Polymorphisms of tumor necrosis factor (TNF) α and β genes in Korean patients with psoriasis

To evaluate the association of TNF-alpha (TNFA) and TNF-beta (TNFB) polymorphisms with psoriasis in the Korean population, we investigated TNF-alpha -238 and -308 promoter region and TNF-beta NcoI polymorphism using PCR-RFLP in 103 Korean psoriasis patients and 125 normal controls. The carriage and allele frequencies of TNFB*2 were significantly increased in patients with psoriasis compared with normal controls. However, TNFB*1/1 homozygote and TNFB*1 allele were significantly decreased in the patients. There were no significant differences in the polymorphism of TNF-alpha promoter -238 and -308 between the patients and controls. We also analyzed the frequencies of TNFB alleles according to the clinical characteristics of the psoriasis patients, but no significant differences were found. However, female patients with early-onset psoriasis showed an association with the TNFB*2 allele. In conclusion, our results suggest that polymorphisms of the TNFB gene may contribute to a predisposition to psoriasis in the Korean population.     

T cells in psoriatic lesional skin that survive conventional therapy with NB-UVB radiation display reduced IFN-γ expression

The type 1 T cell-derived cytokine interferon (IFN-) is overexpressed in psoriatic lesional skin. Recently, we have shown that a single high erythemal dose of broad-band ultraviolet B (UVB) irradiation reduces type 1 and favors type 2, i.e. interleukin-4 (IL-4), cytokine expression in normal and psoriatic skin. In this study, we wanted to see whether conventional narrow-band UVB (NB-UVB) therapy (i.e. repeated exposure to nonerythemal doses) also affects type 1/type 2 cytokine expression of T cells present in chronic plaque type psoriatic lesions. Staining of cryostat sections showed decreased expression of both IFN- and IL-4 in situ after NB-UVB therapy. CD4⁺ dermal T cell lines, derived from psoriatic lesional skin, displayed significantly decreased intracellular IFN- expression during and after NB-UVB therapy as compared to pretreatment values. Intracellular IL-4 expression was increased in most patients after therapy. Analysis of the supernatants of these stimulated dermal T cells revealed that IFN- production decreased significantly following NB-UVB therapy, whereas IL-4 expression increased in the T cell supernatants from most patients, confirming the intracellular determinations. In addition, IL-10 and transforming growth factor- levels in the supernatants appeared to be increased in the majority of patients following UVB therapy. Apart from the well-known killing effect of UVB on T cells, our results show that the improvement in psoriatic skin following NB-UVB therapy is also due to a reduced capacity of the surviving dermal T cells to express the proinflammatory cytokine IFN-.     

Effects of tacrolimus on the expression of nuclear factor-κB and glucocorticoid receptor by HaCaT cells in vitro

Objective To investigate the effect of tacrolimus on the expression of nuclear factor-κB (NF-κB) in HaCaT cells stimulated by tumor necrosis factor-α(TNF-α),and on the expression of glucocorticoid receptor (GR)α and β in untreated HaCaT cells in vitro.Methods Cultured Ha CaT cells were treated with TNF-α(10μg/L) only,combination of TNF-α(10μg/L) and various concentrations (10-8mol/L, 10-7mol/L,10-6moL/L) of tacrolimus or tacrolimus of different concentrations only.After additional 12-,24-, 36- or 48-hour cnlture, Westem blot and immunofluorescenee-confocal laser scanning microscopy were used to detect the expressions of NF-κB,GRα and GRβ in HaCaT cells.Those untreated HaCaT cells served as the control.Results The relative protein expression level of NF-κB was increased in HaCaT cells after treatment with TNF-α for 24 and 48 hours zompared with untreated ceils (0.73±0.0316 and 0.8925±0.0171 vs 0.4988±0.03506,both P<0.05);however,the increase in NF-κB expression was inhibited by the combination treatment with tacrolimus,and the relative expression level of NF-κB protein was 0.6825±0.0263.0.6200±0.0163 and 0.5575±0.0299 in HaCaT cells treated with TNF-α plus tacrolimus of 10-8mol/L 10-7mol/L and 10-6mol/L,respectively;the difference was significant etween TNF-α-treated cells and those dealt with the combination of NF-α and tacrolimus of 10-7 or 10-6 mol/L (both P<0.05).No significant difference was observed in the expression of NF-κB by HaCaT cells between different time oints treated with tacrolimus of 10-8,10-7 or 10-6 mol/L.Also,there was no zignificant difference in the expression of GRα or GRβ between untreated HaCaT cells and those treated with tacrolimus of 10-8, 10-7 or 10-6 mol/L at any time point.Conclusions Tacrolimus ould inhibit the expression of NF-κB by TNF-α-stimulated HaCaT cells,but does not affect the expression of GRα or GRβ,in untreated HaCaT cells.     

