Immunosenescence is a process of immune dysfunction that occurs along with aging. Many studies have focused on the changes of different lymphocyte subsets in diseases and immune aging. However, the fluctuation in the number and phenotype of lymphocyte subset caused by aging have not been comprehensively analyzed, especially the effects of new indicators such as PD-1 and Ki67 in peripheral blood have been rarely reported. We further investigated the humoral and cellular immune parameters of 150 healthy donors over 18 years old. Age was associated with decreased CD4+CD45RA+CD62L+ T cells, decreased CD4+CD45RA+CD31+ T cells, and increased memory CD4+ or CD8+ T cells, dominated by male CD8+ T cells. The loss of CD28 expression on T cells and the transverse trend of activated CD38 and HLA-DR were also related to the increased age. In addition, CD8+ T cells in men were more prominent in activation indicators, and the difference between the old and young groups was obvious. CD4+CD25+CD127- T cells percentage tended to decrease with age and did not differ significantly between gender. Interestingly, we found that age was positively associated with PD-1+ T cells and showed significant age-related variability in men. Similarly, the percentage of CD8+ki-67+ also showed an increasing trend, with significant differences between the young group and other elderly groups in males. Our findings can provide immunological clues for future aging research, offering new insights for clinical monitoring and prevention of certain diseases.

To investigate the clinical features and potential risk factors of active tuberculosis (ATB) in Behçet’s disease (BD), we conducted a case-control study on hospitalized BD patients in our institute from 2010 to 2019. BD patients with ATB were enrolled as the case group. The control group was selected by random number sampling from the remaining BD patients, including those with latent tuberculosis infection, previous tuberculosis, or without tuberculosis. Finally, we reviewed 386 BD patients and identified 21 (5.4%) ATB cases, including four (19.0%) microbiologically confirmed and 17 (81.0%) clinically diagnosed. We found that BD patients with ATB were more prone to have systemic symptoms (fever, night sweating, and unexplained weight loss) and/or symptoms related to the infection site. Multivariate logistic regression analysis revealed that erythrocyte sedimentation rate ESR > 60 mm/h ( OR = 13.710 , 95% CI (1.101, 170.702)), increased IgG ( OR = 1.226 , 95% CI (1.001, 1.502)), and positive T-SPOT.TB ( OR = 7.793 , 95% CI (1.312, 48.464), for 24-200 SFC/106PBMC; OR = 17.705 95% CI (2.503, 125.260), for >200 SFC/106PBMC) were potential risk factors for ATB in BD patients. Our study suggested that when BD patients have systemic symptoms with significantly elevated TB-SPOT, the diagnosis of ATB should be considered.

Rationale: Amebic colitis has been less prevalent in recent times in China, and the similarity of its symptoms to those of inflammatory bowel disease (IBD) results in the difficulty of early identification and diagnosis. Patient concerns: A 31-year-old male who exhibited intermittent diarrhea and hematochezia was highly suspected as IBD initially. Despite the partial relief of symptoms following the administration of mesalamine, the endoscopic ulcers remained largely unchanged. Diagnoses: Two years after the onset of mesalamine therapy, amebic cysts were detected in stool microscopy and trophozoites were found on the surface of cecal ulcers. The patient was then diagnosed with amebic colitis. Interventions: After 2 rounds of standardized metronidazole treatment, amebic colitis remained refractory until diloxanide was administered. Outcomes: The patient remained asymptomatic, and the mucosa of colon was normal during the annual follow-up. Lessons: Individuals newly diagnosed with IBD should undergo essential screening for amebiasis. And the use of steroids should be taken with caution, especially in cases where the effect of mesalamine is limited. For symptomatic intestinal amebiasis, even after the administration of tissue amebicides, the continued use of luminal amebicides is necessary to prevent recurrence.

Background: Fever of unknown origin (FUO) is clinically challenging in the setting of myelodysplastic syndrome (MDS). This study aimed to describe the clinical and laboratory features of patients with MDS and FUO and to explore factors associated with in-hospital fever resolution. Methods: We conducted a retrospective, single-center observational study of hospitalized patients with MDS and FUO at Peking Union Medical College Hospital, China, between January 2013 and December 2022. Patients were categorized into treatment-responsive and treatment-unresponsive groups based on fever outcomes after treatment. Demographic, clinical and laboratory features were collected and compared between the two groups. Results: A total of 98 patients were screened and 89 were included in the study. In approximately 80% of patients, FUO presented as the initial manifestation of MDS. Over half of the patients had high or very high risk per the revised International Prognostic Scoring System (IPSS-R), and complex karyotypes were observed in 25.8% of patients. MDS subtype distribution differed significantly between the groups (p = 0.027). Lower-blast MDS (MDS-LB) was more common in the treatment-responsive group (70.3% vs. 48.1%), whereas increased-blast MDS (MDS-IB) was more frequent in the treatment-unresponsive group (16.2% vs. 42.3%). Mucocutaneous lesions were more frequent among treatment-responsive patients (54.1% vs. 21.2%; p = 0.002). A higher percentage of CD8+CD38+ T-cells was associated with favorable treatment response (66.7 [60.4,80.6] vs. 47.4 [38.5,57.7]; p = 0.003). In addition, use of glucocorticoids and immunosuppressants was significantly associated with fever resolution (p = 0.004 and p = 0.043, respectively). Conclusions: In this selected cohort, MDS patients with FUO were predominantly at high risk and carried unfavorable prognostic factors. Mucocutaneous presentation and elevated CD8+CD38+ T-cell proportions were associated with in-hospital fever improvement. The association between anti-inflammatory treatment and fever resolution suggests a possible immune-mediated contribution to fever in these patients. As no non-MDS FUO comparison group was included and long-term outcomes were not available, these findings should be regarded as descriptive and hypothesis-generating.

Background: Fever of unknown origin (FUO) remains a major diagnostic challenge due to its heterogeneous etiologies and nonspecific clinical manifestations. Although metagenomic next-generation sequencing (mNGS) represents a promising diagnostic tool, its clinical utility in adult patients with FUO remains incompletely characterized. Methods: In this study, we retrospectively analyzed adult FUO patients who underwent mNGS testing at Peking Union Medical College Hospital between March 2022 and April 2024. Clinically meaningful diagnostic contribution was determined according to the final clinical diagnosis following multidisciplinary adjudication. Diagnostic performance, pathogen spectrum, therapeutic impact, specimen type, and predictors of clinically meaningful mNGS results were evaluated. Results: A total of 127 FUO patients were included in the study. Infectious diseases accounted for 53.5% of final diagnoses, followed by noninfectious inflammatory diseases (11.0%), malignancies (10.2%), and undiagnosed conditions (19.7%). mNGS made a clinically meaningful diagnostic contribution in 31.5% (40/127) of patients, despite an overall positivity rate of 56.7% (72/127), and showed a higher sensitivity than conventional culture for infectious etiologies (69.1% vs. 16.9%), though with a lower specificity (57.6% vs. 96.0%). Diagnostic contribution varied significantly by specimen type, with drainage fluid/abscess samples showing the highest diagnostic yield (90.9%). Lower white blood cell count was independently associated with clinically meaningful mNGS results (OR 0.87, 95% CI 0.77–0.98). Conclusions: mNGS provides clinically meaningful diagnostic value in adult patients with FUO, particularly for identifying occult infectious etiologies. Lesion-directed sampling, whenever feasible, and careful interpretation of sequencing results in the clinical context are essential to maximize the diagnostic utility of this approach. A lower white blood cell count was independently associated with clinically meaningful mNGS results, although this finding requires validation in larger prospective studies.