EULAR/ERA-EDTA recommendations for the management of ANCA-associated vasculitis.

In this article, the 2009 European League Against Rheumatism (EULAR) recommendations for the management of antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) have been updated. The 2009 recommendations were on the management of primary small and medium vessel vasculitis. The 2015 update has been developed by an international task force representing EULAR, the European Renal Association and the European Vasculitis Society (EUVAS). The recommendations are based upon evidence from systematic literature reviews, as well as expert opinion where appropriate. The evidence presented was discussed and summarised by the experts in the course of a consensus-finding and voting process. Levels of evidence and grades of recommendations were derived and levels of agreement (strengths of recommendations) determined. In addition to the voting by the task force members, the relevance of the recommendations was assessed by an online voting survey among members of EUVAS. Fifteen recommendations were developed, covering general aspects, such as attaining remission and the need for shared decision making between clinicians and patients. More specific items relate to starting immunosuppressive therapy in combination with glucocorticoids to induce remission, followed by a period of remission maintenance; for remission induction in life-threatening or organ-threatening AAV, cyclophosphamide and rituximab are considered to have similar efficacy; plasma exchange which is recommended, where licensed, in the setting of rapidly progressive renal failure or severe diffuse pulmonary haemorrhage. These recommendations are intended for use by healthcare professionals, doctors in specialist training, medical students, pharmaceutical industries and drug regulatory organisations.

Small-vessel vasculitis with prominent IgG4 positive plasma cell infiltrates as potential part of the spectrum of IgG4-related disease: a case report.

IgG4-related disease (IgG4-RD) is a systemic entity characterised by multiorgan inflammatory lesions with abundant IgG4+ plasma cells, obliterative phlebitis, and storiform fibrosis. Involvement of several organs such as the pancreas, gastrointestinal tract, salivary glands, periorbital tissue and lymph nodes has been described. Up to now, vascular involvement by IgG4-RD has been thought to be essentially confined to large vessels. We present a patient with small-vessel systemic vasculitis involving muscle, peripheral nerve and kidney (glomerulonephritis) in the context of IgG4-RD diagnosed on the basis of elevated serum IgG4+ concentrations and histologically consistent signs in all biopsied tissues. Thoracic and abdominal aortic aneurysms in addition to aortitis, suggestive of large-vessel involvement, were also present. This observation expands the spectrum of vascular involvement in the context of IgG4-RD and supports the inclusion of IgG4-RD in the category of vasculitis associated with systemic disorder.

Influence of the IL17A locus in giant cell arteritis susceptibility.

OBJECTIVE: Different lines of evidence have highlighted the role of IL-17A in the inflammatory process occurring in giant cell arteritis (GCA). The aim of the present study was to assess whether the IL17A locus influences GCA susceptibility and its clinical subphenotypes. METHODS: We carried out a large meta-analysis including a total of 1266 biopsy-proven GCA patients and 3779 healthy controls from four European populations (Spain, Italy, Germany and Norway). Five IL17A polymorphisms (rs4711998, rs8193036, rs3819024, rs2275913 and rs7747909) were selected by tagging and genotyped using TaqMan assays. Allelic combination and dependency tests were also performed. RESULTS: In the pooled analysis, two of the five analysed polymorphisms showed evidence of association with GCA (rs2275913: PMH=1.85E-03, OR=1.17 (1.06-1.29); rs7747909: PMH=8.49E-03, OR=1.15 (1.04-1.27)). A clear trend of association was also found for the rs4711998 variant (PMH=0.059, OR=1.11 (1.00-1.23)). An independent effect of rs2275913 and rs4711998 was evident by conditional regression analysis. In addition, the haplotype harbouring the risk alleles better explained the observed association than the polymorphisms independently (likelihood p value <10(-05)). CONCLUSIONS: Polymorphisms within the IL17A locus show a novel association with GCA. This finding supports the relevant role of the Th17 cells in this vasculitis pathophysiology.

Red flags for clinical suspicion of eosinophilic granulomatosis with polyangiitis (EGPA).

