Preinfection Neutralizing Antibodies, Omicron BA.5 Breakthrough Infection, and Long COVID: A Propensity Score-Matched Analysis.

BACKGROUND: Data are limited on the role of preinfection humoral immunity protection against Omicron BA.5 infection and long coronavirus disease (COVID) development. METHODS: We conducted nested case-control analysis among tertiary hospital staff in Tokyo who donated blood samples in June 2022 (1 month before Omicron BA.5 wave), approximately 6 months after receiving a third dose of COVID-19 mRNA vaccine. We measured live virus-neutralizing antibody titers against wild type and Omicron BA.5, and anti-receptor-binding domain (RBD) antibody titers at preinfection, and compared them between cases and propensity-matched controls. Among the breakthrough cases, we examined association between preinfection antibody titers and incidence of long COVID. RESULTS: Preinfection anti-RBD and neutralizing antibody titers were lower in cases than controls. Neutralizing titers against wild type and Omicron BA.5 were 64% (95% confidence interval [CI], 42%-77%) and 72% (95% CI, 53%-83%) lower, respectively, in cases than controls. Individuals with previous Omicron BA.1/BA.2 infections were more frequent among controls than cases (10.3% vs 0.8%), and their Omicron BA.5 neutralizing titers were 12.8-fold higher than infection-naive individuals. Among cases, preinfection antibody titers were not associated with incidence of long COVID. CONCLUSIONS: Preinfection immunogenicity against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) may play a role in protecting against the Omicron BA.5 infection but not preventing long COVID.

Recommendations on data sharing in HIV drug resistance research.

• Human immunodeficiency virus (HIV) drug resistance has implications for antiretroviral treatment strategies and for containing the HIV pandemic because the development of HIV drug resistance leads to the requirement for antiretroviral drugs that may be less effective, less well-tolerated, and more expensive than those used in first-line regimens. • HIV drug resistance studies are designed to determine which HIV mutations are selected by antiretroviral drugs and, in turn, how these mutations affect antiretroviral drug susceptibility and response to future antiretroviral treatment regimens. • Such studies collectively form a vital knowledge base essential for monitoring global HIV drug resistance trends, interpreting HIV genotypic tests, and updating HIV treatment guidelines. • Although HIV drug resistance data are collected in many studies, such data are often not publicly shared, prompting the need to recommend best practices to encourage and standardize HIV drug resistance data sharing. • In contrast to other viruses, sharing HIV sequences from phylogenetic studies of transmission dynamics requires additional precautions as HIV transmission is criminalized in many countries and regions. • Our recommendations are designed to ensure that the data that contribute to HIV drug resistance knowledge will be available without undue hardship to those publishing HIV drug resistance studies and without risk to people living with HIV.

Virological outcomes of various first-line ART regimens in patients harbouring HIV-1 E157Q integrase polymorphism: a multicentre retrospective study.

BACKGROUND: Integrase strand transfer inhibitors (INSTIs) are recommended as first-line ART for people living with HIV (PLWH) in most guidelines. The INSTI-resistance-associated mutation E157Q, a highly prevalent (2%-5%) polymorphism of the HIV-1 (human immunodeficiency virus type 1) integrase gene, has limited data on optimal first-line ART regimens. We assessed the virological outcomes of various first-line ART regimens in PLWH with E157Q in real-world settings. METHODS: A multicentre retrospective observational study was conducted on PLWH who underwent integrase genotypic drug-resistance testing before ART initiation between 2008 and 2019 and were found to have E157Q. Viral suppression (<50 copies/mL) rate at 24 and 48 weeks, time to viral suppression and time to viral rebound (≥100 copies/mL) were compared among the first-line ART regimens. RESULTS: E157Q was detected in 167 (4.1%) of 4043 ART-naïve PLWH. Among them, 144 had available clinical data after ART initiation with a median follow-up of 1888 days. Forty-five started protease inhibitors + 2 NRTIs (PI group), 33 started first-generation INSTI (raltegravir or elvitegravir/cobicistat) + 2 NRTIs (INSTI-1 group), 58 started once-daily second-generation INSTI (dolutegravir or bictegravir) + 2 NRTIs (INSTI-2 group) and eight started other regimens. In the multivariate analysis, the INSTI-2 group showed similar or favourable outcomes compared with the PI group for viral suppression rates, time to viral suppression and time to viral rebound. Two cases in the INSTI-1 group experienced virological failure. CONCLUSIONS: The general guideline recommendation of second-generation INSTI-based first-line ART for most PLWH is also applicable to PLWH harbouring E157Q.

