Studies on the phagocytic activity of the granulocytes in psoriasis and palmoplantar pustulosis

Neutrophil functions and IL-8 in psoriatic arthritis and in cutaneous psoriasis

The aim of this study is to determine some functions of neutrophil in patients affected by psoriatic arthritis and to compare them to those of patients affected by cutaneous psoriasis and to normal controls. We used a model of experimental cutaneous inflammation allowing to separate a cluster of purified and viable PMN cells. Then we analyzed, within the three groups, the IL-8 concentration in serum and in the supernatant obtained from the inflammatory site to gather data on the possible pathogenic role played by this cytokine in psoriatic arthritis. We studied neutrophil functions in patients with cutaneous psoriasis and psoriatic arthritis, in acute phase, in comparison with healthy control subjects. We investigated in vivo neutrophil migration by Senn's skin window technique and measured adhesion assay and superoxide production in circulating and migrating neutrophils after different stimuli. We also measured IL-8 concentration in serum and in the supernatant obtained from the inflammatory site, artificially created through the skin window scrape. Neutrophil migration in vivo was significantly higher in both groups of patients than in controls. In the presence of fMLP, blood cells showed a burst of superoxide release, which was significantly more pronounced in patients when compared to healthy controls. Neutrophils from skin window scrape showed a much higher response to fMLP as compared to blood cells of all subject groups, but no differences were observed between patients and controls. No correlation was found between the three groups in adhesion ability under basal condition or in response to different stimuli by circulating and migrating neutrophils. Our results also show a great increase of IL-8 in the exudate from patients compared to controls. Our study shows that there is no difference in neutrophil functions between patients with psoriatic arthritis and cutaneous psoriasis; moreover we suggest that the source of high IL-8 levels are neutrophils rather than the keratinocytes.

Neutrophil activating activity of tonsillar cells from patients with tonsillitis

The previous paper demonstrated that tonsillar cells cultured in vitro in the presence or absence of a streptococcal preparation, OK-432, produce factors that activate various neutrophil functions. In the present study, examination was made of the factor productivity of tonsillar cells from patients with chronic tonsillitis of varying severity, and palmoplantar pustulosis (PPP). Tonsillar cells from patients with severe tonsillitis and PPP incubated with culture medium alone produced a much greater amount of active factors compared with those from patients with mild tonsillitis. When tonsillar cells were incubated in the presence of OK-432, augmentation in factor production by the addition of OK-432 was less in former than latter cases, suggesting that factor production from tonsils correlates with the course of inflammation in this organ.

Etretinate or cyclosporin-A treatment normalizes the enhanced respiratory burst of polymorphonuclear leukocytes in psoriasis

During a therapeutic trial to treat psoriasis with either etretinate or cyclosporin A (CyA) we measured the respiratory burst activity of polymorphonuclear leukocytes (PMN). Six patients received 0.5-0.75 mg/kg etretinate and 14 patients 2.5-5.0 mg/kg CyA over a period of 10 weeks. The extent of psoriasis was graded by the psoriasis area-and-severity index (PASI score). The respiratory burst of PMN isolated from the peripheral blood was measured employing luminol-enhanced chemiluminescence at weeks 0, 3 and 10 and compared with that of 26 healthy control individuals. PMN were stimulated with zymosan particles, aggregated immunoglobulin (aggIg) and concanavalin A (ConA). Both treatment regimens improved psoriasis; at 10 weeks there was an approximate 40% PASI score reduction under etretinate and an 80% improvement under CyA. Before treatment the respiratory burst was abnormally high under stimulation with the three stimuli in patients (p = 0.021 to less than 0.0001). After 3 to 10 weeks PMN activity normalized in all patients and even tended to drop below values correlating with an improvement in skin lesions. We conclude that the elevated respiratory burst of PMN in psoriasis normalizes under treatment with both etretinate and CyA.