BACKGROUND: Eosinophilic granulomatosis with polyangiitis (EGPA), is a rare ANCA-associated systemic vasculitis. Its overlapping features with other vasculitic or eosinophilic diseases, and the wide and heterogeneous range of clinical manifestations, often result in a delay to diagnosis. OBJECTIVE: To identify red flags that raise a suspicion of EGPA to prompt diagnostic testing and to present an evidence-based clinical checklist tool for use in routine clinical practice. METHODS: Systematic literature review and expert consensus to identify a list of red flags based on clinical judgement. GRADE applied to generate a strength of recommendation for each red flag and to develop a checklist tool. RESULTS: 86 studies were included. 40 red flags were identified as relevant to raise a suspicion of EGPA and assessed by the experts as being clinically significant. Experts agreed that a diagnosis of EGPA should be considered in a patient aged ≥6 years with a blood eosinophil level >1000 cells/µL if untreated and >500 cells/µL if previously treated with any medication likely to have altered the blood eosinophil count. The presence of asthma and/or nasal polyposis should reinforce a suspicion of EGPA. Red flags of asthma, lung infiltrates, pericarditis, cardiomyopathy, polyneuropathy, biopsy with inflammatory eosinophilic infiltrates, palpable purpura, digital ischaemia and ANCA positivity, usually anti-myeloperoxidase, among others, were identified. CONCLUSION: The identification of a comprehensive set of red flags could be used to raise a suspicion of EGPA in patients with eosinophilia, providing clinicians with an evidence-based checklist tool that can be integrated into their practice.

Identification of the PTPN22 functional variant R620W as susceptibility genetic factor for giant cell arteritis.

OBJECTIVE: To analyse the role of the PTPN22 and CSK genes, previously associated with autoimmunity, in the predisposition and clinical phenotypes of giant cell arteritis (GCA). METHODS: Our study population was composed of 911 patients diagnosed with biopsy-proven GCA and 8136 unaffected controls from a Spanish discovery cohort and three additional independent replication cohorts from Germany, Norway and the UK. Two functional PTPN22 polymorphisms (rs2476601/R620W and rs33996649/R263Q) and two variants of the CSK gene (rs1378942 and rs34933034) were genotyped using predesigned TaqMan assays. RESULTS: The analysis of the discovery cohort provided evidence of association of PTPN22 rs2476601/R620W with GCA (PFDR=1.06E-04, OR=1.62, CI 95% 1.29 to 2.04). The association did not appear to follow a specific GCA subphenotype. No statistically significant differences between allele frequencies for the other PTPN22 and CSK genetic variants were evident either in the case/control or in stratified case analysis. To confirm the detected PTPN22 association, three replication cohorts were genotyped, and a consistent association between the PTPN22 rs2476601/R620W variant and GCA was evident in the overall meta-analysis (PMH=2.00E-06, OR=1.51, CI 95% 1.28 to 1.79). CONCLUSIONS: Our results suggest that the PTPN22 polymorphism rs2476601/R620W plays an important role in the genetic risk to GCA.

A case-control study suggests that the CCR6 locus is not involved in the susceptibility to giant cell arteritis.

OBJECTIVES: Polymorphisms of the CC chemokine receptor 6 (CCR6) gene have been recently reported to be associated with a number of autoimmune diseases. We aimed to investigate the possible influence of CCR6 rs3093024 gene variant in the susceptibility to and clinical expression of GCA. METHODS: The CCR6 polymorphism rs3093024 was genotyped in a total of 463 Spanish patients diagnosed with biopsy-proven GCA and 920 healthy controls using a TaqMan® allelic discrimination assay. PLINK software was used for the statistical analyses. RESULTS: No significant association between this CCR6 variant and GCA was observed (p=0.42, OR=0.94, CI95% 0.79-1.10). Similarly, when patients were stratified according to the specific clinical features of GCA such as polymyalgia rheumatica, visual ischaemic manifestations or irreversible occlusive disease, no statistical significant difference was detected either between the case subgroups and the control set or between GCA patients with and without the specific features of the disease. CONCLUSIONS: Our results suggest that the CCR6 rs3093024 polymorphism may not play a relevant role in the GCA pathophysiology.

Increased expression of the endothelin system in arterial lesions from patients with giant-cell arteritis: association between elevated plasma endothelin levels and the development of ischaemic events.