Dyslipidemia and SARS-CoV-2 spike antibody titres after the second and third doses of the BNT162b2 vaccine among healthcare workers in Japan.

OBJECTIVE: This study aimed to examine the sex-associated differences in the relationship between dyslipidemia and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike immunoglobulin (Ig)G antibodies among BNT162b2 vaccine recipients. METHODS: Participants were staff members (aged 21-75 years) of a medical and research institution who underwent an anti-SARS-CoV-2 spike IgG antibody test after the second (n = 1872) and third doses (n = 1075) of the BNT162b2 vaccine. Dyslipidemia was defined as triglyceride level ≥150 mg/dl, high-density lipoprotein-cholesterol level <40 mg/dl, low-density lipoprotein-cholesterol level ≥140 mg/dl, or lipid-lowering medication use. Multivariable linear regression was used to calculate the ratio of means for SARS-CoV-2 spike IgG titre according to dyslipidemia status. RESULTS: The prevalence of dyslipidemia was 38.0% in men and 19.6% in women. The relationship between dyslipidemia and SARS-CoV-2 spike IgG titres after the second dose differed markedly by sex (P for interaction <0.001). In men, dyslipidemia was associated with significantly lower IgG titres: the ratio of means (95% confidence interval) was 0.82 (0.72-0.93). However, this association disappeared after the third dose (0.96 [0.78-1.18]). Of the dyslipidemia components, hypertriglyceridemia was inversely associated with SARS-CoV-2 spike IgG antibody titre after both the second and third doses (ratio of means: 0.82 [0.70-0.95] and 0.73 [0.56-0.95], respectively). In women, IgG titres did not differ according to dyslipidemia or hypertriglyceridemia status after either dose. CONCLUSIONS: These results suggest a detrimental role of hypertriglyceridemia in the humoral immune response to the BNT162b2 vaccine for COVID-19 in men but not in women.

Cumulative and undiagnosed SARS-CoV-2 infection among the staff of a medical research centre in Tokyo after the emergence of variants.

To describe the trend of cumulative incidence of coronavirus disease 19 (COVID-19) and undiagnosed cases over the pandemic through the emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants among healthcare workers in Tokyo, we analysed data of repeated serological surveys and in-house COVID-19 registry among the staff of National Center for Global Health and Medicine. Participants were asked to donate venous blood and complete a survey questionnaire about COVID-19 diagnosis and vaccine. Positive serology was defined as being positive on Roche or Abbott assay against SARS-CoV-2 nucleocapsid protein, and cumulative infection was defined as either being seropositive or having a history of COVID-19. Cumulative infection has increased from 2.0% in June 2021 (pre-Delta) to 5.3% in December 2021 (post-Delta). After the emergence of the Omicron, it has increased substantially during 2022 (16.9% in June and 39.0% in December). As of December 2022, 30% of those who were infected in the past were not aware of their infection. Results indicate that SARS-CoV-2 infection has rapidly expanded during the Omicron-variant epidemic among healthcare workers in Tokyo and that a sizable number of infections were undiagnosed.

Omicron BA.1 neutralizing antibody response following Delta breakthrough infection compared with booster vaccination of BNT162b2.

BACKGROUND: Longitudinal data are lacking to compare booster effects of Delta breakthrough infection versus third vaccine dose on neutralizing antibodies (NAb) against Omicron. METHODS: Participants were the staff of a national research and medical institution in Tokyo who attended serological surveys on June 2021 (baseline) and December 2021 (follow-up); in between, the Delta-dominant epidemic occurred. Of 844 participants who were infection-naïve and had received two doses of BNT162b2 at baseline, we identified 11 breakthrough infections during follow-up. One control matched to each case was selected from boosted and unboosted individuals. We compared live-virus NAb against Wild-type, Delta, and Omicron BA.1 across groups. RESULTS: Breakthrough infection cases showed marked increases in NAb titers against Wild-type (4.1-fold) and Delta (5.5-fold), and 64% had detectable NAb against Omicron BA.1 at follow-up, although the NAb against Omicron after breakthrough infection was 6.7- and 5.2-fold lower than Wild-type and Delta, respectively. The increase was apparent only in symptomatic cases and as high as in the third vaccine recipients. CONCLUSIONS: Symptomatic Delta breakthrough infection increased NAb against Wild-type, Delta, and Omicron BA.1, similar to the third vaccine. Given the much lower NAb against Omicron BA.1, infection prevention measures must be continued irrespective of vaccine and infection history while the immune evasive variants are circulating.

