Association between the hypokalaemia index based on area over the serum potassium concentration curve and occurrence of acute kidney injury in patients administered liposomal amphotericin B.

BACKGROUND: Acute kidney injury (AKI) and hypokalaemia are common adverse events after treatment with liposomal amphotericin B (L-AMB). OBJECTIVES: Because excess potassium (K) leakage occurs during renal tubular injury caused by L-AMB, measuring the decrease in rate of serum K concentration might be more useful to assess the renal impact of L-AMB than hypokalaemia identified from a one-point measurement. The effects of a decrease in K concentration and duration of hypokalaemia on AKI were investigated. METHODS: A ≥ 10% decrease in K concentration from the reference concentration within a 7-day timeframe was evaluated. The hypokalaemia index, which combines the duration of K concentration lower than the reference and a marked low K concentration, was calculated from the area over the concentration curve. RESULTS: Eighty-six patients were included in the study. The incidences of AKI and decrease in K concentration were 36.0% and 63.9%, respectively. Of patients who developed both adverse events, a decrease in K concentration occurred first in 22 of 26 patients, followed by AKI 7 days later. Hypokalaemia did not increase AKI risk whereas a decrease in K concentration was an independent risk factor for AKI. The hypokalaemia index in patients with AKI was significantly higher than those without AKI (5.35 vs. 2.50 points, p = 0.002), and ≥3.45 points was a significant predictor for AKI. CONCLUSION: A ≥ 10% decrease in the K concentration was a significant factor for AKI in patients receiving L-AMB therapy. In such patients, dose reduction or alternative antifungals could be considered based on the hypokalaemia index.

Timing of Assessment of Humoral and Cell-Mediated Immunity after Influenza Vaccination.

Assessment of the immune response to influenza vaccines should include an assessment of both humoral and cell-mediated immunity. However, there is a lack of consensus regarding the timing of immunological assessment of humoral and cell-mediated immunity after vaccination. Therefore, we investigated the timing of immunological assessments after vaccination using markers of humoral and cell-mediated immunity. In the 2018/2019 influenza season, blood was collected from 29 healthy adults before and after vaccination with a quadrivalent inactivated influenza vaccine, and we performed serial measurements of humoral immunity (hemagglutination inhibition [HAI] and neutralizing antibody [NT]) and cell-mediated immunity (interferon-gamma [IFN-γ]). The HAI and NT titers before and after vaccination were strongly correlated, but no correlation was observed between the markers of cell-mediated and humoral immunity. The geometric mean titer and geometric mean concentration of humoral and cellular immune markers increased within 2 weeks after vaccination and had already declined by 8 weeks. This study suggests that the optimal time to assess the immune response is 2 weeks after vaccination. Appropriately timed immunological assessments can help ensure that vaccination is effective.

Changes in the Epidemiology of Rubella: The Influence of Vaccine-Introducing Methods and COVID-19.

Rubella is an infectious disease caused by the rubella virus. Congenital rubella syndrome is a risk for all newborns if pregnant women are infected with rubella, raising an important public health issue. Rubella is a vaccine-preventable disease, and routine immunization has been conducted in Japan. The timing of the vaccine approval did not differ from that in the United States. In 2004, endemic rubella was eliminated in the United States. However, recent rubella outbreaks have occurred in Japan. This may be related to differences in the introduction of routine rubella immunization. In Japan, routine rubella immunization was initially introduced only for junior high school girls, and the rate of susceptibility is high among males who have not received rubella vaccination, causing an outbreak. Therefore, in Japan, measures have been taken to decrease the number of susceptible males in the vaccination-free generation. The coronavirus pandemic has also affected the epidemiology of rubella as well as other infectious diseases.

Correlation between Antimicrobial Resistance and the Hospital-Wide Diverse Use of Broad-Spectrum Antibiotics by the Antimicrobial Stewardship Program in Japan.

