Clinical improvement and immunohistochemical findings in severe atopic dermatitis treated with interferon gamma.
BACKGROUND
Several clinical studies have focused on the therapeutic effects of interferon gamma (IFN-gamma) in patients with severe atopic dermatitis (AD), although the dosage of recombinant IFN-gamma (rIFN-gamma), therapeutic schedule, and the degree of clinical improvement were different among studies. Although the exact mechanism of action of IFN-gamma therapy in AD is not clear, the beneficial effects of IFN-gamma have been attributed mainly to an immunomodulating effect on the expression of certain immunologic markers.


OBJECTIVE
Our purpose was to study the therapeutic effect of two different dosages of rIFN-gamma on AD and to investigate the change of lesional expression of infiltrating inflammatory cell markers associated with rIFN-gamma therapeutic efficacy.


METHODS
Fifty-one patients with severe recalcitrant AD were treated with rIFN-gamma. Twenty patients were treated with 0.5 x 10(6) IU/m(2) of rIFN-gamma (low-dose [LD] group); 21 patients received 1.5 x 10(6) IU/m(2) of rIFN-gamma (high-dose [HD] group); and 10 patients received placebo. The patients were injected subcutaneously 3 times a week for 12 weeks. Immunohistochemical study was performed in 20 patients of the HD group in the initial visit and after completion of rIFN-gamma therapy with a panel of 14 monoclonal antibodies as markers of inflammatory cells and cytokines.


RESULTS
The disease severity of the 2 groups treated with rIFN-gamma was reduced significantly at the end of treatment compared with that of the placebo group (P<.05). More rapid clinical improvement and more effective treatment outcome were seen in the HD group than in the LD group for the initial 6-week treatment period; however, the clinical improvement in both of the treated groups was stable and maintained after week 8 of treatment. Immunohistochemical findings showed statistically significant reduction in the lesional expression of CD25 and EG2 cells that infiltrated into skin after rIFN-gamma therapy.


CONCLUSIONS
This study demonstrated that rIFN-gamma therapy for AD is safe and effective. In the early phase of therapy, a higher dosage of rIFN-gamma is more effective; and for the maintenance of clinical improvement, a lower dosage of rIFN-gamma is recommended when high cost and effectiveness of rIFN-gamma are considered. The therapeutic efficacy of rIFN-gamma in AD might be in part related to the decreased number of CD25(+) and EG2(+) inflammatory cells infiltrated into skin.
Jang
I G
IG
Department of Dermatology, College of Medicine, Catholic University of Korea, Seoul.
Yang
J K
JK
Lee
H J
HJ
Yi
J Y
JY
Kim
H O
HO
Kim
C W
CW
Kim
T Y
TY
D000293:Adolescent; D000328:Adult; D000970:Antineoplastic Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D015415:Biomarkers / Q000032:analysis; D003362:Cost-Benefit Analysis; D016207:Cytokines / Q000032:analysis; D003876:Dermatitis, Atopic / Q000188:drug therapy* / Q000276:immunology; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D007371:Interferon-gamma / Q000008:administration & dosage / Q000627:therapeutic use*; D008214:Lymphocytes / Q000276:immunology; D008297:Male; D015375:Receptors, Interleukin-2 / Q000032:analysis; D016896:Treatment Outcome
D000970:Antineoplastic Agents; D015415:Biomarkers; D016207:Cytokines; D015375:Receptors, Interleukin-2; D007371:Interferon-gamma