Oral prednisone regulates human skin T cells in delayed-type hypersensitivity reaction elicited by diphencyprone

BACKGROUND

The potential benefit of inducing delayed-type hypersensitivity (DTH) reaction in healthy volunteers (HVs) as experimental models to study skin inflammatory disorders was recently reported using bulk molecular technologies. Immunophenotype of skin T cells, including cellular source of Type 1, 2, and 3 cytokines, in a local DTH reaction and their modulation by oral drugs remain to be investigated.

METHOD

Purified protein derivative (PPD), nickel, diphencyprone (DPCP), or house dust mite (HDM) was administered as sensitizer to 40 HVs. In addition, 20 HVs were randomized to receive oral prednisone or placebo before DPCP challenge. We characterized the immunophenotype and cytokine profile of CD3⁺ T cell infiltrate, and examined the modulation by oral prednisone at single cell level using multi-parameter flow cytometry and unsupervised analysis.

RESULTS

PPD was biased towards a Th1 and Tc1 response, and HDM a Th2/Th17 and Tc2. Nickel and DPCP displayed a mixed Th1/Th2/Th17 and Tc1 response. CD4⁺ CD25⁺ FoxP3⁺ regulatory T cells (Tregs), the minor CD4⁺ CD25⁺ FoxP3^- ICOS⁺ PD-1⁺ (activated PD-1⁺ Th), and CD103⁺ tissue resident memory (TRM) cells were detected in all groups. DPCP uniquely elicited rare CD8⁺ CD103⁺ CD25⁺ RoRγt⁺ PD-1⁺ ICOS⁺ IFNγ⁺ T cells (activated CD8⁺ IFNγ⁺ PD-1⁺ TRM). Oral prednisone decreased frequencies of activated PD-1⁺ Th and CD8⁺ IFNγ⁺ PD-1⁺ TRM subsets relative to placebo in DPCP reaction. The latter was positively correlated with improvement of clinical parameters with prednisone.

CONCLUSION

DTH and skin CD3⁺ T cell profiles elicited by common sensitizers can be modulated by oral drugs. Corticosteroids reduce the frequencies of activated PD-1⁺ Th and CD8⁺ IFNγ⁺ PD-1⁺ TRM cells after DPCP exposure.

The efficacy and safety of intralesional Candida vaccine versus topical diphencyproprobenone in immunotherapy of verruca vulgaris: A randomized comparative study

Various therapeutic options are available for verruca. While physical destruction may be associated with scarring, immunotherapy may be effective in treating warts through stimulating body immune response. The objective of the study was to compare the efficacy, safety, and outcome of Candida antigen vs diphencyprone (DPCP) in the treatment of warts. Fifty patients were randomly assigned to receive either intralesional Candida antigen every 3 weeks or weekly DPCP application. Both treatments were applied only to the mother wart. Lesions' clearance and associated side effects were observed up to 4 weeks after treatment. Two blinded physicians evaluated photos of warts before and 4 weeks after the end of treatment. Both modalities granted wart clearance and/or improvement with no statistically significant difference; however, Candida antigen was significantly better in clearing adjacent untreated warts (p = 0.046). Fewer side effects were observed among the Candida antigen group. The response was duration associated in the Candida groups only. Intralesional Candida antigen injection and DPCP treatments for warts yielded improvement with superiority of Candida injection in eradicating distant lesions and fewer side effects. A shorter wart duration may be associated with a better therapeutic response with Candida antigen.

Use of Contact Immunotherapy in the Treatment of Skin Diseases Other than Alopecia Areata

For decades, contact immunotherapy with dinitrochlorobenzene, diphencyprone, and squaric acid dibutylester has played an important role in both clinical practice and scientific research. It is listed as the first-line treatment for extensive alopecia areata and was more recently approved for melanoma treatment as an orphan drug in the USA. Moreover, owing to the relative low cost and safety, topical immunotherapy has also been used in many infectious, neoplastic, and inflammatory dermatological diseases. It is especially valuable in vulnerable groups, for cosmetic/pain sensitive areas, or for multiple lesions. In this review, we summarize the current evidence supporting the use of contact immunotherapy for treatment of skin diseases, from articles collected from PubMed database. Owing to space limitation and already numerous studies focusing on alopecia areata, we include only skin diseases other than alopecia areata. In addition to diseases that have been reported to be treated by contact immunotherapy, the hypothesized mechanism, prognosis prediction, efficacy, and safety of these topical agents are discussed.

A prospective comparative study of two regimens of diphenylcyclopropenone (DPCP) in the treatment of alopecia areata

BACKGROUND

Alopecia areata (AA) is a chronic disorder and the best treatment regimen for it is unknown. Currently, one of the best documented treatment modalities for AA is topical immunotherapy.

AIM

To evaluate the safety and efficacy of a novel method (multi-concentration patch test) versus standard protocol for topical immunotherapy.

METHODS

A prospective randomized clinical trial was conducted on 30 patients with Alopecia areata, half of them received DPCP with a novel method using multi-concentration patch test to determine the optimal initiating concentration of DPCP (case group) and the other half experienced immunotherapy according to the standard protocol (control group). Percentage of hair regrowth after 6 months of treatment and the incidence of drug-related adverse effects were evaluated and compared between the two groups. (IRCT registration code: IRCT20141209020250N5).