Relaxation therapies in the treatment of psoriasis and possible pathophysiologic mechanisms

Psychologic factors play a role in many dermatologic disorders, giving rise to the possible use of psychotherapeutic modalities in treatment. Regarding psoriasis, emotional factors have a strong correlation with onset and flare-ups. The psychophysiologic mechanisms involved are not known; however, stress and its effect on the autonomic nervous system and the immune system may play a significant role in the onset and course of psoriasis. Relaxation and mere suggestion also affect the autonomic nervous system and the immune system and therefore may affect the course of the skin disorder. A few case studies have documented successful treatment of psoriasis with hypnosis and biofeedback. Further study of this process is needed, and the role of stress in dermatologic diseases must always be given consideration.

Reduced expression of surface receptors for synthetic N-formylated chemotactic oligopeptides by stimulated peripheral blood neutrophils in psoriasis

Receptors for synthetic N-formylated chemotactic peptides on peripheral blood neutrophils were studied by the binding of fluorescein-labeled hexapeptide (N-formyl-Nle-Leu-Phe-Nle-Tyr-Lys) to the cells in vitro at the range of concentrations 0.01-100 nM. Mean fluorescence of neutrophils was quantitated by a flow cytometry using FACS III. Comparison was made between 27 patients with psoriasis vulgaris and 14 normal controls. Various receptor states related to cell activities were induced by different temperatures, by incubation of cells with cytochalasin B and by preincubation with nonlabeled N-formyl-Met-Leu-Phe. This allowed us to distinguish between the specific binding of fluoresceinated hexapeptide to plasma membrane receptor already present (0 degree C), modulation of receptors by peptide and cytochalasin B stimulated degranulation (25 degrees C), and net binding, including internalization of peptide and receptor recycling system (37 degrees C). At peptide concentrations of 1-10 nM, the labeling of neutrophils at 25 degrees C and 37 degrees C, but not at 0 degree C, was found to be about 10-35% lower in psoriatic than in healthy subjects (p less than 0.002). The amount of fluorescein-labeled peptide bound to the cells at 25 degrees C was markedly increased by cytochalasin B, but to a much lower extent in psoriatic patients than in normal controls. Although the number of plasma membrane receptor for chemotactic peptides in the nonstimulated neutrophils was not altered in psoriasis, the receptor up-regulation induced by preincubation of the cells with 1-10 nM of nonlabeled N-formyl-Met-Leu-Phe at 37 degrees C was reduced when measured by subsequent fluoresceinated hexapeptide uptake at 0 degree C. Receptor recycling, as measured by an increase with time (0-30 min) in the binding of chemotactic peptide by neutrophils in which receptors had been down-regulated, was found to be within normal range in patients with psoriasis. These data indicate that nonstimulated, circulating neutrophils have a normal number of chemotactic peptide receptors on the cell surface, but are less able to recruit intracellular receptors to the cell surface. This finding may be related to smaller internal pools or less efficient translocation of these receptors.

Circulating immune complexes in untreated psoriasis. A comparison of Raji-cell radioimmunoassay and polymorphonuclear leukocyte phagocytosis

Three different in vitro assays for the demonstration of circulating immune complexes were compared in 49 patients with psoriasis. Granulocytes from psoriatic subjects contained immune complex-like material in 25 patients (51%). When psoriatic serum was incubated with granulocytes from healthy blood donors, phagocytosed material was found in 18 patients (37%). The Raji-cell assay was only positive in two of 27 subjects (7%). Of the patients 71% tested positively with one of the granulocyte phagocytosis tests. Both tests were positive simultaneously in 16% and negative in 29% of the patients. The pathogenetic significance of the immune complex-like material is unclear.

Impaired function of numerically augmented Fc-receptors on granulocytes in a HLA B8+ patient with palmoplantar pustulosis