Site-selective heat current analysis of α-helical protein with linear-homopolymer-like model.

Although thermal transport is among the essential biophysical properties of proteins, its relationship with protein structures, dynamics, and functions is still elusive. The structures of folded proteins are highly inhomogeneous, giving rise to an anisotropic and non-uniform flow of thermal energy during conformational fluctuations. To illustrate the nature of proteins, we developed a theoretical framework for analyzing local thermal transport properties based on the autocorrelation function formalism, constructed a linear-homopolymer-like model, and applied it to a small α-helical protein, the villin headpiece subdomain (HP36), using equilibrium molecular dynamics simulations. As a result, the model reproduced the exact value of the protein's thermal conductivity with an error of less than 1%. Interestingly, the site-selective analysis of the local, residue-wise, thermal conductivity demonstrated its distinct residue-type dependence, i.e., its magnitude decreased in the order of charged, polar, and hydrophobic residues. In addition, the local density dependence of the residue-wise thermal transport property was also discussed.

Comparison of the clinical characteristics and outcomes of Japanese patients with COVID-19 treated in primary, secondary, and tertiary care facilities.

AIM: To compare the characteristics and clinical course of patients with coronavirus disease (COVID-19) according to the healthcare level of the admitted hospital, to provide an insight into determining the appropriate level of care for each patient. METHODS: This retrospective, observational study utilized data from the COVID-19 Registry Japan (COVIREGI-JP), the largest Japanese registry of hospitalized patients with COVID-19. Datasets were obtained from reports filed as of May 31, 2022. RESULTS: A total of 59,707 patients (2004 in the primary care group, 41,420 in the secondary care group, and 16,283 in the tertiary care group) from 585 facilities were included in the analysis. Patients with established risk factors for severe disease, such as old age and the presence of comorbidities, were treated at higher care facilities and had poorer initial conditions and in-hospital clinical course, as well as higher mortality. Analysis of the fatality rates for each complication suggested that patients with complications requiring procedures (e.g. pleural effusions, myocardial ischemia, and arrhythmia) may have better survival rates in facilities with specialist availability. The number of deaths and severe COVID-19 cases in this study were notably less than those reported overseas. CONCLUSION: Our results showed that more difficult COVID-19 cases with poor outcomes were treated at higher care level facilities in Japan. Attending to possible complications may be useful for selecting an appropriate treatment hospital. Healthcare providers need to maintain a broad perspective on the distribution of medical resources.

Efficacy of convalescent plasma therapy for COVID-19 in Japan: An open-label, randomized, controlled trial.

BACKGROUND: Convalescent plasma is a potential therapeutic option for patients with coronavirus disease 2019 (COVID-19). Despite its use for treating several viral infections, we lack comprehensive data on its efficacy against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). METHODS: We conducted a multicenter, open-label, randomized controlled trial of convalescent plasma therapy with high neutralizing activity against SARS-CoV-2 in high-risk patients within five days after the onset of COVID-19 symptoms. The primary endpoint was the time-weighted average change in the SARS-CoV-2 viral load in nasopharyngeal swabs from days 0-5. RESULTS: Between February 24, 2021, and November 30, 2021, 25 patients were randomly assigned to either convalescent plasma (n = 14) or standard of care (n = 11) groups. Four patients discontinued their allocated convalescent plasma, and 21 were included in the modified intention-to-treat analysis. The median interval between the symptom onset and plasma administration was 4.5 days (interquartile range, 3-5 days). The primary outcome of the time-weighted average change in the SARS-CoV-2 viral load in nasopharyngeal swabs did not significantly differ between days 0-5 (1.2 log10 copies/mL in the convalescent plasma vs. 1.2 log10 copies/mL in the standard of care (effect estimate, 0.0 [95% confidence interval, -0.8-0.7]; P = 0.94)). No deaths were observed in either group. CONCLUSIONS: The early administration of convalescent plasma with high neutralizing activity did not contribute to a decrease in the viral load within five days compared with the standard of care alone.

