Retrospective analysis of skin bacterial colonization in patients with cutaneous T cell lymphoma from a tertiary hospital in China

Summary: Abstract Body: Primary cutaneous T-cell lymphoma (CTCL) is characterized by the clonal proliferation of neoplastic T lymphocytes within the skin. This study aimed to investigate the risk factors for cutaneous bacterial colonization and to evaluate their impact, along with the administration of systemic antibiotics, on the long-term prognosis of a cohort of Chinese patients diagnosed with CTCL. A total of 113 CTCL patients were included in this research, with a median age at diagnosis of 49 years (interquartile range, 38-58); among them, 49 were male, representing 43.3% of the cohort. The patient demographic comprised 101 individuals with mycosis fungoides (89.4%) and 12 with Sézary syndrome (10.6%). Within this cohort, 85 patients (75.2%) tested positive for bacterial skin colonization, with Staphylococcus aureus (SA) identified in 68 patients (60.2%), and methicillin-resistant Staphylococcus aureus (MRSA) detected in 13 patients (11.5%). Ulcerated lesions significantly increased the likelihood of a positive result in bacterial skin cultures, with an odds ratio of 16.95 (95% CI, 3.95-97.23) according to multivariate analysis. Univariate analysis indicated that advanced stages, the presence of tumors, erythroderma, lymphopenia, and eosinophilia were associated with an elevated risk of positive skin cultures. However, skin bacterial colonization and antibiotic intervention were not correlated with overall survival (OS)—the weighted hazard ratio for the Bacteria+ antibiotics- group was 0.56 (95% CI, 0.10-3.26) and for the Bacteria+ antibiotics+ group was 0.52 (95% CI, 0.07-3.77) after applying inverse probability of treatment weighting. This retrospective study provides data on the prevalence of bacterial skin colonization in Asian CTCL patients, demonstrating a predominance of SA colonization. The findings did not reveal a significant correlation between bacterial skin colonization and worse prognosis for Asian CTCL patients, nor did the administration of systemic antibiotics improve long-term outcomes. Huizhong Wang¹, Yang Wang¹, Jingru Sun¹ 1. Dermatology and Venerology, Peking University First Hospital, Beijing, Beijing, China. Clinical Research: Epidemiology and Observational Research