Clinical improvement and immunohistochemical findings in severe atopic dermatitis treated with interferon gamma

Clinical improvement and immunohistochemical findings in severe atopic dermatitis treated with interferon gamma In-Gang Jang, Jong-Kyu Yang, Hyun-Jeong Lee, Jong-Yuk Yi, Hyung-Ok Kim, Chung-Won Kim, and Tae-Yoon Kim Seoul, Korea Background: Several clinical studies have focused on the therapeutic effects of interferon gamma (IFN-γ) in patients with severe atopic dermatitis (AD), although the dosage of recombinant IFN-γ (rIFN-γ), therapeutic schedule, and the degree of clinical improvement were different among studies. Although the exact mechanism of action of IFN-γ therapy in AD is not clear, the beneficial effects of IFN-γ 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-γ on AD and to investigate the change of lesional expression of infiltrating inflammatory cell markers associated with rIFN-γ therapeutic efficacy. Methods: Fifty-one patients with severe recalcitrant AD were treated with rIFN-γ. Twenty patients were treated with 0.5 × 106 IU/m2 of rIFN-γ (low-dose [LD] group); 21 patients received 1.5 × 106 IU/m2 of rIFNγ (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-γ 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-γ 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-γ therapy. Conclusion: This study demonstrated that rIFN-γ therapy for AD is safe and effective. In the early phase of therapy, a higher dosage of rIFN-γ is more effective; and for the maintenance of clinical improvement, a lower dosage of rIFN-γ is recommended when high cost and effectiveness of rIFN-γ are considered. The therapeutic efficacy of rIFN-γ in AD might be in part related to the decreased number of CD25+ and EG2+ inflammatory cells infiltrated into skin. (J Am Acad Dermatol 2000;42:1033-40.)

A

topic dermatitis (AD) is a chronic inflammatory skin disease characterized by severe pruritus and typical morphology. Among the multi-

From the Department of Dermatology, College of Medicine, Catholic University of Korea. Supported by a grant from LG Chemical Ltd and from Catholic Medical Center Research Fund for special projects. Reprint requests: Associate Professor Tae-Yoon Kim, Department of Dermatology, Kangnam St. Mary’s Hospital, The Catholic University of Korea, 505, Banpo-Dong, Seocho-ku, Seoul 137-040, Korea. Copyright © 2000 by the American Academy of Dermatology, Inc. 0190-9622/2000/$12.00 + 0 16/1/104793 doi:10.1067/mjd.2000.104793

ple immunologic abnormalities associated with AD, it is accompanied by the defective regulation of IgE production in 60% to 80% of the patients.1 IgE production is regulated by different factors that are produced by activated T lymphocytes, such as interleukin 4 (IL-4) and interferon gamma (IFN-γ).2-4 These cytokines are released from different subpopulations of activated helper T cells. T helper type 1 (TH1) cells secrete IL-2 and IFN-γ, whereas TH2 cells secrete IL-4 and IL-5. IL-4 acts as an IgE isotype-specific switch factor.5 IL-5 is important in differentiation, vascular endothelial adhesion, and survival of eosinophils.6 In contrast, IFN-γ inhibits IgE synthesis and the proliferation of TH2 cells producing IL-4 and IL-5.3,7 The reduced production of IFN-γ with the 1033

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Table I. Subjective characteristics

Table II. Expression of various markers was investigated by immunohistochemical technique in lesional skin of patients with atopic dermatitis before and after rIFN-γ therapy

Group

LD

HD

PL

Total

No. of patients Age (y) Sex (No.) Female Male Duration of AD (y)

20 21 ± 6

21 23 ± 4

10 21 ± 2

51 21 ± 4

13 7 13 ± 4

15 6 14 ± 8

7 3 12 ± 6

35 16 13 ± 7

CD3*

Data are expressed as mean ± SD. HD, High dosage (1.5 × 106 IU/m2 rIFN-γ); LD, low dosage (0.5 × 106 IU/m2 rIFN-γ); PL, placebo.

CD8*

concurrent upregulation of IL-4 and IL-5 may be critical in the pathogenesis of AD.3,8,9 Recently, several clinical studies have focused on the therapeutic effects of IFN-γ in patients with severe AD although the dosage of rIFN-γ, the therapeutic schedule, and the degree of clinical improvement were different among studies.10-14 Musial et al14 reported that the number of CD25positive cells in peripheral blood was reduced parallel with clinical improvement. Hanifin et al11 reported a significant reduction in blood eosinophil count after IFN-γ therapy in AD. To date, however, the exact mechanism of action of IFN-γ therapy in AD is not clear. The present study investigated the therapeutic efficacy of two different dosages of rIFN-γ on AD and the change of lesional expression of infiltrating inflammatory cell markers associated with rIFN-γ therapy.

