Yukinori Ohta

Expression of IL-18 in psoriasis.

Abstract Interleukin-18 (IL-18) is a novel cytokine that plays an important role in the T-helper 1 (Th1) response, primarily via its ability to induce IFN-γ production in T cells and NK cells. Human keratinocytes produce IL-18, as do monocytes and macrophages, which are the two major sources of this molecule. It is thought that IL-18 derived from keratinocytes might be involved in the cutaneous Th1-type immune response. In the present study, we investigated the expression of IL-18 in psoriatic lesional skin and attempted to determine whether immunoreactive IL-18 in crude extracts of psoriatic scales is processed to the mature, active form. Immunohistochemical and RT-PCR analysis showed that the expression of IL-18 was increased in psoriatic lesional skin relative to that in normal skin. Western blotting and an ELISA for IL-18 in combination demonstrated that the immunoreactive IL-18 in extracts of psoriatic scales contained the mature form of IL-18, but most of the IL-18 was pro-IL-18. No bioactivity of IL-18 or IFN-γ inducibility in human PBMC could be detected in psoriatic scales. Taken together, these findings indicate that keratinocyte-derived IL-18 participates in the development of the Th1 response in psoriatic lesions, and that its bioactivity appears to be tightly regulated in cutaneous inflammation.

In situ expression of messenger RNA of interleukin-1 and interleukin-6 in psoriasis: interleukin-6 involved in formation of psoriatic lesions

SummaryPsoriasis is a disease of abnormal proliferation and differentiation of epidermal cells. Several cytokines released by keratinocytes are implicated as factors responsible for this pathological condition of the epidermis. In order to elucidate the role of these cytokines in psoriasis, messenger RNA (mRNA) expression of interleukin-1 (IL-1) and IL-6 in psoriatic epidermis was investigated using biotin-labelled complementary DNA (cDNA) of the cytokines. Messenger RNA of IL-1α was weakly detected in some normal healthy epidermis specimens and more strongly in all the perilesional uninvolved psoriatic epidermis specimens. It was also expressed in the transitional zone between uninvolved and fully developed psoriatic skin, but was not expressed in lesional skin. In contrast, IL-6 mRNA was rarely expressed in normal healthy epidermis, but was expressed in perilesional uninvolved psoriatic epidermis, in the transitional zone and in the fully developed lesional epidermis, with the maximum intensity in the transitional zone. Expression of mRNA of IL-6 receptor showed a similar tendency to that of IL-6. It was expressed in psoriatic epidermis, most strongly in the transitional zone, but not in normal healthy epidermis. IL-6 was demonstrated immunohistochemically in psoriatic epidermis, but IL-6 receptor was demonstrated only in the transitional zone. Thus IL-6 and its receptor expression correlated well with the formation of psoriatic lesions where IL-1 may initiate their expression. IL-6 may play an important role in the pathogenesis of psoriasis.

High efficiency genetic modification of hair follicles and growing hair shafts

A technique for genetic modification of hair follicles was developed which results in efficient alteration of the hair shaft phenotype. High-level in vivo transgene expression was maintained in hair follicles such that growing hair shafts were phenotypically altered. Mouse anagen skin fragments, maintained in histoculture, were genetically modified at high efficiency with adenoviral-GFP. The histocultured skin fragments were treated with collagenase which made hair follicles accessible to the adenoviral GFP gene, allowing high-efficiency transduction. These skin fragments were subsequently grafted on to nude mice where GFP was readily visualized in as many as 75% of hair follicles. Most follicles produced GFP-fluorescent growing hair shafts. This technique has produced efficient genetic modification of the hair shaft.

In situ Expression of CD40 and CD40 Ligand in Psoriasis

Background: The interaction between CD40 and CD40 ligand (CD40L) provides a signal that contributes to the initiation of cellular immune responses. However, little information on the in vivo expression of CD40 and CD40L in cutaneous inflammation has been reported. Objective: To investigate the potential role of CD40-mediated signals in the pathogenesis of psoriasis. Materials and Methods: In situ CD40 and CD40L expression was examined immunohistochemically in different stages of psoriatic lesions: fully developed and initial pinpoint. Results: In normal skin, faintly positive immunoreactivity for CD40 was seen in the basal keratinocytes and dermal endothelial cells. These showed almost the same intensity as that seen in psoriatic lesional skin. In the dermal infiltrates of psoriatic lesions, CD40 was intensely expressed and some of these positive cells appeared to be dendritic in shape. Whereas CD40 expression was observed almost in all specimens of psoriatic lesions, the expression of CD40L was predominantly detected in the initial pinpoint lesions of psoriasis. These seemed to be distributed close to CD40-positive cells. Conclusion: These results suggested that CD40L-triggered signals could be involved in the early stage of psoriatic lesion formation.

