Shojiro Nakagawa

Studies on the retest reaction in contact sensitivity to DNCB.

DNCB-sensitized guinea pigs demonstrated an accelerated reactivity on retest of DNCB at the site of prior contact reaction, though presenting normal contact sensitivity at the virgin site. The retest reaction reached maximal at 9 h and waned at 24 h after antigenic challenge. Massive accumulation of eosinophils in either the epidermis or dermis was its distinguishing histologic feature. The reaction was induced at the site of delayed skin reaction to DNP-GPE in the animals sensitized with DNCB or DNP-GPE. A retest reaction in delayed sensitivity to DNP-GPE was also elicited at the site of contact reaction to DNCB in the animals. The significance of these findings is discussed.

APPEARANCE OF MEMBRANOCYSTIC LESION (NASU)- LIKE CHANGES IN BEHÇET'S SYNDROME. An Electron Microscopic Study of Erythema Nodosum-like Lesions

Membranocystic lesion (Nasu)‐like changes were seen in the subcutaneous fat tissues of erythema nodosum‐like lesions in three of 18 patients with Behcets syndrome. The membranocystic structures, which were derived from degenerative fat cells with a loss of the cell membrane, were observed in the edematous connective tissues accompanied by fibrin deposition and diapedesis of erythrocytes. Electron microscopic evaluation revealed two different patterns of peculiar membranous structures in the cytoplasm of the degenerative fat cells. One was proliferating membrane structures such as well developed Golgi‐endoplasmic reticulum, and the other was minute tubular structures such as intracytoplasmic microvesicles. These degenerative fat cells are considered to be derived from abnormal fat cells which lack a cell membrane, but whose cellular and nuclear configurations appear to be normal morphologically, because the cytoplasm of these abnormal cells showed the same tubular structures as those seen in the characteristic architecture of membranocystic lesion‐like change. The relation between the appearance of such abnormal cells and the pathologic conditions of erythema nodosum‐like lesions in Behcets syndrome was discussed. ACTA PATHOL JPN 38: 1001∼1010, 1988.

Distribution of 2,4-dinitrophenyl groups on the epidermal Langerhans cells of guinea pigs following skin painting with 2,4-dinitrochlorobenzene.

It has been postulated that epidermal Langerhans cells (LC) are essential for induction and elicitation of contact sensitivity (CS) to simple chemical allergens. Although the precise role of LC in CS has not been determined, recent reports have focused on a function for LC in the presentation of antigen to T lymphocytes. To investigate this possibility, the distribution of allergen on the epidermal LC of inbred strain 13 guinea pigs was observed by the immunofluorescent method using antibodies against Ia antigen and hapten. 2,4-Dinitrophenyl groups were found to be localized on/in Ia-positive epidermal LC of the animals following skin painting with 2,4-dinitrochlorobenzene. This finding is discussed in relation to the role of LC as antigen presenting cells in CS.

The suppressive effect of tape-stripping treatment of guinea-pig skin on the induction of contact sensitivity by intradermal injection of haptenated epidermal cells

SummaryContact sensitivity (CS) to 2,4-dinitrochlorobenzene (DNCB) was produced in inbred JY1-strain guinea pigs by the intradermal injection of epidermal cells (ECs) prepared from DNCB-painted skin (DNP-ECs). When the site of DNP-EC-induced CS was pretreated by tape stripping, the rate and intensity of the challenge reactions to DNCB were diminished. The ability of DNP-ECs to induce CS returned to normal when normal peritoneal macrophages together with DNP-ECs were administered into the stripped skin. Normal ECs had a similar effect. Using either anti-Ia antiserum and complement or allogeneic ECs (strains 2 and 13), Ia-positive cells among the ECs (presumably Langerhans cells) were found to be essential for the recovery of CS. Tape-stripping treatment also resulted in the development of immunological tolerance, as assessed by subsequent painting with a sensitizing dose of DNCB. These findings suggest that the immunological function of the mononuclear-phagocyte system in the dermis may be impaired when the epidermal surface is markedly disturbed by tape-stripping treatment.