OBJECTIVE: Approximately 15-20% of patients with giant-cell arteritis (GCA) develop ischaemic complications often preceded by transient ischaemia. The expression of the endothelin (ET) system in GCA lesions was investigated to assess its relationship with the development of ischaemic complications. METHODS: Plasma ET-1 was quantified by immunoassay in 61 patients with biopsy-confirmed GCA and 16 healthy donors. ET-1, endothelin-converting enzyme (ECE-1) and endothelin receptor (ET(A)R and ET(B)R) messenger RNA were measured by real-time quantitative reverse transcriptase-PCR in temporal arteries from 35 of these patients and 19 control arteries. Proteins were measured by immunoassay and Western blot. RESULTS: ET-1 concentration was increased at the protein level in temporal artery samples from GCA patients compared with controls (0.98 (SEM 0.32) vs 0.28 (SEM 0.098) fmol/mg, p = 0.028). ECE-1, ET(A)R and ET(B)R/actin ratios (Western blot) were also significantly higher in GCA patients. Intriguingly, mRNA expression of ET-1, ECE-1 and both receptors was significantly reduced in GCA lesions compared with control arteries. When investigating mechanisms underlying these results, platelet-derived growth factor and IL-1beta, present in GCA lesions, were found to downregulate ET-1 mRNA in cultured human temporal artery-derived smooth muscle cells. Glucocorticoid treatment for 8 days did not result in significantly decreased endothelin tissue concentration (0.87 (SEM 0.2) vs 0.52 (SEM 0.08); p = 0.6). Plasma endothelin concentrations were higher in patients with ischaemic complications (1.049 (SEM 0.48) vs 1.205 (SEM 0.63) pg/ml, p = 0.032). CONCLUSIONS: The endothelin system is increased at the protein level in GCA lesions creating a microenvironment prone to the development of ischaemic complications. Recovery induced by glucocorticoids is delayed, indicating persistent exposure to endothelin during initial treatment.

EULAR recommendations for the management of large vessel vasculitis.

OBJECTIVES: To develop European League Against Rheumatism (EULAR) recommendations for the management of large vessel vasculitis. METHODS: An expert group (10 rheumatologists, 3 nephrologists, 2 immunolgists, 2 internists representing 8 European countries and the USA, a clinical epidemiologist and a representative from a drug regulatory agency) identified 10 topics for a systematic literature search through a modified Delphi technique. In accordance with standardised EULAR operating procedures, recommendations were derived for the management of large vessel vasculitis. In the absence of evidence, recommendations were formulated on the basis of a consensus opinion. RESULTS: Seven recommendations were made relating to the assessment, investigation and treatment of patients with large vessel vasculitis. The strength of recommendations was restricted by the low level of evidence and EULAR standardised operating procedures. CONCLUSIONS: On the basis of evidence and expert consensus, management recommendations for large vessel vasculitis have been formulated and are commended for use in everyday clinical practice.

EULAR recommendations for the management of primary small and medium vessel vasculitis.

OBJECTIVES: To develop European League Against Rheumatism (EULAR) recommendations for the management of small and medium vessel vasculitis. METHODS: An expert group (consisting of 10 rheumatologists, 3 nephrologists, 2 immunologists, 2 internists representing 8 European countries and the USA, a clinical epidemiologist and a representative from a drug regulatory agency) identified 10 topics for a systematic literature search using a modified Delphi technique. In accordance with standardised EULAR operating procedures, recommendations were derived for the management of small and medium vessel vasculitis. In the absence of evidence, recommendations were formulated on the basis of a consensus opinion. RESULTS: In all, 15 recommendations were made for the management of small and medium vessel vasculitis. The strength of recommendations was restricted by low quality of evidence and by EULAR standardised operating procedures. CONCLUSIONS: On the basis of evidence and expert consensus, recommendations have been made for the evaluation, investigation, treatment and monitoring of patients with small and medium vessel vasculitis for use in everyday clinical practice.

Imatinib mesylate inhibits in vitro and ex vivo biological responses related to vascular occlusion in giant cell arteritis.

