Dysregulation of circulating T follicular helper cell subsets and their potential role in the pathogenesis of syphilis.

Introduction: The role of the host immune response could be critical in the development of Treponema pallidum (Tp) infection in individuals with latent syphilis. This study aims to investigate the alterations in T follicular helper T (Tfh) cell balance among patients with secondary syphilis and latent syphilis. Methods: 30 healthy controls (HCs), 24 secondary syphilis patients and 41 latent syphilis patients were enrolled. The percentages of total Tfh, ICOS+ Tfh, PD-1+ Tfh, resting Tfh, effector Tfh, naïve Tfh, effector memory Tfh, central memory Tfh,Tfh1, Tfh2, and Tfh17 cells in the peripheral blood were all determined by flow cytometry. Results: The percentage of total Tfh cells was significantly higher in secondary syphilis patients compared to HCs across various subsets, including ICOS+ Tfh, PD-1+ Tfh, resting Tfh, effector Tfh, naïve Tfh, effector memory Tfh, central memory Tfh, Tfh1, Tfh2, and Tfh17 cells. However, only the percentages of ICOS+ Tfh and effector memory Tfh cells showed significant increases in secondary syphilis patients and decreases in latent syphilis patients. Furthermore, the PD-1+ Tfh cells, central memory Tfh cells, and Tfh2 cells showed significant increases in latent syphilis patients, whereas naïve Tfh cells and Tfh1 cells exhibited significant decreases in secondary syphilis patients when compared to the HCs. However, no significant change was found in resting Tfh and effector Tfh in HCs and secondary syphilis patients or latent syphilis patients. Discussion: Dysregulated ICOS+ Tfh or effector memory Tfh cells may play an important role in immune evasion in latent syphilis patients.

Dysregulated Tfr/Tfh2 cells in patients with polycystic ovarian syndrome.

Recent research revealed the pathogenic role of B cells in the pathogenesis of polycystic ovary syndrome (PCOS), while the Tfh cell plays a critical role in the B cell mediated autoantibody production and humoral immunity, but had not been investigated in PCOS patients. The frequency of Tfh and B cell subsets (Tfh1, Tfh2, Tfh17, naïve B, memory B, and plasma cells) in the peripheral blood of 21 PCOS patients and 15 healthy controls were investigated by flow cytometry. And the levels of follicle-stimulating hormone, luteinizing hormone, testosterone, prolactin and estradiol progesterone were measured by using the immunoluminescence method. Also, the associations between these hormone levels and Tfh cell subsets or B cell subsets were analyzed. No significant difference was observed in total Tfh cells between 21 PCOS patients and 15 healthy controls (p > 0.05). But the percentages of Tfh2 and plasma cells were significantly higher in 21 PCOS patients compared to 15 healthy controls (p < 0.05). In contrast, the frequency of Tfr cells and Tfr/Tfh2 ratio were significantly lower than healthy controls (p < 0.01). Importantly, among these cells, only the percentage of Tfh2 cells was positively correlated with the levels of testosterone (r = 0.513, p = 0.018). And the percentage of Tfr cells and Tfr/Tfh2 ratio were also positively correlated with the levels of testosterone (r = 0.567, p = 0.007; r = 0.434, p = 0.05) and prolactin (r = 0.511, p = 0.018; r = 0.490, p = 0.024). These new findings provide unique insights into dysregulated Tfh/Tfr cells in mediating the immunopathogenesis of PCOS patients.

A primary amoebic meningoencephalitis case associated with swimming in seawater.

This case report describes a 62-year-old male fisherman who presented with persistent vomiting, headache, and behavior changes. Despite initial antibiotic and corticosteroid treatment, his condition worsened, leading to coma and subsequent death. Macro-genome sequencing of cerebrospinal fluid (CSF) revealed the presence of Naegleria fowleri infection, which had been missed during initial laboratory tests. The patient's exposure history included sea-swimming near Zhoushan Island.