We examined granulocytes or polymorphonuclear leukocytes (PMN) in an HLA B8+ patient with palmoplantar pustulosis (PPP). Controls included another patient with PPP, however, lacking this antigen and a healthy, HLA B8+ person. Chemiluminescence (CL) served to monitor the respiratory burst in PMN comparing as stimuli zymosan, opsonized zymosan, phorbol myristate acetate, as well as aggregated immunoglobulin (aggIg), the latter as Fc-receptor (FcR) stimulus. FcR density on PMN was determined using 125I-IgG and expressed in the form of Scatchard plots. The effects of serum on the aggIg-induced CL were also measured. We found both control individuals to respond to stimulation by aggIg as a function of a dose-dependent increase of CL. By contrast, the HLA B8+ patient with PPP failed to respond to aggIg; only the highest concentration of aggIg induced marginal CL. Conversely, stimulation by the other agents was similar in all three individuals. The patient with the functional FcR defect expressed 2.5 times more FcR/PMN than the controls. No difference emerged in comparing autologous serum with a reference normal serum on the aggIg-induced CL, ruling out saturation by serum factors alone to be a cause for the defect. In remission, the functional FcR was absent. Our results suggest a defect of signal transduction in PMN from numerically enhanced FcR to the cytosol in the patient with PPP.

Neutrophil leukocyte morphology, cigarette smoking, and palmoplantar pustulosis

Neutrophil leukocyte morphology was examined in whole blood films from 20 patients with palmoplantar pustulosis (PPP) and 32 healthy controls. In the PPP patients, there was a significant increase in the number of neutrophils having polarized morphology or membrane ruffling; however, there was no significant difference in neutrophil morphology between cigarette smokers and nonsmokers, suggesting that the epidemiologic link between smoking and PPP is not explained by increased polarization of peripheral blood neutrophils.

Polymorphonuclear leukocyte function in psoriasis vulgaris

Polymorphonuclear leukocyte (PMN) migration was assessed in vitro using the agarose plate method in patients with psoriasis vulgaris, and compared with an age- and sex-matched control group. No significant difference was found between the two groups in the PMN response to the chemotactic substances F-Met-Leu-Phe (FMLP) or zymosan activated serum (ZAS). Equally, the chemokinetic or chemotactic potential of psoriatic serum did not differ from control serum. Our results do not support a primary abnormality of PMN function in psoriasis.

Neutrophil locomotion and serum chemotactic and chemokinetic activities in pustulosis palmoplantaris compared with psoriasis

Twenty patients with palmoplantar pustulosis (PPP) and 21 patients with psoriasis were compared with respect to the chemotactic response and random migration of their neutrophils (PMNs) and to the chemotactic and chemokinetic activities of their serum. The Boyden chamber technique was used. Compared with the reference group, the PPP neutrophils showed a significant decrease in random migration (p = 0.036) and chemotactic response to casein (p = 0.031), but not to zymosan-activated serum. The psoriasis PMNs had normal chemotactic response, but decreased random migration (p = 0.001). The chemokinetic effects of serum from PPP and psoriatic patients on normal neutrophils were increased (for PPP, p = 0.019 and for psoriasis p = 0.024). The chemokinetic activity of the heated sera was decreased and inversely correlated to the serum level of IgA in both disorders (PPP, p = 0.021; psoriasis, p = 0.013). The chemotactic activity of serum on normal PMNs was decreased in both conditions (PPP, p = 0.001; psoriasis, p = 0.047); this was due to the presence of chemotactic factor inhibitors in 34% of the sera. It seems likely that the high chemokinetic effect of serum both from the PPP and from the psoriasis patients compensates for the slightly low or normal migratory activity of neutrophils from these patients.

Marked increase in the frequency of psoriatic arthritis in psoriasis patients with HLA-DR+ keratinocytes

Immunocytochemical studies with a monoclonal anti-HLA-DR antibody were performed on skin sections and keratinocyte (KTC) suspensions obtained from suction blisters of active psoriatic plaques. HLA-DR+ KTCs were found in the plaques of 23 of 38 patients with active psoriasis. Of these 23, 16 had clinical findings typical of psoriatic arthritis (PA); none of the 15 patients who lacked HLA-DR+ KTCs had PA. Although KTC HLA-DR expression was more prevalent in patients with severe skin disease, 7 of the 23 patients with HLA-DR+ KTCs in active psoriatic plaques had mild skin disease; 4 of these 7 had PA. Nail pitting or duration of skin disease did not account for increased incidence of PA in patients with HLA-DR+ KTCs. All psoriasis patients with arthritis received nonsteroidal antiinflammatory drug therapy; 14 received additional therapy directed primarily to the cutaneous manifestations of psoriasis. Nine of these noted arthritis improvement with concurrent skin response; however, in 5 patients, arthritis activity increased, despite improvement of the cutaneous disease. Two other patients, treated with methotrexate, also had concurrent skin and joint improvement. These data suggest that psoriasis patients with HLA-DR+ KTCs are at increased risk for the development of associated arthritis.

