Phosphodiesterase inhibition by Ro 20-1724 reduces hyper-IgE synthesis by atopic dermatitis cells in vitro

Peripheral blood mononuclear leukocytes (MNL) from patients with atopic dermatitis spontaneously produce large amounts of IgE in vitro. These cells also show markedly elevated levels of cAMP phosphodiesterase (PDE) which may be responsible for the observed abnormal cAMP responsiveness. Treatment of atopic dermatitis MNL with varying concentrations of the cAMP PDE inhibitor Ro 20-1724 resulted in progressively decreasing amounts of IgE synthesis, statistically significant at the 10(-4) M and 10(-5) M concentrations. There was a close correlation between PDE inhibition and inhibition of IgE synthesis, r = 0.93, p less than 0.05. To define the cellular target of the drug, we used monoclonal antibodies directed toward MNL subsets (Lyt 3, OKT8, OKT4, monocyte-myeloid) in a modified "panning" method to perform experiments with purified subsets. With untreated subsets, removal of OKT4-positive cells significantly reduced IgE synthesis; readdition of OKT4-positive cells enhanced IgE synthesis. OKT8 cells and monocytes did not affect IgE synthesis. Pretreatment of T cell-depleted MNL with Ro 20-1724 resulted in significantly more inhibition of IgE synthesis than did pretreatment of T enriched cells prior to recombination with the reciprocal untreated subset and subsequent culture. Similarly, pretreatment of monocyte-depleted cells resulted in significantly more inhibition of IgE synthesis than pretreatment of monocyte-enriched cells prior to recombination and culture. The majority of the effect appeared to be mediated by a direct effect on the B cells. However, some inhibition of IgE synthesis was also achieved through pretreatment of T enriched cells. Since pretreatment of isolated suppressor/cytotoxic or helper/inducer T-cell subsets did not give the same degree of inhibition as with unfractionated T cells, a T-T interaction may be involved in this aspect. The imidazolidinone derivative, Ro 20-1724, significantly and consistently inhibited both the elevated cAMP phosphodiesterase activity and the elevated spontaneous IgE synthesis of MNL from patients with atopic dermatitis. These findings demonstrate a previously undescribed link between cAMP PDE levels and in vitro IgE synthesis.     

Sequential enumeration of peripheral blood T cell subsets in lichen planus

Peripheral blood T lymphocytes and T cell subsets were examined in fifteen patients with lichen planus prior to and for 4 months during treatment. The percentages of different T cell sub-populations were defined by indirect immunofluorescence using monoclonal antibodies OKT₃, OKT₄ and OKT₈. These are specific markers of total T cells, helper-inducer T cells and suppressor-cytotoxic T cells respectively. Decreased percentages of suppressor T cells and elevated helper suppressor ratios were observed before treatment and after 1 month of therapy. These changes had disappeared by the second month of treatment, by which time all the lesions had healed.     

Reduction of the fraction of circulating helper-inducer T cells identified by monoclonal antibodies in psoriatic patients treated with long-term psoralen/ultraviolet-A radiation (PUVA)

Ultraviolet radiation has been found to alter the distribution and function of human lymphocytes. To determine whether photochemotherapy (PUVA) alters circulating levels of T cell subset marker-bearing lymphocytes, cells from 9 patients with psoriasis undergoing PUVA therapy for several years (mean 4.6 +/- 1.4 yr), 17 patients with active untreated psoriasis, and 20 healthy volunteers were reacted with monoclonal antibodies to T cell surface markers, including OKT3 (all peripheral blood T cells), OKT4 (helper/inducer T cells), OKT6 (common thymocytes), and OKT8 (suppressor/cytotoxic T cells), and analyzed by flow cytometry. There were no differences in the distribution of T cell subsets between healthy volunteers and patients with active psoriasis. In contrast, the percentages of lymphocytes reacting with OKT3 and OKT4 were lower (by 16% and 12% percent respectively, p less than 0.0025) in the PUVA-treated patients compared to healthy volunteers or patients with active psoriasis that had not received PUVA therapy. There was no difference in the percentage of OKT8 and OKT6 bearing cells. Squamous cell carcinoma of the skin subsequently developed in 2 of 3 PUVA-treated patients with the lowest percentages of T4-bearing cells. These findings indicate that long-term PUVA therapy is associated with a reduction in circulating helper/inducer T cells. This reduction may have a role in the altered immune function reported in PUVA-treated patients.     