Effects of tacrolimus on the expression of nuclear factor-κB and glucocorticoid receptor by HaCaT cells in vitro

Objective To investigate the effect of tacrolimus on the expression of nuclear factor-κB (NF-κB) in HaCaT cells stimulated by tumor necrosis factor-α(TNF-α),and on the expression of glucocorticoid receptor (GR)α and β in untreated HaCaT cells in vitro.Methods Cultured Ha CaT cells were treated with TNF-α(10μg/L) only,combination of TNF-α(10μg/L) and various concentrations (10-8mol/L, 10-7mol/L,10-6moL/L) of tacrolimus or tacrolimus of different concentrations only.After additional 12-,24-, 36- or 48-hour cnlture, Westem blot and immunofluorescenee-confocal laser scanning microscopy were used to detect the expressions of NF-κB,GRα and GRβ in HaCaT cells.Those untreated HaCaT cells served as the control.Results The relative protein expression level of NF-κB was increased in HaCaT cells after treatment with TNF-α for 24 and 48 hours zompared with untreated ceils (0.73±0.0316 and 0.8925±0.0171 vs 0.4988±0.03506,both P<0.05);however,the increase in NF-κB expression was inhibited by the combination treatment with tacrolimus,and the relative expression level of NF-κB protein was 0.6825±0.0263.0.6200±0.0163 and 0.5575±0.0299 in HaCaT cells treated with TNF-α plus tacrolimus of 10-8mol/L 10-7mol/L and 10-6mol/L,respectively;the difference was significant etween TNF-α-treated cells and those dealt with the combination of NF-α and tacrolimus of 10-7 or 10-6 mol/L (both P<0.05).No significant difference was observed in the expression of NF-κB by HaCaT cells between different time oints treated with tacrolimus of 10-8,10-7 or 10-6 mol/L.Also,there was no zignificant difference in the expression of GRα or GRβ between untreated HaCaT cells and those treated with tacrolimus of 10-8, 10-7 or 10-6 mol/L at any time point.Conclusions Tacrolimus ould inhibit the expression of NF-κB by TNF-α-stimulated HaCaT cells,but does not affect the expression of GRα or GRβ,in untreated HaCaT cells.     

Proliferation and interferon-γ receptor expression in psoriatic and healthy keratinocytes are influenced by interactions between keratinocytes and fibroblasts in a skin equivalent model

Epidermal-dermal interactions were studied in a skin equivalent model. Six combinations of keratinocytes and fibroblasts from healthy and psoriatic skin were used. TPA (12-O-tetradecanoylphorbol-13-acetate) was used to determine whether the expression of the IFN- receptors in keratinocytes was related to epidermal differentiation and proliferation. These phenomena were assessed by immunohistochemistry. In all epidermal outgrowths, the epidermal growth factor receptor was expressed throughout the epidermis, cytokeratin 16 suprabasally, and filaggrin and involucrin in its superficial part. The IFN- receptor was expressed throughout the epidermis, but was unevenly distributed. The expression of the IFN- receptor was quantified by confocal laser scanning microscopy both in the whole of epidermis and in areas with the strongest intensity. The total amount varied to a minor degree in the epidermal outgrowths of different origins and was unaffected by TPA. In high-intensity areas interactions between keratinocytes and fibroblasts did influence the amount of IFN- receptor expression and TPA decreased the expression by 13%. There was no correlation between the proliferation rate and the expression of the IFN- receptor. Psoriatic and healthy keratinocytes were equally well differentiated in the skin equivalents. The interferon- receptor was similarly expressed under these conditions. The growth rate, assessed by Ki-67-positive nuclei in the basal layer, was highest in healthy keratinocytes. Keratinocytes from psoriatic lesions increased their growth rate when cocultured with psoriatic fibroblasts compared with normal ones, indicating that fibroblasts may be of importance for epidermal hyperproliferation in psoriatic lesions.     