OBJECTIVES: Ischaemic complications occur in 15-20% of patients with giant cell arteritis (GCA). The aim of our study was to explore the effect of mesenchymal growth factors expressed in GCA lesions on myointimal cell responses related to the development of intimal hyperplasia and vessel occlusion. METHODS: We developed a method to obtain primary human temporal artery derived myointimal cells (HTAMCs) based on the culture of temporal artery sections on Matrigel. RESULTS: Among the factors tested (platelet-derived growth factor (PDGF)-AB, fibroblast growth factor (FGF)-2, vascular endothelial growth factor (VEGF), epidermal growth factor (EGF), transforming growth factor (TGF)beta, chemokine (C-C motif) ligand (CCL)2, interleukin (IL)6 and IL1beta), PDGF exhibited the strongest activity in inducing HTAMC proliferation and migration. As assessed by protein array, immunoassay and quantitative real-time reverse transcriptase (RT)-PCR, PDGF stimulated matrix proteins (collagen I, collagen III and fibronectin) as well as CCL2 and angiogenin production by HTAMCs. Imatinib mesylate inhibited PDGF-mediated activation of signalling pathways (Src, extracellular signal-regulated kinase (ERK) and Akt phosphorylation) related to cell motility and survival, efficiently resulting in inhibition of PDGF-induced HTAMC responses. Myointimal cell outgrowth from cultured temporal artery sections from patients with GCA, where multiple interactions take place, was also efficiently reduced by imatinib. CONCLUSION: Among several mediators produced in GCA, PDGF has the highest vaso-occlusive potential. PDGF may also contribute to disease perpetuation by stimulating the production of angiogenic factors (angiogenin) and chemoattractants (CCL2). Imatinib mesylate strongly inhibits PDGF-mediated responses, suggesting a therapeutic potential to limit vascular occlusion and ischaemic complications in large vessel vasculitis.

Identification of haptoglobin as an angiogenic factor in sera from patients with systemic vasculitis.

Angiogenesis is an important process in chronic inflammatory diseases. We observed that sera from patients with systemic vasculitis stimulated angiogenesis in an in vitro model using human umbilical vein endothelial cells cultured on a basement membrane (Matrigel) substrate. After 40% ammonium sulfate precipitation, angiogenic activity remained in the low molecular weight fraction and could be inactivated by heat. SDS-page of serum FPLC fractions exhibiting maximal angiogenic activity demonstrated two prominent species of 45 and 16-20 kD in patients' sera. These bands were much less apparent in sera obtained from control subjects. Amino-terminal sequencing of the 45-kD protein demonstrated that it was haptoglobin. Purified haptoglobin stimulated angiogenesis in a dose-dependent manner. The angiogenic activity of vasculitis patients' sera was partially inhibited by an antihaptoglobin antibody. Furthermore, serum haptoglobin levels in vasculitis patients correlated both with disease and angiogenic activity. Haptoglobin angiogenic activity was confirmed in two in vivo models using an implanted disc and a subcutaneous injection of basement membrane. Stimulation of angiogenesis is a newly recognized biological function of haptoglobin. The increased levels of haptoglobin found in chronic inflammatory conditions may play an important role in tissue repair. In systemic vasculitis, haptoglobin might also compensate for ischemia by promoting development of collateral vessels.

Estradiol enhances leukocyte binding to tumor necrosis factor (TNF)-stimulated endothelial cells via an increase in TNF-induced adhesion molecules E-selectin, intercellular adhesion molecule type 1, and vascular cell adhesion molecule type 1.

Adhesion of leukocytes to endothelial cells is a critical step in the development of acute and chronic inflammatory lesions. We report here that estradiol treatment of cultured human umbilical vein endothelial cells stimulated up to a twofold increase in TNF-induced adhesion of both polymorphonuclear leukocytes and PMA-activated peripheral blood mononuclear cells. This effect was more evident (threefold increase) when endothelial cells were cultured on the basement membrane glycoprotein laminin. Progesterone, but not testosterone, had a similar stimulatory effect. Estradiol also promoted a slight increase in interferon gamma-stimulated endothelial cell adherence for peripheral blood mononuclear cells, but no effect of estradiol was observed when adhesion of leukocytes to endothelial cells was stimulated with IL-1 or IL-4. The estradiol-induced increase in leukocyte binding to human umbilical vein endothelial cells was partially blocked by antibodies to the adhesion molecules E-selectin, intercellular adhesion molecule type 1 (ICAM-1), and vascular cell adhesion molecule type 1 (VCAM-1). Indirect immunofluorescence techniques showed that estradiol produces an increase in TNF-induced cell surface expression of these molecules. Northern blot analysis demonstrated a transient increase in TNF-induced expression of mRNA for E-selectin, ICAM-1, and VCAM-1 in endothelial cells treated with estradiol. Our data demonstrate that estradiol has important regulatory functions in promoting leukocyte-endothelial cell interactions that might contribute to the observed predominance in females of some autoimmune inflammatory diseases.

Expression of beta-integrin adhesion molecules in non-Hodgkin's lymphoma: correlation with clinical and evolutive features.

