AUTOLOGOUS LYMPHOCYTE THERAPY FOR EXPERIMENTAL CANINE LYMPHEDEMA - A PILOT-STUDY

Obstructive lymphoedema, an accumulation of protein-rich fluid in inte rstitial spaces, was created in five dogs by a combination of the irra diation of one groin and subsequent surgical ablation of any remaining lymphatics. The lymphoedema was stable for up to 2 years. The aim was to test the efficacy of intra-arterial injection of autologous lympho cytes as a therapy for lymphoedema. The hypothesis was that cytokines produced by lymphocytes mediate proteolysis by macrophage proteinases in the lymphoedematous limb to remove the excess protein and relieve t he oedema. A concentrated lymphocyte-rich preparation was isolated fro m blood by the Ficoll-Paque method. These preparations were injected i nto the femoral artery four times at approximately 4 weekly intervals. Three months after the first injection of lymphocytes, lymphoedematou s limbs showed a marked 69% reduction in the mean excess circumference s compared with opposite control limbs. After treatment, skin thicknes s and hydroxyproline content (both measures of fibrosis) as well as wa ter content (a measure of oedema) had reduced significantly. In specim ens of interstitial fluid and in skin homogenates acidic proteinase ac tivity increased and the protein concentration decreased significantly compared with controls. It is concluded that increased proteolysis, p ossibly due to activated macrophages recruited to the lymphoedematous limb, may partly explain these results.