Variable CD7 expression on T cells in the leukemic phase of cutaneous T cell lymphoma (Sézary syndrome)

CD7, a molecule normally expressed on 90% of normal CD4+ T cells, is often deficient on the malignant T cells of cutaneous T cell lymphoma. To investigate the clinical and biologic implications of CD7 expression, blood lymphocytes from 42 patients with the leukemic phase of cutaneous T cell lymphoma (CD4/CD8 ratio of 10 or more with evidence of a T cell clone in the blood) were analyzed for level of expression of CD7 by flow cytometry. CD7 expression by cells did not clearly segregate into two distinct subgroups that are either CD7 positive or CD7 negative as generally thought; however, nine of 17 patients with a predominantly CD4+CD7+ tumor population on early studies became CD4+CD7- over time whereas the converse situation was not observed. In addition, of three patients with evidence of large tumor cells in the blood coexisting with smaller cells, discordant CD7 expression was observed in one instance. In lymph node specimens, the percentage of cells expressing CD7 and other T cell markers did not correlate with histologic evidence of involvement. CD7 expression on blood lymphocytes also did not correlate with patients' survival nor to serum IgE levels or blood eosinophil counts, a finding suggesting that this marker does not identify functional cell subsets that produce serum interleukin-4 or -5, respectively. We speculate that the level of CD7 expression on malignant T cells may be the effect of sustained antigen stimulation in vivo analogous to what has been proposed to occur with normal T cells during aging.     

Caspase-9 expression is increased in endothelial cells of active Behçet's disease patients

Background Behçet's disease is a multisystem disease of unknown etiology. Caspase‐9 is responsible for initiating the caspase activation cascade during apoptosis. The aim of this study was to examine caspase‐9 expression in both endothelial and perivascular infiltrates of patients with active Behçet's disease. Methods Fifteen patients with active Behçet's disease, attending the First Dermatology Department, Ankara Numune Hospital, Ankara, Turkey between June 2003 and December 2005, were included in the study. Oral biopsy specimens from nine healthy volunteers were taken as the healthy control group, and skin biopsies from 18 psoriasis patients were used as the inflammatory control group. The specimens were examined with caspase‐9 primary antibody. Statistical analyses were performed using SPSS 11.5. Results The mean caspase‐9‐positive endothelial cell counts were 7.17 ± 2.45 in active Behçet's disease, 4.81 ± 0.76 in healthy controls, and 4.35 ± 1.34 in inflammatory controls. The difference between Behçet's disease and healthy controls was statistically significant, with increased endothelial staining in active Behçet's disease (P = 0.049). The difference between Behçet's disease and inflammatory controls was also statistically significant; the rate of staining was higher in Behçet's disease (P = 0.006). The mean caspase‐9‐positive dermal perivascular cell counts were 5.15 ± 2.32 in Behçet's disease, 3.32 ± 0.82 in healthy controls, and 5.54 ± 4.95 in inflammatory controls. These values did not show any statistically significant difference (P = 0.407). Conclusion Endothelial cells are one of the key cells in Behçet's disease, and our findings support the role of endothelial cells in the etiopathogenesis of Behçet's disease.     

Genetic variations in the genes encoding receptor activator nuclear factor κ B (RANK), receptor activator nuclear factor κ B ligand (RANKL) and osteoprotegerin (OPG) in patients with psoriasis and psoriatic arthritis: a case-control study

Psoriasis (Ps) and psoriatic arthritis (PsA) are diseases of unknown origin. However, the receptor activator nuclear factor κ B ligand (RANKL) might play a key role in the pathomechanisms of the disease. Our aim was to study seven single nucleotide polymorphisms (SNP) in the genes encoding for receptor activator nuclear factor κ B (RANK, two SNP), osteoprotegerin (OPG, two SNP) and RANKL (three SNP in patients with Ps and PsA). A case-control study with 156 Ps patients (45 with PsA) and 516 healthy blood donors was conducted to evaluate an association of the SNP with Ps and PsA by genotyping of DNA by polymerase chain reaction. None of the seven SNP showed any differences in the allelic or genotype frequencies between Ps patients and controls. Our study showed no significant association between the SNP in the genes encoding for RANK, OPG and RANKL with susceptibility of disease in Ps and PsA patients.     