ANTIGEN IN CONTACT SENSITIVITY

The distribution of DNP groups on epidermal single cells and epidermal sheets prepared from the skin of guinea pigs three hours after painting with 5% DNCB‐ethanol solution was examined by scanning immunoelectron microscopy using bacteriophage T4 as a visual marker. The study showed that DNP groups were distributed diffusely on the surface of epidermal cells, in particular keratinocytes, and suggests that DNCB may bind to the surface components of epidermal cells when painted on the skin.

IMMUNOPATHOLOGICAL STUDIES ON PSORIASIS

In vivo deposits of fibrin, fibrinogen, plasminogen, complements and immunoglobulins were observed using immunofluorescent (IF) staining of psoriatic lesions. Deposits of fibrin were seen in either the horny layer or the dermal papillae. A linear cytoplasmic appearance of fluorescence in the psoriatic scales was a common pattern of the staining. IF staining of the psoriatic horny layer for fibrinogen and plasminogen yielded essentially the same pattern as those of fibrin and IgG.

Ultrastructural localization of 2,4-dinitrophenyl groups on draining lymph node cells of guinea pigs following skin painting with 2,4-dinitrochlorobenzene: I. Scanning immunoelectron microscopic studies.

The distribution of DNP groups on cells taken from draining lymph nodes of guinea pigs 12 hours after painting the skin with DNCB was examined by scanning immunoelectron microscopy using antibody directed against DNP groups with bacteriophage T4 as a visual marker. The studies showed that DNP groups were distributed on the surface of the cells, demonstrating some differences in distribution pattern among the cells. The incidence of cells on which DNP groups were detected was approximately 60% in the normal animals, higher than that detected by a previous immunofluorescent study. The incidence was markedly reduced to approximately 3% by pretreatment with tolerogen, DNBSO3Na. DNP groups were detected on the surface of the cells forming both rabbit red cell rosettes and complement coated red cell rosettes. It is suggested that DNCB penetrates through the skin into the lymphatics carrying lymph from the painted site and combines with cell membrane components in the peripheral lymphoid system.

A case of Schönlein-Henoch-purpura: an immunopathological study.

A case of Schönlein‐Henoch‐purpura is presented. The immunofluorescent study of skin lesions of the patient showed granular deposits of IgA and C3 in the blood vessel walls perivascular deposits of plasminogen and diffuse localization of fibrin and fibrinogen in the upper dermis. Complement activation via the alternative pathway through IgA, C3 and plasminogen deposits was suggested.

Effects of topical cyclosporin A on guinea-pig toxic contact dermatitis

SummaryIt is known that the topical application of cyclosporin A (CsA) has a significant suppressive effect on allergic contact dermatitis. In this study, we investigated the effect of topical CsA on toxic (non-allergic) contact dermatitis. Topical CsA significantly suppressed the toxic contact reaction to croton oil. This suppressive effect was short-lived and reversible. Significant inhibition of the reaction to croton oil persisted for 3 days after stopping the CsA. The toxic reaction was blocked when CsA was applied within 6 h of the croton oil application, but when application of CsA was delayed until 12 h after the oil application there was no significant suppressive effect. Topical administration of CsA could become a valuable tool for treating toxic and allergic contact dermatitis without producing the adverse reactions caused by systemic therapy.

The Distribution of 2,4‐Dinitrophenyl Groups on Thy‐1 Positive Cells in the Epidermis of Mouse Following Skin Painting with 2,4‐Dinitrochlorobenzene

The distribution of 2,4‐dinitrophenyl (DNP) groups on Thy‐1 positive epidermal cells in vivo after 2,4‐dinitrochlorobenzene (DNCB) was painted on the skin surface of C3H/He mice was examined. Epidermal cell suspensions (EC) derived from trypsin‐separated mouse ear skin painted with DNCB were double‐stained for DNP groups and Thy‐1 protein using FITC‐anti‐DNP antibody, biotinylated anti‐mouse Thy‐1,2 monoclonal antibody, and phyco‐erythrin conjugated avidin. There were on the average 1.7% Thy‐1+ ECs; DNP groups were detectable on 77.8% of them when the specimen was treated with anti‐DNP followed by anti‐Thy‐1,2 incubation. The incidence of Thy‐1,2+ EC with DNP groups decreased when cells were treated with these antibodies in the reverse order. The significance of these findings is discussed in relationship to the mode of DNCB Thy‐1+ EC binding.