Clinical Characteristics of Corynebacterium ulcerans Infection, Japan.

Corynebacterium ulcerans is a closely related bacterium to the diphtheria bacterium C. diphtheriae, and some C. ulcerans strains produce toxins that are similar to diphtheria toxin. C. ulcerans is widely distributed in the environment and is considered one of the most harmful pathogens to livestock and wildlife. Infection with C. ulcerans can cause respiratory or nonrespiratory symptoms in patients. Recently, the microorganism has been increasingly recognized as an emerging zoonotic agent of diphtheria-like illness in Japan. To clarify the overall clinical characteristics, treatment-related factors, and outcomes of C. ulcerans infection, we analyzed 34 cases of C. ulcerans that occurred in Japan during 2001-2020. During 2010-2020, the incidence rate of C. ulcerans infection increased markedly, and the overall mortality rate was 5.9%. It is recommended that adults be vaccinated with diphtheria toxoid vaccine to prevent the spread of this infection.

Plasma matrix metalloproteinase 7, CC-chemokine ligand 18, and periostin as markers for pulmonary sarcoidosis.

BACKGROUND: Some patients with sarcoidosis experience worsening of pulmonary lesions. However, no biomarker has been identified that reflects pulmonary disease status in sarcoidosis. We investigated the usefulness of potential markers of pulmonary fibrosis in patients with sarcoidosis. METHODS: Plasma matrix metalloproteinase 7 (MMP-7), CC-chemokine ligand 18 (CCL-18), and periostin levels were evaluated in 60 patients with sarcoidosis and 30 healthy controls; bronchoalveolar lavage fluid levels were analyzed in 22 patients with sarcoidosis. To determine the usefulness of these markers, we explored potential correlations between these markers and sarcoidosis clinical characteristics. RESULTS: Plasma MMP-7, CCL-18, and periostin concentrations were significantly higher in patients with sarcoidosis than those in healthy controls. MMP-7 concentrations in plasma and bronchoalveolar lavage fluid were higher in patients with sarcoidosis with parenchymal infiltration than in those without lung lesions. Moreover, MMP-7 concentration was negatively correlated with pulmonary function. CONCLUSION: Among these novel biomarkers, MMP-7 most precisely reflected pulmonary sarcoidosis disease status and thus, might be useful for diagnosing and evaluating sarcoidosis, particularly in patients with pulmonary parenchymal lesions.

Activation of mucosal-associated invariant T cells in the lungs of sarcoidosis patients.

Although the pathogenesis of sarcoidosis is not fully understood, immunological characterization has elucidated highly polarized expression of the type 1 T helper cell response. Mucosal-associated invariant T (MAIT) cells are innate T cells that recognize bacterial riboflavin and rapidly produce cytokines such as interferon γ and tumor necrosis factor α. We prospectively evaluated the proportion of MAIT cells and the expression levels of cell surface markers in peripheral blood from 40 sarcoidosis patients and 28 healthy controls. MAIT cells in bronchoalveolar lavage fluid (BALF) were also examined in 12 sarcoidosis patients. In peripheral blood, the proportion of MAIT cells was lower (P = 0.0002), but the expression levels of CD69 and programmed death 1 on MAIT cells were higher in sarcoidosis patients than in healthy controls. Moreover, CD69 expression levels were significantly correlated with clinical biomarkers. Sarcoidosis patients with parenchymal infiltration in the lungs showed a significantly higher proportion and number of MAIT cells in BALF compared to patients without parenchymal infiltration. CD69 expression levels on MAIT cells in BALF were higher than levels in peripheral blood. The activation status of MAIT cells might reflect the disease activity of sarcoidosis. Therefore, it is a potential target for sarcoidosis treatment.

Development of Propionibacterium acnes-associated Sarcoidosis During Etanercept Therapy.

Although numerous recent studies have reported the development of sarcoidosis in patients treated with tumor necrosis factor alpha (TNF-α) inhibitors, it is unclear whether the pathogenesis of drug-induced sarcoidosis is identical to that of spontaneous sarcoidosis. We herein present the case of a patient who developed sarcoidosis 6 months after the introduction of etanercept as treatment for rheumatoid arthritis. Typical clinical symptoms with noncaseating epithelioid granulomas detected in a mediastinal lymph node specimen were consistent with the diagnosis of sarcoidosis. Immunohistochemistry revealed Propionibacterium acnes in the noncaseating granulomas. The present findings suggest that Propionibacterium acnes is a cause of sarcoidosis, even when the disease is induced by TNF-α inhibitors.

Fatal Invasive Pulmonary Aspergillosis Associated with Nonspecific Interstitial Pneumonia: An Autopsy Case Report.

Invasive pulmonary aspergillosis (IPA) usually occurs in patients with severe immunodeficiencies involving neutropenia. Underlying lung disease is a well-known risk factor of IPA; however, interstitial lung disease has not been recognized as a risk factor of IPA. We herein report a patient with fibrotic nonspecific interstitial pneumonia who experienced IPA without neutropenia. His IPA was fatal and showed unusually slow disease progression over one month. The computed tomography findings showed only nonspecific consolidation and no typical lesions suggestive of IPA. Finally, the autoptic findings revealed numerous Aspergillus fungi, neutrophilic pulmonary necrosis, and vessels invaded by Aspergillus fungi.

Severe Pneumonia Caused by Toxigenic Corynebacterium ulcerans Infection, Japan.

Corynebacterium ulcerans infection was recently recognized as a zoonosis. We present 2 cases of severe pneumonia complicated by diffuse pseudomembrane formation on the bronchus caused by C. ulcerans-producing diphtheria toxin. Our purpose is to alert medical professionals to the virulence of Corynebacterium species other than C. diphtheriae.