ADONIS 000991049100232L
Clin. exp. Immunol. (1991) 85, 293-296
Soluble IL-2 receptor and CD25 cells in psoriasis: effects of cyclosporin A and PUVA therapy J. I. DUNCAN, C. HORROCKS, A. D. ORMEROD*, A. V. POWLESt, P. H. WHITINGi, L. FRY & A. W THOMSON Immunopathology Laboratory, Department of Pathology, and tDepartment of Clinical Biochemistry, University of Aberdeen, *Department of Dermatology, Aberdeen Royal Infirmary, Foresterhill, Aberdeen, Scotland, and tDepartment of Dermatology, St. Mary's Hospital Medical School, Paddington, London, England (Acceptedfor publication 12 February 1991)
SUMMARY A study was conducted to quantify soluble IL-2 receptor (sIL-2R) levels in sera of 57 chronic plaque psoriasis patients and correlate these measurements with disease activity and the numbers of IL-2Rpositive (CD25+) lymphocytes in lesional biopsies of 11 cyclosporin A (CsA) and 13 psoralen plus ultraviolet radiation (PUVA) treated patients. Levels of sIL-2R showed a strong correlation with the psoriasis area and severity index (PASI). CsA and PUVA significantly reduced the PASI and sIL-2R levels to a similar degree after 4 weeks of treatment. Although the majority of CsA-treated patients who were biopsied showed reductions in lesional CD25+ cells, these did not reach statistical significance; in five patients biopsied who had PUVA treatment, no consistent effect on the numbers of CD25+ cells was observed. A significant correlation was found between CD25+ cells in lesional biopsies and the PASI score. Keywords IL-2 receptor cyclosporin A PUVA INTRODUCTION Psoriasis is a disease characterized by hyperproliferation of epidermal keratinocytes and may owe its pathogenesis to the presence of activated T lymphocytes within lesional skin. Evidence supporting this hypothesis is found both in established lesions, where the epidermal infiltrate consists predominantly of HLA-DR+ T helper (CD4+) cells, and in resolving plaques, where the numbers of these cells decline and numbers of HLADR+ T suppressor/cytotoxic (CD8 +) cells increase (Baker et al., 1984). Similar reductions in CD4+ lymphocytes have been shown to precede the clearance of psoriatic lesions during therapy with systemic PUVA (psoralen plus long-wave u.v. radiation) (Baker et al., 1985) and cyclosporin A (CsA) (Baker et al., 1987; Horrocks et al., 1989). The mechanism by which PUVA induces the disappearance of CD4+ cells is not understood, although it has been shown to impair the production of IL-2 by murine spleen cells in vitro (Okamoto et al., 1987). However, it is well established that CsA suppresses the synthesis of IL-2 and other T cell-derived cytokines both in vitro and in vivo (Thomson & Duncan, 1989; Granelli-Piperno, 1990). The induction of IL-2 production by T cells, either following exposure to antigen, mitogen or cytokines, results in the Correspondence: Dr Janet I. Duncan, Immunopathology Laboratory, Department of Pathology, University of Aberdeen, Medical School, Foresterhill, Aberdeen AB9 2ZD, UK.
293
sequential expression of its receptor. The functional IL-2 receptor (IL-2R) is a high-affinity binding complex, composed of two non-covalently linked polypeptide chains-a 75-kD /3 chain of intermediate IL-2-binding affinity and through which signal transduction takes place (Wang & Smith, 1987; Tsudo et al., 1989) and a 55-kD a chain of low IL-2-binding affinity (Kuziel & Greene, 1990). A soluble form of the a chain, which is 10 kD smaller than its membrane-bound counterpart, has been found both in the supernatants of activated lymphocyte cultures (Rubin et al., 1985) and in serum at low levels in healthy individuals (Rubin et al., 1986). The rate of release of this protein is proportional to the number of molecules expressed on the cell surface (Rubin et al., 1985). Raised sIL-2R levels have been found in patients undergoing allograft rejection (Colvin et al., 1987) and during the active phases of certain diseases with a presumed T cell involvement, such as systemic lupus erythematosus (Wolf & Brelsford, 1988), rheumatoid arthritis (Wood et al., 1988) and atopic eczema (Colver et al., 1989). There are also recent reports of elevated serum sIL-2R levels in psoriatic patients (Kapp et al., 1988). Unlike other conditions, however, in which significant reductions in sIL-2R have been reported upon disease resolution, chronic plaque psoriasis patients undergoing successful tar treatment showed no reduction in serum sIL-2R (Kemmet et al., 1990). This study was conducted to determine the effects of CsA and PUVA on sIL-2R levels and numbers of lesional IL-2R+
