Gael Tavernier1,2, Stephen Fowler2, Dorothy Ryan1,2 and Robert Niven1,2
West Lung Centre, University Hospital of South Manchester, Manchester, United Kingdom, 2Institue
of Inflammation and Repair, University of Manchester, Manchester, United Kingdom
Sputum eosinophil monitoring
a powerful tool in severe asthma management, due to the role of
eosinophils as markers of airway inflammation steroid-responsiveness.
However, sputum processing is very time consuming which has impaired
its uptake in many clinical settings.
reduce the time ?from expectoration to Differential Cell
We compared 2 different
sputum processing to see if a fast track method would yield the same
clinical decision outcome for patients.
After expectoration, sputum
treated with DTT for 15 min following an established protocol (Thorax
1997;52:498?501). Following PBS, filtration and
centrifugation, the cell pellet was resuspended in PBS. This cell
suspension was then split in two: one half following the regular
established protocol with cell viability before cytospinning, the other
half diluted until the experienced operator deemed the opacity of the
suspension good enough for cytospinning.
Both cytospins were then
the air drying time for the fast track sample was reduced), fixed, and
stained with Rapid Diff before 400 non-squamous cells were counted. DCC
for both methods were compared using Bland-Altman plots.
The fast track method yielded
a DCC in
60 min, whereas the traditional method took twice as long. Bland-Altman
plots of the preliminary results show that the DCC obtained using the
fast track method are comparable to those using the traditional method
for all cell types.
This improved processing time
enabled patients to attend their clinic appointment one hour after
their sputum appointment with physicians having reviewed the laboratory
results. This has cut repeated visits to the hospital for additional