Transient and partial effect of high-dose intravenous immunoglobulin in polyarteritis nodosa

A 57-year-old male patient suffered from polyarteritis nodosa. He presented with articular pain, polyneuropathy, subcutaneous nodules and nodes on the lower legs. After several immunosuppressive agents (methotrexate, mycophenolate mofetil and prednisolone) had proven to be ineffective, 2 g intravenous immunoglobulin (IVIG) per kilogram body weight were administered within 2 days in combination with 10 mg prednisolone per day. Subsequently, 6 cycles of IVIG were applied in increasing intervals from 4 to 6 weeks resulting in a minimum dosage of 0.33 g/kg/week IVIG. The polyarteritis improved within a few days after the first IVIG application. The intensity of polyneuropathy and arthralgia of polyarteritis decreased during the period of IVIG treatment. Finally, a dose reduction of less than 0.25 g/kg/week IVIG resulted in recurring polyarteritis nodosa, which could not be controlled by further administration of IVIG. Therefore, our data indicate that: (1) IVIG is partially effective in cases of polyarteritis nodosa, but the therapeutic effect is only transient; (2) the success of treatment may be correlated with the dose of IVIG per body weight and week; (3) the efficacy/cost ratio of IVIG in polyarteritis nodosa appears to be low.