Marker

CD4*

CD4/CD8 ratio CD45RO* CD45RA* CD25† IFN-γ§ CD54§ CD11a† IgE† EG2† HLA-DR (epidermis)† HLA-DR (dermis)§ CD1a (epidermis)† CD1a (dermis)† CD36§

Before

After

50.8 ± 10.4 (114/219) 36.7 ± 12.8 (82/211) 12.7 ± 4.6 (31/239) 3.3 ± 1.5 25.2 ± 9.8 4.1 ± 3.5 4.9 ± 4.1 1.5 ± 0.6 3.0 ± 1.3 10.1 ± 4.4 4.9 ± 3.4 4.9 ± 5.4 6.7 ± 4.0 3.8 ± 0.4 12.3 ± 5.7 8.0 ± 4.3 2.0 ± 0.7

49.8 ± 10.4 (105/208) 41.6 ± 11.9 (75/182) 12.0 ± 8.1 (22/189) 4.8 ± 2.6 25.8 ± 12.3 2.3 ± 2.8 2.1 ± 2.4‡ 1.6 ± 0.9 2.8 ± 1.0 12.2 ± 7.3 5.0 ± 4.3 1.2 ± 1.5‡ 6.7 ± 4.1 3.7 ± 0.5 10.3 ± 3.6 6.7 ± 3.2 1.7 ± 0.6

Data in parentheses represent the number of CD3+, CD4+, or CD8+ cells per total infiltrating cells. Results are expressed as mean ± SD. *The percentage of cells labeled with each antibody. †The mean number of cells per high-power field (×400) around perivascular area. ‡Statistically significant (P<.05). §5-point scale (0 to 4). 0: None; 1: very few; 2: few; 3: moderate; 4: many.

METHODS A total of 51 patients with severe AD defined by Hanifin and Rajka’s criteria15 were enrolled in a randomized, placebo-controlled study (Table I). They had AD that involved at least 20% of their body surface and had refractory severe AD not responding to conventional therapy. All patients were older than 15 years. An informed consent was obtained from either the patient or his/her parent. The patients were allowed only steroid-free hydrophilic or emollient ointment to be used on their skin as an adjunctive therapy. For this study, 20 patients were treated with 0.5 × 106 IU/m3 of rIFN-γ (low-dose [LD] group), 21 patients with 1.5 × 106 IU/m3 of rIFN-γ (high-dose [HD] group), and 10 patients with placebo. The patients were treated with 3 subcutaneous injections a week for 12 weeks on an outpatient basis. The patients with adverse reactions of flu-like symptoms were permitted to take 1200 mg of oral acetaminophen. The rIFN-γ (LG Co, Seoul, Korea) was supplied as a concentration of 2 × 106 U/ml (specific gravity; 3 × 107 U/mg). Assessments before and after

treatment included routine laboratory evaluation (blood chemistry, hematology, and urinalysis), total serum IgE, radioallergosorbent test (RAST) to Dermatophagoides pteronyssinus and Malassezia furfur, eosinophil cationic protein (ECP), and CD4 and CD8 lymphocyte subpopulation in peripheral blood. The number of eosinophils in peripheral blood was measured on weeks 0, 2, 6, and 12. Disease severity was measured by the total clinical severity (TCS) and total body surface area (TBSA). TCS consisted of 8 parameters (erythema, edema/ vesicle, excoriation, scale, lichenification, pruritus, pigmentation/depigmentation, and loss of sleep). Each parameter was graded from 0 to 3 as none, mild, moderate, or severe, and TCS was defined as the sum of individual scores. TBSA was measured as the percentage of lesional skin according to the rule of nines. The same physician measured the disease severity at every 2-week period.

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Fig 1. Changes in clinical improvement with rIFN-γ treatment at week 12. *Significant difference between rIFN-γ treated groups (LD 0.5 × 106 IU/m2 rIFN-γ; HD 1.5 × 106 IU/m2 rIFN-γ) and placebo group (P<.05). **Significant difference in clinical improvement between LD and HD group (P<.05).

