBV DNA levels>141 500 copies/ml, and previous treatment failure with an adequate regimen were treated with a combination of peg-IFN 1.5μg/kg and lamivudine 100 mg/day for 52 weeks and followed up for a further 24 weeks. Biochemical response was defined as normalization of ALT and DNA response as HBV DNA<141 500 copies/ml. Secondary efficacy measures included HBsAg loss, HBeAg loss and appearance of anti-HBe (in cases of HBeAg-positive patients). RESULTS: Twenty patients were treated, of whom 16 were HBeAg positive. At 52 weeks, normal ALT was seen in 10 (50%) (8 of 16 HBeAg+ and 2 of 4 HBeAg), HBV DNA response in 5 (25%) (5 of 16 in HBeAg+ and none in HBeAg-), and HBeAg loss with appearance of anti-HBe in 5 (31.3%) of the 16 HBeAg positive patients. At 76 weeks, 8 (80%) of the 10 patients with normal ALT at 52 weeks relapsed, with normal ALT only in 2 (10%) (1 of 16 HBeAg+ and 1 of 4 HBeAg-), and all 5 patients who had a DNA response at 52 weeks relapsed at 76 weeks and had no DNA response. HBeAg loss with appearance of anti-HBe was seen in 1 (6.3%) of 16 HBeAg-positive patients. None of the patients lost HBsAg. CONCLUSIONS: The combination of peg-IFN and lamivudine for 52 weeks is not effective for treatment of CHB patients with a failed treatment. New treatment strategies need to be developed.

Unsolved problems and future perspectives of hepatitis B virus vaccination

Hepatitis B virus(HBV) infection is still a serious worldwide problem, and vaccination is the most effective strategy for primary prevention of the infection. Although universal vaccination may be required for total eradication, several countries, including Japan, have not yet adopted universal vaccination programs. Some individuals are non-responders to HBV vaccine and several mechanisms responsible for their poor response have been proposed. To overcome non-response, third generation vaccines with pre-S proteins have been developed. These vaccines have shown better antiHBs responses and may also be effective in preventing infection by HBV with S mutant. Improvement of vaccine efficacy by intradermal administration, or coadministration with cytokines or adjuvants, may also be effective in non-responders. The necessity, timing and method of booster vaccination in responders with decreased anti-HBs responses, and effective vaccination against S-mutant HBV, are issues requiring resolution in the global prevention of HBV infection.

T cell responses to hepatitis B surface antigen are detectable in non-vaccinated individuals

AIM: To evaluate, whether humoral hepatitis-B-vaccine non-responders also fail to mount a T cell response and to compare these results to normal vaccinees. METHODS: Fourty-seven health care employees were enrolled in this study including all available non- responders (n = 13) with an anti-HBsAg titer < 10 kU/L and all available low-responders (n = 12) with an anti- HBsAg titer < 100 kU/L. Also, 12 consecutive anti-HBsAg negative pre-vaccination subjects were enrolled as well as 10 subjects (+7 from the vaccinated group) with titers > 1000 kU/L as controls. PBMC from all subjects were analyzed by IFN-γ and IL-4 ELISPOT assays for the presence of hepatitis B surface antigen (HBsAg) reactive T cells. RESULTS: Non-responders and low-responders had no or only very limited T cell responses, respectively. Indi- viduals responding to vaccination with the induction of a high anti-HBsAg titer showed a strong T cell response after the third vaccination. Surprisingly, these individuals showed response even before the first vaccination. T cell response to control antigens and mitogens was similar in all groups. CONCLUSION: Our data suggest that there is no gen- eral immune deficiency in non-/low-responders. Thus, we hypothesize that the induction of anti-HBsAg re- sponses by vaccination is significantly dependent on the pre-existing T cell repertoire against the specific antigen rather than the presence of a general T cell defect.

Dominating expression of negative regulatory factors downmodulates major histocompatibility complex Class-Ⅱexpression on dendritic cells in chronic hepatitis C infection

AIM: To elucidate the molecular mechanisms leading to development of functionally impaired dendritic cells(DCs) in chronic hepatitis C(CHC) patients infected with genotype 3 virus.METHODS: This prospective study was conducted on the cohorts of CHC individuals identified as responders or non-responders to antiviral therapy. Myeloid DCs were isolated from the peripheral blood of each subject using CD1c(BDCA1)+ DC isolation Kit. Monocytes from healthy donor were cultured with DC growth factors such as IL-4 and GM-CSF either in the presence or absence of hepatitis C virus(HCV) viral proteins followed by LPS stimulation. Phenotyping was done by flowcytometry and gene expression profiling was evaluated by real-time PCR.RESULTS: Non-responders [sustained virological response(SVR)-ve] to conventional antiviral therapy had significantly higher expression of genes associated with interferon responsive element such as IDO1 and PD-L1(6-fold) and negative regulators of JAK-STAT pathway such as SOCS(6-fold) as compared to responders(SVR+ve) to antiviral therapy. The downregulated genes in non-responders included factors involved in antigen processing and presentation mainly belonging to major histocompatibility complex(MHC) Class-Ⅱ family as HLA-DP, HLA-DQ(2-fold) and superoxide dismutase(2-fold). Cells grown in the presence of HCV viral proteins had genes downregulated for factors involved in innate response, interferon signaling, DC maturation and co-stimulatory signaling to T-cells, while the genes for cytokine signaling and Toll-like receptors(4-fold) were upregulated as compared to cells grown in absence of viral proteins.CONCLUSION: Underexpressed MHC class-Ⅱ genes and upregulated negative regulators in non-responders indicate diminished capacity to present antigen and may constitute mechanism of functionally defective state of DCs.

Atrioventricular intrinsic conduction and cardiac resynchronization therapy

Cardiac resynchronization therapy （CRT） is a major breakthrough in therapy for patients with advanced congestive heart failure, however, a number of key clinical research questions remain, perhaps most importantly the issue of why apparently suitable patients do not respond to CRT. These issues are also relevant to patients who do respond to CRT as potentially their response might be further increased. Though patients do not respond to CRT because of many known postulated reasons, we review the importance of maintaining atrioventricular intrinsic conduction during CRT in this paper, which maybe is one of methods to reduce the rates of non-response to CRT.