Increased antibiotic use and antibiotic homogeneity cause selective pressure. This study investigated the correlation between antibiotic diversity and antimicrobial resistance (AMR) in Gram-negative organisms. The days of therapy/100 patient-days (DOT) for four broad-spectrum antibiotic classes were evaluated for 2015-2022. The antibiotic heterogeneity index (AHI) for the equal use of four classes (25%) and the modified AHI for the equal use of three classes (30%), excluding fluoroquinolones (10%), were measured (target: 1.0). Quarterly antibiotic use markers and the resistance rates against ≥2 anti-Pseudomonas antibiotics were compared. The DOT value was 9.94, and the relative DOT were 34.8% for carbapenems, 32.1% for piperacillin/tazobactam, 24.3% for fourth generation cephalosporins/ceftazidime/aztreonam, and 8.9% for fluoroquinolones. Although no correlation was found between the total DOT and the resistance rate for any bacterium, a significant negative correlation was found between the heterogeneity indices and resistance rates for Pseudomonas aeruginosa and Klebsiella pneumoniae. The significant cutoffs that discriminate the risk of resistance were 0.756 for the AHI and 0.889 for the modified AHI for K. pneumoniae. Antibiotic diversity is more important in preventing AMR than overall antibiotic use. The ideal ratio of broad-spectrum antibiotics should be studied for diversified use to prevent AMR.

I536T variant of RBM20 affects splicing of cardiac structural proteins that are causative for developing dilated cardiomyopathy.

RBM20 is one of the genes predisposing to dilated cardiomyopathy (DCM). Variants in the RS domain have been reported in many DCM patients, but the pathogenicity of variants within the RNA-recognition motif remains unknown. Two human patients with the I536T-RBM20 variant without an apparent DCM phenotype were identified in sudden death cohorts. A splicing reporter assay was performed, and an I538T knock-in mouse model (Rbm20I538T) was generated to determine the significance of this variant. The reporter assay demonstrated that the human I536T variant affected the TTN splicing pattern compared to wild-type. In the mouse experiments, Rbm20I538T mice showed different splicing patterns in Ttn, Ldb3, Camk2d, and Ryr2. The expressions of Casq1, Mybpc2, and Myot were upregulated in Rbm20I538T mice, but Rbm20I538T mice showed neither DCM nor cardiac dysfunction on histopathological examination and ultrasound echocardiography. The I536T-RBM20 (I538T-Rbm20) variant changes gene splicing and affects gene expression, but the splicing and expression changes in Ttn and Ca handling genes such as Casq1, Camk2d, and Ryr2 do not cause DCM morphology in the mouse model. KEY MESSAGES: • Two human patients with the I536T-RBM20 variant without a DCM phenotype were identified. • A splicing reporter assay demonstrated that the variant affected the TTN splicing. • Rbm20I538T mice showed neither DCM nor cardiac dysfunction. • Rbm20I538T mice showed different splicing patterns and the gene expressions.

Comparison of the Hemagglutination Inhibition Titers against Influenza Vaccine Strains in Japan from the 2017/2018 to 2021/2022 Seasons Using a Single Set of Serum Samples.

In Japan, inactivated influenza vaccines are used. We measured titers of antibodies to vaccine strains of three influenza types-influenza A (H1N1), influenza A (H3N2), and influenza B/Victoria-from the 2017/2018 to 2021/2022 seasons, but not for influenza A (H3N2) from the 2018/2019 season, using a single set of serum samples from 34 healthy volunteers, and assessed the consistency in antibody positivity between seasons. The antibody titers in the 2017/2018 season were used as a reference. The influenza A (H1N1) antibody titer in 2019/2020 did not differ significantly from that in the 2017/2018 season, but the titers varied in the two subsequent seasons. The influenza A (H3N2) antibody titers toward the 2019/2020, 2020/2021, and 2021/2022 seasonal viruses differed significantly from that in the 2017/2018 season. The influenza B/Victoria antibody titer toward the 2019/2020 seasonal antigen differed from that in the 2017/2018 season, and the antibody positivity was inconsistent between seasons; however, the antibody titer in the 2020/2021 season did not differ significantly from those in the prior two seasons, and the antibody positivity was consistent between seasons. Antibody titers and their consistency can be used to evaluate cross-immunity of antibodies.

