Immunophenotype of lymphoid cells in positive patch tests of allergic contact dermatitis.

The immune phenotype of the infiltrating cells in 13 positive patch tests from 8 cases of contact dermatitis and 1 case of poison ivy was studied. An indirect immunoperoxidase technique was used in conjunction with monoclonal antibodies directed against mature T cells (Leu-1, T11), helper T cells (Leu-3A), suppressor/cytotoxic T cells (Leu-2A), killer and natural killer cells (HNK 1), B cells (B1), Langerhans cells (HLA-DR), and the common acute lymphoblastic leukemia antigen (CALLA), (J5). The majority of infiltrating mononuclear cells were Leu-1+, T11+, Leu-3A+, Leu-2A-, HLA-DR+, T9-, T10-, HNK-, B1-, J5-. Occasional T6+ cells were observed in the epidermis (including spongiotic microvesicles) and also isolated in the dermis and within the dermal mononuclear infiltrates. The phenotype was compared with cutaneous T-cell lymphoma, a disease in which contact allergy and antigenic persistence may play a role.

The lysosomal granule membrane protein, LAMP-2, is also present in platelet dense granule membranes.

Lysosomal Associated Membrane Protein-2 (LAMP-2) is an inherent component of lysosomal granule membranes in diverse cell types, including platelets. We examined platelets for evidence of LAMP-2 in dense granule membranes as CD63 has previously been shown to be present in both lysosomal and dense granule membranes. Immunological techniques were used to examine the localization of LAMP-2 in control platelets and those from an individual with Hermansky-Pudlak syndrome (HPS), a condition characterised by platelet dense granule deficiency. Immunoblotting studies demonstrated that LAMP-2 was enriched in a dense granule preparation. Flow cytometry of thrombin-stimulated control platelets was consistent with biphasic surface expression of LAMP-2. The early expression was accompanied by dense granule, but minimal lysosomal granule, release. The late expression was accompanied by additional lysosomal granule release only. Thrombin stimulation of HPS platelets showed only late, lysosome-associated LAMP-2 expression. Immunoelectron microscopy indicated the presence of LAMP-2 in the membranes of serotonin-containing granules as identified by an anti-serotonin polyclonal antibody. These data indicate that LAMP-2 is present in the membranes of platelet dense granules in addition to lysosomal granules, and has a similar distribution to CD63.

Identification of T-lymphocytes and T-subsets in human tonsil using monoclonal antibodies and the immunoperoxidase technic.

A study was performed using monoclonal antibodies and the immunoperoxidase technic to identify T-cells and T-subsets in human tonsil sections. The in situ topographic identification of T-cells, helper cells, and suppressor cells was achieved. This model may therefore be applied to other normal lymphoid tissues. Its potential pathologic importance lies in the fact that certain disorders may be associated with depletion of lymphocyte subsets from their normal areas of "homing," and that lymphoma cells may mirror their putative normal counterparts in their selective metastatic migration pattern. The improved knowledge of normal lymphocyte subset microenvironment afforded by this technic may therefore be of value in applied pathology.

Identification of T cell in parapsoriasis infiltrates. Use of an anti-human T-cell serum and the immunoperoxidase technique.

"Parapsoriasis" is a term used to include a heterogeneous group of conditions, one variant of which, at least, eventuates in mycosis fungoides in a substantial percentage of cases. The T-cell origin of mycosis fungoides is well established. The lack of similar information on lymphoid cell types in parapsoriasis prompted an immunoperoxidase study using a specific antihuman T-cell serum in a group of seven patients with parapsoriasis. Our findings demonstrated a preponderantly T-cell infiltrate in the categories of parapsoriasis examined.

Monoclonal antibody patterns in cutaneous lymphoid infiltrates. Their possible relevance to the diagnosis and categorization of cutaneous lymphomas.

