Behcet's disease (ED) is a chronic multisystemic inflammatory disorder
characterized mainly by recurrent oral and genital aphthous ulceratio
ns and uveitis. Etiology and pathogenesis of ED remain unknown. T cell
receptor (TCR) V alpha/N beta gene product expression as well as J be
ta gene segment expression in peripheral blood of BD patients were ana
lysed to investigate the possible role of T lymphocytes in the etiopat
hogenesis of BD. Flow cytometry with 12 TCR V-specific MoAbs was used
for TCRV analyses. J beta gene segment usage by T cell populations exp
ressing certain V beta s was determined by polymerase chain reaction (
PCR) technique with V beta- and C beta-specific primers, Southern blot
ting of PCR products, and subsequent hybridization with radiolabelled
J beta gene segment-specific probes. Although 13 of the 23 ED patients
exhibited increases in expression of one or more TCR V-gene products,
only expansions among the CD4(+) T cell subset were significantly mor
e frequent in ED patients (7/23) compared with healthy controls (0/15)
(P = 0.019). Six out of eight cases followed for up to 20 months had
at least one expansion correlated with disease activity. A strict pref
erence for particular J beta gene segments implicating clonality was a
pparent in all analysed T cell expansions and correlated well with dis
ease activity. These results suggest a possible involvement of antigen
-specific T lymphocytes in the pathogenesis of ED.