IMMUNOMODULATING EFFECTS OF SYNCHRONIZED PLASMAPHERESIS AND INTRAVENOUS BOLUS CYCLOPHOSPHAMIDE IN SYSTEMIC LUPUS-ERYTHEMATOSUS

Recent studies have suggested that synchronised plasmapheresis and int ravenous pulse cyclophosphamide therapy reduce disease activity in SLE patients. The aim of the present study was to examine the immunomodul ating effects of this therapy and compare it with changes seen with cy clophosphamide alone. Four patients with active SLE were studied. Two were treated with synchronised therapy and two received cyclophosphami de only for up to 26 weeks. Disease activity was measured by the SLE d isease activity index (SLEDAI). Immunological studies were performed i mmediately prior to each treatment. Patients in both treatment groups improved as reflected by a fall in mean SLEDAI scores: synchronised th erapy 33.5 to 11; cyclophosphamide only 13.5 to 4.5. Following synchro nised therapy only there was a prompt and sustained increase in the me an percentage of CD8(+) cells (20.8 to 54.8) which resulted in a fall in the CD4:CD8 ratio (1.95 to 0.62). With both treatment modalities th ere was a fall in the proportion of CD20(+) cells (B lymphocytes) (syn chronised therapy 10.5 to 3.2; cyclophosphamide only 5.6 to 2.2). Howe ver, only synchronised therapy resulted in a fall in the in vitro prod uction of immunoglobulins which was unchanged or increased following c yclophosphamide alone. These results suggest that although both treatm ent modalities are efficacious in the treatment of active SLE they pro duce different immunomodulatory effects. Thus, both therapies reduce t he number of circulating B lymphocytes whereas synchronised therapy al so modifies cellular immunity by promoting the emergence of a phenotyp ic suppressor T lymphocyte population.