RESULTS

Absolute and relative hair regrowth percentages were reported 25% and 41.49% in case group and 8.2% and 14.21% in control group respectively. Considerable response (more than 75% hair regrowth) was observed in 4 (26.6%) patients in case and 1 (6.6%) patient in control group. The clinical response was initiated about 7 weeks sooner in case compared to the control group (14 versus 7.38 weeks, P: 0.001). Overall, clinical response was higher in patients received new protocol, compared to control group. Moreover, patients who experienced new protocol had a higher level of treatment satisfaction in comparison with patients having standard protocol (P: 0.012).

CONCLUSION

This study revealed the effectiveness and safety of the novel multi-concentration patch test DPCP therapy for AA and its priority to conventional method, at least in terms of shortened duration of DPCP immunotherapy.

A randomized trial of diphenylcyclopropenone (DPCP) combined with anthralin versus DPCP alone for treating moderate to severe alopecia areata

BACKGROUND

Alopecia areata (AA) is a chronic autoimmune disorder. Finding the best treatment regimen for it remains a challenge. Currently, one of the best documented treatment modalities for AA is topical immunotherapy.

AIM

To evaluate the safety and efficacy of combined DPCP and anthralin versus standard protocol (DPCP alone).

METHODS

A prospective randomized clinical trial was conducted on 50 patients with Alopecia areata who received DPCP alone (group D) or in combination with anthralin (group D/A). Percentage of hair regrowth after 6 months of treatment and the incidence of drug-related adverse effects were evaluated and compared between the two groups.

RESULTS

Complete hair regrowth was observed among three patients in each group (18.75% in Group D and 15.79% in Group D/A) after 6 months. Moreover, 25% and 31% of patients in group D and 21% and 47% of patients in group D/A had > 75% and > 50% hair regrowth respectively at the end of the study (P-value: 0.696). In addition, earlier age of onset, chronicity of lesions, nail involvement, facial hair loss and extensive lesions at baseline were associated with poor clinical outcome.

CONCLUSION

DPCP and anthralin was as effective as DPCP alone and anthralin did not add to the effect of DPCP in treating AA.

Topical immunotherapy in combination with anthralin in the treatment of refractory alopecia areata

BACKGROUND

Treatment is often challenging in patients with alopecia areata. We often try topical immunotherapy to treat alopecia areata in Japan. Anthralin is sometimes used in other countries.

OBJECTIVES

The aim of this study was to examine effectiveness of combination therapy with both topical immunotherapy with squaric acid dibutylester or diphenylcyclopropenone and anthralin in the treatment of refractory alopecia areata.

METHODS

We treat four patients with refractory alopecia areata by topical immunotherapy and anthralin. Two patients had alopecia areata multilocularis and the other two patients had alopecia totalis. The entire scalp was treated with weekly application of squaric acid dibutylester or diphenylcyclopropenone and daily 0.5% anthralin ointment. Patients were followed up weekly, and adverse effects were recorded.

RESULTS

One patient with multifocal patches of alopecia areata got complete hair regrowth at week 30, the other patient with multifocal patches of alopecia areata turned for the worse at week 30 and recovered at week 52. Hair regrowth was not seen in the other two patients with alopecia totalis. Localized pruritis and hyperpigmentation of the scalp were seen in two patients.

CONCLUSIONS

To treat alopecia areata unresponsive to topical immunotherapy alone, topical immunotherapy in combination with anthralin is worth a try.

Subclinical sensitization with diphenylcyclopropenone is sufficient for the treatment of alopecia areata: Retrospective analysis of 159 cases

BACKGROUND

Contact immunotherapy with diphenylcyclopropenone (DPCP) is presently considered the treatment of choice for extensive alopecia areata. However, a major concern with contact immunotherapy is that it causes various adverse effects (AEs) that contribute to discontinuation of treatment.

OBJECTIVE

We investigated whether a modified DPCP treatment protocol can promote hair regrowth with fewer AEs.

METHODS

All patients were sensitized with 0.1% DPCP and began treatment with 0.01% DPCP. Thereafter, the DPCP concentration was slowly increased according to the treatment response and AEs. This was a retrospective review of DPCP treatment with modified protocols in 159 patients with alopecia areata.

RESULTS

Of the 159 patients, 46 (28.9%) showed a complete response and 59 (37.1%) showed a partial response. No patients had AEs after sensitization. During the treatment, only 3 patients (1.9%) showed severe AEs, and 55 showed moderate AEs; however, all were well controlled with antihistamines alone or antihistamines and medium-potency topical steroids. There was no association between treatment response and AEs.

LIMITATIONS

Sample size, subject composition, and the retrospective study design represent potential limitations.

CONCLUSION

A modified DPCP treatment protocol with subclinical sensitization could induce a favorable therapeutic response and result in fewer AEs.

Practicality in using diphenyl cyclo propenone for alopecia areata

Diphenyl cyclo propenone (DPCP) is used as a topical immunomodulator in alopecia areata. It is a potent allergen. The process of procuring, dilution and application limits its wider use. This short communication aims to make the DPCP application easy to use.