ALVEOLAR-LAVAGE FLUID (ALF) OF NORMAL VOLUNTEER SUBJECTS - CYTOLOGIC,IMMUNOCYTOCHEMICAL, AND BIOCHEMICAL REFERENCE VALUES

Objective: Pooled bronchoalveolar lavage fluid (PALE), the return of l avage, contains both bronchial and alveolar material which differ from each other. Artifacts may be created by filtering, centrifuging and w ashing cells before cytopreparation. This study presents reference val ues of healthy volunteers for the alveolar sample, ALF, cytopreparatio n being performed without filtration or centrifugation. Methods: Eight een healthy, non-smoking volunteers underwent a standard bronchoalveol ar lavage using 10 aliquots of 20 mi of saline. Excluding the return o f the first and second aliquots, the rest were pooled and examined cyt ologically, immunocytochemically and biochemically. The mean, standard deviation, and 95% confidence limits were calculated for the followin g variables: amount of return, estimated content of epithelial lining fluid (ELF), total and differential cell counts on filter and cytocent rifuge (CCF) preparations, computed cell counts per unit volume of ALF , distribution of lymphocyte subgroups CD3 + CD2, CD4, CD8, CD19, CD25 and CD57, and the ratio of CD4 to CD8, the amounts of lymphocytes in the same subgroups per volume of ALF, and the concentrations of total protein, albumin, immunoglobulins A, G and M, hyaluronic acid, eosinop hilic cationic protein (ECP), procollagen III aminoterminal propeptide (PCP) and beta(2)-microglobulin in ALF and in ELF, as well as the rat ios of the concentrations of the solutes in ALF to the same in serum. Results: The 95% confidence limits of means for the most important var iables were as follows: estimated ELF content 0.42-0.74%; total cells in ALF 76.6-143.0 x 10(6) l(-1); distribution of inflammatory cells on filter and CCF slides: macrophages 74.9-83.6 and 81.4-90.1%, lymphocy tes 13.1-22.5 and 8.1-16.4%, and neutrophils 1.0-4.1 and 0.7-2.7%, res pectively; distribution of lymphocyte subsets: CD3 + CD2 85.6-90.6%, C D4 44.3-53.1%, CD8 26.9-35.8%; concentration of solutes in ALF: total protein 44.8-61.3 mg l(-1), albumin 15.4-22.2 mg l(-1), IgA 1.8-3.4 mg l(-1), IgG 3.1-6.1 mg l(-1) IgM 0.05-0.26 mg l(-1), hyaluronic acid 8 .8-11.1 mu g l(-1), ECP 0.19-0.77 mu g l(-1), PCP 0.005-0.058 mu g l(- 1), beta(2)-microglobulin 62.2-81.5 mu g l(-1). Conclusions: Our resul ts show that excluding the bronchial sample from ALF of volunteer subj ects and omitting filtering and washing before cytopreparation produce s cytologic, immunocytochemical and biochemical reference values with reasonable 95% confidence limits to be used in clinical settings.