Tissue and blood T-lymphocyte subpopulations in erythema nodosum leprosum

To study T lymphocytes in erythema nodosum leprosum (ENL), monoclonal antibodies were used to identify T-lymphocyte subpopulations in the blood and skin lesions of patients with ENL and patients with nonreactional lepromatous leprosy. The blood of nonreactional lepromatous patients had a lymphopenia and a proportionate reduction in pan T cells, helper-inducer, and suppressor-cytotoxic subsets, but a normal helper-suppressor ratio, as compared with controls. Patients with ENL did not differ significantly from the controls. In skin lesions, an admixture of helper and suppressor phenotypes among foamy histiocytes was found. The ENL tissue had more numerous cells of the helper-inducer phenotype and fewer of the suppressor-cytotoxic phenotype, as compared with nonreaction lepromatous tissues. In 22 patients with simultaneous examination of tissue and blood T-cell subsets, there was no correlation between tissue and blood helper-suppressor ratios, indicating that some sort of selection process brings lymphocytes into tissues from peripheral blood.     

应用单克隆抗体研究寻常型银屑病患者外周血中的T细胞及其亚群

以抗人T细胞表面坑原的单克隆抗体OKT3、OKT4和OKT8用直接免疫荧光法分析了进行期、静止期和退行期寻常型银屑病(各10例)患者外周血中的总T细胞、协助/诱导性T细胞和抑制/细胞毒性T细胞的百分数、以及OKT4⁺/OKT8⁺细胞的比率.10名正常健康人为对照组.结果发现,与健康人对照组比较,各期寻常型银屑病患者的OKT3⁺,OKT4⁺,OKT8⁺细胞数和OKT4⁺/OKT8⁺细胞的比率无显著差异(P>0.05),各期寻常型银屑病患者间亦无显著性差异(P>0.05).最后,对本研究结果进行了讨论,认为银屑病中所见的T细胞、抑制性和协助性T细胞亚群数的异常可能是一种继发现象.     

Distribution of T-cell subpopulations in the peripheral blood of patients with erythrodermic psoriasis

In the present study the percentages of T cells and T-cell subsets, as defined by Fc receptors and monoclonal antibodies (OKT3, OKT4, OKT8, HLA-DR) were determined in the peripheral blood of 12 patients with psoriasis, including six patients with erythroderma and 6 with active, but limited disease. The patients with erythroderma were studied before treatment and 4-8 weeks following. The mean percentages of E-rosette-forming cells and T-cell subsets reactive with the monoclonal antibodies OKT3, OKT4 and OKT8 were within normal limits, as were the percentages of T mu-cells, irrespective of the extent or activity of the disease. The mean percentage of T gamma-cells was reduced in the patients with untreated erythrodermic psoriasis but not in the patients with limited disease. Comparison of the T gamma values in the erythroderma group before and after therapy showed a slight, but statistically significant increase (P less than 0.03). These results indicate a direct relationship between the T gamma deficit and the extent of skin involvement, and argue against a primary suppressor T-cell defect in psoriasis vulgaris.     

Immunologic differentiation of the Sézary syndrome due to cutaneous T-cell lymphoma and chronic actinic dermatitis

Peripheral blood mononuclear cells from two well-defined groups of patients with the Sézary syndrome have been studied employing indirect immunofluorescent and indirect immunogold techniques in light and electron microscopy, using monoclonal antibodies against T-cell subpopulations. Four patients had chronic actinic dermatitis (CAD) of the actinic reticuloid variant, with erythroderma. Eight patients had cutaneous T-cell lymphoma. All patients showed the clinical features of the Sézary syndrome, including erythroderma, palmoplantar hyperkeratosis, and peripheral lymphadenopathy, and in all patients significant numbers (0.5-30.5 X 10(9) cells/liter) of circulating mononuclear cells were observed with Sézary cell morphology on light-microscopic examination of blood films. Major differences were observed in the circulating T-cell subpopulations in the two groups. In the erythrodermic CAD patients, there was a moderately elevated T-cell count (1.6 +/- 0.6 X 10(9) cells/liter; normal, 1.0 +/- 0.3 X 10(9) cells/liter) of which the majority of the cells was suppressor T cells (OKT8+) giving a very low helper:suppressor T-cell ratio of 0.1:1-0.36:1 (normal, 1.7:1-3.5:1). In cutaneous T-cell lymphoma, there was also an elevation of the T-cell count (9.5 +/- 12.9 X 10(9) cells/liter), but in these patients the predominant cell was the helper T cell (OKT4+) with a high helper:suppressor T-cell ratio of 3.7:1-98:1.     

