Endocrine Abstracts

There is preliminary evidence that B cell depletion with rituximab (RTX), a chimeric mouse-human monoclonal antibody directed against the CD 20 antigen on B lymphocytes, may be effective for the treatment of moderate-severe Graves’ orbitopathy (GO). While mostly non-controlled studies have shown that this modality of immunosuppression has potential in the therapy of moderate–severe GO, in particular for the control of the active, inflammatory phase of the disease. The main question, when one has to approach treatment of GO, is whether RTX may act as a disease modifying drug, when compared to i.v. methylprednisolone (IVMP) at immunosuppressive doses. Based on the limited, but promising, experience, it is reasonable to hypothesize a potential utility of RTX in the treatment of active GO, although several questions still need to be answered. What do we know about the effects of RTX in controlling the progression of inflammation in GO? What do we know about the mechanisms by which RTX counteracts tissue expansion within the inflamed orbit? Has RTX been used in randomized controlled studies? Preliminary results of one randomized trial confirm a better therapeutic outcome of RTX in active moderate–severe GO, when compared to IVMP and seem to suggest a disease modifying effect of the drug. The data reported on RTX therapy in GO suggest that B-cell depletion may be pursued shortly after diagnosis, and not only as a therapeutic option when standard immunosuppression has failed.