Coronavirus Disease 2019 (COVID-19) Breakthrough Infection and Post-Vaccination Neutralizing Antibodies Among Healthcare Workers in a Referral Hospital in Tokyo: A Case-Control Matching Study.

BACKGROUND: While increasing coverage of effective vaccines against coronavirus disease 2019 (COVID-19), emergent variants raise concerns about breakthrough infection. Data are limited, however, whether breakthrough infection during the epidemic of the variant is ascribed to insufficient vaccine-induced immunogenicity. METHODS: We describe incident COVID-19 in relation to the vaccination program among workers of a referral hospital in Tokyo. During the predominantly Delta epidemic, we followed 2415 fully vaccinated staff (BNT162b2) for breakthrough infection and selected 3 matched controls. We measured post-vaccination neutralizing antibodies against the wild-type, Alpha (B.1.1.7), and Delta (B.1.617.2) strains using live viruses and anti-spike antibodies using quantitative assays, and compared them using the generalized estimating equation model between the 2 groups. RESULTS: No COVID-19 cases occurred 1-2 months after the vaccination program during the fourth epidemic wave in Japan, dominated by the Alpha variant, while 22 cases emerged 2-4 months after the vaccination program during the fifth wave, dominated by the Delta variant. In the vaccinated cohort, all 17 cases of breakthrough infection were mild or asymptomatic and participants had returned to work early. There was no measurable difference between cases and controls in post-vaccination neutralizing antibody titers against the wild-type, Alpha, Delta, and anti-spike antibody titers, while neutralizing titers against the variants were considerably lower than those against the wild-type. CONCLUSIONS: Post-vaccination neutralizing antibody titers were not decreased among patients with breakthrough infection relative to their controls under the Delta variant outbreak. The result points to the importance of infection-control measures in the post-vaccination era, irrespective of immunogenicity profile.

Cardiovascular Complications of Hospitalized Patients With Coronavirus Disease 2019 in a Japanese Registry in 2020.

BACKGROUND: Cardiovascular complications of coronavirus disease 2019 (COVID-19) are critical for prognosis but have not been elucidated in Japan.Methods and Results:The COVID-19 Registry Japan, which included data from 19,853 individuals at the end of 2020, was analyzed. The incidences of cardiovascular complications were 0.098% for myocarditis/pericarditis/cardiomyopathy, 0.48% for ventricular tachycardia/fibrillation, 0.17% for myocardial ischemia, 0.062% for endocarditis, 0.59% for deep vein thrombosis, 0.19% for pulmonary embolism, and 0.37% for cerebral infarction/hemorrhage. Excluding endocarditis, all complications were associated with increased in-hospital mortality. CONCLUSIONS: Cardiovascular complications of COVID-19 were infrequent in Japan but were associated with poor prognosis.

Neutralising activity and antibody titre in 10 patients with breakthrough infections of the SARS-CoV-2 Omicron variant in Japan.

The Omicron variant of severe acute respiratory syndrome coronavirus 2 has multiple amino acid mutations in its spike proteins, which may allow it to evade immunity elicited by vaccination. We examined the neutralising activity and S1-IgG titres in patients with breakthrough infections caused by the Omicron variant after two doses of vaccination. We found that neutralising activity was significantly lower for the Omicron variant than for the Wuhan strain. Two doses of vaccination might not induce sufficient neutralising activity for the Omicron variant.

Successful use of casirivimab/imdevimab anti-spike monoclonal antibodies to enhance neutralizing antibodies in a woman on anti-CD20 treatment with refractory COVID-19.

Management of COVID-19 patients with humoral immunodeficiency is challenging. We describe a woman with COVID-19 with multiple relapses due to anti-CD20 monoclonal antibody treatment. She was successfully treated with casirivimab/imdevimab and confirmed to have neutralizing antibodies. This case suggests that monoclonal antibodies have therapeutic and prophylactic value in patients with humoral immunodeficiency.

Clinical Epidemiology of Hospitalized Patients With Coronavirus Disease 2019 (COVID-19) in Japan: Report of the COVID-19 Registry Japan.