Lichen Planus and Sjögren‐type Sicca Syndrome in a Patient with Chronic Hepatitis C

We report a 54‐year‐old Japanese male with lichen planus and Sjögren‐type sicca syndrome, accompanied by the latent complication of chronic hepatitis C. The patient first showed erythematous and erosive lesions with white irregular striae in the buccal mucous membrane, and blepharitis and hyperemia of conjunctiva in his eyes. He later had two small erosions on the glans penis, and flat‐topped violaceous papules on the dorsa manus and nape. A biopsy specimen of the lower lip lesion demonstrated a lichenoid tissue reaction at the basement membrane zone, and lymphocytic focal accumulations in the salivary glands. Immunohistochemical study of this specimen revealed CD45RO+ (T) cells associated with the expression of HLA‐DR antigens predominantly in both the lichenoid tissue reaction and the lymphocytic sialadenitis. Objective keratoconjunctivitis sicca was confirmed by the Schirmer and Rose‐Bengal tests. Anti‐DNA antibody was positive; however anti‐SS‐A, and anti‐SS‐B antibodies were negative. Increased levels of transaminase enzymes, TTT, ZTT, and IgG were observed in first laboratory examinations; thereafter, anti‐hepatitis C virus (HCV) antibodies and HCV‐RNA were detected. The high serum amylase level, in which salivary amylase predominated, was normalized by etretinate therapy in parallel with the clinical improvement of the oral LP lesions. Our case is considered to support the hypothesis that an etiologic association may be present among lichen planus, Sjögrens syndrome, and chronic hepatitis C.

Efficacy of oral fluconazole in tinea pedis of the hyperkeratotic type. Stratum corneum levels

Summary. In this study, in addition to studying the efficacy and safety of the once‐daily administration of 100‐mg capsules of fluconazole over an 8‐week administration period with six patients with hyperkeratotic‐type tinea pedis, we also measured the serum and horny layer concentrations of fluconazole to study the mobility into the horny layer in diseased areas of the sole skin. The final overall efficacy and overall safety were both 100% (six out of six), and no side‐effects, including abnormal‐laboratory changes, were observed in any of the patients. The drug mobility study revealed that in the horny layer of the skin a steady state was reached after 4 weeks of administration, with the mean concentration being 12.8μgg‐1. This concentration was a high concentration that was no less than 13 times the geometric mean MIC (0.972 μg ml‐1) for fresh clinical isolates of Trichophyton rubrum. Based on the above results, fluconazole is considered to be highly useful for treating various kinds of dermato‐mycosis, including hyperkeratotic‐type tinea pedis.

Butenafine hydrochloride (Mentax®) cream for the treatment of hyperkeratotic type tinea pedis and its transfer into the horny layer, with or without concomitant application of 20% urea ointment (Keratinamin®)

Summary. Forty‐five patients were divided into two groups: group I, 23 patients, treated with butenafine hydrochloride (Mentax®) cream alone, and group II, 22 patients, treated with butenafine hydrochloride and 20% urea ointment (Keratinamin®) to evaluate the usefulness of the treatments. We also measured the transfer of these drugs to the horny layer in some patients. The clinical improvement rate of dermatological symptoms (marked improvement+ improvement) was 91.3% in group I, 100% in group II, with therapeutic effects evident earlier in group II than in group I. The mycological eradication rate was found to be 47.4% in group I, 50.0% in group II after 4 weeks of treatment, and 81.8 and 87.5% at 12 weeks thereafter, respectively, with no adverse reactions found. The clinical utility rate (markedly useful+useful) was 91.3% in group I and 86.4% in group II. These results demonstrate that application of butenafine hydrochloride alone was extremely effective for the treatment of hyperkeratotic‐type tinea pedis and that combination application with urea ointment resulted in an earlier improvement of dermatological symptoms. The concentration of butenafine in the horny layer from healthy volunteers reached a steady state in both groups I and II at 2 weeks after the application, with a lower concentration found in group II (about 70 ng mg−1) than in group I (about 100 ng mg−1). Although some variations in concentration were found in case by case, patients in whom the treatment was determined to be ‘markedly effective and effective’ showed the increase in concentration of the drug in the lesional horny layer to be directly proportional to the number of days of treatment, with a lower concentration found in group II than in group I. This trend was also seen in healthy volunteers.

Characterization of infiltrating T cells in human scalp explants from alopecia areata to SCID nude mice: possible role of the disappearance of CD8+ T lymphocytes in the process of hair regrowth.

T cells may play a role in the pathogenesis of alopecia areata (AA). We attempted to elucidate the linkage between infiltrating T cells and hair regrowth processes by grafting scalp skin from the affected region of patients with AA onto severe combined immune deficiency (SCID) nude mice.

Lichen planus annularis: an immunohistochemical study.

Lichen planus annularis is a relatively rare skin manifestation of lichen planus. The mechanisms in the formation of annular lesions are not fully understood. We reported here a 57‐year‐old female with this disease. The eruption initially occurred as lichen‐papules, then enlarged (bean‐sized, umbilicated small plaques), and finally developed annular manifestations. We performed immunohistochemical examinations of specimens taken from different types of eruptions.

In situ Expression of Interleukin-6 in Psoriatic Epidermis during Treatment

Interleukin‐6 (IL‐6) is a multipotential cytokine which may act as a growth factor for keratinocytes. The epidermal hyperplasia of psoriasis may be explained in part by an overproduction of this cytokine. We have previously shown by in situ hybridization that IL‐6 mRNA is most strongly expressed in the peripheral lesion of an advancing psoriatic plaque. In the present study, we investigated whether there were differences between the expression of IL‐6 in untreated psoriatic epidermis and the lesion during the course of clinical improvement. In the untreated psoriatic lesion, the weak expression of IL‐6 mRNA was localized in the lower epidermis. However, IL‐6 mRNA was not detected in the clearly improved lesion. In the improving lesion, with clinically less scaling, less induration, and histologically thinner epidermis, IL‐6 mRNA‐expressing keratinocytes were detectable in a greater proportion of the total epidermal components than in the untreated, fully developed lesion. These results showed that IL‐6 mRNA was strongly expressed in lesions with moderate epidermal hyperproliferation, indicating that this cytokine may play a role in the transitional phase during the course of improvement as well as in the lesions formation.