Psoriasis confined strictly to vitiligo areas – a Koebner‐like phenomenon?

Vitiligo and psoriasis are both common skin disorders. However, psoriasis strictly confined to pre-existing vitiligo areas is rare and suggests a causal relationship. We report here on two patients with a strict anatomical colocalization of vitiligo and psoriasis. The histopathological examinations showed typical changes for both diseases together with a dense infiltrate of CD4+ and CD8+ T cells. By immunohistochemistry, intracytoplasmatic granzyme B and tumour necrosis factor alpha (TNF-alpha) were detected within the T-cell population, suggesting the functional activity of these cells and the creation of a local T helper 1 (Th1)-cytokine milieu. Additionally, in one patient we could identify anti-melanocytic T cells by tetramer staining and enzyme-linked immunospot (ELISPOT) analysis. These skin-infiltrating lymphocytes might trigger, by the local production of Th-1 cytokines such as TNF-alpha and interferon-gamma (IFN-gamma), the eruption of psoriatic plaques in patients with a genetic predisposition for psoriasis.     

Suppression by Trypanosoma brucei rhodesiense of the capacities of human T lymphocytes to express interleukin-2 receptors and proliferate after mitogenic stimulation.

We studied the suppressive effects induced in phytohemagglutinin (PHA)-stimulated human peripheral blood mononuclear cells (PBMC) by purified blood forms of Trypanosoma brucei rhodesiense. The parasite was found to markedly impair lymphocyte proliferation (measured in terms of [3H]thymidine incorporation). The extent of this effect increased with parasite concentration and was not due to mitogen absorption, depletion of medium nutrients, or PBMC killing by the parasite. Significant reductions in interleukin-2 receptor (IL-2R) expression, determined by flow cytometric analysis, were also observed in PHA-stimulated PBMC cultured in the presence of T. b. rhodesiense as evidenced by marked decreases in the surface density of the receptor. Concomitant decreases in the percentage of IL-2R+ cells were recorded in approximately half of the experiments. A discrete, dimly stained subpopulation of IL-2R+ cells were consistently demonstrable whether or not a reduction in the percentage of IL-2R+ cells occurred. Living, but not glutaraldehyde-fixed, parasites suppressed IL-2R expression. In kinetic studies, a low but reproducible level of suppression of IL-2R was demonstrable as early as 6 h after PHA stimulation; the extent of this effect became considerably more pronounced as additional culture time elapsed. Levels of IL-2 biological activity in cocultures of T. b. rhodesiense with PHA-stimulated PBMC were comparable with or higher than those present in control cultures lacking the parasite. Therefore, insufficient levels of this cytokine would be an unlikely explanation for the noted suppression of IL-2R expression and lymphoproliferation. These effects of T. b. rhodesiense could represent an important component of the mechanism by which immunosuppression develops in African sleeping sickness.     

Circannual variation in lymphocyte subsets, revisited

BACKGROUND: Circadian and circannual variations in lymphocyte subsets, especially CD8+ T-lymphocytes, have been reported. This study focuses on CD4+ T-lymphocyte seasonal variation over a 6-year 8-month period. STUDY DESIGN AND METHODS: Lymphocyte subsets were quantitated monthly for four healthy individuals from 1986 through 1992 as part of a flow cytometry quality-control program. RESULTS: In general, there were no significant seasonal changes in the total number of white cells or in total lymphocyte counts. The absolute numbers of CD4+ T-lymphocytes were lowest in summer when the CD8+ T-lymphocytes were highest. Mean CD4+ T-lymphocyte counts were 846, 967, 618, and 695 per microL for Subjects 1 through 4, respectively, in winter and 432, 670, 355, and 766 per microL, respectively, in summer. Two healthy subjects had CD4+ T-lymphocyte counts lower than 300 per microL on one or more occasions during the study period. In three of the four subjects, the percentage of B-lymphocytes in winter was almost double that in summer. In one of the four subjects, no circannual rhythm was observed in these lymphocyte subpopulations. CONCLUSION: The seasonal variation in CD4+ T- lymphocyte counts demonstrated in three healthy individuals over almost 7 years is again of interest in light of renewed consideration of using surrogate tests, such as CD4+ T-lymphocyte counts, to screen for AIDS- like diseases that may be in the blood supply.     

