<![CDATA[Diabetes mellitus (DM) is associated with immune dysfunction and increased susceptibility to pulmonary tuberculosis (TB). Procalcitonin (PCT) is widely used as a biomarker of bacterial infection, but its concentrations in patients with DM and pulmonary TB remain insufficiently characterized. To compare serum PCT concentrations between patients with DM with and without active pulmonary TB. This analytical cross-sectional study included 50 patients with DM recruited from two primary healthcare centers in Jambi, Indonesia, from March to June 2025. Participants comprised 34 patients without pulmonary TB and 16 with active pulmonary TB. Serum PCT was measured using fluorescence immunoassay. Non-normally distributed PCT concentrations were summarized using the median and interquartile range (IQR) and compared using the Mann–Whitney U test.PCT concentrations were within the normal reference range (<0.05 ng/mL) in 33/34 (97.1%) patients without pulmonary TB and 13/16 (81.3%) patients with active pulmonary TB. Because measurements at or below 0.05 ng/mL were retained as thresholded values, the median (IQR) was ≤0.05 (≤0.05–≤0.05) ng/mL in both groups. No statistically significant between-group difference was identified (U = 230.000, Z = −1.857, p = 0.063). Serum PCT concentrations did not differ significantly between patients with DM with and without active pulmonary TB. Larger studies with standardized TB confirmation, assessment of treatment status and relevant confounders, and diagnostic-accuracy analyses are warranted.]]>