Determination of circulating lymphocyte subpopulations in atopic dermatitis using monoclonal antibodies

Monoclonal antibodies were used to determine the level of circulating helper and suppressor T cells in 34 infants and adults with severe atopic dermatitis and in normal controls. The percentage of OKT3 (total T lymphocytes) was reduced significantly in all the atopic infants. The percentage of OKT8 (suppressor-cytotoxic T lymphocytes) was reduced significantly in all patients with active lesions. The percentage of T gamma lymphocytes was reduced in all the atopic patients with or without active lesions.     

Immunophenotyping of the cutaneous infiltrate and of the mononuclear cells in the peripheral blood in patients with atopic dermatitis

Fourteen adult patients with chronic atopic dermatitis and active skin lesions had a skin biopsy and venous blood sample taken on the same day. Absolute numbers of circulating lymphocytes were normal in all patients. Fluorescence-activated cell sorter (FACS) analysis revealed normal numbers of total T lymphocytes and T-helper and T-suppressor subsets (helper:suppressor ratio, 2:1) in the atopic patients' peripheral blood, but an increase in circulating B lymphocytes and in HLA-D-related antigen-bearing cells. The skin biopsy showed a dermal infiltrate of predominantly T-helper lymphocytes (helper:suppressor ratio, 7:1). These cells showed strong HLA-DR plasma membrane staining. There was no HLA-DR staining in the membranes of epidermal keratinocytes. Using a monoclonal antihuman IgE, positive staining was observed in the dermis, though none was identified in the epidermis. The dermal anti-IgE staining was concentrated around clusters of T lymphocytes.     

Suppressor cell decrease in alopecia areata

Summary There is considerable evidence to suggest that autoimmunity plays a role in the pathogenesis of alopecia areata. Since it is known that T cells regulate the immune system, a study was undertaken to measure T helper (OKT-4) and T suppressor (OKT-8) cells in the peripheral blood of patients with alopecia areata (both active and stable) and in controls. Total T cells, B cells, immunoglobulins, and autoantibodies were also measured. There was a highly significant decrease in the T-suppressor cell population of patients with alopecia areata (P>0.001). Two of ten patients had microsomal antibodies and three of ten had elevated IgE levels. Other parameters were not significantly different. The decrease in suppressor cells suggests an impairment of the prime negative regulator of the immune system, with loss of tolerance and resultant autoimmunity.     

CD4+ cutaneous T-cell lymphomas show the phenotype of helper/inducer T cells (CD45RA-, CDw29+)

CD4+ T cells are heterogenous and include at least two subsets that differ in their influence to immunoglobin synthesis, cytokine secretion pattern and immunophenotype. Among others these subsets have been designated as suppressor/inducer or naive T cells (CD45RA+, CDw29-) and helper/inducer or memory T cells (CD45RA-, CDw29+). Current theories suggest that these CD4+ T-cell subsets either reflect sequential stages of maturation before and after activation (antigen contact) or represent distinct lineages. In this study, we systematically analyzed the participation of both suppressor/inducer (CD45RA+) and helper/inducer (CDw29+) T cells in the dermal lymphohistiocytic infiltrate of various CD4+ cutaneous T-cell lymphomas. Although in peripheral blood both subsets are equally distributed, we present evidence that all CD4+ cutaneous T-cell lymphomas are of the helper/inducer T cell phenotype. These findings are of importance both for pathogenetic and clinical considerations: the presence of plasma cells in dermal infiltrates and the elevation of serum immunoglobulins in patients of mycosis fungoides may be the consequence of interleukin-4 secretion of the neoplastic CD4+ helper/inducer cells. The exclusive memory T cell phenotype of cutaneous T-cell lymphomas may be due to a general predominance of this subset in the skin, or be the consequence of cellular activation during malignant transformation.     