Myeloperoxidase of polymorphonuclear leukocytes in psoriasis vulgaris

The specific activity of myeloperoxidase (MPO), an enzyme located in the primary granules of polymorphonuclear leukocytes, was measured in patients with psoriasis vulgaris and compared with that in patients with atopic dermatitis and in healthy subjects. MPO catalyzes the oxidation of guaiacol into tetraguaiacol in the presence of H2O2. The activity was determined by photometric measurement of tetraguaiacol. The specific MPO activity showed no statistically significant difference between the healthy subjects and the patients with atopic dermatitis. In comparison to these two groups the specific MPO activity of the psoriatic patients showed a slight reduction which was, however, not statistically significant.

Defects in polymorphonuclear neutrophil function and susceptibility to infection in children

Polymorphonuclear neutrophil (PMN) migration, phagocytosis, chemiluminescence production and chemotactic and chemokinetic activities in serum were investigated in 38 infection-prone children, aged 1 month to 15 years, and in healthy controls. The patients were grouped according to the clinical pattern, that is, into children with mainly upper respiratory tract infections, with frequent middle ear infections, with lower respiratory tract infections and with 'multifocal' infections occasionally accompanied by complications, and according to the severity of the infections. Forty-two defects were found in 28 of the 38 patients examined. Good accordance was found between clinical symptoms and abnormal PMN function. Several of the observed abnormalities are most likely inherited and primary causes of the increased susceptibility, but some of them probably occur as a consequence of the infections. The results indicate that defects in oxidative PMN metabolism and defects in Fc-receptor-dependent phagocytosis are major determinants of susceptibility to infection and that such defects seem to be especially common in patients with severe 'multifocal' infections.

Expression of HLA-DR molecules by keratinocytes, and presence of Langerhans cells in the dermal infiltrate of active psoriatic plaques

Immunoperoxidase staining of skin sections and immunofluorescence analysis of keratinocyte suspensions obtained from suction blisters of psoriatic plaques were performed using an mAb, Josh 524.4.1, and Fab'2 fragments of a rabbit antiserum, both of which are directed against nonpolymorphic determinants of HLA-DR molecules. HLA-DR+ keratinocytes were present in plaques, but not normal-appearing skin, from a significant portion of patients with active psoriasis. Double-labelling immunofluorescence experiments with either the monoclonal or polyclonal anti-HLA-DR antibody, in conjunction with the mAb OKT6, which identifies DR+ Langerhans cells, demonstrated that HLA-DR molecules were present on OKT6- keratinocytes. The dermal infiltrate of psoriatic plaques contained T cells expressing the activation antigens, IL-2 receptor (Tac) and HLA-DR, as well as macrophages and OKT6+ cells. There was little difference in the characteristics of the dermal infiltrate between the lesions with or without HLA-DR+ keratinocytes. OKT6+ presumptive Langerhans cells were also found in the dermal infiltrates of patients with lichen planus, contact dermatitis, spongiotic dermatitis, erythema multiforme, basal and squamous cell carcinoma. Studies of keratinocyte suspensions showed that 7-84% of keratinocytes were HLA-DR+. Flow cytometry experiments showed that keratinocytes at all stages of differentiation were HLA-DR+. However, the stem cell-enriched population contained the highest proportion of HLA-DR+ cells. HLA-DR expression by keratinocytes correlated with disease activity. The expression was reversible with successful medical therapy. HLA-DR+ keratinocytes may activate T cells directly or may present an as yet unknown antigen to T cells. These studies provide further support for the hypothesis that immunological mechanisms play an important role in the pathogenesis of psoriasis.