BACKGROUND: There is limited understanding of the characteristics of patients with coronavirus disease 2019 (COVID-19) requiring hospitalization in Japan. METHODS: This study included 2638 cases enrolled from 227 healthcare facilities that participated in the COVID-19 Registry Japan (COVIREGI-JP). The inclusion criteria for enrollment of a case in COVIREGI-JP are both (1) a positive severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) test and (2) inpatient treatment at a healthcare facility. RESULTS: The median age of hospitalized patients with COVID-19 was 56 years (interquartile range [IQR], 40-71 years). More than half of cases were male (58.9%, 1542/2619). Nearly 60% of the cases had close contact to confirmed or suspected cases of COVID-19. The median duration of symptoms before admission was 7 days (IQR, 4-10 days). The most common comorbidities were hypertension (15%, 396/2638) and diabetes without complications (14.2%, 374/2638). The number of nonsevere cases (68.2%, n = 1798) was twice the number of severe cases (31.8%, n = 840) at admission. The respiratory support during hospitalization includes those who received no oxygen support (61.6%, 1623/2636) followed by those who received supplemental oxygen (29.9%, 788/2636) and invasive mechanical ventilation/extracorporeal membrane oxygenation (8.5%, 225/2636). Overall, 66.9% (1762/2634) of patients were discharged home, while 7.5% (197/2634) died. CONCLUSIONS: We identified the clinical epidemiological features of COVID-19 in hospitalized patients in Japan. When compared with existing inpatient studies in other countries, these results demonstrated fewer comorbidities and a trend towards lower mortality.

Switching from entecavir to tenofovir disoproxil fumarate for HBeAg-positive chronic hepatitis B patients: a phase 4, prospective study.

BACKGROUND: Tenofovir disoproxil fumarate (TDF) is widely used and recommended as first-line treatment for patients infected with the hepatitis B virus (HBV). However, current data are limited regarding the efficacy and safety of switching to TDF for the treatment of chronic hepatitis B in hepatitis B e-antigen (HBeAg)-positive patients who are virologically suppressed with another nucleos(t)ide analogue. The primary objective of this study was to evaluate the hepatitis B surface antigen (HBsAg) reduction potential of switching from entecavir (ETV) to TDF at week 48 in HBeAg-positive chronic hepatitis B patients with undetectable serum HBV-DNA. METHODS: In this multicenter, single-arm, open-label, phase 4 clinical study, 75 participants currently treated with ETV 0.5 mg once daily were switched to TDF 300 mg once daily for 96 weeks. RESULTS: At week 48, 3/74 participants (4%) achieved 0.25 log10 reduction of HBsAg levels from baseline (the primary endpoint). Mean HBsAg reduction was -0.14 log10 IU/mL and 12% (9/74) achieved 0.25 log10 reduction by 96 weeks. No participants achieved HBsAg seroclearance. HBsAg reduction at weeks 48 and 96 was numerically greater in participants with higher alanine aminotransferase levels (≥ 60 U/L). Seventeen participants (25%) achieved HBeAg seroclearance up to week 96. No participants experienced viral breakthrough. All drug-related adverse events (18 participants [24%]) were mild in intensity, including an increase in urine beta-2-microglobulin (15 participants [20%]). CONCLUSIONS: In conclusion, HBsAg reduction was limited after switching from ETV to TDF in this study population. Further investigation is warranted to better understand the clinical impact of switching from ETV to TDF. ClinicalTrials.gov: NCT03258710 registered August 21, 2017. https://clinicaltrials.gov/ct2/show/NCT03258710?term=NCT03258710&draw=2&rank=1.

Randomized prospective study showing the non-inferiority of tenofovir to entecavir in treatment-naïve chronic hepatitis B patients.