Immunohistochemical study Immunohistochemical study was performed in 20 patients from the HD group. Punch biopsy specimens for immunohistochemical stain were obtained in the initial visit. After completion of rIFN-γ therapy, a second biopsy specimen was taken from a lesion located near the previous biopsy site. The biopsy specimen was embedded in Tissue-Tek (OCT compound, Miles Inc, Elkhart, Ind), snap-frozen in liquid nitrogen, and stored at -70°C. The panel of 14 monoclonal antibodies used in this study are listed in Table II. The samples were stained by the indirect immunoperoxidase technique (Histostain-Bulk kits, Zymed Lab Inc, South San Francisco, Calif). Stained cells were counted at high-power fields (HPF; × 400) by two independent observers. Staining intensities were expressed as the percentage or mean number of positively labeled cells, or graded on a 5-point scale from 0 to 4 (0 = none, 1 = very few, 2 = few, 3 = moderate, 4 = many) according to the markers used. All results were shown as mean ± standard deviation (SD). Statistical analysis Disease severity of two treated and placebo groups was assessed for comparability at baseline and every 2 weeks. The score at each time point was subtracted from the baseline score; this difference was analyzed by means of the ANOVA procedures of the computerized SAS system. The results of the immunohistochemical studies were analyzed by means of the two-tailed Student t test. A P value less than .05 was considered statistically significant.

RESULTS Clinical effects of rIFN-γ therapy in patients with AD Fig 1 shows the mean percent improvement of the clinical parameters between the beginning and end of the therapy. Erythema severity was reduced by a mean value of 37% in the HD group compared with 13% in the placebo group. Pruritus declined 43%, and loss of sleep was reduced by a mean of 70% in the HD group. Pigmentation and depigmentation showed significant improvement only in the HD group. Each of the other parameters (edema/vesicle, scale, lichenification) showed significant improvement for both groups treated with rIFN-γ compared with the placebo group. The percent reductions in the individual parameters were also analyzed relative to the physician’s global assessment data (more than 50% improvement relative to baseline) at treatment end. At least a 50% reduction in severity was noted in 7 of 20 patients in the HD group (35%) versus 6 of 20 in the LD group (30%) for erythema, 8 of 20 HD patients (40%) versus 9 of 20 LD patients (45%) for pruritus, 8 of 20 HD patients (40%) versus 7 of 20 LD patients (35%) for excoriation, and 12 of 20 HD patients (60%) versus 10 of 20 LD patients (50%) for loss of sleep. However, none of the 10 patients receiving placebo achieved at least a 50% reduction in severity of the individual parameters at treatment end. The TCS was 19.4 ± 2.6 in the LD group, 20.1 ± 2.2 in the HD group, and 18.4 ± 2.8 in the placebo group at the initial visit. Fig 2 shows the improvement of TCS between the beginning and the end of therapy. The patients from two rIFN-γ-treated groups

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Table III. The changes of total IgE, ECP, RAST for D pteronyssinus and M furfur, CD4, CD8, CD4/CD8 ratio, and eosinophil count after rIFN-γ therapy

Total IgE (kU/L)

ECP (kU/L)

Fig 2. Changes in total clinical severity with rIFN-γ treatment. *Significant difference between HD (1.5 × 106 IU/m2 rIFN-γ) and placebo group, P<.05. **Significant difference in total clinical severity between LD (0.5 × 106 IU/m2 rIFN-γ) and placebo group, P<.05.

RAST for D pteronyssinus (kU/L) RAST for M furfur (kU/L) CD4 (%)

CD8 (%)

CD4/CD8 ratio

Eosinophil (cells/mm3)

Group

Baseline

Week 12

LD HD Placebo LD HD Placebo LD HD Placebo LD HD Placebo LD HD Placebo LD HD Placebo LD HD Placebo LD HD Placebo

3949 ± 5519 4289 ± 5910 2477 ± 1938 19.8 ± 23.1 31.2 ± 43.0 28.4 ± 29.7 38.4 ± 42.2 56.0 ± 44.7 36.6 ± 43.5 8.9 ± 15.4 23.9 ± 27.0 10.2 ± 12.0 37 ± 11 45 ± 11 43 ± 11 24 ± 7 34 ± 11 34 ± 12 1.56 ± 0.41 1.38 ± 0.33 1.44 ± 0.59 499 ± 425 724 ± 654 627 ± 567

5747 ± 7171 4233 ± 5699 4929 ± 4580 9.3 ± 8.5 25.6 ± 40.7 17.7 ± 29.8 50.3 ± 45.7 62.2 ± 43.4 36.9 ± 45.6 9.4 ± 12.6 19.9 ± 13.3 10.3 ± 12.9 40 ± 7 44 ± 8 48 ± 14 27 ± 7 30 ± 7 32 ± 15 1.59 ± 0.56 1.53 ± 0.34 1.64 ± 0.67 475 ± 473 575 ± 443 708 ± 679

HD, High dosage (1.5 × 106 IU/m2 rIFN-γ); LD, low dosage (0.5 × 106 IU/m2 rIFN-γ).

