ELECTRONIC CELL COUNTING TO MEASURE TOTAL CELL NUMBERS IN BRONCHOALVEOLAR LAVAGE FLUID

Cell counting of bronchoalveolar lavage (BAL) fluid is performed manua lly in routine practice. This has both methodological and inherent err ors; however, the accuracy and suitability of automated counting devic es have been questioned. In this study, a Coulter(R) Counter D Industr ial model was calibrated and then used to measure the total cell count in unprocessed bronchoalveolar lavage fluid, and compared to a standa rd manual method. Bronchoalveolar lavage was performed on 34 patients undergoing routine bronchoscopy. An aliquot of unprocessed bronchoalve olar lavage fluid was taken for all counting procedures. Manual counts were performed blind by two experienced independent observers using i mproved Neubauer chambers. Electronic counting measured 1 ml aliquots suspended in 10 and 20 ml Isoton(R) counting 0.5 and 1 ml duplicates. The correlation coefficients between electronic and manual counts were good. The coefficients of repeatability of electronic counts, for rep eat counts, both on the same dilution Intra-Coulter(R): 0.1x10(5) cell s.ml(-1) and different dilutions (Interdilution-Coulter(R): 0.48x10(5) cells ml(-1)), were superior compared to those for repeat manual coun ts by the same observer (1.03x10(5) cells.ml(-1)), and counts between observers (1.82x10(5) cells.ml(-1)). This method offers a quick, preci se and simple method for counting cells in unprocessed bronchoalveolar lavage fluid, which is both less labour intensive and subjective than manual counting.