AIM: The study aimed to evaluate the efficacy and safety of tenofovir disoproxil fumarate (TDF) and entecavir hydrate (ETV) in nucleos(t)ide analog (NA)-naïve Japanese chronic hepatitis B (CHB) patients. METHODS: This multicenter, randomized, double-blinded study assessing the efficacy and safety of TDF 300 mg and ETV 0.5 mg in NA-naïve CHB subjects was carried out from November 2011 to November 2014, and funded by GlaxoSmithKline. The subjects were assigned to the TDF arm or ETV arm in a 2:1 ratio. The primary efficacy endpoint was the non-inferiority of TDF to ETV at week 24. RESULTS: A total of 166 subjects (TDF arm, 110; ETV arm, 56) were enrolled. The change (mean ± SE) in serum hepatitis B virus (HBV)-DNA levels from baseline to week 24 was -4.63 ± 0.044 and -4.50 ± 0.063 log10 copies/mL in the TDF and ETV arms, respectively, indicating the non-inferiority of TDF to ETV (P < 0.0001). The proportion of subjects with undetectable HBV-DNA increased from 54 to 77% and 39 to 66% in the TDF and ETV arms with continuation of the treatment from week 24 to 48, respectively. Reduction in hepatitis B surface antigen level was greater in subjects with hepatitis B envelope antigen (+) and high alanine aminotransferase levels (≥80 IU/L). Prevalence of drug-related adverse events at week 48 was 20% and 18% in the TDF and ETV arms, respectively. CONCLUSIONS: The study is the first to report that TDF has non-inferiority to ETV in treatment effectiveness (lowering of serum HBV-DNA level) at week 24. ClinicalTrials.gov trial registration nos. NCT01480284 and GSK LOC115409.

Structural Insights into HIV-1 Vif-APOBEC3F Interaction.

UNLABELLED: The HIV-1 Vif protein inactivates the cellular antiviral cytidine deaminase APOBEC3F (A3F) in virus-infected cells by specifically targeting it for proteasomal degradation. Several studies identified Vif sequence motifs involved in A3F interaction, whereas a Vif-binding A3F interface was proposed based on our analysis of highly similar APOBEC3C (A3C). However, the structural mechanism of specific Vif-A3F recognition is still poorly understood. Here we report structural features of interaction interfaces for both HIV-1 Vif and A3F molecules. Alanine-scanning analysis of Vif revealed that six residues located within the conserved Vif F1-, F2-, and F3-box motifs are essential for both A3C and A3F degradation, and an additional four residues are uniquely required for A3F degradation. Modeling of the Vif structure on an HIV-1 Vif crystal structure revealed that three discontinuous flexible loops of Vif F1-, F2-, and F3-box motifs sterically cluster to form a flexible A3F interaction interface, which represents hydrophobic and positively charged surfaces. We found that the basic Vif interface patch (R17, E171, and R173) involved in the interactions with A3C and A3F differs. Furthermore, our crystal structure determination and extensive mutational analysis of the A3F C-terminal domain demonstrated that the A3F interface includes a unique acidic stretch (L291, A292, R293, and E324) crucial for Vif interaction, suggesting additional electrostatic complementarity to the Vif interface compared with the A3C interface. Taken together, these findings provide structural insights into the A3F-Vif interaction mechanism, which will provide an important basis for development of novel anti-HIV-1 drugs using cellular cytidine deaminases. IMPORTANCE: HIV-1 Vif targets cellular antiviral APOBEC3F (A3F) enzyme for degradation. However, the details on the structural mechanism for specific A3F recognition remain unclear. This study reports structural features of interaction interfaces for both HIV-1 Vif and A3F molecules. Three discontinuous sequence motifs of Vif, F1, F2, and F3 boxes, assemble to form an A3F interaction interface. In addition, we determined a crystal structure of the wild-type A3F C-terminal domain responsible for the Vif interaction. These results demonstrated that both electrostatic and hydrophobic interactions are the key force driving Vif-A3F binding and that the Vif-A3F interfaces are larger than the Vif-A3C interfaces. These findings will allow us to determine the configurations of the Vif-A3F complex and to construct a structural model of the complex, which will provide an important basis for inhibitor development.

Efficacy and safety of tenofovir disoproxil fumarate rescue therapy for chronic hepatitis B patients who failed other nucleos(t)ide analogs.