The cell population in the cutaneous infiltrate of mycosis fungoides: in situ studies using monoclonal antisera

T cell antigens were studied in cutaneous sections from five patients with mycosis fungoides (MF). The method allowed cell counting to be undertaken for each monoclonal antiserum. OKT3 (pan T cell) antiserum confirmed the predominantly T lymphocytic nature of the infiltrate, labelling the majority of infiltrating cells. OKT4 (helper/inducer) antiserum positively labelled 90% of the lymphocytes identified as OKT3⁺. OKT8 (suppressor) antiserum marked only single or small groups of dermal lymphocytes, which comprised 24% of the cells identified as T lymphocytes. OKT6 (anti-Langerhans) showed positive labelling of dendritic cells in the epidermis and dermis. Fewer positively labelled epidermal dendritic cells were observed in sections from patients receiving PUVA, but no difference was found in the number of OKT6 positive dermal cells. The ratio of helper to suppressor cells in the dermal infiltrate significantly exceeded the normal circulating ratio.     

对DLE皮损内T细胞及其亚群的观察

用单克隆抗体借助间接酶标技术观察了5例DLE患者的皮损.在真皮内,总T细胞(OKT11⁺约70%;T辅助/诱导细胞(Leu3⁺)约40%;T抑制/细胞毒细胞(Leu2⁺)约30%.其中4例基底层附近的表皮内和毛囊上皮处以T抑制/细胞毒细胞为主.在一初发患者较为明显.提示T细胞及亚群在该病中的作用.     

The effect of oral retinoid therapy on the normal human immune system

Twenty four patients were studied prior to and after 6 and 12 weeks therapy with isotretinoin (17 patients) for acne and related disorders, or with etretinate (7 patients) for psoriasis and related disorders. Patients treated with isotretinoin had a significant reduction in natural killer cell activity at an effector: target cell ratio of 100: 1 at 12 weeks and also a reduction in natural killer cell numbers at this time. Patients treated with etretinate had elevated natural killer cell activity and a significant elevation of natural killer cell numbers at 12 weeks. Other tests which were performed and showed no significant change at 6 or 12 weeks compared with starting levels included lymphocyte transformation in response to phytohaemagglutinin, pokeweed mitogen and concanavalin A, total numbers of circulating T lymphocytes, B lymphocytes and T helper and T suppressor subsets, numbers of epidermal Langerhans cells and serum levels of IgA, IgM and IgE. In view of the involvement of natural killer cells in the initial phase of organ rejection, these results suggest that isotretinoin is the safer of the two retinoids if administration to renal transplant recipients is considered, particularly in the immediate post-transplant period.     

Subpopulations of mononuclear cells in microscopic lesions of psoriatic patients. Selective accumulation of suppressor/cytotoxic T cells in epidermis during the evolution of the lesion

The age of microscopic lesions in psoriatic subjects was assessed from the stacking characteristics in the horny layer and related to type and density (cells/tissue volume) of mononuclear cells in the epidermis and the dermis determined by immunoperoxidase methods using monoclonal antibodies. Pan T cells (Lyt-2+, Lyt-3+, Leu-4+, OKT3+), T helper cells (Leu-3a+, OKT4+), T suppressor/cytotoxic cells (Leu-2a+, OKT8+), Ia+ cells and monocytes (OKM2+, BRL alpha mono+) were determined in epidermis and dermis. The psoriatic lesion was divided into regions underneath a parakeratotic and an orthohyperkeratotic/hypergranular portion of the horny layer and contrasted with perilesional and uninvolved psoriatic skin as well as with healthy skin. In the various regions and skin layers, the cell density was highest in parakeratosis and decreased toward normality with decreasing histologic abnormality. The relation between epidermal and dermal cell densities of the T-cell subsets was modified in the involved psoriatic skin with a selective preponderance of T suppressor/cytotoxic cells in the epidermis. The accumulation was present in the youngest lesion found (3 days) and cell densities were unchanged in older lesions. The findings suggests that the altered relationship in the subsets of T cells has an important role during the induction and progress of the psoriatic process in the skin.     