PURPOSE: To analyze beta-integrin expression in non-Hodgkin's lymphomas (NHLs) in order to assess its distribution among histologic subtypes and correlate with clinical features and outcome. PATIENTS AND METHODS: The expression of alpha2 through alpha6 and beta1 common chains of very late activation antigen (VLA ) molecules and alphaL (CD11a) and beta2 common (CD18) chains of leukocyte function-associated antigen 1 molecule were studied in 137 patients with NHL. Immunostaining was performed by a streptavidin-biotin alkaline phosphatase method, and integrin expression was semiquantitatively assessed. Correlation with clinical features was analyzed in 80 patients consecutively diagnosed as having immunocytoma (five cases), follicular lymphoma (19 cases), mantle-cell lymphoma (MCL; four cases), diffuse large-cell lymphoma (DLCL; 40 cases), lymphoblastic lymphoma (LL; six cases), anaplastic Ki-1-positive lymphoma (one case), and other peripheral T-cell lymphoma (five cases). RESULTS: MCL cells did not show alpha2 and alpha6 expression, whereas most expressed weak to moderate levels of alpha3, alpha4, and alpha5. LL mostly showed alpha2 to alpha5 expression, whereas alpha6 was observed in seven of 11 cases (higher proportion than that shown in other subgroups). Alpha chains of VLA molecules were present more frequently in T-cell than in B-cell lymphomas. Patients with moderate/strong alpha4, CD11a, and beta2 common chain expression presented more frequently with advanced stage and bone marrow infiltration. Moderate/strong alpha4, alpha5, and beta1 common chain expression correlated with extranodal involvement. In the subset of B-cell DLCL patients, negative/weak expression of alpha3 and alpha4 chains was related to a higher complete response rate. Moreover, negative or weak expression of alpha2, alpha3, alpha4, and beta1( )common chain had favorable significance for overall and failure-free survivals. CONCLUSION: In NHL, beta-integrin expression is related to histologic subtype. The expression pattern of these molecules probably influences disease dissemination and patients' prognoses.

Expression of the adhesion molecule ICAM-1 in non-Hodgkin's lymphoma: relationship with tumor dissemination and prognostic importance.

PURPOSE: To study the expression of intercellular adhesion molecule-1 (ICAM-1) by non-Hodgkin's lymphomas and to assess its correlation with disease extension and prognosis. PATIENTS AND METHODS: ICAM-1 (CD54-IOL54) expression was studied in 70 patients (35 male/35 female; median age, 56 years) with non-Hodgkin's lymphoma from a single institution. Immunostaining was performed using a streptavidine-biotin alkaline phosphatase method and ICAM-1 expression was evaluated in a semiquantitative manner. The histologic distribution of the cases was the following: small lymphocytic, five cases; follicular, 14; mantle cell, five; diffuse large cell, 41; and T lymphoblastic, five. Forty patients (57%) were in stage IV, bulky disease was observed in 25 patients (36%), and extranodal involvement in 48 patients (69%). RESULTS: ICAM-1 expression was negative (-) in 14 patients (20%), weak (+) in 21 (30%), positive (++) in 30 (43%), and strongly positive ( ) in five (7%). No significant relationship was found between ICAM-1 expression and the lymphoma histologic subtype. Patients with negative or weak ICAM-1 expression had more frequently disseminated (stage IV) disease (74% v 40%; P = .007), extranodal involvement (86% v 51%; P = .004), and bone marrow infiltration (57% v 26%; P = .015) than the remainders. Positive ICAM-1 patients had survival rates significantly better than those in whom ICAM-1 was negative or weakly expressed [2-year overall survival: 77% v 50%, respectively; P < .025]. In a multivariate study, ICAM-1 (P = .005) maintained, along with histologic subtype (P = .001) and the international prognostic index (IPI) (P = .056), its importance for predicting survival. Finally, when the group of aggressive non-Hodgkin's lymphoma patients was analyzed, ICAM-1 expression inversely correlated with advanced stage (P = .025), extranodal involvement (P = .01), and bone marrow infiltration (P = .01), complete response (CR) achievement (65% v 32%; P = .025), and overall survival (70% v 26% at 2 years; P < .005). CONCLUSION: In lymphoma patients, ICAM-1 expression correlates with lymphoma dissemination and is useful to assess prognosis.

Membrane attack complex deposits in cutaneous lesions of dermatomyositis.