Peroxisome proliferator receptor (PPAR) β/δ in psoriatic patients before and after two conventional therapeutic modalities: methotrexate and PUVA

Peroxisome proliferator-activated receptor β/δ is a member of the nuclear hormone receptor superfamily suggested to contribute to psoriasis pathogenesis. Methotrexate and PUVA mainly target the T cell-mediated immunopathology of psoriasis. Our work aimed at estimating PPARβ/δ in psoriatic patients and investigating whether the standard therapeutic modalities (methotrexate and PUVA) exert their anti-psoriatic activity partially through altering PPARβ/δ levels. RT-PCR was used to measure PPAR β/δ mRNA levels in twenty four chronic plaque psoriasis patients. Patients were divided into two groups (12 patients each); group A received intramuscular methotrexate and group B was treated by PUVA 3 times/week in a PUVA 1000 cabin for ten weeks each, followed by measurement of PPAR β/δ mRNA levels. Twelve healthy volunteers served as controls. PPAR β/δ mRNA levels were significantly elevated in all patients and significantly decreased ten weeks after treatment, however, post treatment levels were still significantly elevated in comparison with those of controls. PPAR β/δ mRNA levels showed a significant positive correlation with disease duration.     

Quality of life in leprosy: a comparative analysis between patients in the Amazon region and patients in Santo André in the ABC region of São Paulo, Brazil

This study analyzed the quality of life of individuals with leprosy and compared quality of life indexes of patients in two different socioeconomic scenarios. The study was conducted at the leprosy clinic of the ABC School of Medicine, S?o Paulo, Brazil and during visits to the populations living along the Purus River in the Brazilian state of Amazonas. The Dermatology Life Quality Index (DLQI) was used to evaluate the patients. Quality of life was found to be impaired in 76.9% of the patients evaluated in the Amazon compared to 19% of the patients in Santo André. In the group of patients in the Amazon who had sequelae of the disease, quality of life was impaired.     

Functional and phenotypical alterations of polymorphonuclear cells in Sézary syndrome patients

Sézary syndrome (SS), the leukemic variant of cutaneous T-cell lymphoma (CTCL), has a poor prognosis and infections represent the most frequent cause of death. Polymorphonucleate granulocytes (PMNs) constitute an essential part of the innate immune system: their phagocytic and killing activity against pathogens is mediated by the interactions between Toll-like receptors (TLRs) and the Pathogen-associated molecular patterns (PAMPs). The aim of this study was to investigate PMN functional activity and phenotype in SS patients and their correlation with the onset of infectious complications. This prospective study enrolled 18 consecutive SS patients; PMN functional activity was evaluated by phagocytosis and intracellular killing tests towards Klebsiella pneumoniae. Flow-cytometry was applied to analyze PMN phenotype. PMNs from SS patients displayed a reduced phagocytic activity and intracellular killing against K. pneumoniae at 30 min and 60 min, more pronounced in SS patients with recurrent infections. CD11b and CD66b median fluorescence intensity (MFI) was significantly higher in SS than in healthy subjects, whereas CD62L MFI was decreased. No significant differences in TLR2, 4, 8 and 9 percentage expression or MFI were found. An increased TLR5 percentage expression was documented. The impairment in PMN functional activities in SS could favour the immune-suppression and raise infection risk.     

Expression of BMP type ⅠA receptor in the scalp of AGA patients and its significance

目的:探讨骨形成蛋白Ⅰ型受体(BMPR-Ⅰ)A在正常人及雄激素源性脱发(androgenetic alopecia,AGA)患者头皮毛囊中的表达及其意义.方法:采用Western blot、免疫组化及RT-PCR分析8例AGA患者额顶部脱发区与枕部非脱发区毛囊及11例正常人头皮毛囊中BMPR-ⅠA蛋白及基因水平表达差异;毛囊分组培养,观察双氢睾酮(dihydrotestosterone,DHT)10-9mol/L对BMPR-ⅠA表达及毛囊生长的影响.结果:各组头皮毛囊均可见BMPR-ⅠA阳性染色.与正常毛囊相比,AGA患者脱发区毛囊阳性染色A值降低(P ＜ 0.05).Western blot结果显示,AGA患者头顶部毛囊BMPR-ⅠA含量较正常人下调,目的蛋白与内参灰度比由1.733±0.058下调为0.396±0.036(P ＜ 0.05);AGA枕部毛囊目的蛋白与内参灰度比值为1.574±0.039,与正常人组差异无统计学意义.毛囊培养DHT组与生理盐水对照组相比,目的蛋白与内参灰度比由3.441±0.172下降为0.367±0.026(P ＜ 0.05).RT-PCR结果示,AGA脱发区毛囊BMPR-ⅠA mRNA下调为正常组的53%(P ＜ 0.05),AGA枕部无明显下调;毛囊培养DHT组下调为对照组的13%(P ＜ 0.05).结论:AGA脱发区毛囊与DHT组毛囊BMPR-ⅠA表达均降低,提示BMPR-ⅠA表达下降部分是由DHT升高引起;DHT可引起的毛囊生长减慢及退行性变;BMPR-ⅠA表达下降可能是DHT升高的直接作用或者是AGA生长期与退行期毛囊比例下降的代偿机制;其参与AGA发病可能与毛干及内根鞘形成障碍引起毛发脱落有关.     

