The Langerhans cell: from gold to glitter

Spontaneous transient remission of disseminated histiocytosis X during pregnancy

Disseminated histiocytosis X with cutaneous and lymph node involvement was diagnosed in a 25-year-old women. The diagnosis was established on the basis of a positive cell-surface staining with OKT 6 and typical signs on electron microscopy. Both the specific skin rash and lymph node swelling completely disappeared during pregnancy, but recurred 2 weeks before delivery. Therapeutic trials with 0.25 mg ethinylestradiol/day and a later application of human chorionic gonadotropin up to 5000 IU i.m. twice weekly as well as prednisolone 25 mg three times per day were unsuccessful. A second pregnancy was not desired. Polychemotherapy with initial high-dose prednisolone plus vincristine and a consolidation therapy with 5-mercaptopurine 300 mg/day led to full recovery. The observation of transient remission of histiocytosis X during pregnancy suggests that at least some forms of this disease may have prevailing immunological features where an immunosuppressive effect of pregnancy could be beneficial.

Enrichment of unlabelled human Langerhans cells by modified discontinuous Ficoll-metrizoate density medium and following Langerhans cell culture

Highly enriched and specifically unlabelled human Langerhans cells (LC) from epidermal cell suspensions (ECS) are indispensable for the intensive study of LC function. Discontinuous Ficoll-metrizoate density gradient centrifugation was found to be a satisfactory method of enriching LC from ECS. In contrast to a previous study, however, the majority of LC floated on Ficoll-metrizoate with a density of 1.057 g/cm3 instead of 1.068 g/cm3. The concentration of unlabelled LC can be enriched to as high as 92% from the original 1.8-3.1% LC in ECS. Approximately 40-50% of original LC can be harvested. The procedure was also simplified by using a Schick razor instead of a dermatome to obtain thin epidermal sheets (about 0.25 mm in thickness), omitting the density gradients of 1.089 and 1.10 g/cm3 and using the avidin-biotin complex method to identify LC. LC are non-proliferative cells in in vitro culture systems. The viability of LC dropped to 20-30% after 3 days in the culture medium. It was also observed that LC tended to attach to aggregated keratinocytes in the culture system.

Mitotic Langerhans cell as a possible sign of activation in ichthyosis

The fine structure of Langerhans cells (LC) in four rare types of ichthyosis, namely recessive ichthyosis congenita type II, III and IV and ichthyosis hystrix Curth-Macklin was examined. Signs of LC activation were observed in eight of 21 patients. In IC type IV, the rare occurrence of a mitotic LC was observed. It is possible that LCs are secondarily activated in keratinization disorders.

Accumulation of membrane-bound melanosomes occurs in Langerhans cells of patients with the Leopard syndrome

The Langerhans cells in the lentigines of four patients with the Leopard syndrome contained large membrane bound accumulations of melanin granules. Giant melanosomes were only seen in two patients. The patients had no immune-based symptoms relating to their lentigines. The Leopard Syndrome, also known as multiple lentigines syndrome, progressive cardiomyopathic lentiginosis, lentiginosis profusa syndrome and the cardiocutaneous syndrome, refers to an inherited abnormality of the skin, often associated with cardiomyopathy. The aetiology of the condition is so far unknown and the penetrance is variable. Here we describe electron microscopical findings of large accumulations of melanin within Langerhans cells.

Simultaneous assessment of inflammation and epidermal proliferation in psoriatic plaques during long-term treatment with the vitamin D3 analogue MC903: modulations and interrelations