Fig 3. Changes in total body surface area with rIFN-γ treatment. *Significant difference in total body surface area between HD (1.5 × 106 IU/m2 rIFN-γ) and placebo group, P<.05. **Significant difference in total body surface area between LD (0.5 × 106 IU/m2 rIFN-γ) and placebo group, P<.05. ***Significant difference in total body surface area between HD and LD groups, P<.05.

responded well to the rIFN-γ treatment, but the patients in the placebo group failed to improve. TCS in the LD group was reduced significantly starting from the 8th week of rIFN-γ therapy to the end of the treatment compared with that in placebo group. TCS in the HD group showed significantly earlier reduction starting from the 4th week of rIFN-γ therapy compared with that in the placebo group. TCS revealed more rapid and effective improvement in the HD group than in the LD group. However, no significant statistical difference was observed between the HD group and the LD group throughout the observation period.

TBSA in the LD group decreased from 35.7 ± 12.9 at baseline to 22.6 ± 14.4 at treatment end (Fig 3). Although TBSA in the LD group was reduced continuously during the treatment period, only slight reduction was seen until the 12th week of treatment when TBSA was significantly reduced compared with that in the placebo group (P<.05). In contrast, TBSA in the HD group was diminished significantly at week 4 of treatment (P<.05). The significant difference of TBSA between the HD and placebo groups persisted during the observation period. Significant difference was observed in TBSA between the LD and HD groups at 4, 6, 8, and 10 weeks (P<.05). However, no difference in TBSA was observed between two treated groups at week 12 of treatment. Immunologic parameters in peripheral blood Total serum IgE was initially markedly elevated in all the AD patients. However, these levels remained unchanged during the rIFN-γ therapy (Table III). Although the value of ECP decreased in the LD group compared with the baseline value (P<.05), the ECP value in treated groups did not change sig-

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Fig 4. Immunohistochemical staining of lesional skin with a monoclonal antibody in CD25+ cells (A) before and (B) after rIFN-γ therapy (× 100). CD25+ cells with distinct membranous staining are found in papillary dermis, especially around upper dermal capillaries. Note reduced number of CD25+ cells in papillary dermis after treatment.

nificantly compared with that in the placebo group at the treatment end. No changes were observed in the levels of RAST for D pteronyssinus and M furfur. The CD4 and CD8 lymphocyte subpopulation and CD4/CD8 ratio in all the groups revealed no difference between the baseline value and the value at week 12 of therapy. Although eosinophil count in the treated groups tended to decrease at the treatment end, eosinophil count did not drop significantly in either of the rIFN-γ treated groups or in the placebo group (Table III). Lesional expression of inflammatory cell markers About 50% of the dermal infiltrating cells were CD3+ cells (50.8% ± 10.4% before treatment; 49.8% ± 10.4% after treatment) (Table II). CD4+ T cells (36.7% ± 12.8% before treatment; 41.6% ± 11.9% after treatment) predominated over CD8+ T cells (12.7% ± 4.6% before treatment; 12.0% ± 8.1% after treatment). CD4/CD8 ratio before and after rIFN-γ treatment was 3.3 ± 1.5 (36.7% ± 12.8%/12.7% ± 4.6%) and 4.8 ± 2.6 (41.6% ± 11.9%/12.0% ± 8.1%), respectively. The number of lesional CD3+, CD4+, or CD8+ cells and total inflammatory cells tended to decrease slightly. CD45RO+ memory T cells (25.2% ± 9.8% before treatment; 25.8% ± 12.3% after treatment) were predominant over CD45RA+ naive T cells (4.1% ± 3.5% before treatment; 2.3% ± 2.8% after treatment). Statistically significant alteration was observed in the lesional expression of CD25 and EG2 after rIFN-γ therapy. Before rIFN-γ treatment, a substantial number of CD25+ cells was found in the dermis, especially in the perivascular area, with a distinct membranous staining pattern (4.9 ± 4.1

