Background and purpose: Identifying the types of immune cells in patients with tuberculosis (TB) including single-core and multi-core is of great benefit in control and treatment of these patients. The aim of this research was to compare differential cell count in Bronchoalveolar lavage (BAL) samples in patients with and without TB. 

Materials and methods: In this descriptive-analytical study 100 patients were selected using purposive sampling. They were divided into two groups of positive and negative smear (n= 50 per group). BAL samples were divided into two sections; one was used for culture and the other was fixed. Four smear slides were prepared from the sediments that were stained by Papanicolaou, Giemsa, hematoxylin-eosin (H&E), and Ziehl-Neelsen. Single-core and multi-core cell differential count was done and the association between the presence of TB bacteria and differential cell counts were studied in patients with TB. Also, the sensitivity, specificity, positive and negative predictive values for diagnosis of TB were investigated.

Results: Pearson correlation coefficients indicated that by increase in number of TB bacteria, the rate of neutrophil cells increased significantly (r=0.526, P<0.001), but the lymphocytes and eosinophils decreased significantly (r=0.458, P=0.003 and r=0.363, P=0.021, respectively) and no significant change occurred in plasma cells (r=0.205, P=0.201)

Conclusion: The findings showed that neutrophils is the predominant cells in (BAL) samples of TB patients and increasing levels were detected when the severity of bacteria increased.