Neutrophils are often seen first at sites of granulomatous inflammation such as in
tuberculous exudates. There was a report which supported the hypothesis that
neutrophils might initiate inflammatory responses to tubercle bacilli by releasing
chemotaxins which attracted monocytes. Neutrophil chemotaxis is inhibited by
Mycobacterium tuberculosis, which seems to be a kind of microbial defenses against
phagocytes.
We measured neutrophil chemotaxis activity in 33 active pulmonary tuberculosis
patients and 19 normal healthy controls by the modified Boyden chamber method with
cellulose nitrate membrane micropore filter and formyl-methionyl-leucyl-phenylalanine
(f-Met-Leu-Phe) as a chemoattractant. The neutrophil chemotaxis activity was
evaluated by the leading front method; the neutrophil chemotaxis index (NCI)
represented the measured distance of active migration divided by the one of random
migration.
The mean NCI (mean±SD) was 1.45±0.221 in active pulmonary tuberculosis (n=33),
which was significantly decreased than that of control (n=19) 1.78±0.446 (p<0.005). The
mean NCl was 1.52±0.226, 1.42±0.210, and 1.28±0.181 in the minimal (n=15),
moderately (n=15) and far advanced (n=3) pulmonary tuberculosis patients. The mean
NCI was 1.43±0.233, 1.45±0.171, and 1.48±0.274 in the sputum AFB bacilli
smear/culture positive (n=13), smear negative/culture positive (n=11), and smear/culture
negative (n=9) patients.
In conclusion we observed that neutrophil chemotaxis activity was decreased in the
active pulmonary tuberculosis patients, and the tendoncy of the more impaired neutrophil
chemotaxis in the more extensive disease patients.
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