The development of monoclonal antibodies to T cells at various stages of differentiation, B cells and histiocytes, suggests that these reagents may be of use in the diagnosis and categorization of cutaneous lymphomas. The findings to date in skin and blood are discussed.

OKT 6-positive cells: their demonstration in human thymus, and the effect of fixation on the immunoperoxidase reaction.

Human thymocytes at an intermediate stage of differentiation were demonstrated in situ in tissue sections of thymus using the mouse monoclonal antibody OKT 6 THY (Ortho Immunobiology Ltd, Raritan, NJ) and the immunoperoxidase technique. These cells were found to reside mainly within the thymic cortex. The effects of on-slide fixation on the ease of demonstration of the antigen involved were assessed. The choice of fixative was found to have a marked effect, acetone and paraformaldehyde producing the most satisfactory results.

Monoclonal antibodies and cutaneous T cell lymphoma. Theoretical and practical considerations.

The T cell nature of mycosis fungoides and Sézary syndrome was established a decade ago. The recent advent of monoclonal antibodies to T cells and other lymphoid subpopulations has resulted in an explosion of knowledge on the biology of this group of disorders. These reagents have increased our knowledge on thymic differentiation status, pathogenesis, the phenotype of premalignant vs malignant lymphocytic infiltrates, the identification of other previously unrecognized cells within lymphomas, and the phenotype of circulating vs skin lymphocytes. Therapeutic applications may result. These new developments are discussed.

Plasma zinc in psoriasis: relation to surface area involvement.

Plasma zinc, serum albumin and alkaline phosphatase (a zinc-dependent enzyme) were measured in thirty-five psoriatics and their age- and sex-matched controls. No significant difference was seen between these two groups as a whole, but psoriatics with less than 10% surface involvement had significantly higher mean plasma zinc levels than their respective control group. Psoriatic patients also showed a relationship between the extent of surface involvement and the plasma zinc level, those with more extensive involvement having lower levels than those with minimal involvement. The differences were not due to disturbances in serum albumin, and no abnormalities in serum alkaline phosphatase were observed.

Sex hormones influence growth and surfactant production in fetal lung explants.

Sex-related differences may be present during fetal lung growth and at the onset of surfactant synthesis. In this study we investigated the role of dihydrotestosterone (DHT) and estrogen (EST) on cell division and on labeled palmitate incorporation into disaturated phosphatidylcholine (DSPC) at various times of gestation. Using organ cultures of fetal rat lung from sexed littermates, it was shown that both DHT and EST reduce DNA synthesis only in tissue taken during the rapid growth phase from day 16 to 19 of gestation. From autoradiographic counts, epithelial cell division was most affected. Both hormones reduced DSPC synthesis in explants prepared at day 18, when levels are normally low. At day 19, DHT reduced palmitate incorporation into DSPC of female explants to the male level; subsequently DHT had no effect on any tissue. In contrast, the addition of EST stimulated DSPC synthesis 40% above controls in both male and female explants taken at day 20 only. The results suggest that sex differences seen in late fetal lung development may arise from the combined effects of slowed epithelial growth induced by these hormones followed by inhibition of DSPC synthesis by DHT and acceleration by EST at the crucial period when surfactant synthesis begins.

In situ demonstration of OKT 6-positive cells in cutaneous lymphoid infiltrates.

A monoclonal antibody, OKT 6, has been developed against an antigen which is expressed by immature T cells as part of their normal intrathymic differentiation, but not by mature peripheral T cells. It was though that a search for the expression of such an antigen might be worthwhile in prelymphomatous conditions. This communication describes the investigation of lymphocytic infiltrates of atropic parapsoriasis, lymphomatoid papulosis, and a small group of miscellaneous skin conditions with OKT 6 and the immunoperoxidase technic. OKT 6-positive cells were identified in the dermis in varying numbers in four cases of atrophic parapsoriasis and in one case of lymphomatoid papulosis, but not in any of the other disorders. Positive epidermal staining was noted in all tissues examined. The pattern obtained suggested that epidermal dendritic cells may react with OKT 6. The findings indicate that OKT 6-positive cells may be found outside the thymus in certain conditions. The observations in epidermis cast doubt on the exact nature of the positively reacting cells observed in dermis, suggesting that may either be immature thymocytes or possibly Langerhans cells.