294
J. L Duncan et al.
(CD25+) cells in psoriasis patients. In addition, investigations were made of the relationship between sIL-2R levels, disease activity, numbers of intralesional CD25+ and circulating CsA levels.
SUBJECTS AND METHODS Patients and treatment Fifty-seven adult patients with severe, stable plaque psoriasis were assessed for disease severity using the psoriasis area and severity index (PASI) score and concurrently for sIL-2R levels in serum. Of these, 11 patients underwent systemic CsA treatment (Sandimmun®, Sandoz, Basle, Switzerland, 3-5 mg/ kg per day) and 13 received PUVA treatment for 4 weeks. Both treatment regimes commenced following a 2-week 'washout' period, when all other therapies ceased, except for local application of bland emolients. Prior to and following treatment, 3-mm punch biopsies were taken from lesional skin, under local anaesthesia (Lignocaine), snap-frozen in arcton/liquid nitrogen and stored at - 70'C. sIL-2R measurements A small quantity of venous blood was allowed to clot at room temperature, and following centrifugation serum was collected and stored at -20'C. Levels of sIL-2R in serum defrosted at room temperature were measured using a sandwich enzyme immunoassay technique and results were expressed in U/ml ('Cell free®' IL-2R test kit, T Cell Sciences, Laboratory Impex, Teddington, UK).
CsA Measurements Estimations of CsA levels were made on serum samples using a monoclonal antibody 125I radioimmunoassay kit (Cyclo-Trac® SP, Incstar, Atlantic Antibodies, Vinnersh, UK) which measures only the parent compound of CsA. The lower sensitivity limit of the assay was 25 ng/ml.
Immunohistochemistry Cryostat sections (6 gm) were fixed in acetone for 20 min and air dried before incubating for I h with the monoclonal antibody anti-IL-2R (CD25) (Dako, High Wycombe, UK) diluted to an optimum titre of 1:20 with Tris-buffered saline, pH 7-6. CD25 (a)
(b)
PUVA
5C
3000
was visualized using the enhanced alkaline phosphatase-antialkaline phosphatase procedure as previously described (Horrocks et al., 1989). Positively staining cells in coded sections were counted at x 320 magnification. Ten sequential grid fields along the dermo-epidermal border in both the epidermis and dermis were examined and the mean count was calculated per 10 fields in three sections.
Statistical analysis The effects of treatment on PASI scores, sIL-2R levels and on the number of CD25 + cells in lesional skin were assessed by the non-parametric Wilcoxon's rank sum test. Measurements of correlation were performed using the Pearson's product moment correlation (r). Smaller samples, not displaying a normal distribution had correlation measurements made using Spearman's rank correlation (rs). RESULTS
Effect of treatment on disease activity, sIL-2R levels and CD25+ cells The effects of CsA and PUVA treatment on individual patient PASI scores, serum sIL-2R levels and numbers of CD25+ cells in lesional skin are shown in Fig. 1. Significant improvements in PASI scores and reductions in sIL-2R levels were achieved with CsA and PUVA treatment (Table 1). Neither CsA nor PUVA, however, produced a significant reduction in the number of CD25 + cells in lesional skin. Two PUVA-treated patients exhibited particularly high initial CD25+ cell counts. After 4 weeks of PUVA treatment one patient showed a marked reduction in the number of CD25 + cells which was accompanied by a similar change in PASI score, while the other patient exhibited an increase in CD25 + cells and only a slight decrease in PASI score. Neither patient, however, demonstrated any change in sIL-2R levels. Correlation between disease activity and sIL-2R levels A strong correlation between PASI score and sIL-2R levels was demonstrated in stable plaque psoriasis patients (n = 104, r=0-696, P
Clin. exp. Immunol. (1991) 85, 293-296
Soluble IL-2 receptor and CD25 cells in psoriasis: effects of cyclosporin A and PUVA therapy J. I. DUNCAN, C. HORROCKS, A. D. ORMEROD*, A. V. POWLESt, P. H. WHITINGi, L. FRY & A. W THOMSON Immunopathology Laboratory, Department of Pathology, and tDepartment of Clinical Biochemistry, University of Aberdeen, *Department of Dermatology, Aberdeen Royal Infirmary, Foresterhill, Aberdeen, Scotland, and tDepartment of Dermatology, St. Mary's Hospital Medical School, Paddington, London, England (Acceptedfor publication 12 February 1991)
