Dermoscopy in Mycobacterium marinum infection and its correlation with clinical and histopathological features: a prospective observational study.

BACKGROUND: Mycobacterium marinum is a nontuberculous mycobacterium and a conditional pathogen to humans, which can be inoculated directly and cause chronic skin granulomas. Dermoscopy has been applied to other granulomatous skin diseases, but not to M. marinum infection. AIM: To explore the dermoscopic features of M. marinum infection, and its correlation with clinical and histopathological features. METHODS: In total, 27 lesions from 27 patients (19 women, 8 men, age range 28-71 years) diagnosed with M. marinum infection were identified by clinical examination, histopathological results, PCR sequencing and mycobacterial culture in the dermatology outpatient department of our hospital from March 2020 to February 2022. The dermoscopy images and pathological characteristics were analysed. RESULTS: Lesions were located on the hands, forearms and upper arms. The following dermoscopic features were observed: yellowish-orange structureless areas (85·2%), white striped structures (59·3%), follicular plugs (29·6%), yellowish oval clods (14·8%) and reddish or pinkish areas (14·8%). Vessel structures were visible in all cases: long hairpin vessels (81·5%), corkscrew vessels (25·9%), comma-shaped vessels (22·2%) and linear vessels (22·2%). CONCLUSION: Yellowish-orange structureless areas, white striped structures and long hairpin vessels are the most common dermoscopic features of M. marinum infection. Thus, dermoscopy could be used as a noninvasive auxiliary diagnostic method to provide a diagnostic basis for this disease.

The role of the 47-kDa membrane lipoprotein of Treponema pallidum in promoting maturation of peripheral blood monocyte-derived dendritic cells without enhancing C-C chemokine receptor type 7-mediated dendritic cell migration.

BACKGROUND: The 47-kDa membrane lipoprotein (Tp47) is the most representative membrane protein of Treponema pallidum (T. pallidum). Dendritic cells (DCs) are the most potent professional antigen-presenting cells (APCs) that connect innate and acquired immunity. The regulatory role of Tp47 on DCs remains unclear. OBJECTIVES: To evaluate the effects of Tp47 on DC maturation and migration, and research the changes of the main chemokine C-C chemokine receptor type 7 (CCR7) involved in DC migration. MATERIAL AND METHODS: A transwell assay was applied to assess the migration of DCs. Cytokines (interleukin (IL)-6, IL-10, IL-12, and tumor necrosis factor alpha (TNF-α)) in the supernatants were measured using enzyme-linked immunosorbent assay (ELISA), and the expression of cell surface markers (CD80, CD86, CD40, and human leukocyte antigen (HLA)-DR) and CCR7 was assessed using flow cytometry. The expression of CCR7 in DCs was analyzed using quantitative real-time polymerase chain reaction (qRT-PCR). RESULTS: The Tp47 promoted DC phenotypic maturation, such as increased CD40, CD80, CD86, and HLA-DR expression, as well as DC functional maturation, thus stimulating DCs to secrete inflammatory cytokines, including IL-6, IL-10, IL-12, and TNF-α. At the same time, Tp47 did not enhance DC migration and did not increase the expression of CCR7. CONCLUSIONS: The Tp47 promoted the maturation of DCs while not enhancing CCR7-mediated DC migration ability. This may be one of the mechanisms by which T. pallidum escapes host immune clearance.

Decreased blood natural killer cells in serofast patients: a systematic review and meta-analysis.

Currently, increasing attention has been paid to the association of the serofast status with natural killer (NK) cells. Remarkable diversity among the results of different studies has been observed. We conducted this meta-analysis to evaluate the variation of the proportion of NK cells in serofast patients compared with that of healthy controls and cured patients. Through the designed retrieval methods, 631 serofast patients, 562 healthy controls and 160 patients whose serology turned negative following treatment were derived from 16 publications for further analysis. The established items were used for the standard selection and quality assessment. The Stata software was used for meta-analysis. The final results indicated that serofast patients exhibited a dramatic decrease in the number of NK cells in the peripheral blood compared with that noted in healthy control subjects [standardized mean difference (SMD) = -0.63, 95% CI (-1.08, -0.17), p = 0.007]. The proportion of NK cells was significantly lower in serofast patients than that noted in cured patients [SMD = -0.25, 95% CI (-0.48, -0.02), p = 0.033] and no significant difference was noted in the proportion of NK cells between cured patients and healthy controls [SMD = -0.39, 95% CI (-0.93, 0.14), p = 0.148]. The present meta-analysis indicated that the proportion of NK cells in the peripheral blood was significantly lower in serofast patients compared with that of the healthy controls and cured patients, indicating that the reduction in the number of NK cells may be closely associated with the syphilis serofast status.