Analysis of αv integrin protein expression in human eyelid and periorbital squamous cell carcinomas

Background: Alpha v integrins are receptors for many extracellular matrix (ECM) protein ligands, including latent transforming growth factor betas (TGFβs). Various studies in mice have shown that ablation of genes encoding αv integrin or TGFβ signaling pathway components leads to spontaneous squamous cell carcinomas (SCCs) in the conjunctiva and periocular skin. Here, we have analyzed patterns of αv integrin protein expression and TGFβ signaling in human eyelid and periorbital SCC samples. Methods: An anti‐αv integrin antibody was used to immunostain 19 eyelid and periorbital SCC samples. Additionally, tissue lysates from resected normal eyelid and SCC samples were analyzed by immunoblotting for αv integrin protein. Tumor sections were also immunostained with an antibody directed against Smad2, an intracellular signaling protein that is phosphorylated by TGFβ receptors. Results: Alpha v integrin protein was highly expressed in the invasive and less‐differentiated components of human SCCs. Lower levels of αv integrin protein were detected in more differentiated components of tumors, as well as in SCC in situ. Patterns of phosphorylated Smad2 immunoreactivity correlated with levels αv integrin expression. Conclusions: Alpha v integrin was expressed at robust levels in tumor cells representing less differentiated, more invasive components of SCC; by contrast, well‐differentiated cells as well as SCC in situ expressed low levels of αv integrin protein. Hsu A, Esmaeli B, Hayek B, Hossain MG, Shinder R, Lazar AJ, McCarty JH. Analysis of αv integrin protein expression in human eyelid and periorbital squamous cell carcinomas.     

Proliferation–differentiation relationships in the expression of heparin-binding epidermal growth factor-related factors and erbB receptors by normal and psoriatic human keratinocytes

The topological relationships between erbB receptors and ligands of the epidermal growth factor family were characterized by immunocytochemistry in normal and psoriatic epidermis and in proliferating and differentiating human keratinocytes in culture. Spatial colocalization of receptors and ligands was assessed by dual immunostaining. Expression of epidermal growth factor receptor (EGFr), erbB2, and erbB3, but not erbB4, was detected throughout the epidermis, although labeling for erbB2 and erbB3 was accentuated in the upper spinous layers, and EGFr was more strongly labeled in basal cells. Of the tested growth factors, heparin-binding epidermal growth factor (HB-EGF) was diffusely expressed throughout normal and psoriatic epidermis and sparsely colocalized with EGFr in all viable epidermal layers, with increased colocalization in psoriatic epidermis. In contrast, betacellulin and heregulin/neu differentiation factor (NDF) alpha were largely restricted in their distribution to the upper spinous and granular layers. Betacellulin was downregulated in psoriatic keratinocytes. Although heregulin/NDF-beta was undetectable in normal epidermis, it was upregulated in psoriasis. Betacellulin and heregulin/NDF-alpha strikingly colocalized with EGFr and erbB3 receptors in the granular layer and in a declining gradient from the granular zone to the basal layer, respectively. Similar patterns were observed in cultured keratinocytes under proliferative conditions and upon differentiation in high-calcium medium. These morphological data collectively suggest divergent functions for members of the growth factor family, and in particular, we propose that betacellulin and heregulin/NDF-alpha are involved in epidermal morphogenesis and/or in maintenance of the differentiated phenotype.     

In vivo levels of IL-4, IL-10, TGF-β1 and IFN-γ mRNA of the peripheral blood mononuclear cells in patients with alopecia areata in comparison to those in patients with atopic dermatitis