SUMMARY A study was conducted to quantify soluble IL-2 receptor (sIL-2R) levels in sera of 57 chronic plaque psoriasis patients and correlate these measurements with disease activity and the numbers of IL-2Rpositive (CD25+) lymphocytes in lesional biopsies of 11 cyclosporin A (CsA) and 13 psoralen plus ultraviolet radiation (PUVA) treated patients. Levels of sIL-2R showed a strong correlation with the psoriasis area and severity index (PASI). CsA and PUVA significantly reduced the PASI and sIL-2R levels to a similar degree after 4 weeks of treatment. Although the majority of CsA-treated patients who were biopsied showed reductions in lesional CD25+ cells, these did not reach statistical significance; in five patients biopsied who had PUVA treatment, no consistent effect on the numbers of CD25+ cells was observed. A significant correlation was found between CD25+ cells in lesional biopsies and the PASI score. Keywords IL-2 receptor cyclosporin A PUVA INTRODUCTION Psoriasis is a disease characterized by hyperproliferation of epidermal keratinocytes and may owe its pathogenesis to the presence of activated T lymphocytes within lesional skin. Evidence supporting this hypothesis is found both in established lesions, where the epidermal infiltrate consists predominantly of HLA-DR+ T helper (CD4+) cells, and in resolving plaques, where the numbers of these cells decline and numbers of HLADR+ T suppressor/cytotoxic (CD8 +) cells increase (Baker et al., 1984). Similar reductions in CD4+ lymphocytes have been shown to precede the clearance of psoriatic lesions during therapy with systemic PUVA (psoralen plus long-wave u.v. radiation) (Baker et al., 1985) and cyclosporin A (CsA) (Baker et al., 1987; Horrocks et al., 1989). The mechanism by which PUVA induces the disappearance of CD4+ cells is not understood, although it has been shown to impair the production of IL-2 by murine spleen cells in vitro (Okamoto et al., 1987). However, it is well established that CsA suppresses the synthesis of IL-2 and other T cell-derived cytokines both in vitro and in vivo (Thomson & Duncan, 1989; Granelli-Piperno, 1990). The induction of IL-2 production by T cells, either following exposure to antigen, mitogen or cytokines, results in the Correspondence: Dr Janet I. Duncan, Immunopathology Laboratory, Department of Pathology, University of Aberdeen, Medical School, Foresterhill, Aberdeen AB9 2ZD, UK.
293
sequential expression of its receptor. The functional IL-2 receptor (IL-2R) is a high-affinity binding complex, composed of two non-covalently linked polypeptide chains-a 75-kD /3 chain of intermediate IL-2-binding affinity and through which signal transduction takes place (Wang & Smith, 1987; Tsudo et al., 1989) and a 55-kD a chain of low IL-2-binding affinity (Kuziel & Greene, 1990). A soluble form of the a chain, which is 10 kD smaller than its membrane-bound counterpart, has been found both in the supernatants of activated lymphocyte cultures (Rubin et al., 1985) and in serum at low levels in healthy individuals (Rubin et al., 1986). The rate of release of this protein is proportional to the number of molecules expressed on the cell surface (Rubin et al., 1985). Raised sIL-2R levels have been found in patients undergoing allograft rejection (Colvin et al., 1987) and during the active phases of certain diseases with a presumed T cell involvement, such as systemic lupus erythematosus (Wolf & Brelsford, 1988), rheumatoid arthritis (Wood et al., 1988) and atopic eczema (Colver et al., 1989). There are also recent reports of elevated serum sIL-2R levels in psoriatic patients (Kapp et al., 1988). Unlike other conditions, however, in which significant reductions in sIL-2R have been reported upon disease resolution, chronic plaque psoriasis patients undergoing successful tar treatment showed no reduction in serum sIL-2R (Kemmet et al., 1990). This study was conducted to determine the effects of CsA and PUVA on sIL-2R levels and numbers of lesional IL-2R+