Predominant cutaneous infiltration by OKT6- and OKT8-positive cells in a case of Sézary syndrome

Summary Using an immunoperoxidase (skin biopsy) and an immunofluorescence (peripheral blood, bone marrow punctate) technique, and monoclonal antibodies raised against peripheral mature lymphocytes, T helper subsets, T suppressor subsets, and Langerhans cells, we found a predominant dermal infiltration with lymphocytes of the suppressor phenotype and a predominant epidermal infiltration with Langerhans cells in a patient with Sézary syndrome (cutaneous T-cell lymphoma, CTCL). Repeated peripheral blood examinations showed an increased percentage of lymphocytes of the helper phenotype. A bone marrow examination revealed a ratio of suppressor/helper subsets of 1:4. The findings in the skin seem to be inconsistent with most of the results of previous studies in patients with CTCL; the significance of these findings is discussed.This study was partly supported by the Deutsche Forschungsgemeinschaft, Grant no. Lo 285/2-1This work is dedicated to Prof. Th. Nasemann on occasion of his 60th birthday     

Distribution of natural killer cells and lymphocyte subclasses in Jessner's lymphocytic infiltration of the skin and in cutaneous lesions of discoid and systemic lupus erythematosus

We studied the cell infiltrates in biopsies from lymphocytic infiltration of the skin (LIS), with six monoclonal T cell antigen-specific antibodies and compared the reactivity pattern with those in biopsies from discoid and systemic lupus erythematosus skin lesions and allergic contact skin reactions. A newly described antibody (NK₉) recognizing natural killer (NK) cells and activated cytotoxic T lymphocytes was included, and the numbers and activity of circulating NK cells was determined. Immunohistochemical staining revealed that the numbers of NK₉-positive cells were highest in LIS. The distribution of T lymphocytes (OKTii + ve), helper T cells (OKT₄+ ve), suppressor T celts (OKT8 + ve), Langerhans cells (OKT6 + ve) and activated T cells (anti-Tac + ve) in LIS differed from those in DLE, SLE and allergic contact reactions. However, the number of circulating NK cells (large granular lymphocytes) and the NK activity in peripheral blood were normal in LIS. We conclude that in LIS a distinct type of T cell activation occurs; the cause of this remains to be determined.     

Immediate hypersensitivity parameters in bullous pemphigoid

Elevated serum IgE levels gave rise to the hypothesis that type 1 immune reaction is implicated in the pathology of Bullous Pemphigoid. IgE serum levels were estimated in 91 patients with Bullous Pemphigoid (BP) and in 26 healthy individuals. In 30 of the patients, the dermal mast cell infiltrate and peripheral blood eosinophils (%) were studied. Patients were subdivided in four groups according in diagnostic criteria or treatment. It was found that all patients, including those receiving treatment, had considerably elevated serum IgE compared to controls. Patients fulfilling all criteria had markedly increased IgE compared to those with negative indirect immunofluorescence. A significant correlation was found between serum IgE and dermal mast cell infiltrate but not between serum IgE and peripheral blood eosinophils, or between peripheral eosinophilia and dermal mast cells. Immediate hypersensitivity parameters, systemic or local, are apparently involved in BP lesion formation although to date it remains unknown at which particular step such parameters might be crucial. The possible biological significance of IgE overproduction and its interrelationship with local inflammatory cellular events is discussed.     

Effect of etretinate on peripheral T lymphocytes in psoriatic patients before, during and after 6 months of therapy

Total peripheral T lymphocytes, OKT4 helper/inducer cells and OKT8 suppressor/cytotoxic cells, as well as T lymphocyte function determined by the local xenogeneic graft-versus-host reaction (GVHR), were investigated in 14 psoriatic patients prior to institution of treatment with etretinate, during the course of treatment and 6 months after its initiation. After approximately 2 months of treatment, there was a significant increase in the number of E-rosette-forming lymphocytes and OKT4 subpopulations with a return to normal levels after 6 months of treatment. The GVHR was positive in only 5/11 patients prior to therapy but in 9/11 patients after 2 and 6 months. Our results indicate that etretinate has a stimulatory effect on T lymphocytes and their subset counts.     

Progressive vaccinia associated with combined variable immunodeficiency

Progressive vaccinia developed in a previously healthy woman following smallpox vaccination and was successfully treated with vaccinia immune human globulin and methisazone. Immunologic evaluation over the next 4 1/2 years revealed evidence for combined variable immunodeficiency with increased numbers of circulating OKT 8 positive (suppressor-cytotoxic T) cells and the virtual absence of OKT 4 positive (helper-inducer T) cells.