cells/HPF; Fig 4, A). After treatment, a significant reduction in the number of CD25+ cells was observed with scattered distribution throughout the dermis (2.1 ± 2.4 cells/HPF; P<.05; Fig 4, B). EG2binding cells were reduced significantly after IFN-γ treatment (4.9 ± 5.4 cells/HPF before treatment; 1.2 ± 1.5 cells/HPF after treatment; P<.05; Fig 5). EG2, which recognizes the secreted form of ECP and marks activated eosinophils, showed a distinct membranous staining pattern. Cells with positive labeling were very few in the epidermis except for the expression of HLA-DR and CD1a. Safety Of the 41 patients treated with rIFN-γ, only 3 discontinued rIFN-γ therapy: 2 from the LD group because of disease flare and 1 from the HD group because of hepatic transaminase elevation. Of patients receiving active therapy, 54% experienced adverse effects. A total of 27 patients experienced fever, the most common adverse effect; among these 27, 23 experienced LDH elevation. Seven patients experienced myalgia. Mild respiratory difficulty occurred in 2 patients receiving rIFN-γ. These adverse effects were transient, not constant, and dose-limiting.

DISCUSSION IFN-γ has been administered as an alternative or adjuvant therapy for infectious diseases such as warts16,17 and multidrug-resistant tuberculosis,18 or for neoplastic diseases such as basal cell carcinomas,19 mycosis fungoides,20 myelodysplastic syndromes,21 and renal cell carcinoma,22 or for immunologic disorders such as Behçet’s disease,23

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Fig 5. Immunohistochemical staining of lesional skin with a monoclonal antibody in EG2+ cells (A) before and (B) after rIFN-γ therapy (×100). After treatment, a significant reduction in number of EG2+ cells is observed with scattered distribution throughout the dermis.

psoriatic arthritis,24 scleroderma,25-27 rheumatoid arthritis,28 chronic granulomatous disease,29 and prurigo30 because it enhances macrophage oxidative and antimicrobial activity and because of its immunomodulatory action on various cell systems. AD may be related to an imbalance in the production of IFN-γ and IL-4. These two cytokines have been shown to have reciprocal functions in the pathogenesis of AD.31 Recent reports show that lymphocytes from patients with AD have an impaired ability to produce IFN-γ,32 and open studies have documented remission of AD in patients treated with IFN-γ.10-12,14,33 Of the individual symptoms constituting the total severity score, pruritus and erythema were most significantly reduced between 3 and 6 weeks of IFN-γ therapy. These studies demonstrated that IFN-γ is safe, well accepted, and effective in reducing inflammation and pruritus of AD and that IFN-γ has the potential to reduce the use of systemic and topical corticosteroids in AD. In these studies, the dosage of rIFN-γ and the therapeutic schedule were different among the investigators; the dosage of rIFN-γ ranged from 500,000 IU to 2,000,000 IU within a 4- to 12-week period. Among these studies, Nishioka, Matsunaga, and Katayama13 used the smallest amount of rIFN-γ, 500,000 IU per injection for 8 weeks, without seeing any significant improvement over the conventional therapy. Other studies have recommended the use of higher dosage rIFN-γ, that is, above 1,000,000 IU, and have reported significant improvement in AD.10-12,14 In these studies, therapeutic responses were progressive and continuous, and significant improvement was observed from 2 to 6 weeks during rIFN-γ therapy. The discontinuation of therapy at the end of the study revealed early relapse in some cases without an over-

shoot phenomenon. The present study consisted of two study groups according to the dose of rIFN-γ. At the end of the study, significant improvement was observed in both groups treated with rIFN-γ compared with the placebo group. The response to the treatment of rIFN-γ in the HD group was more rapid than that in the LD group. TCS in the LD group was reduced significantly starting from week 8 compared with that in the placebo group. However, TCS in the HD group also showed significant reduction starting from the 4th week of rIFN-γ therapy. TBSA in the LD group was significantly reduced at the 12th week compared with that in placebo. In contrast, TBSA in the HD group was reduced significantly at week 4. In both treated groups therapeutic response continuously improved until week 6 but showed stable improvement and plateaued after week 8. The present study confirmed that therapy with HD rIFN-γ (1,500,000 IU/m3 rIFN-γ) was more effective at least until 8 weeks than was therapy with LD rIFN-γ (500,000 IU/m3 rIFN-γ). However, administration of LD rIFN-γ, 500,000 IU/m3, after 8 weeks into the therapy is recommended considering the high cost of rIFN-γ and the stable improvement seen with both dosages after 8 weeks. The majority of dermal infiltrating cells were T cells in immunohistochemical staining of lesional skin of AD. In the present study, the expression of CD4 and CD8 and the ratio of CD4/CD8 did not reveal any significant differences after IFN-γ therapy, in contrast to the results of Ellis et al.34 However, IFN-γ therapy resulted in significant reduction in CD25 expression on dermal infiltrates. These findings of the present study agree with the results of Musial et al,14 in which the IFN-γ therapy had no influence on CD4 and CD8 lymphocyte subsets and