Decreased extracellular release of granule enzymes from in vitro-stimulated polymorphonuclear leukocytes in guttate psoriasis

In vitro degranulation of polymorphonuclear leukocytes, which were stimulated either with synthetic chemotactic peptide (N-formyl-methionyl-leucyl-phenylalanine, FMLP) or with C3b-opsonized zymosan as a promotor of phagocytosis, was studied in 66 patients with psoriasis, 18 lesion-free psoriatics, 18 healthy subjects, and 14 other dermatological disorder controls. Stimulated release of lysozyme (from specific granules and azurophil granules) and beta-glucuronidase (from azurophil granules) in the presence of both FMLP and serum-activated zymosan was markedly reduced in patients with actively spreading guttate psoriatic lesions, in whom relapse of lesions lasted for less than 1 month and papules involved about 13-25% of skin surface. In contrast, stimulated degranulation was within normal range in active plaque psoriasis, stationary plaque psoriasis, symptomless psoriatics, and patients with disseminated eczema. Spontaneous release of lysozyme and beta-glucuronidase (background) was found to be not different in all groups studied; however, patients with active guttate psoriasis had significantly lower total lysozyme activity than those with active and stationary plaque psoriasis as well as psoriatics in the remission. These data are in favor of in vivo activation of neutrophils in active guttate psoriasis by some factors related to the early relapse of the lesions. This results in a possible combination of the following phenomena: (1) in vivo partial degranulation of neutrophils; (2) induction of "unresponsiveness state" of these cells to subsequent in vitro stimulation; and/or (3) migration of highly responsive neutrophils to skin lesions, which leaves in the circulation the subpopulation less reactive to chemotactic and phagocytic stimuli.

Granulocyte-activating mediators (GRAM): I. Generation by lipopolysaccharide-stimulated mononuclear cells

We undertook a study to determine whether cytokines exist which are responsible for the activation of polymorphonuclear neutrophilic granulocytes (PMN) besides the already well-known stimuli. Lucigenin-dependent chemiluminescence was used to measure human PMN activation. Addition of supernatants from mononuclear cells stimulated with bacterial lipopolysaccharide produced a long-lasting activation of granulocytes. Induction of chemiluminescence was dose-dependent and inhibitable by superoxide dismutase. Fractionation of mononuclear cells by adherence to plastic dishes or counterflow elutriation proved that monocytes were able to generate granulocyte-activating mediators (GRAM). Production of GRAM was dependent on the dose of the stimulus and appeared to be maximal after 24 h of incubation. Addition of cycloheximide resulted in significantly decreased release of GRAM. Partial characterization of the activity showed GRAM to be heat-labile and sensitive to trypsin, indicating a protein nature of GRAM. The activity fractionated into 2 distinct peaks, one corresponding to 60 kD and another below 10 kD. The interleukin 1 activity did not appear to co-fractionate with GRAM. Evidence presented suggests that the activity corresponds to factors unlikely to have been described previously.

Increased in vivo secretory activity of neutrophil granulocytes in patients with psoriasis and palmoplantar pustulosis

The relationship between psoriasis and palmoplantar pustulosis (PPP) is uncertain, as is the role of the neutrophil granulocyte in these conditions. In a previous comparative study of the rate of polymorphonuclear leucocyte (PMN) phagocytosis of IgG- and IgG-C3b-coated particles, an increased uptake rate was found in both diseases. Further information on the in vivo activity of PMNs in these conditions may be obtainable by determining the level of lactoferrin (LF) in serum from such patients, since LF serves as a specific marker of the turnover and activity of the circulating pool of neutrophils. In this study on 19 patients with psoriasis and 20 patients with PPP, elevated levels of LF were found in both conditions. In contrast, the levels of lysozyme and beta 2-microglobulin, which are markers of monocyte-macrophage and lymphocyte activity, respectively, were normal. This suggests the selective activation of neutrophils in these disorders. LF was significantly correlated (P less than 0.05 and 0.001, respectively) to the rates of phagocytosis of IgG- and IgG-C3b-coated particles, but not to the chemotaxis of isolated PMNs. There was no correlation between the severity of the disease and the levels of serum LF. The data suggest the increased in vivo activity of neutrophils in psoriasis and PPP.