The influence of topical application of MC903, an analogue of 1 alpha,25-dihydroxyvitamin D3, on psoriatic plaques was investigated during a long-term treatment study. The parameters for epidermal growth and for inflammation were assessed on frozen sections using immunohistochemical methods to elucidate their modulations in time and the interrelations between the different cell types involved during treatment with MC903. Biopsies were taken before and after 1, 2, 4 and 12 weeks of treatment. Monoclonal antibodies against the hyperproliferation-associated keratin 16, against cycling nuclei, and against T lymphocytes, B lymphocytes, Langerhans cells and CD14-positive cells were used in combination with a polyclonal antibody against polymorphonuclear leucocyte (PMN)-elastase. The earliest change was a statistically significant decrease in PMN after 1 week of treatment followed by a decline of cycling nuclei after 2 weeks. These changes preceded a decrease of T lymphocytes which occurred after 4 weeks. Keratin 16 content tended to diminish after 4 weeks of treatment. CD14+ cells decreased slightly during the observation period, whereas Langerhans cells tended to increase. No B lymphocytes were found. These results suggest that MC903 influences the number of PMN and epidermal growth rather than the number of T lymphocytes.

Halo giant congenital melanocytic nevus: in vitro immunologic studies

We have assessed in vitro humoral and cell-mediated immune reactions of a patient with a giant congenital melanocytic nevus that showed clinical and histologic evidence of spontaneous regression. Nevus cell-specific antibody was detected in the patient's serum, which was cytotoxic to epidermal cells isolated from the pigmented nevus and specifically to cells of a human melanoma line in a complement-dependent fashion. The presence of epidermal Langerhans cells, known to be antigen-presenting cells, was required for nevus cell-specific activation of the patient's T lymphocytes. Antibody-independent inhibition of melanoma cell growth was detected by the use of the patient's mononuclear cells. Therefore both humoral and cell-mediated immunity may be involved in nevus cell rejection and halo formation.

Effect of donor epithelium on corneal transplant survival

Two hundred thirty-two penetrating keratoplasties in 228 eyes were performed with or without the removal of donor corneal epithelium in a prospective, randomized clinical trial to determine the effect of epithelial removal on graft survival. The removal of epithelium did not reduce the likelihood of graft failure, irreversible allograft reaction, or reversible allograft reaction.

Epidermal Langerhans cell density in patients with pulmonary malignancies and chronic obstructive pulmonary disease

To evaluate the relationship between ELC density and pulmonary malignancies, as reported in previous investigations, we examined the nonsun-exposed epidermis of 18 patients with pulmonary cancer (CA) not receiving immunosuppressive therapy, 20 patients with chronic obstructive pulmonary disease (COPD-S), and 10 patients with COPD receiving glucocorticosteroid (GCS) therapy (COPD + S). The ELC density was not significantly different between lung tumor patients (1024 +/- 167) and COPD-S (1072 +/- 200, p less than 0.4) control patients, and we found no significant correlation between ELC density and tumor cell type, presence or absence of metastases, tumor stage, or present smoking status. Although we did detect that systemic GCS therapy significantly reduced the ELC density in COPD + S patients (910 +/- 211, p less than 0.05); use of inhaled or chronic low dose (less than or equal to 20 mg daily) GCS did not appear to significantly alter ELC density. In addition, anergy to epicutaneous dinitrochlorobenzene in CA and COPD + S patients positively correlated with a reduction in ELC density, suggesting a possible functional deficit arising from the numerical change. Further investigation is needed to elucidate whether factor(s) other than a reduction in ELC density are involved in the anergic state.

Muramidase, alpha-1 antitrypsin, alpha-1 antichymotrypsin, and S-100 protein immunoreactivity in giant cell lesions

A spectrum of giant cell lesions was evaluated for muramidase, alpha-1 antitrypsin, alpha-1 antichymotrypsin, and S-100 protein immunoreactivity using an avidin-biotin-complex immunoperoxidase method. Peripheral giant cell granuloma, central giant cell granuloma, giant cell tumor, osteitis fibrosa cystica, cherubism, and giant cell tumor of tendon sheath showed similar patterns of reactivity. Granulomatous inflammatory lesions stained more intensely for muramidase than did noninflammatory lesions. Alpha-1-antichymotrypsin was a slightly better marker of giant cell lesions than was alpha-1-antitrypsin. Positive S-100 protein staining in half the lesions was thought to be due to the presence of Langerhans cells. The results supported the belief that giant cell lesions of bone and tendon sheath are differentiated toward cells of the mononuclear-phagocyte system and that multinucleated giant cells are derived from macrophages.