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the CD4/CD8 ratio in peripheral blood. In addition, they found a decreased number of circulating CD25+ activated lymphocytes, which paralleled the clinical improvement after IFN-γ therapy. These activated lymphocytes infiltrating into the lesional skin of AD were probably TH2 cells producing IL-4 and IL5 but relatively little IFN-γ.10,35-38 IL-4 has a critical function in the induction of IgE responses.2,5,39-41 IL5 is an essential cytokine needed for differentiation, vascular endothelial adhesion, and survival of eosinophils.6 Recent studies of murine T cells also demonstrated that IFN-γ can selectively inhibit the proliferation of TH2 cells but not TH1 cells.7,42 From these findings it is suggested that IFN-γ may exert its effect by down-regulating the activity of IL-4 and IL-5 producing TH2 cells, thus restoring the balance between TH1 and TH2-derived cytokines.43 EG2-reactive activated eosinophils decreased significantly after treatment with IFN-γ in this study. Eosinophils release ECP in response to IL-3, IL-5, and granulocyte-macrophage colony-stimulating factor.44 EG2 recognizes only the secreted form of ECP but not the stored form: EG2 fails to react with resting eosinophils but marks activated eosinophils.45 Bruijnzeel et al46 showed the lesional infiltration of eosinophils by detecting major basic protein and ECP,46 and suggested an involvement of eosinophils in the pathogenesis of AD.47 Recently, Noh and Lee48 reported that blood eosinophil count is a predictor for prognosis of IFNγ therapy in AD. Several studies revealed a marked reduction in the absolute eosinophil count of peripheral blood in the IFN-γ treated group.11,34,49 The present study also revealed this reduction in the activated eosinophils, suggesting that IFN-γ acts by reducing the activated eosinophils, although the reduction in the number of eosinophils in peripheral blood was not significantly observed at the end of treatment. In conclusion, this study demonstrated that rIFNγ therapy in AD is safe and effective. In the induction period, high dosage therapy is more effective; in the maintenance period, low dosage therapy is recommended when the high cost and effectiveness of rIFN-γ are considered. Immunohistochemical study of lesional inflammatory cells revealed that IFN-γ treatment decreased skin inflammation by reducing the activated T cells and eosinophils. It was suggested that IFN-γ in AD exerts its effectiveness by the alteration of lesional expression of infiltrating inflammatory cells.

3.

4.

5. 6. 7.

8.

9.

10.

11.

12.

13.

14.

15. 16.

17.

18. 19.

20.

21.

22. REFERENCES 1. Hanifin JM. Atopic dermatitis. J Am Acad Dermatol 1982;6:1-13. 2. Pene J, Rousset F, Briere F, Chretien I, Paliard X, Banchereau J, et

23.