Correction of thrombocytopenia caused by linezolid with scheduled sequential tedizolid use in patients with vertebral osteomyelitis by antibiotic resistant Gram-positive organisms.

INTRODUCTION: Because of thrombocytopenia, linezolid treatment tends to be stopped before the completion of therapy for complicated infections that require prolonged antimicrobial administration. In contrast, tedizolid shows a favorable hematologic profile. The primary end-point of this study was to evaluate the efficacy of switching treatment to tedizolid in patients who developed thrombocytopenia during linezolid therapy. METHODS: This retrospective study was conducted in patients with vertebral osteomyelitis (VO) caused by antibiotic-resistant Gram-positive bacteria. Treatment failure was defined as the reappearance of infection signs within 2 weeks after stopping tedizolid and discontinuation of tedizolid because of continued thrombocytopenia or other adverse effects. RESULTS: Eight patients with native VO (n = 3) and postoperative VO (n = 5) were included in the study. The causative organisms were MRSA in all patients except one. Platelet counts decreased from 35.2 ± 11.5 × 104/mm3 to 17.8 ± 6.2 × 104/mm3 during linezolid therapy and improved without washout period in all patients after switching to tedizolid on days 5-7 (28.6 ± 4.9 × 104/mm3, p = 0.002). Tedizolid therapy was completed and treatment failure was not observed in any patient. The duration of treatment was 20.0 ± 11.2 days for linezolid and 30.3 ± 9.5 days for tedizolid (total, 50.3 ± 10.7 days). One patient died because of underlying disease, and there was no recurrence in the remaining 7 patients (median follow-up 501 days). CONCLUSIONS: Switching therapy to tedizolid improved thrombocytopenia that occurred during linezolid therapy, and it enabled the completion of therapy for VO patients.

Effect of Routine Varicella Immunization on the Epidemiology and Immunogenicity of Varicella and Shingles.

Varicella-zoster virus (VZV) causes varicella as a primary infection and remains latent in the ganglia until it becomes reactivated to cause herpes zoster. Individuals with varicella develop adaptive humoral and cell-mediated immunity. Compromised cell-mediated immunity is thought to contribute to the development of herpes zoster. Recent evidence suggests that changes in the epidemiology of varicella have affected the epidemiology of herpes zoster. The incidence of herpes zoster is higher in older adults; thus, the herpes zoster vaccine is recommended for older adults. However, the incidence of herpes zoster is expected to rise among younger individuals; hence, vaccination with the varicella vaccine should also be considered in younger adults. In order to determine the need for vaccination in different populations, it is important to establish methods to accurately assess the activity of cell-mediated immunity and humoral immunity.

Validation of Vancomycin Area under the Concentration-Time Curve Estimation by the Bayesian Approach Using One-Point Samples for Predicting Clinical Outcomes in Patients with Methicillin-Resistant Staphylococcus aureus Infections.

Area under the concentration-time curve (AUC)-guided vancomycin treatment is associated with decreased nephrotoxicity. It is preferable to obtain two samples to estimate the AUC. This study examined the usefulness of AUC estimation via trough concentration (Cmin)-only sampling of 260 adults infected with methicillin-resistant Staphylococcus aureus (MRSA) who received vancomycin. The exact Cmin sampling time was used for Bayesian estimation. A significantly higher early treatment response was observed in patients with a day 2 AUC ≥ 400 µg·h/mL than those with <400 µg·h/mL, and a significantly higher early nephrotoxicity rate was observed in patients with a day 2 AUC ≥ 600 µg·h/mL than those with <600 µg·h/mL. These AUC cutoff values constituted independent factors for each outcome. In sub-analysis, the discrimination ability for early clinical outcomes using these AUC cutoffs was confirmed only in patients with q12 vancomycin administration. A significant difference in early treatment response using the 400 µg·h/mL cutoff was obtained only in patients with low-risk infections. The usefulness of the vancomycin AUC target to decrease nephrotoxicity while assuring clinical efficacy was even confirmed with a single Cmin measurement. However, assessment with two samples might be required in patients with q24 administration or high/moderate-risk MRSA infections.

