TREATMENT OF IMMUNE-MEDIATED NEUROPATHIES WITH INTRAVENOUS HUMAN IMMUNE GLOBULIN - OPEN STUDY IN 16 CASES

Between June 1989 and February 1992 in an open controlled study 16 patients with various types of polyneuropathy were treated with high-dose intravenous immunoglobulins (IgIV). Every month during 3 months, each patient received three courses of IgIV in doses of 0.4 g/kg/day during 5 successive days. The trial was discontinued in case of no response or if the neuropathy was considered as being in remission. In the other cases, at most one course of IgIV was given once a month if there was significant improvement (assessed by previously published clinical functional scales, electrophysiological examinations and titers of specific antibodies), or spaced at intervals which varied according to each patient, and sometimes in low doses. Results : 1) A first group of 6 patients had chronic demyelinating polyneuropathy with severe motor disability. The first infusions of IgIV resulted, in 4/6 cases, in a dramatic improvement which lasted under regularly spaced courses in lower doses. 2) Four patients had chronic neuropathy associated with monoclonal IgM gammopathy of undertermined significance (3 had anti-MAG and anti-SPG antibodies, and 1 had anti-GD1a and GD1b antibodies) and had not been improved by the usual immunosuppressive treatments. In 1 case the IgIV treatment had to be discontinued because of skin allergy. In the remaining 3 patients the clinical disorders (mainly the sensory ones) were reduced, but no significant improvement of neurophysiological or immunological data was observed 3) Three patients had a purely multifocal motor neuropathy with persistent conduction blocks at EMG and high titers of anti-GM1 antibodies in 2/3 cases. IgIV therapy resulted in improvement of the motor functional scale in all cases, marked in 2/3; there was no significant improvement of the neurophysiological and immunological data in these 3 cases. 4) In the last group of 3 patients with severe axonopathy associated with signs of mild systemic disease, IgIV therapy was ineffective. The effectiveness and mechanism of action of IgIV in immune-mediated polyneuropathies are discussed.