Yoshihiro Honda

Differentiation of Monocytes to Macrophages Switches the Mycobacterium tuberculosis Effect on HIV-1 Replication from Stimulation to Inhibition: Modulation of Interferon Response and CCAAT/Enhancer Binding Protein β Expression

HIV-1 replication is inhibited in uninflamed lung macrophages and is stimulated during tuberculosis. Attempts to recapitulate activation of HIV-1 replication in primary monocytes and macrophages ex vivo and in the untreated and PMA-treated THP-1 cell line model in vitro have produced opposite results depending on the state of differentiation of the cells. After infection with Mycobacterium tuberculosis, monocytes enhanced HIV-1 replication and produced a stimulatory 37-kDa CCAAT/enhancer binding protein β (C/EBPβ) transcription factor, whereas macrophages suppressed HIV-1 replication and produced an inhibitory 16-kDa C/EBPβ transcription factor. IFN-β induced inhibitory 16-kDa C/EBPβ in macrophages, but had no effect on C/EBPβ expression in monocytes. Macrophages, but not monocytes, were able to activate IFN-stimulated gene factor-3 (ISGF-3), a transcription factor composed of STAT-1, STAT-2, and IFN regulatory factor (IRF)-9, after infection with M. tuberculosis or stimulation with type I IFN. Macrophages expressed IRF-9 DNA-binding activity, but monocytes did not, and addition of the IRF-9 component reconstituted ISGF-3 in extracts of IFN-treated monocytes. Modulation of IFN responsiveness upon differentiation occurred at least in part through a post-transcriptionally regulated increase in IRF-9 expression. Both monocytes and macrophages maintained IFN responsiveness, activating STAT-1 homodimer formation and transcription of the STAT-1 gene after IFN stimulation. In addition, both monocytes and macrophages were able to activate NF-κB upon infection with M. tuberculosis. These results show that induction of ISGF-3, expression of the inhibitory 16-kDa C/EBPβ, and suppression of HIV-1 replication via a transcriptional mechanism are macrophage-specific responses to infection with M. tuberculosis.

Phase I study of daily S-1 combined with weekly irinotecan in patients with advanced non-small cell lung cancer

BackgroundS-1 is a novel oral fluorouracil prodrug active against non-small cell lung cancer (NSCLC). To determine the feasibility of S-1 combined with weekly irinotecan for patients with advanced NSCLC, we performed a phase I study to determine the maximum tolerated dose (MTD) and the recommended dose (RD) of irinotecan.MethodsPatients with advanced NSCLC received S-1 (80 mg/m2) on days 1–14 and irinotecan (50–80 mg/m2) on days 1, 8, and 15 of each 28-day cycle. Three to six patients were treated with each dose of irinotecan, with the MTD defined as the dose at which dose-limiting toxicity (DLT) appeared in 33% of patients.ResultsAt doses of 50–70 mg/m2, no patients experienced any DLT, whereas, at a dose of 80 mg/m2, two of four patients experienced DLTs. Two patients experienced grade 3 toxicities — neutropenia and diarrhea.ConclusionThe MTD of weekly irinotecan was 80 mg/m2, making its RD for phase II trials 70 mg/m2.

Association of Immune‐Related Adverse Events with Clinical Benefit in Patients with Advanced Non‐Small‐Cell Lung Cancer Treated with Nivolumab

BACKGROUND Immune-related adverse events (irAEs) are frequently observed with nivolumab monotherapy. This study aimed to evaluate whether the development of irAEs correlates with treatment response in advanced non-small-cell lung cancer (NSCLC). PATIENTS AND METHODS We conducted a retrospective study of patients who received nivolumab monotherapy at Sendai Kousei Hospital (n = 70). The patients were categorized into two groups based on the incidence of irAEs: those with irAEs (irAE group) or those without (non-irAE group). Treatment efficacy was evaluated in each group. The patients were further categorized into responders and nonresponders, and predictive factors of treatment response were determined. RESULTS The objective response rate was 57% in the irAE group versus 12% in the non-irAE group. Median progression-free survival was 12.0 months in the irAE versus 3.6 months in the non-irAE group. The incidence of both irAEs and pre-existing antithyroid antibody was significantly higher in responders than in nonresponders. Multivariate analysis identified incidence of irAEs and pre-existing antithyroid antibody as an independent predictor of treatment response. CONCLUSION Objective response rate and progression-free survival were significantly better in the irAE than in the non-irAE group in patients with advanced NSCLC treated with nivolumab monotherapy. The development of irAEs was associated with clinical efficacy, and the presence of pre-existing antithyroid antibody might be correlated with treatment response to nivolumab monotherapy. IMPLICATIONS FOR PRACTICE Immune-related adverse events (irAEs) are frequently observed with nivolumab monotherapy. This study evaluted whether the development of irAEs correlates with treatment response in advanced non-small-cell lung cancer. Results showed that the objective response rate and progression-free survival were significantly better in the patients who developed irAEs than in the patients who did not develop irAEs, and the incidence of irAEs and positivity for antithyroid antibody at pretreatment were independent predictors of treatment response of nivolumab monotherapy. Therefore, the development of irAEs predicts clinical benefit and suggests that cautious management of irAEs can lead to achieving maximum clinical benefit from nivolumab monotherapy.

Observational study of chemotherapy-induced Clostridium difficile infection in patients with lung cancer

BackgroundDiarrhea post-antibiotic use is primarily attributed to Clostridium difficile infection (CDI)-induced mucosal lesions, and evidence of CDI in patients undergoing chemotherapy without prior antibiotic treatment is also increasing. However, few studies have investigated the relationship between chemotherapy use and diarrhea. This study aimed to determine whether the incidence of CDI increased in patients with lung cancer undergoing chemotherapy even without prior antibiotic treatment.MethodsWe conducted a retrospective study and investigated the presence of Clostridium difficile (C. difficile) and its toxins in patients who experience diarrhea during chemotherapy. If grade 2 or higher diarrhea was noted, a stool culture was performed to detect anaerobic organisms and C. difficile toxins A and B.ResultsA total of 345 consecutive patients (492 in terms of chemotherapy regimens) were enrolled in the study. Grade 2 or higher diarrhea was observed in patients using 36 (7.3%) of these regimens, among which CDI without prior antibiotic exposure was confirmed in patients using 8 regimens (22.2%).ConclusionsCDI may remain undetected in patients undergoing chemotherapy even in those who had not received antibiotic treatment previously, unless due attention is paid to its possibility. Testing for C. difficile toxins is highly recommended to expedite timely treatment for diarrhea in such patients. Further studies are needed to clarify the relationship between chemotherapy drug use and CDI to facilitate prevention.