Enhanced loading dose of teicoplanin for three days is required to achieve a target trough concentration of 20 µg/mL in patients receiving continuous venovenous haemodiafiltration with a low flow rate.

INTRODUCTION: Because of its lower risk of renal toxicity than vancomycin, teicoplanin is the preferred treatment for methicillin-resistant Staphylococcus aureus infection in patients undergoing continuous venovenous haemodiafiltration (CVVHDF) in whom renal function is expected to recover. The dosing regimen for achieving a trough concentration (Cmin) of ≥20 µg/mL remains unclear in patients on CVVHDF using the low flow rate adopted in Japan. METHODS: The study was conducted in patients undergoing CVVHDF with a flow rate of <20 mg/kg/h who were treated with teicoplanin. We adopted three loading dose regimens for the initial 3 days: the conventional regimen, a high-dose regimen (four doses of 10 mg/kg), and an enhanced regimen (four doses of 12 mg/kg). The initial Cmin was obtained at 72 h after the first dose. RESULTS: Overall, 60 patients were eligible for study inclusion. The proportion of patients achieving the Cmin target was significantly higher for the enhanced regimen than for the high-dose regimen (52.9% versus 8.3%, p = 0.003). In multivariate analysis, the enhanced regimen (odds ratio [OR] = 39.93, 95% confidence interval [CI] = 5.03-317.17) and hypoalbuminaemia (OR = 0.04, 95% CI = 0.01-0.44) were independent predictors of the achievement of Cmin ≥ 20 µg/mL. CONCLUSIONS: An enhanced teicoplanin regimen was proposed to treat complicated or invasive infections by methicillin-resistant Staphylococcus aureus in patients receiving CVVHDF even with a low flow rate.

Changes in Cell-Mediated Immunity (IFN-γ and Granzyme B) Following Influenza Vaccination.

Interferon gamma (IFN-γ) is considered a key moderator of cell-mediated immunity. However, little is known about its association with granzyme B, which plays an important role in the effector function of cytotoxic T lymphocytes (CTLs). In the present study, we collected blood samples from 32 healthy adults before and after vaccination with inactivated influenza vaccine in 2017/18 to measure the levels of IFN-γ and granzyme B, which play roles in cell-mediated immunity, and hemagglutination inhibition (HAI) antibody, which plays a role in humoral immunity. The levels of IFN-γ and granzyme B were significantly correlated both before and after vaccination. Furthermore, the post-vaccine fold increases in the IFN-γ and granzyme B levels were significantly correlated. The levels of IFN-γ and granzyme B decreased five months after vaccination in more than half of the subjects who exhibited an increase in IFN-γ and granzyme B at two weeks post-vaccination. This is the first study to investigate the correlation between IFN-γ and granzyme B levels following influenza vaccination. Our study suggests that both IFN-γ and granzyme B can be used as markers of cell-mediated immunity.

Sensitivity and specificity of different antibody tests for detecting varicella-zoster virus.

INTRODUCTION: Antibody tests for detecting varicella-zoster virus include the fluorescent-antibody-to-membrane-antigen (FAMA) assay, immune adherence hemagglutination assay (IAHA), enzyme immunoassay (EIA), and the glycoprotein-based enzyme-linked immunosorbent assay (gpELISA). Although FAMA and gpELISA are highly sensitive, FAMA is not available commercially. Therefore, this study was performed to compare potential high-sensitivity tests with commercially available tests. METHODS: Four antibody tests, FAMA, gpELISA, EIA, and IAHA, were performed using sera collected from 32 children aged 7 months-10 years. Using FAMA as a reference, the sensitivity and specificity of gpELISA, EIA, and IAHA were assessed. Subsequently, using gpELISA as a reference, the positive agreement rate of EIA and IAHA was assessed. RESULTS: On a reference scale with FAMA set at 100%, the sensitivity and specificity of the antibody tests were as follows: gpELISA, 67% and 100%; EIA, 67% and 100%; and IAHA, 47% and 100%, respectively. The positive agreement rates of EIA and IAHA relative to gpELISA were 86% and 64%, respectively. CONCLUSIONS: gpELISA had a lower positive rate than did FAMA, and showed comparable sensitivity to that of EIA.