HLA-DR-positive cells in large plaque (atrophic) parapsoriasis.

The development of a monoclonal antibody directed against HLA DR (Ia-like) antigens of B cells and monocytes but not against normal peripheral human T cells suggested that this antibody might be used as a marker of B cells and monocytes in tissue sections. The T cell nature of large plaque (atrophic) parapsoriasis has recently been demonstrated by the immunoperoxidase technic. Immunoperoxidase examination of serial sections of tissues from two cases of large plaque parapsoriasis with one T cell antiserum, two monoclonal T cell antibodies, and one monoclonal reagent directed against HLA DR indicated that T cells in the cutaneous infiltrates were also HLA DR-positive. Evidence is accumulating that HLA DR positivity may be expressed by activated T cells. The findings here therefore suggest that many of the T lymphoid cells in two cases of large plaque (atrophic) parapsoriasis examined were activated in nature, and that HLA DR may not be a specific marker for B cells and monocytes in certain pathologic conditions. Caution should therefore presently be exercised in attempting to use this marker for the specific identification of B cells and monocytes in pathologic specimens, without simultaneous testing for T cell markers.

Deficient collagen-induced activation in the newborn platelet.

We have investigated the impaired secretion response of neonatal platelets. We compared the response of washed neonatal and adult platelets to thrombin and collagen, and to specific activators of calcium flux (inositol trisphosphate) and protein kinase C activation (oleoyl-acetyl glycerol). Neonatal platelets show no impairment of aggregation, secretion of [14C]serotonin or phosphorylation of specific intracellular proteins in response to thrombin, inositol trisphosphate, or oleoyl-acetyl glycerol. However, neonatal platelets have a markedly decreased response to collagen. To further evaluate this deficient response, we examined specific aspects of the collagen activation pathway. Collagen-platelet interaction as measured by adhesion of platelets to collagen-coated dishes showed no difference in adhesion of neonatal platelets compared to adult controls (20.1 +/- 11.6 versus 18.6 +/- 9.3%). The presence of GPIa/IIa, a Mg2(+)-dependent collagen receptor, was evaluated by flow cytometric analysis of binding of fluorescein-tagged monoclonal antibody, 6F1 (directed against GPIa/IIa). There was no difference either in the percent of platelets that bound antibody (80 versus 81%) or in the mean fluorescence intensity of the adult and neonatal samples. Phosphoinositide hydrolysis was decreased in neonatal platelets in response to collagen but normal in response to thrombin. Neonatal platelets released more arachidonic acid than adult platelets in response to thrombin (29.5 +/- 3.2 versus 19.6 +/- 1.8%) but less than adult platelets in response to 10 micrograms/mL collagen (3.2 +/- 1.1 versus 9.3 +/- 3.0%).(ABSTRACT TRUNCATED AT 250 WORDS)

Diurnal stage of circadian rhythm of plasma zinc in healthy and psoriatic volunteers.

The characteristics of circadian variation of human plasma zinc concentrations in health and psoriasis are compared by the cosinor method. Sequential measurements of plasma zinc were performed at 0800 (fasting), 1000 (1 hr after breakfast), 1330 (1 hr after lunch), and 1900 (1 hr after supper) on groups of 20 patients with psoriasis, a disorder in which zinc metabolism may be disturbed, and 16 clinically healthy individuals. The limited sampling notwithstanding, groups showed a statistically significant circadian rhythm when analyzed by the cosinor method with the least-squares fit of a 24-hr cosine curve. The rhythm's timing in the clinically healthy group was similar to that derived by the same cosinor method from much denser series (covering the entire 24-hr span) published earlier by others. The diurnal portion of the circadian rhythm of human plasma zinc differed in the two groups investigated; this difference was not seen in the mean fasting plasma zinc concentrations. Circadian studies may reveal differences between groups that are not apparent by conventionally used single fasting estimates. More generally, in future studies of zinc, e.g., in skin disease, sampling time and the subjects' routine should be strictly standardized as a minimum, and rhythm characteristics should be quantified as an optimum.

