Vaccine-induced humoral and cellular immunity against SARS-CoV-2 at 6 months post BNT162b2 vaccination

To evaluate vaccine-induced humoral and cell-mediated immunity at 6 months post BNT162b2 vaccination, immunoglobulin G against SARS-CoV-2 spike protein (SP IgG), 50% neutralizing antibody (NT50), and spot-forming cell (SFC) counts were evaluated by interferon-{gamma} releasing ELISpot assay of 98 healthy subjects (median age, 43 years). The geometric mean titers of SP IgG and NT50 decreased from 95.2 (95% confidence interval (CI) 79.8-113.4) to 5.7 (95% CI 4.9-6.7) and from 680.4 (588.0-787.2) to 130.4 (95% CI 104.2-163.1), respectively, at 3 weeks and 6 months after the vaccination. SP IgG titer was negatively correlated with age and alcohol consumption. Spot-forming cell counts at 6 months did not correlate with age, gender, and other parameters of the patients. SP IgG, NT50, and SFC titers were elevated in the breakthrough infected subjects. Although the levels of vaccine-induced antibodies dramatically declined at 6 months after vaccination, a certain degree of cellular immunity was observed irrespective of the age.

Antibody titers against the Alpha, Beta, Gamma, and Delta variants of SARS-CoV-2 induced by BNT162b2 vaccination measured using automated chemiluminescent enzyme immunoassay

BackgroundLevels of 50% neutralizing titer (NT50) reflect a vaccine-induced humoral immunity after the vaccination against the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). Measurements of NT50 are difficult to implement in large quantities. A high-throughput laboratory test is expected for determining the level of herd immunity against SARS-CoV-2. MethodsWe analyzed samples from 168 Japanese healthcare workers who had completed two doses of the BNT162b2 vaccine. We analyzed immunoglobulin G (IgG) index values against spike protein (SP) using automated chemiluminescent enzyme immunoassay system AIA-CL and analyzed the background factors affecting antibody titer. SP IgG index was compared with 50% neutralization titers. ResultsThe median SP IgG index values of the subjects (mean age = 43 years; 75% female) were 0.1, 1.35, 60.80, and 97.35 before and at 2, 4, and 6 weeks after the first dose, respectively. At 4 and 6 weeks after the first dose, SP IgG titers were found to have positive correlation with NT50 titer (r=0.7535 in 4 weeks; r=0.4376 in 6 weeks). Proportions of the SP IgG index values against the Alpha, Beta, Gamma, and Delta variants compared with the original strain were 2.029, 0.544, 1.017, and 0.6096 respectively. Older age was associated with lower SP IgG titer index 6 weeks after the first dose. ConclusionsSP IgG index values were raised at 3 weeks after two doses of BNT162b2 vaccination and have positive correlation with NT50. SP IgG index values were lower in the older individuals and against Beta and Delta strain.

Clinical impact of preoperative serum p53 antibody titers in 1487 patients with surgically treated esophageal squamous cell carcinoma: a multi-institutional study.

BACKGROUND: Although the clinicopathological significance of serum p53 antibodies (s-p53-Abs) in esophageal cancer have been evaluated previously, previous reports only analyzed around 100-200 patients. This study was a multi-institutional study promoted by the Japan Esophageal Society to evaluate the clinical significance of preoperative s-p53-Ab status and antibody titers in 1487 esophageal cancer patients without neoadjuvant therapy. METHODS: A total of 1487 patients with esophageal squamous cell carcinoma surgically treated between 2008 and 2016 in 15 hospitals in Japan were enrolled. The cut-off value to classify the patients into s-p53-Ab positive and negative groups was 1.30 U/ml. A receiver operating characteristic curve was constructed to assess the s-p53-Abs cut-off levels to differentiate poor prognosis among the s-p53-Ab positive group. Univariate and multivariate analyses were used to evaluate the clinicopathological and prognostic significance of s-p53-Ab status and titers. RESULTS: Although s-p53-Ab status was significantly associated with tumor depth (P = 0.002), nodal status (P = 0.027), and pathological stage (P = 0.002). The s-p53-Ab positive status was not significantly associated with poor overall survival (P = 0.699). Using 9.82 U/ml as a cut-off, the high s-p53-Ab titer group showed a significantly worse overall survival than the low s-p53-Ab titer group (P = 0.038). However, the difference was not significant in the multivariate analysis. CONCLUSION: The presence of s-p53-Abs was associated with tumor progression. Although high s-p53-Ab titers more than 9.82 U/ml, might be associated with poor prognosis for patients with esophageal squamous cell carcinoma, it was not an independent risk factor.

Panel of autoantibodies against multiple tumor-associated antigens for detecting gastric cancer.

Gastric cancer is the second leading cause of cancer death in the world, and effective diagnosis is extremely important for good outcome. We assessed the diagnostic potential of an autoantibody panel that may provide a novel tool for the early detection of gastric cancer. We analyzed data from patients with gastric cancer and normal controls in test and validation cohorts. Autoantibody levels were measured against a panel of six tumor-associated antigens (TAAs) by ELISA: p53, heat shock protein 70, HCC-22-5, peroxiredoxin VI, KM-HN-1, and p90 TAA. We assessed serum autoantibodies in 100 participants in the test cohort. The validation cohort comprised 248 participants. Autoantibodies to at least one of the six antigens showed a sensitivity/specificity of 49.0% (95% confidence interval [CI], 39.2-58.8%)/92.4% (95% CI, 87.2-97.6%), and 52.0% (95% CI, 42.2-61.8%)/90.5% (95% CI, 84.8-96.3%) in the test and validation cohorts, respectively. In the validation cohort, no significant differences were seen when patients were subdivided based on age, sex, depth of tumor invasion, lymph node metastasis, distant metastasis, peritoneal dissemination, or TNM stage. Patients who were positive for more than two antibodies in the panel tended to have a worse prognosis than those who were positive for one or no antibody. Measurement of autoantibody response to multiple TAAs in an optimized panel assay to discriminate patients with early stage gastric cancer from normal controls may aid in the early detection of gastric cancer.