Clinical efficacy and safety in patients treated with teicoplanin with a target trough concentration of 20 µg/mL using a regimen of 12 mg/kg for five doses within the initial 3 days.

BACKGROUND: A trough concentration (Cmin) ≥20 µg/mL of teicoplanin is recommended for the treatment of serious methicillin-resistant Staphylococcus aureus (MRSA) infections. However, sufficient clinical evidence to support the efficacy of this target Cmin has not been obtained. Even though the recommended high Cmin of teicoplanin was associated with better clinical outcome, reaching the target concentration is challenging. METHODS: Pharmacokinetics and adverse events were evaluated in all eligible patients. For clinical efficacy, patients who had bacteremia/complicated MRSA infections were analyzed. The primary endpoint for clinical efficacy was an early clinical response at 72-96 h after the start of therapy. Five dosed of 12 mg/kg or 10 mg/kg was administered as an enhanced or conventional high loading dose regimen, respectively. The Cmin was obtained at 72 h after the first dose. RESULTS: Overall, 512 patients were eligible, and 76 patients were analyzed for treatment efficacy. The proportion of patients achieving the target Cmin range (20-40 µg/mL) by the enhanced regimen was significantly higher than for the conventional regimen (75.2% versus 41.0%, p < 0.001). In multivariate analysis, Cmin ≥ 20 µg/mL was an independent factor for an early clinical response (odds ratio 3.95, 95% confidence interval 1.25-12.53). There was no significant difference in the occurrence of adverse events between patients who did or did not achieve a Cmin ≥ 20 µg/mL. CONCLUSION: A target Cmin ≥ 20 µg/mL might improve early clinical responses during the treatment of difficult MRSA infections using 12 mg/kg teicoplanin for five doses within the initial 3 days.

Effects of the Use of Air Purifier on Indoor Environment and Respiratory System among Healthy Adults.

Air purifiers have become popular among ordinary families. However, it remains controversial whether indoor air purification improves the respiratory health of healthy adults. A randomized crossover intervention study was conducted with 32 healthy individuals. The subjects were categorized into two groups. One group continuously used true air purifiers, and the other followed with sham air purifiers for 4 weeks. Following this first intervention, all the subjects underwent a 4-week washout period and continued with the second 4-week intervention with the alternate air purifiers. We collected fine particulate matter (PM) ≤ 2.5 µm in aerodynamic diameter (PM2.5), coarse particulate matter between 2.5 and 10 µm in aerodynamic diameter (PM10-2.5) and ozone (O3). The subjects' pulmonary function and fractional exhaled nitric oxide (FeNO) were measured during the study period. The indoor PM2.5 concentrations decreased by 11% with the true air purifiers compared to those with sham air purifiers. However, this decrease was not significant (p = 0.08). The air purification did not significantly improve the pulmonary function of the study subjects. In contrast, an increase in the indoor PM10-2.5 and O3 concentration led to a significant decrease in the forced expiratory volume in one second (FEV1.0)/forced vital capacity (FVC) and maximal mid-expiratory flow (MMEF), respectively. In conclusion, air purification slightly improved the indoor PM2.5 concentrations in ordinary homes but had no demonstrable impact on improving health.

Vancomycin loading dose is associated with increased early clinical response without attainment of initial target trough concentration at a steady state in patients with methicillin-resistant Staphylococcus aureus infections.

