T-cell response to phytohemagglutinin in the interferon-γ release assay as a potential biomarker for the response to immune checkpoint inhibitors in patients with non-small cell lung cancer

Influence of age, IGRA results, and inflammatory markers on mortality in hospitalized tuberculosis patients

INTRODUCTION

Tuberculosis (TB) remains a leading cause of death globally. Identifying the factors associated with mortality during hospitalization for TB is crucial for improving patient outcomes. This study aimed to investigate the potential risk factors, including T-SPOT.TB test results and routine laboratory markers of inflammation, associated with death during hospitalization due to TB.

METHODS

A retrospective analysis was conducted on 244 hospitalized TB patients. Demographic data, clinical characteristics, T-SPOT.TB results, and laboratory parameters were collected. Univariate and multivariate analyses were performed to identify independent risk factors for in-hospital mortality.

RESULTS

Among the patients, 206 survived and 38 died during hospitalization. Multivariate analysis revealed that age (HR: 1.08, 95% CI: 1.02-1.15, p = 0.001), a negative T-SPOT.TB test result (HR: 4.01, 95% CI: 1.78-9.01, p < 0.001), elevated C-reactive protein (CRP) levels (HR: 1.04, 95% CI: 1.01-1.08, p = 0.007), and increased neutrophil-to-lymphocyte ratio (NLR) (HR: 1.04, 95% CI: 1.00-1.07, p = 0.025) were independent risk factors for mortality.

CONCLUSIONS

This study identified age, a negative T-SPOT.TB result, elevated CRP levels, and a high NLR as significant independent risk factors for death in hospitalized TB patients. These findings underscore the importance of these parameters in the risk stratification and management of hospitalized TB patients. Further research is warranted to elucidate the mechanisms behind these associations and to validate these results in different populations.

T-Cell Response and Antibody Production Induced by the COVID-19 Booster Vaccine in Japanese Chronic Kidney Disease Patients Treated with Hemodialysis

Humoral and cellular responses are critical in understanding immune responses to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination. Here, we evaluated these responses in hemodialysis (HD) patients after the booster vaccination. SARS-CoV-2 immunoglobulin (IgG) levels, neutralizing antibody titers, and the T-SPOT®.COVID test (T-SPOT) were measured prior to, three weeks after, and three months after the booster administration. The HD group had significantly higher SARS-CoV-2 IgG levels and neutralizing antibody titers against the original strain at three weeks and three months after the booster vaccination compared to the control group, albeit the HD group had lower SARS-CoV-2 IgG levels and neutralizing antibody titers before the booster administration. Moreover, the HD group had significantly higher T-SPOT levels at all three time points compared to the control group. The HD group also had significantly higher local and systemic adverse reaction rates than the control group. By booster vaccination, HD patients could acquire more effective SARS-CoV-2-specific humoral and cellular immunity than the control group.

Intracellular inflammatory signalling cascades in human monocytic cells on challenge with phytohemagglutinin and 2,4,6-trinitrophenol

Phytohemagglutinin (PHA) is a plant mitogen that can agglutinate human leukocytes and erythrocytes. PHA is mainly derived from red kidney beans and can act as an exogenous pyrogen. When entering into the blood circulation, exogenous pyrogens principally interact with monocytes and macrophages and induce the release of pro-inflammatory cytokines. Monocytes and macrophages are the cells that fight against foreign invaders and acts as a primary line of immune defence. Similar to PHA, the chemical 2,4,6-trinitrophenol (TNP) also acts as an exogenous pyrogen. The study focused on the in vitro interaction of PHA and TNP with the human monocyte/macrophage cell model THP-1. The exposure and associated change in cellular morphology, organelle function, mechanism of cell death, inflammatory signalling and expression of inflammation-related genes were analyzed in different time periods. It was observed that PHA and TNP induce dose and time-dependent toxicity to monocytes/macrophages where the mechanism of cell death was different for PHA and TNP. Both PHA and TNP can evoke immune signalling with increased expression of inflammatory genes and associated activation of intracellular signalling cascades.

T-cell response to phytohemagglutinin in the interferon-γ release assay as a potential biomarker for the response to immune checkpoint inhibitors in patients with non-small cell lung cancer

Background

Immune checkpoint inhibitors are a standard treatment for advanced lung cancer, although it remains important to identify biomarkers that can accurately predict treatment response. Immune checkpoint inhibitors enhance the antitumor T‐cell response, and interferon‐γ plays an important role in this process. Therefore, this study evaluated whether the number of interferon‐γ‐releasing peripheral T cells after phytohemagglutinin stimulation in the interferon‐γ release assay might act as a biomarker for the response of non‐small cell lung cancer to immune checkpoint inhibitor treatment.

Methods

Data were retrospectively collected regarding 74 patients with non‐small cell lung cancer who had received immune checkpoint inhibitors. Pretreatment screening tests had been performed using the T‐SPOT.TB assay, which quantifies the number of interferon‐γ‐releasing T cells (as immunospots) in response to phytohemagglutinin and tuberculosis‐specific antigen stimulation. Clinical factors and the number of spots in the T‐SPOT fields were evaluated for associations with patient outcomes. The median number of spots was used to categorize patients as having high or low values, and the two groups were compared.

Results

Relative to patients with a low ratio, patients with a high ratio of phytohemagglutinin/tuberculosis‐specific antigen spots (i.e. more responsive T cells) had significantly better progression‐free survival after immune checkpoint inhibitor treatment. When we only considered patients with negative T‐SPOT results, a high number of phytohemagglutinin‐stimulated spots corresponded to significantly longer progression‐free survival.

Conclusion

The T‐SPOT.TB assay can be used to quantify the number of immunospots in response to antigen stimulation, which may predict the response to immune checkpoint inhibitors in patients with non‐small cell lung cancer.