E. Grebski et al., Effect of physical and chemical methods of homogenization on inflammatory mediators in sputum of asthma patients, CHEST, 119(5), 2001, pp. 1521-1525
Citations number
22
Categorie Soggetti
Cardiovascular & Respiratory Systems","Cardiovascular & Hematology Research
Background: Dithiothreitol (DTT), which is used for sputum homogenization,
may split S-S bonds of the bronchial mucins as well as other proteins and,
thus, may have a detrimental effect on inflammatory mediators that are pres
ent in sputum.
Objective: To evaluate the effects of physical sputum homogenization, using
ultrasonic and chemical (ie, DTT) means, on the concentrations of eosinoph
il cationic protein (ECP), eosinophil protein X (EPX), eosinophil peroxidas
e (EPO), and myeloperoxidase (MPO) in the sputum of patients with asthma.
Methods: The collection of sputum samples from nine patients with asthma wa
s induced by their inhaling a sterile 3% saline solution for 10 min from an
ultrasonic nebulizer. One half of the sputum sample was homogenized by ult
rasound, and the other half was liquefied by DTT. The supernatant of the ul
trasonically homogenized specimen was divided into the following three port
ions: (1) immediately frozen; (2) stored for 15 min at 37 degreesC; and (3)
additionally treated with DTT. The supernatant of the sputum sample that w
as Liquefied by DTT was divided into the following two portions: (1) immedi
ately frozen; and (2) additionally subjected to ultrasound. The concentrati
ons of ECP, EPO, EPX, and MPO in the sputum samples were measured using imm
unoassays.
Results: Statistically significant differences were found between the ultra
sonically homogenized specimens that had been either processed immediately
or stored at 37 degreesC and those treated by DTT, but only for concentrati
ons of EPO and MPO (p < 0.005). No effect of temperature on the mediators i
n the ultrasonically homogenized specimens could be detected. Ultrasonic ho
mogenization had no influence on the mediators in the samples liquefied by
DTT. However, the addition of DTT to the cell-free supernatant of the ultra
sonically homogenized sputum samples caused a significant fall in measured
EPO and MPO concentrations.
Conclusions: The sputum processing by DTT caused a statistically significan
t fall in EPO and MPO concentrations but did not significantly influence th
e measured concentrations of ECP and EPX.