Trypanosoma cruzi-induced suppression of human peripheral blood lymphocytes activated via the alternative (CD2) pathway.

Coculture of blood forms of Trypanosoma cruzi with human peripheral blood mononuclear cells stimulated with anti-CD2(2) and anti-CD2(3) monoclonal antibodies, i.e., via an antigen-independent pathway of T-lymphocyte activation, resulted in marked immunosuppression compared with that in parallel cultures in which parasites were absent. This effect was evidenced by a decreased lymphoproliferative capacity, a significant reduction in the proportion of cells expressing interleukin-2 receptors, and a significant diminution in the cell surface density of this receptor.     

A rapid microagglutination test for the diagnosis of Legionella pneumophila (serogroup 1) infection

A rapid microagglutination test has been developed which can be performed in 30 minutes. Ninety-seven percent of 96 patients diagnosed as having Legionella pneumophila (serogroup 1) infection by indirect immunofluorescence were also detected by the rapid microagglutination test.     

Neuropeptide Y-immunoreactive cells in the caudal medulla project to the median preoptic nucleus

The region surrounding the anteroventral third ventricle, particularly the median preoptic nucleus, has been implicated in the control of fluid balance and blood pressure. Previous studies indicate that catecholaminergic inputs from the caudal medulla are important in these controls. In this study we report that neuropeptide Y-immunoreactive cells in the caudal medulla project to the median preoptic nucleus in the basal forebrain. Notably these cells are found in the caudal ventral lateral medulla and the nucleus of the solitary tract. Since catecholaminergic projections to the median preoptic nucleus also arise from these regions the possibility of interactions between NPY and catecholamines exists, particularly in the control of fluid balance and blood pressure.     

Detection of antibodies to human immunodeficiency virus by latex agglutination with recombinant antigen.

Recombinant human immunodeficiency virus (HIV) env antigen was attached to polystyrene particles, and these complexes were used to develop the first latex agglutination assay for antibodies to HIV. A total of 95 positive and 116 negative human serum samples were assayed for antibodies to HIV by latex agglutination, and results were compared with those of a commercial enzyme immunoassay. Latex agglutination was also compared with, and found to be completely concordant with, Western blot (immunoblot) analysis with virion antigens.     

Studies on the origin of redox enzymes in seminal plasma and their relationship with results of in-vitro fertilization

Glutathione (GSH), GSH peroxidase (GPX), GSH reductase (GRD), superoxide dismutase (SOD) and catalase-like enzyme activity were quantified in seminal plasma from normozoospermic patients, men with known distal ductal occlusion, proven fathers and male partners of couples receiving in-vitro fertilization (IVF) treatment for both male and female causes. Glutathione was non-detectable (< 2.5 microM) in seminal plasma. None of the enzyme activities per unit volume were lower in semen from vasectomized men, suggesting that they did not originate substantially from the testis or epididymis. The strongest relationships between enzyme activities and accessory gland markers were between zinc and GRD (r = 0.678), SOD (r = 0.602) and GPX (r = 0.548), suggesting a largely prostatic origin of these enzymes. Only weak relationships between accessory gland markers and catalase-like activity suggested a multi-glandular source of this enzyme. There was no relationship between the activity of any of the enzymes in the IVF patients with their fertilization rates in vitro or the establishment of pregnancy after IVF. Nor was there any correlation of enzyme activity with the morphology and percentage of motile spermatozoa in semen or with the percentage motility of spermatozoa immediately after swim-up or after overnight incubation. These findings suggest that the protective enzymes in the seminal plasma are contributed largely by the prostate and little by the epididymis, and that in most cases of IVF, they have no major influence on the outcome.