WHAT IS KNOWN AND OBJECTIVE: Vancomycin therapeutic guidelines suggest a loading dose of 25-30 mg/kg for seriously ill patients. However, high-quality data to guide the use of loading doses are lacking. We aimed to evaluate whether a loading dose (a) achieved a target trough concentration at steady state and (b) improved early clinical response. METHODS: Patients with an estimated glomerular filtration rate ≥ 90 mL/min/1.73 m2 were included. A loading dose of 25 mg/kg vancomycin followed by 15 mg/kg twice daily was compared with traditional dosing. A Cmin sample was obtained before the fifth dose. An early clinical response 48-72 hours after the start of therapy and clinical success at end of therapy (EOT) was evaluated in patients with methicillin-resistant Staphylococcus aureus (MRSA), methicillin-resistant coagulase-negative Staphylococci or Enterococcus faecium. RESULTS: There was no significant difference in Cmin between the regimen with and without a loading dose (median: 10.4 and 10.2 µg/mL, P = .54). Proportions of patients achieving 10-20 and 15-20 µg/mL were 56.9% and 5.6%, respectively, in patients with a loading dose. Although there was no significant difference in success rate at EOT between groups, a loading dose was associated with increased early clinical response for all infections (adjusted odds ratio [OR]: 4.588, 95% confidence interval [CI]: 1.373-15.330) and MRSA infections (OR: 12.065, 95% CI: 1.821-79.959). Study limitations included no Cmin measurements within 24 hours and the inclusion of less critically ill patients. WHAT IS NEW AND CONCLUSION: A loading dose of 25 mg/kg followed by 15 mg/kg twice daily did not achieve the optimal Cmin at steady state in patients with normal renal function. However, more early clinical responses were obtained with a loading dose compared with traditional dosing, possibly because of a prompt albeit temporary achievement of a more effective concentration.

Clinical efficacy of teicoplanin in the treatment of bloodstream infection caused by methicillin-resistant coagulase-negative staphylococci.

Empirical combination therapy with ß-lactams and glycopeptides is recommended for patients with presumed staphylococcal bloodstream infection (BSI). While coagulase-negative staphylococci (CNS) remain susceptible to vancomycin, such isolates have become less susceptible to teicoplanin. The aim of this retrospective study was to evaluate the clinical efficacy of teicoplanin in the treatment of BSI caused by methicillin-resistant CNS according to teicoplanin susceptibility. Inclusion criteria were patients with intravascular-catheter related BSIs caused by methicillin-resistant CNS (positive for two or more specimens); teicoplanin therapy; and at least one of the signs or symptoms caused by BSI. Antimicrobial resistance was defined as minimum inhibitory concentration (MIC) ≥8 µg/mL. The primary efficacy endpoint was clinical success evaluated 2 weeks after the completion of teicoplanin therapy [test of cure (TOC)]. Resistant rate of CNS was 0% for vancomycin and 22.9% for teicoplanin, and geometric mean MICs were 1.31 µg/mL and 3.41 µg/mL, respectively (p < 0.001). The catheter was removed in all patients except one, and high early clinical response at 72 h after starting therapy was obtained irrespective of teicoplanin susceptibility. The clinical success rate at TOC was 60% in patients with BSIs caused by teicoplanin-resistant strains, while 90% in patients with BSIs caused by susceptible strains (p = 0.052). In multivariate analyses, teicoplanin resistance was significant factor for decreased clinical success at TOC (adjusted odds ratio 0.138, 95% confidence interval 0.020-0.961, p = 0.045). Because of the poor clinical efficacy of teicoplanin against teicoplanin-resistant CNS, combination therapy comprising vancomycin and ß-lactam antibiotics should be considered in presumed staphylococci BSI.

Evaluation of influenza vaccine-induced cell-mediated immunity: Comparison between methods using peripheral blood mononuclear cells and whole blood.

Assessment of cell-mediated immunity (CMI) may be critical to evaluating the ability of individuals to protect themselves against influenza virus infection. However, it has been difficult to evaluate CMI because no simple means of measuring it is currently available. The aim of this study was to compare the performance of a CMI measurement method developed by us, which involves reacting whole blood with antigen, with the conventional method, which is based on isolating peripheral blood mononuclear cells (PBMCs). Correlations between these methods before and after vaccination of 26 healthy adults (aged 28-58 years; 12 men and 14 women) were assessed and changes in CMI after influenza vaccination in PBMCs cultured with antigen for 48 and 96 hr and whole blood cultured with antigen for 48 hr were studied. Results of CMI measurement using whole blood on Day 2 and PBMCs on Day 4 were found to be correlated. Spearman's correlation coefficients with four antigens (A [H1N1], A [H3N2], B [Yamagata lineage], and B [Victoria lineage]) before vaccination were 0.55, 0.61, 0.58, and 0.70, respectively and 0.40, 0.45, 0.62, and 0.52, respectively, after vaccination. CMI was detected sooner when whole blood was reacted with antigen than when PBMCs were reacted with antigen. The rate of positive reaction of influenza A (H1N1 and H3N2) in whole blood on Day 2 was higher than that in PBMCs on Day 2. Our method is simple and may be useful for vaccine development because it can measure CMI in a small amount of blood without separating off PBMCs.