Immunologic aspects of leprosy

Twenty seven cases of leprosy from Egypt were examined. Monocytes were found to be high in peripheral blood in lepromatous cases. The percentage of small lymphocytes in blood was increased in tuberculoid patients. The immunoglobulins were higher in all types of leprosy patients than in normal persons.

Epidermal Langerhans cells in patients with primary Sjögren's syndrome

IgG-binding to the surface of Langerhans cells (LC) is a feature of primary Sjögren's syndrome and might be associated with qualitative and quantitative defects in LC. Fifteen patients with primary Sjögren's syndrome and 15 healthy controls had a punch biopsy performed from clinically unaffected skin. LC were enumerated in epidermal sheets by an immunoperoxidase technique, as well as demonstrated by immunofluorescence in vertical sections, which were furthermore examined for in vivo deposits of immunoglobulins, fibrinogen and C3. A significant (P less than 0.05) reduction in number of LC, measured on epidermal sheets, was found in patients as compared with controls. Examination of vertical sections did not reveal abnormalities in morphology or localisation of epidermal LC. Intraepidermal IgG deposits were demonstrated in 7/15 patients. In vivo deposits were not found in any of the controls. The density of epidermal LC was not correlated to the presence of intraepidermal IgG deposits.

Immunohistological skin investigations in patients with the acquired immune deficiency syndrome

Twenty-one male patients with acquired immune deficiency syndrome (AIDS), 6 male patients with AIDS-related complex (ARC) and 23 controls' had a punch biopsy taken from clinically unaffected skin of the buttock. Vertical skin sections were examined by immunofluorescence for in vivo deposits of immunoglobulins (Ig) and other plasma proteins, as well as for morphology and distribution of Langerhans cells (LC). Deposits of IgM in the dermo-epidermal junction zone (DEJ) were found in one patient with ARC. Apart from this single finding, no in vivo deposits of IgG, IgM, IgA, IgD, IgE, complement C1q and C3, fibrinogen or albumin were demonstrated in epidermis, DEJ or dermal vessel walls, either in patients or in controls. Epidermal LC were more superficially situated in patients as compared to controls. No differences in number and localisation of dermal LC were seen. We concluded that it was not possible to confirm a recent report of in vivo Ig deposits in the epidermis of patients with AIDS. The abnormalities observed in epidermal LC should be interpreted together with the recent finding of reduced numbers of epidermal LC; they thus support the hypothesis that LC are involved in the pathological processes in AIDS.

Immunohistochemical staining of Langerhans cells and macrophages in oral lichen planus

Twenty patients with clinically and microscopically confirmed lichen planus were studied immunohistochemically. Monoclonal antibody to HLA-DR antigens and polyclonal antisera to S-100 protein and muramidase were applied to paraffin-embedded sections for the purpose of elaborating on the pathogenesis of this disease. Trypsin incubation of sections was also done in order to determine its effect on immunostaining. Langerhans cells were identified with anti-S-100 and anti-HLA-DR, and macrophages were identified with antimuramidase and anti-HLA-DR. Keratinocytes also expressed HLA-DR membrane activity in lichen planus tissue. Trypsinization significantly improved the expression of S-100 protein and muramidase antigens. It was concluded that Langerhans cells, macrophages, and keratinocytes play important roles in antigen processing and/or phagocytosis during the natural history of this disease.

Detection of OKT6-positive cells (without visible Birbeck granules) in normal peripheral blood

The specificity of a monoclonal antibody (OKT6) for peripheral blood mononuclear cells was examined by indirect immunofluorescence and ultrastructural immunogold labelling. Some rare peripheral blood mononuclear cells (approximately 1%) expressed T6 antigen on their membrane surface, as determined by light microscopy and cytofluorometry. Electron microscopic examination of immunogold-labelled cells revealed that OKT6-positive cells were dendritic, lacking the Birbeck granules and expressed variable density of the membrane T6 antigen. The relationship of such cells with Langerhans' cells is discussed.