al. IgE production by normal human B cells induced by alloreactive T cell clones is mediated by IL-4 and suppressed by IFNgamma. J Immunol 1988;141:1218-24. Jujo K, Renz H, Abe J, Gelfand EW, Leung DYM. Decreased interferon gamma and increased interleukin-4 production in atopic dermatitis promotes IgE synthesis. J Allergy Clin Immunol 1992; 90:323-31. Well S, Diel F. In vitro interleukin 4 and interferon gamma production by mononuclear cells from atopic dermatitis patients. Mediators Inflamm 1993;2:411-5. Geha RS. Regulation of IgE synthesis in humans. J Allergy Clin Immunol 1992;90:143-50. Weller PF. Role of eosinophils in allergy. Curr Opin Immunol 1992;4:782-7. Gajewski TF, Fitch FW. Anti-proliferative effect of IFN-γ in immune regulation: IFN-γ inhibits the proliferation of TH2 but not TH1 murine helper T lymphocyte clones. J Immunol 1988; 140:4245-52. Renz H, Jujo K, Bradley L, Domenico J, Gelfand EW, Leung DYM. Enhanced IL-4 production and IL-4 receptor expression in atopic dermatitis and their modulation by interferon gamma. J Invest Dermatol 1992;99:403-8. Robinson DS, Hamid Q, Ying S, Tsicopoulos A, Barkans J, Bentley AM, et al. Predominant TH2-like bronchoalveolar T-lymphocyte population in atopic asthma. N Engl J Med 1992;326:298-304. Reinhold U, Wehrmann W, Kukel S, Kreysel HW. Recombinant interferon-γ in severe atopic dermatitis [letter]. Lancet 1990; 335:1282. Hanifin JM, Schneider LC, Leung DYM, Ellis CN, Jaffe HS, Izu AE, et al. Recombinant interferon gamma therapy for atopic dermatitis. J Am Acad Dermatol 1993;28:189-97. Reinhold U, Kukel S, Brzoska J, Kreysel HW. Systemic interferon gamma treatment in severe atopic dermatitis. J Am Acad Dermatol 1993;29:58-63. Nishioka K, Matsunaga T, Katayama I. Gamma-interferon therapy for severe cases of atopic dermatitis of the adult type. J Dermatol 1995;22:181-5. Musial J, Milewski M, Undas A, Kopinski P, Duplaga A, Szczeklik A. Interferon-gamma in the treatment of atopic dermatitis: influence on T-cell activation. Allergy 1995;50:520-3. Hanifin JM, Rajka G. Diagnostic features of atopic dermatitis. Acta Derm Venereol Suppl (Stockh) 1980;92:44. Kirby PK, Kiviat N, Beckman A, Wells D, Sherwin S, Corey L. Tolerance and efficacy of recombinant human interferon gamma in treatment of refractory genital warts. Am J Med 1988;85:183-8. Shiohara T, Hayakawa J, Nagashima M. Interferon-gamma as adjuvant therapy for resistant warts. J Am Acad Dermatol 1989; 21:387-91. Condos R, Rom WN, Schluger NW.Treatment of multidrug-resistant pulmonary tuberculosis. Lancet 1997;349:1513-5. Edwards L, Whiting D, Rogers D, Luck K, Smiles KA. The effect of intralesional interferon gamma on basal cell carcinomas. J Am Acad Dermatol 1990;22:496-500. Yamamoto T, Sasaki G, Sato T, Katayama I, Nishioka K. Cytokine profile of tumor cells in mycosis fungoides: successful treatment with intralesional interferon-gamma combined with chemotherapy. J Dermatol 1995;22:650-4. Maiolo AT, Cortelezzi A, Calori R, Polli EE. Recombinant gammainterferon as first line therapy for high risk myelodysplastic syndromes. Leukemia 1990;4:480-5. Aoyagi T, Murai M, Kimura F, Sawamura M, Asano T, Odajima K, et al. Hinyokika Kiyo 1992;38:1357-60. Mahrle G, Schulze HJ. Recombinant interferon-gamma (rIFN-γ) in dermatology. J Invest Dermatol 1990:95 (Suppl 6):132S-137S.

1040 Jang et al

24. Fierlbeck G, Rassner G. Treatment of psoriasis and psoriatic arthritis with interferon gamma. J Invest Dermatol 1990; 95(Suppl):138S-41S. 25. Hensing H. Therapy of progressive scleroderma with gammainterferon. Hautarzt 1991;42:380-3. 26. Hunzelmann N, Anders S, Fierlbeck G, Hein R, Herrmann K, Albrecht M, et al. Systemic scleroderma: multicenter trial of 1 year of treatment with recombinant interferon gamma. Arch Dermatol 1997;133:609-13. 27. Grassegger A, Schuler G, Hessenberger G, Walder-Hantich B, Jabkowski J, MachHeiner W, et al. Interferon-gamma in the treatment of systemic sclerosis: a randomized controlled multicentre trial. Br J Dermatol 1998;139:639-48. 28. Lammel EM, Franke M, Gaus W, Hartl PW, Hofschneider PH, Machalke K, et al. Rheumatol Int 1987;7:127-32. 29. Sechler JM, Malech HL, White CJ, Gallin JI. Recombinant human interferon-gamma reconstitutes defective phagocyte function in patients with chronic granulomatous disease of childhood. Proc Natl Acad Sci U S A 1988;85:4874-8. 30. Tokura Y, Yagi H, Hanaoka K, Ito T, Towyama K, Tanaka K, et al. Subacute and chronic prurigo effectively treated with recombinant interferon-gamma: implications for participation of TH2 cells in the pathogenesis of prurigo. Acta Derm Venereol (Stockh) 1997;77:231-4. 31. Snapper CM, Finkelman FD, Paul WE. Differential regulation of IgG1 and IgE synthesis by interleukin 4. J Exp Med 1988;1677: 183-96. 32. Reinhold U, Wehrmann W, Kukel S, Kreysel HW. Evidence that defective interferon gamma production in atopic dermatitis is due to intrinsic abnormalities. Clin Exp Immunol 1990;79:374-9. 33. Pung YH, Vetro SW, Bellanti JA. Use of interferons in atopic (IgEmediated) diseases. Ann Allergy 1993;71:234-8. 34. Ellis CN, Stevens SR, Blok BK, Taylor RS, Cooper KD. Interferongamma therapy reduced blood leukocyte levels in patients with atopic dermatitis: correlation with clinical improvement. Clin Immunol 1999;92:49-55. 35. Van der Heijden FL, Wierenga EA, Bos JD, Kapsenberg ML. High frequency of IL-4 producing CD4+ allergen-specific T lymphocytes in atopic dermatitis lesional skin. J Invest Dermatol 1991;97:389-94. 36. Ramb-Lindhauer C, Feldman A, Rotte M, Neumann C. Characterisation of grass pollen reactive T cell lines derived lesional skin. Arch Dermatol Res 1991;283:71-6. 37. Van Reijsen FC. Bruijnzeel-Koomen CA, Kalthoff FS, Maggi E, Romagnani S, Westland JKT, et al. Skin-derived aeroallergen