BACKGROUND AND DESIGN: The presence of membrane attack complex of complement (MAC) deposits in the intramuscular vasculature of biopsy specimens taken from patients with dermatomyositis (DM) has been implicated in the pathogenesis of this myopathy. The purpose of this study was to investigate the presence of MAC deposition in the skin lesions of patients with DM. Using immunohistochemical methods, we examined 22 biopsy specimens from lesional skin, six biopsy specimens from uninvolved skin, and 12 muscle biopsy specimens from patients with DM for the presence of MAC and vitronectin and CD59, two regulatory proteins of complement. RESULTS: The deposition of MAC was demonstrated in a large percentage of biopsy specimens obtained from the lesional skin of patients with DM. Deposits were found along the dermoepidermal junction in 19 (86%) of 22 biopsy specimens. Deposits on the vessel walls of the dermis were found in 17 (77%) of 22 biopsy specimens; but only in six of these biopsy specimens (27%) were deposits present in more than 10% of blood vessels. In contrast, deposits along the dermoepidermal junction and the vessel walls of the dermis were absent in specimens from uninvolved skin. In 12 muscle biopsy specimens obtained simultaneously from these patients, MAC deposits were found on the vessel walls in nine (75%), but only in six (50%) were deposits found in more than 10% of the intramuscular vessels. The pattern of vitronectin immunoreactivity in skin and muscle biopsy specimens obtained from patients with DM was similar to MAC deposits. The expression of CD59 was normal in all skin and muscle biopsy specimens. CONCLUSIONS: The deposition of MAC was found in a high percentage of biopsy specimens from the lesional skin of patients with DM; it was absent in uninvolved skin. These findings suggest that the complement system may be involved in the pathogenesis of the skin lesions of DM.

Tissue targeting and disease patterns in systemic vasculitis.

The systemic vasculitides include a group of diseases with highly heterogeneous organ distribution and disease expression patterns. The mechanisms mediating tissue targeting in systemic vasculitis are largely unknown. Mechanical forces may contribute to the distribution of lesions in immune complex-mediated vasculitis. The site at which the antigen is encountered may be crucial in determining the location of inflammatory infiltrates in some vasculitides. Co-existence of different immunopathogenic mechanisms with variable dominance may generate diversity in disease presentation patterns. Heterogeneous and incompletely understood triggering mechanisms attract inflammatory cells to the site of interest through sophisticated molecular mechanisms: interplay between leukocyte receptors and endothelial ligands, and interactions between chemokines and chemokine receptors. Even with a similar distribution of lesions, patients with vasculitis may display highly variable clinical manifestations. Variations in genes involved in immune response might determine the severity of disease, the intensity of the systemic inflammatory response, the degree of vessel occlusion and the response to therapy.

Late thrombotic events in patients with temporal arteritis and anticardiolipin antibodies.

IgG and IgM isotypes of anticardiolipin (aCL) antibodies were measured in a group of 40 patients with biopsy-proven temporal arteritis (TA), 13 of them with ischemic complications related to the disease. High levels of aCL antibodies were found in only 3 (7.5%) patients. Two had high titres of both IgG and IgM isotypes and the third had high titres of the IgM isotype. No relationship between aCL antibody positivity and the development of any of the classical early occlusive complications of TA was found. However, 2 out of the 3 patients with positive aCL antibody titres later developed ischemic phenomena on conventional corticosteroid treatment. This finding suggests that aCL antibodies could perhaps have a role in the development of the late ischemic complications that occasionally occur in adequately treated TA patients.

T-cell population of primary and secondary cutaneous B-cell lymphomas does not express the cutaneous lymphocyte-associated antigen (CLA).

Primary cutaneous B-cell lymphomas (CBCL) are a group of malignant lymphomas with apparently distinct clinicopathological and immunophenotypical features. As in other B-cell lymphomas, the accompanying benign cell population in CBCL includes a variable number of T lymphocytes whose role is not well understood. In the present study we characterized the immunophenotype of these T cells and compared it with that of the reactive T-cell population in specific skin involvement by noncutaneous B-cell malignancies. Our results indicated that most T cells in both primary and secondary B-cell lymphomas were CLA+ memory/effector helper T cells which differed from the currently known CLA+ memory/effector helper T lymphocytes of the skin-associated lymphoid tissue (SALT) system. However, the endothelial CLA ligand, E-selectin, was expressed on dermal vessels. These results suggest that a B cell environment and/or a lack of epidermal involvement promote(s) the recruitment into the skin of a different, apparently less specific, subset of memory helper T cells from those seen in T-cell-mediated dermatoses.