Relationship between the frequency of influenza vaccination and cell-mediated immunity.

Despite established guidelines for population-level assessments of immunity after vaccination, standard methods for individual-level analyses have not been established, limiting the ability to optimize vaccination strategies within a particular season. In this study, we evaluated changes in cell-mediated immunity (CMI) with respect to the number of influenza vaccine doses. In particular, the influenza vaccine was administered to 21 adults during the 2015-2016 season. IFN-γ production induced by the influenza vaccine antigens [A (H1N1), A (H3N2), B (Yamagata lineage), and B (Victoria lineage)] increased after the first dose of vaccination in 11, 10, 10, and 11 subjects, respectively. In 5 of 10 (H1N1), 4 of 10 (H3N2), 3 of 9 (Yamagata lineage), and 3 of 8 (Victoria lineage) subjects who did not exhibit an increase in IFN-γ production after the first dose, CMI was enhanced after the second dose. The production of IFN-γ increased after the first or second dose of the vaccine in 16, 14, 13, and 14 of the 21 subjects, respectively. The results of this study showed that two doses of the influenza vaccine effectively enhance CMI in subjects with primary vaccine failure.

Evaluation of influenza vaccine-immunogenicity in cell-mediated immunity.

The immunological effect of influenza vaccines cannot be evaluated accurately using an antibody titer. Therefore, we used a new method that measures cell-mediated immunity to investigate changes in the amount of interferon-gamma (IFN-γ) produced after vaccination in response to the vaccine antigen. The study was conducted during the 2014-2015 influenza season in 23 adults, using a vaccine that contained three types of antigen. The IFN-γ level increased by at least 1.5 times in 65% (15/23) of cases in response to the H1N1 antigen, in 57% (13/23) of cases in response to the H3N2 antigen, and in 57% (13/23) of cases in response to the B antigen. During the study period, 4 subjects developed type A influenza. Our data showed that the IFN-γ level did not increase by 1.5 times in these subjects. We propose that the efficacy of influenza vaccines may be evaluated by measuring changes in the level of IFN-γ produced in response to influenza vaccine.

Varicella zoster virus antibody detection: A comparison of four commonly used techniques.

BACKGROUND: Antibody tests for the varicella zoster virus (VZV) include neutralization, fluorescent antibody to membrane antigen (FAMA), immune adherence hemagglutination (IAHA), enzyme immunoassay (EIA), glycoprotein-based enzyme-linked immunosorbent assay (gpELISA), and complement fixation (CF) tests. Of these, FAMA is considered the most sensitive. However, in Japan, the EIA method is most frequently employed. OBJECTIVE: The VZV antibody detection rate of the FAMA, EIA, gpELISA, and IAHA methods was compared. METHODS: Four types of antibody tests were conducted with sera collected from 83 college students. The relationships between two antibody tests were examined using Pearson's correlation coefficients. RESULTS: All 83 subjects were observed to be VZV antibody-positive using the FAMA method. The Pearson correlation coefficients of gpELISA, EIA, and IAHA relative to FAMA were 0.808, 0.782, and 0.356, respectively. The positive agreement rate of IAHA relative to FAMA was 88.0% (73/83), whereas those of gpELISA and EIA were both 97.6% (81/83). Furthermore, EIA showed 100% positive agreement with gpELISA and a high correlation coefficient of 0.911, whereas these values for IAHA compared to gpELISA were much lower (90.1% and 0.530). The calculated Pearson correlation coefficient for comparison of the EIA and IAHA methods was 0.498, with a positive agreement rate of 90.1% (73/81). CONCLUSIONS: The EIA method should be employed in Japan based on the similarity of the positivity between EIA and gpELISA, as it is more available and practical than gpELISA.