AIM: Acquisition of nucleos(t)ide analog (NA) inhibitor resistance is critical in successful chronic hepatitis B treatment. As the pattern of tenofovir disoproxil fumarate (TDF) resistance mutations differs from that of other antiviral drugs, we sought to clarify the salvaging potential of TDF in patients with hepatitis B virus (HBV) infection who are poor responders or resistant to other NAs. METHODS: A prospective, multicenter, single-arm, open-label study was carried out from December 2011 to October 2014. Poor responders defined as subjects with serum HBV-DNA levels >4 log10 copies/mL were enrolled. Subjects receiving lamivudine (LAM) + adefovir pivoxil (ADV) before the initiation of the study were switched to LAM + TDF. Subjects on entecavir hydrate (ETV) with or without ADV were switched to ETV + TDF. The primary efficacy end-point was the proportion of subjects achieving HBV-DNA <2.1 log10 copies/mL (LLQ) at week 24. The secondary efficacy end-points were the proportion of subjects with LLQ at weeks 48 and 96, serum alanine aminotransferase normalization, hepatitis B envelope antigen/antibody and hepatitis B surface antigen/antibody seroconversion. RESULTS: Thirty-four subjects were enrolled, 21 subjects were switched to ETV + TDF, and 13 subjects were switched to LAM + TDF. Drug resistance mutations were determined in 85% of the subjects at the time of the enrolment. The proportion of subjects who achieved LLQ was 59%, 62%, and 71% at weeks 24, 48, and 96, respectively. No serious adverse event related to TDF was reported. CONCLUSION: Our study clearly showed that TDF containing regimens were effective in salvaging poor responders and/or those who are drug-resistant to other NAs. This study is registered with ClinicalTrials.gov (NCT01475851) and the GSK Clinical Study Register (GSK LOC115912).

[Investigation of the Pathophysiology and Diagnostic Methods Through a Case of Acute HIV Infection in which the Western Blot Method Remained Negative Over the Long Term and the 4th Generation Screening Assay Became Negative for a Certain Period of Time after Initiating Antiretroviral Therapy].

Confirmatory tests using Western blot (WB) and HIV-1 nucleic acid testing (HIV-1 RNA) following a positive screening test are required for the diagnosis of HIV-1 infection according to the current Japanese guidelines for HIV-1/2 diagnosis. We report herein on a rare case in a patient who remained negative for WB over 10 months in spite of being positive by fourth-generation immunoassays (4thGIA) and who subsequently seroreverted by 4thGIA for three months after initiating antiretroviral therapy. Case: A man in his early twenties previously visited a hospital because of fever in October 2012. Laboratory data revealed leukocytopenia, thrombocytopenia and increased serum ferritin, suggesting hemophagocytic syndrome (HPS). During that visit, he tested positive for a 4thGIA, but negative for HIV-1 WB and his result of HIV-1 RNA result was detected invalid because of the presence of some inhibitory material in his RNA preparation. Thereafter, he was diagnosed as having cytomegalovirus-associated HPS treatment was for which initiated. In January 2013, he developed Pneumocystis jirovecii pneumonia, and his HIV-1 RNA viral load was 7.7 × 105 copies/mL in February 2013. Acute HIV infection was suspected, because the HIV-1 WB remained negative. He was started on antiretroviral therapy in April 2013. His 4thGIA was converted to negative in May 2013 and was reconverted to positive in August 2013. HIV-1 WB, however, continued to be indeterminant until February 2014, in which it turned positive for the first time according to the CDC criteria. Methods and Results: The genetic analyses of HIV-1 were done on the gag, env, nef and pol region of the HIV-1 gene from the patient. There was no clear element to delay antibody production on the virus side. Preserved specimens of the patient were measured with eight kinds of HIV screening assay. It was thought that the fourth generation assay was positive only by the presence of the antigen until March 2013 because the antibody had not been detected. Discussion: We encountered a case of acute HIV infection in which the WB result was negative for 10 months after the first positive response of the 4thGIA. The 4thGIA is essential for the early diagnosis and early treatment of HIV infection; therefore, the 4thGIA should be strictly recommended to avoid the use of older generations of immunoassay in the diagnostic guidelines. The role of the WB test should be examined closely from various aspects for use as a confirmatory test under recent laboratory situations in which highly sensitive and specific methods, e.g. the 4th GIA, have become available. In addition, unnecessary confusion due to the diversities of antibody formation should be avoided. The antibody detection tests for HIV are still necessary and indispensable for the confirmation of the disease or the diagnosis of the acute infection stage. Therefore development of a newer antibody measuring method which could achieve an easier operation and should have a higher sensitivity and specificity for HIV confirmation is strongly expected.