High-dose intravenous immunoglobulin therapy for eosinophilic granulomatosis with polyangiitis.
BACKGROUND
Regulatory T (Treg) cells are implicated in the development and progression of eosinophilic granulomatosis with polyangiitis (EGPA). We previously showed beneficial effects of intravenous immunoglobulin (IVIG) therapy combined with corticosteroid and immunosuppressant treatment on clinical symptoms, including mononeuritis multiplex and cardiac dysfunction, and Treg cell frequency, during EGPA. Whether the timing of administration (during initial treatment or at relapse after remission) or previous treatment affects the clinical and immunologic efficacy of IVIG is unknown. We evaluated whether the frequency of Treg cells varied depending on when IVIG was provided relative to the start of conventional therapy for EGPA.


METHODS
The patient population for this retrospective analysis comprised 17 patients with severe mononeuritis multiplex or heart failure whose EGPA did not respond to corticosteroids combined with immunosuppressant therapy. Ten patients first received IVIG during initial treatment, whereas the remaining 7 patients first received IVIG on relapse after remission. We measured the percentage of Treg cells, defined as FOXP3(+)CD4(+) T cells, present before the first round of IVIG and at 1 month after the last IVIG treatment.


RESULTS
FOXP3(+)CD4(+) T cells were increased in patients who required only a single course of IVIG to achieve remission compared with those who needed two or more courses. The dosage of prednisolone at initial IVIG was inversely correlated with the ratio of the number of FOXP3(+)CD4(+) T cells before IVIG and that at 1 month thereafter.


CONCLUSIONS
Patients with severe EGPA who receive IVIG after nonresponse to high-dose prednisolone during initial treatment may need multiple courses of IVIG to achieve remission. An increase in the frequency of Treg cells after IVIG may predict the need for additional IVIG in EGPA.
Departments of Allergy and Respirology, National Hospital Organization Sagamihara National Hospital, 18-1 Sakuradai, Minami-ku Sagamihara, Kanagawa, 252-0392 Japan.
Naomi
N
Tsurikisawa
Clinical Research Center for Allergy and Rheumatology, National Hospital Organization Sagamihara National Hospital, 18-1 Sakuradai, Minami-ku Sagamihara, Kanagawa, 252-0392 Japan.
Hiroshi
H
Saito
Departments of Allergy and Respirology, National Hospital Organization Sagamihara National Hospital, 18-1 Sakuradai, Minami-ku Sagamihara, Kanagawa, 252-0392 Japan.
Chiyako
C
Oshikata
Departments of Allergy and Respirology, National Hospital Organization Sagamihara National Hospital, 18-1 Sakuradai, Minami-ku Sagamihara, Kanagawa, 252-0392 Japan.
Takahiro
T
Tsuburai
Departments of Allergy and Respirology, National Hospital Organization Sagamihara National Hospital, 18-1 Sakuradai, Minami-ku Sagamihara, Kanagawa, 252-0392 Japan ; Clinical Research Center for Allergy and Rheumatology, National Hospital Organization Sagamihara National Hospital, 18-1 Sakuradai, Minami-ku Sagamihara, Kanagawa, 252-0392 Japan.
Kazuo
K
Akiyama
Churg–Strauss syndrome; Eosinophilic granulomatosis with polyangiitis; IgG; Intravenous immunoglobulin; Regulatory T cells