294
J. L Duncan et al.
(CD25+) cells in psoriasis patients. In addition, investigations were made of the relationship between sIL-2R levels, disease activity, numbers of intralesional CD25+ and circulating CsA levels.
SUBJECTS AND METHODS Patients and treatment Fifty-seven adult patients with severe, stable plaque psoriasis were assessed for disease severity using the psoriasis area and severity index (PASI) score and concurrently for sIL-2R levels in serum. Of these, 11 patients underwent systemic CsA treatment (Sandimmun®, Sandoz, Basle, Switzerland, 3-5 mg/ kg per day) and 13 received PUVA treatment for 4 weeks. Both treatment regimes commenced following a 2-week 'washout' period, when all other therapies ceased, except for local application of bland emolients. Prior to and following treatment, 3-mm punch biopsies were taken from lesional skin, under local anaesthesia (Lignocaine), snap-frozen in arcton/liquid nitrogen and stored at - 70'C. sIL-2R measurements A small quantity of venous blood was allowed to clot at room temperature, and following centrifugation serum was collected and stored at -20'C. Levels of sIL-2R in serum defrosted at room temperature were measured using a sandwich enzyme immunoassay technique and results were expressed in U/ml ('Cell free®' IL-2R test kit, T Cell Sciences, Laboratory Impex, Teddington, UK).
CsA Measurements Estimations of CsA levels were made on serum samples using a monoclonal antibody 125I radioimmunoassay kit (Cyclo-Trac® SP, Incstar, Atlantic Antibodies, Vinnersh, UK) which measures only the parent compound of CsA. The lower sensitivity limit of the assay was 25 ng/ml.
Immunohistochemistry Cryostat sections (6 gm) were fixed in acetone for 20 min and air dried before incubating for I h with the monoclonal antibody anti-IL-2R (CD25) (Dako, High Wycombe, UK) diluted to an optimum titre of 1:20 with Tris-buffered saline, pH 7-6. CD25 (a)
(b)
PUVA
5C
3000
was visualized using the enhanced alkaline phosphatase-antialkaline phosphatase procedure as previously described (Horrocks et al., 1989). Positively staining cells in coded sections were counted at x 320 magnification. Ten sequential grid fields along the dermo-epidermal border in both the epidermis and dermis were examined and the mean count was calculated per 10 fields in three sections.
Statistical analysis The effects of treatment on PASI scores, sIL-2R levels and on the number of CD25 + cells in lesional skin were assessed by the non-parametric Wilcoxon's rank sum test. Measurements of correlation were performed using the Pearson's product moment correlation (r). Smaller samples, not displaying a normal distribution had correlation measurements made using Spearman's rank correlation (rs). RESULTS
Effect of treatment on disease activity, sIL-2R levels and CD25+ cells The effects of CsA and PUVA treatment on individual patient PASI scores, serum sIL-2R levels and numbers of CD25+ cells in lesional skin are shown in Fig. 1. Significant improvements in PASI scores and reductions in sIL-2R levels were achieved with CsA and PUVA treatment (Table 1). Neither CsA nor PUVA, however, produced a significant reduction in the number of CD25 + cells in lesional skin. Two PUVA-treated patients exhibited particularly high initial CD25+ cell counts. After 4 weeks of PUVA treatment one patient showed a marked reduction in the number of CD25 + cells which was accompanied by a similar change in PASI score, while the other patient exhibited an increase in CD25 + cells and only a slight decrease in PASI score. Neither patient, however, demonstrated any change in sIL-2R levels. Correlation between disease activity and sIL-2R levels A strong correlation between PASI score and sIL-2R levels was demonstrated in stable plaque psoriasis patients (n = 104, r=0-696, P
![[Psoriasis and PUVA].](/assets/img/hold.png)