Alopecia areata (AA) has been considered to be supported by an aberrant expression of IFN-γ as a result of antigen dependent immune response. On the other hand, AA sometimes concurs with atopic diseases, although the mechanism of the concurrence is not clear. This study was designed to elucidate the immune status of AA and the similarity between AA and atopic dermatitis (AD) by analysis of in vivo levels of mRNA of Th1, Th2, and suppressive cytokines of peripheral blood mononuclear cells (PBMC). Using semiquantitative RT-PCR, the levels of cytokine mRNA were measured in freshly isolated PBMC of 47 patients with AA, 15 patients with AD, and 12 healthy controls (HC). The levels of IL-4, IFN-γ, and TGF-β1 mRNA were lower in patients with AA than those in HC. The levels of IL-10 mRNA in AA were comparable with those in HC. Decreased levels of IFN–γ and TGF-β1 were also shown in patients with AD. These results indicated a similarity (decreased levels of IFN-γ and TGF-β1) between AD and AA based on the cytokine profile. In addition, decreased levels of IL-4 mRNA in AA might also explain the experience that the severity of atopic disease coincident with AA is mild in the most of cases. Next, we compared the levels of these cytokine mRNA among the three subgroups of AA that were categorized based on the severity of the symptoms: mild, severe and totalis. Although there was no significant difference between any combinations of the subgroups, there was a tendency to increase the levels of IFN-γ mRNA and to decrease the levels of IL-4 mRNA according to the severity of alopecia. However, the levels of IFN-γ mRNA in any subgroups were less than those of HC. These results suggest that IFN-γ is therefore involved in the pathogenesis of AA, although the information from PBMC is limited. In conclusion, AA might be induced by an aberrant expression of IFN-γ in individuals whose PBMC produce low amounts of IFN-γ and TGF-β1. Further analysis is therefore required to investigate the phenotypes of the population in PBMC with or without reference to regulatory T cells.     

Etanercept in the treatment of psoriasis and psoriatic arthritis with concomitant hepatitis C virus infection: clinical and virological study in three patients

Treatment of patients with psoriasis and concomitant hepatitis-C virus (HCV) infection poses a therapeutic challenge because most systemic drugs are associated with potential hepatotoxicity, either due to direct liver damage or to immunosuppression. Among newly available drugs for the treatment of psoriasis and psoriatic arthritis, studies investigating the effect of anti-tumour necrosis factor-α in such patients are still limited. We describe three psoriatic patients with HCV, one with concomitant alcoholic hepatitis, who were treated with etanercept monotherapy for six months. We obtained good clinical responses for both psoriasis and arthritis in all three patients. While no significant changes in viral load and transaminases were observed in two patients, alanine aminotrasferase and gamma-glutamyltransferase levels were raised during treatment in the patient with concomitant alcoholic hepatitis. At baseline, one patient was negative and two were positive for mixed-type cryoglobulins. During treatment, none of the patients developed cryoglobulinemia-related clinical symptoms, and one of the two patients positive at baseline was negative for cryoglobulins at the end of follow-up. Our results add to accumulating data suggesting that etanercept represents a valuable therapeutic option for treatment of HCV-positive psoriatic patients, with an acceptable safety profile in the short-term. However, etanercept treatment of HCV cases with concomitant alcoholic hepatitis must be undertaken with caution.     

CD4(+)CD7(-) T cells compose the dominant T-cell clone in the peripheral blood of patients with Sézary syndrome

BACKGROUND: Absence of CD7 antigen expression in T cells defines a subset of normal CD4(+) CD45RO(+) CD45RA(-) memory cells and is furthermore observed in Sézary syndrome (SS). OBJECTIVE: Our purpose was to identify circulating T-cell clones in patients with SS and to elucidate whether the dominant T-cell clones express the CD7 antigen. METHODS: Peripheral blood lymphocytes of patients with SS were analyzed by two-color flow cytometry using antibodies to the V beta region of the T cell receptor (TCR) in combination with an antibody to CD7. In addition, T cells were analyzed for TCR-gamma gene rearrangement by polymerase chain reaction (PCR) techniques. RESULTS: Clonal T-cell expansion was detected in 7 patients with SS by immunostaining of the TCR V beta regions. PCR analysis confirmed the presence of dominant T cell clones. Double-immunostaining revealed that in each case cells of the clonal V beta TCR rearrangement homogeneously express the CD4(+)CD7(-) phenotype. Furthermore, CD4(+)CD7(-) cells express the CD15s antigen but lack expression of CD26 and CD49d. CONCLUSION: Expansion of clonal T cells strongly correlates with the expansion of CD4(+)CD7(-) T cells in 7 tested patients with SS. This supports our model that a subset of late differentiated, normal CD4(+)CD7(-) memory T cells may represent the physiologic counterpart of Sézary cells. Monitoring of circulating T cells with the CD4(+)CD7(-)CD15s(+)CD26(-)CD49d(-) phenotype proved to be useful for the identification of clonal T cells in patients with SS.