Abstract:

Objective: To analyze the characteristics of immune function and nutritional status and their relationship with pulmonary tuberculosis (PTB) patients combined with extrapulmonary tuberculosis (EPTB). Methods: In this retrospective study, 226 PTB-only patients and 226 patients combined with EPTB (PTB+EPTB group) from Fuzhou Tuberculosis Prevention and Control Hospital in Fujian Province and the Department of Tuberculosis, Beijing Chest Hospital, Capital Medical University from March 2019 and October 2023 were enrolled according to inclusion criteria. The differences in immune function indicators (CD3⁺, CD4⁺, CD8⁺, and CD45⁺ T cells) and nutritional status indicators (body mass index (BMI), serum albumin, hemoglobin) were compared between the two groups, and their correlation was analyzed. The relationship between immunonutritional status and the extent of disease dissemination (number of extrapulmonary infection sites) was also evaluated. Results: The PTB+EPTB group demonstrated significantly lower BMI (19.35 (17.65, 21.59) kg/m² vs. 20.30 (19.02, 22.05) kg/m²), serum albumin (35.70 (31.70, 38.98) g/L vs. 41.05 (38.50, 44.10) g/L), and hemoglobin levels (117.00 (102.00, 128.00) g/L vs. 128.00 (119.00, 139.00) g/L) compared with the PTB-only group (W=30593.500, 40415.000, 34752.500, respectively; all P<0.001). The levels of immune function indicators (CD3⁺, CD4⁺, CD8⁺, CD45⁺ T cells) in the PTB+EPTB group were significantly lower than those in the PTB-only group. The CD4⁺ T cell counts with the smallest change showed statistical significance (303.50 (172.25, 459.75) cells/μl vs. 430.50 (306.25, 572.75) cells/μl; W=34000.000, P<0.001). The serum albumin levels in patients with a single extrapulmonary infection site was significantly higher than that in patients with multiple infection sites (36.20 (32.50, 39.20) g/L vs. 34.40 (29.75, 37.45) g/L; W=6430.500, P=0.014). Correlation analysis revealed moderate correlations between albumin and hemoglobin and CD3⁺ T cells (r=0.420 and r=0.322, respectively) and CD4⁺ T cells (r=0.412 and r=0.336, respectively) in the PTB+EPTB group, whereas these correlations were weak in the PTB-only group (r=0.192 and r=0.177; r=0.100 and r=0.102, respectively). Conclusion: Compared to PTB-only patients, PTB+EPTB patients demonstrate more severe cellular immuno-suppression and malnutrition, a stronger correlation between immune function and nutritional status, and worse nutritional status in those with multiple infection sites. It is recommended to routinely assess immunonutritional status, emphasized the role of nutritional support therapy, and dynamically monitor PTB-only patients to reduce the risk of EPTB development.

Key words: Tuberculosis, pulmonary, Extrapulmonary tuberculosis, T lymphocytes, Nutritional status