J AM ACAD DERMATOL JUNE 2000

38.

39.

40.

41.

42. 43.

44.

45.

46.

47.

48.

49.

specific T-cell clones of TH2 phenotype in patients with atopic dermatitis. J Allergy Clin Immunol 1992;90:184-92. Kagi MK, Wuthrich B, Montano E, Barandun J, Blaser K, Walker C. Differential cytokine profiles in peripheral blood lymphocyte supernatants and skin biopsies from patients with different forms of atopic dermatitis, psoriasis, and normal individuals. Int Arch Allergy Immunol 1994;103:332-40. Gerondakis S. Structure and expression of murine germline immunoglobulin ε heavy chain transcripts induced by interleukin 4. Proc Natl Acad Sci U S A 1990;87:1581-5. Chretien I, Pene J, Briere F, De Waal Malefijt R, Rousset F, De Vries JE. Regulation of human IgE synthesis. I. Human IgE synthesis in vitro is determined by the reciprocal antagonistic effects of interleukin 4 and interferon-gamma. Eur J Immunol 1990;20: 243-51. Byron KA, Varigos GA, Wooton AM. Recombinant interferongamma inhibits the expression of IL-4 receptors on human lymphocytes. Clin Exp Immunol 1991;85:307-11. Gajewski TF, Fitch FW. Regulation of helper T lymphocyte activation by IFN-γ. J Interferon Res 1990;10(Suppl 1):82S. Hamid Q, Boguniewicz M, Leung DYM. Differential in situ cytokine gene expression in acute versus chronic atopic dermatitis. J Clin Invest 1994;94:870-6. Fujisawa T, Abu-Ghazaleh R, Kita H, Sanderson CJ, Gleich GJ. Regulatory effect of cytokines on eosinophil degranulation. J Immunol 1990;144:642-6. Peters MS,Winkelmann RK, Greaves MW, Kephart GM, Gleich GJ. Extracellular deposition of eosinophil granule major basic protein in pressure urticaria. J Am Acad Dermatol 1987;16:513-7. Bruijnzeel PLB, Kuijper PHM, Kapp A, Warringa RAJ, Betz S, Bruijnzeel-Koomen CAFM. The involvement of eosinophils in the patch test reaction to aeroallergens in atopic dermatitis: its relevance for the pathogenesis of atopic dermatitis. Clin Exp Allergy 1993;23:97-109. Kapp A. The role of eosinophils in the pathogenesis of atopic dermatitis—eosinophil granule proteins as markers of disease activity. Allergy 1993;48:1-5. Noh GW, Lee KY. Blood eosinophils and serum IgE as predictors for prognosis of interferon-gamma therapy in atopic dermatitis. Allergy 1998;53:1202-7. Stevens SR, Hanifin JM, Hamilton T, Tofte SJ, Cooper KD. Longterm effectiveness and safety of recombinant human interferon gamma therapy for atopic dermatitis despite unchanged serum IgE levels. Arch Dermatol 1998;134:799-804.