Expression of adhesion molecules, CD11a, CD11b and CD18, and of the fu
nction-associated molecules CD3, CD4, CD8, CD16, CD19, CD56 and CD57 w
as assayed on peripheral blood leukocytes from normal control subjects
(n= 10), and from patients with adult periodontitis PD (n=9), ankylos
ing spondylitis AS (n = 11) and rheumatoid arthritis RA (n = 14). A no
vel rapid fixation leukocyte preparation technique was used which prev
ents artefactual up-regulation of surface antigens. In RA patients, th
e percentage of CD18+ lymphocytes was decreased and that of CD11b+ neu
trophils was increased. On lymphocytes the mean fluorescence intensity
(MFI) of both CD11b and CD18 was decreased whereas that of CD57 was i
ncreased. In AS patients the percentages of CD11b+ lymphocytes and neu
trophils were increased and CD18+ lymphocytes and neutrophils were dec
reased. On lymphocytes the MFIs of CD11b and CD18 were decreased, whil
st that of CD16 was increased. On neutrophils the MFI for CD 1 8 was i
ncreased. No significant differences (p < 0.01) were seen for the peri
odontitis patients. It is suggested that the antigen expression on per
ipheral blood cells from RA and AS patients is consistent with leukocy
te activation.