In situ demonstration of T cell subsets in atrophic parapsoriasis.

It has been demonstrated recently in mycosis fungoides and lichen planus that T lymphocyte subsets may be identified in cutaneous lymphocytic infiltrates using the immunoperoxidase technic in conjunction with monoclonal antibodies produced by the technic of Kohler and Milstein. This communication describes the application of this technic to cutaneous lymphoid infiltrates of parapsoriasis in which T cell predominance has been demonstrated previously. The lymphoid infiltrates of six patients with atrophic parapsoriasis were examined by the indirect immunoperoxidase technic using monoclonal antibodies (from two commercial sources) directed against "helper" and "suppressor" T cell subsets. Both "helper" and "suppressor" cells (as defined by a positive reaction with monoclonal antibodies) could be identified in cutaneous infiltrates. "Helper" cells predominated, but in varying degrees among patients. The relevance of these findings in relation to the possible development of clinical mycosis fungoides from atrophic parapsoriasis is discussed. In addition, factors causing difficulty in the consistent identification of cell subtypes are discussed. These factors suggest that in the present state of imperfection, difficulty will be experienced in using this technic for the accurate quantification of percentages of lymphocyte subsets in tissue sections.U

Deficient thromboxane synthesis and response in platelets from premature infants.

In vitro function of cord blood platelets from 35 premature infants (gestational age 32 +/- 3.2 wk) was compared with that of 12 full-term infants and 14 adult control subjects. In comparison with adult platelets, preterm platelets showed impaired aggregation, in response to thrombin, collagen, ADP, and U46619 [a stable analog of thromboxane A2 (TxA2)], and impaired [14C]serotonin secretion in response to collagen and U46619. The production of TxB2 (the stable TxA2 metabolite) in response to collagen was reduced in preterm platelets (30.2 +/- 5.5 ng/mL) compared with full-term (52.7 +/- 12.6 ng/mL) or adult control platelets (132.3 +/- 38.7 ng/mL). The deficient TxB2 production and U46619 response prompted further investigation of TxA2 receptor number and binding characteristics. Immunoblotting using an anti-TxA2 receptor antibody (anti-P2) identified a single, identical 55-kD band in solubilized membranes of control, full-term, and preterm platelets. Flow cytometry using anti-P2 produced histograms that did not differ between adults and neonates. Ligand binding studies using [3H]U46619 were carried out on 10 samples from each group. Scatchard analysis yielded a single class of binding sites with no significant difference among the Kd values (85 +/- 16 versus 99 +/- 12 versus 100 +/- 12 nM) or number of binding sites per platelet (1876 +/- 460 versus 2450 +/- 478 versus 2777 +/- 536) for preterm and full-term infants and adults. Therefore platelets of preterm infants show impaired TxA2 production and response. The poor response is not related to altered binding characteristics of the TxA2 receptor but may lie in the postreceptor signal transduction pathway.

Demonstration in situ of "T" cells and "T" cell subsets in lichen planus using monoclonal antibodies.

This report describes the in situ demonstration of "T" lymphocytes and "T" lymphocyte subsets in tissue sections using a case of lichen planus as a model. The technique utilized is the indirect immunoperoxidase method with monoclonal antibodies to "T" cells and "T" cell subsets. In the case examined a predominance of helper "T" cells was found. The potential application of this method in the immunopathology of skin and internal organs is discussed.