Peripheral Blood T-cell Clones Research Articles

Association of a Dominant T-Cell Clone in Peripheral Blood With Time to Systemic Treatment in Patients With Stage IB Mycosis Fungoides

This cohort study of data from 39 patients assesses whether the presence of a dominant T-cell receptor clone in peripheral blood is associated with time to systemic treatment in patients with stage IB mycosis fungoides.

Abstract CT079: Neoadjuvant PD-1 blockade in resectable lung cancer

Abstract Background: Programmed death-1 (PD-1) blocking antibodies improve survival in patients with advanced non-small-cell lung cancer (NSCLC) but have not been tested in resectable NSCLC, where little progress has been made over the last decade. Methods: Adults with untreated surgically resectable stage I-IIIA NSCLC received two doses of nivolumab (anti-PD-1) preoperatively. The primary endpoints of the study were safety and feasibility. Tumor pathologic response, PD-L1 expression, mutation burden and mutation-associated neoantigen-specific T-cell responses were evaluated. Results: Neoadjuvant nivolumab was had an acceptable side effect profile without surgical delays, and 20 of 21 tumors were completely resected. Major pathologic response occurred in 45% (9/20) of resected tumors. Responses occurred in both PD-L1 positive and negative tumors. Pathologic response significantly correlated with pre-treatment tumor somatic mutation burden. T-cell clones shared between the tumor and peripheral blood increased systemically upon anti-PD-1 treatment in 8 of 9 patients analyzed. Mutation-associated neoantigen-specific T-cell clones, from a primary tumor that underwent pathologic complete response, rapidly expanded in peripheral blood at 2-4 weeks post-treatment, some of these clones were not detected before anti-PD-1. Conclusions: Neoadjuvant nivolumab was associated with few side effects, did not delay surgery, and induced major pathologic responses in 45% of resected tumors. Tumor mutation burden is predictive of pathologic response to anti-PD-1. Anti-PD-1 can induce expansion of mutation-associated neoantigen-specific T-cell clones in peripheral blood. [P.M.F., J.E.C., and K.N.S. contributed equally to this work.] Citation Format: Patrick M. Forde, Jamie E. Chaft, Kellie N. Smith, Valsamo Anagnostou, Tricia R. Cottrell, Matthew D. Hellmann, Marianna Zahurak, Stephen C. Yang, David R. Jones, Stephen Broderick, Richard J. Battafarano, Moises J. Velez, Natasha Rekhtman, Zachary Olah, Jarushka Naidoo, Kristen A. Marrone, Franco Verde, Haidan Guo, Jiajia Zhang, Justina X. Caushi, Hok Yee Chan, John-William Sidhom, Robert B. Scharpf, James White, Edward Gabrielson, Hao Wang, Gary L. Rosner, Valerie Rusch, Jedd D. Wolchok, Taha Merghoub, Janis M. Taube, Victor E. Velculescu, Suzanne L. Topalian, Julie R. Brahmer, Drew M. Pardoll. Neoadjuvant PD-1 blockade in resectable lung cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr CT079.

Neoadjuvant PD-1 Blockade in Resectable Lung Cancer

BackgroundAntibodies that block programmed death 1 (PD-1) protein improve survival in patients with advanced non–small-cell lung cancer (NSCLC) but have not been tested in resectable NSCLC, a condition in which little progress has been made during the past decade.MethodsIn this pilot study, we administered two preoperative doses of PD-1 inhibitor nivolumab in adults with untreated, surgically resectable early (stage I, II, or IIIA) NSCLC. Nivolumab (at a dose of 3 mg per kilogram of body weight) was administered intravenously every 2 weeks, with surgery planned approximately 4 weeks after the first dose. The primary end points of the study were safety and feasibility. We also evaluated the tumor pathological response, expression of programmed death ligand 1 (PD-L1), mutational burden, and mutation-associated, neoantigen-specific T-cell responses.ResultsNeoadjuvant nivolumab had an acceptable side-effect profile and was not associated with delays in surgery. Of the 21 tumors that were removed, 20 were completely resected. A major pathological response occurred in 9 of 20 resected tumors (45%). Responses occurred in both PD-L1–positive and PD-L1–negative tumors. There was a significant correlation between the pathological response and the pretreatment tumor mutational burden. The number of T-cell clones that were found in both the tumor and peripheral blood increased systemically after PD-1 blockade in eight of nine patients who were evaluated. Mutation-associated, neoantigen-specific T-cell clones from a primary tumor with a complete response on pathological assessment rapidly expanded in peripheral blood at 2 to 4 weeks after treatment; some of these clones were not detected before the administration of nivolumab.ConclusionsNeoadjuvant nivolumab was associated with few side effects, did not delay surgery, and induced a major pathological response in 45% of resected tumors. The tumor mutational burden was predictive of the pathological response to PD-1 blockade. Treatment induced expansion of mutation-associated, neoantigen-specific T-cell clones in peripheral blood. (Funded by Cancer Research Institute–Stand Up 2 Cancer and others; ClinicalTrials.gov number, NCT02259621.)

Coeliac disease: immunogenicity studies of barley hordein and rye secalin-derived peptides.

Coeliac disease (CD) is an inflammatory disorder of the small intestine. It includes aberrant adaptive immunity with presentation of CD toxic gluten peptides by HLA-DQ2 or DQ8 molecules to gluten-sensitive T cells. A ω-gliadin/C-hordein peptide (QPFPQPEQPFPW) and a rye-derived secalin peptide (QPFPQPQQPIPQ) were proposed to be toxic in CD, as they yielded positive responses when assessed with peripheral blood T-cell clones derived from individuals with CD. We sought to assess the immunogenicity of the candidate peptides using gluten-sensitive T-cell lines obtained from CD small intestinal biopsies. We also sought to investigate the potential cross-reactivity of wheat gluten-sensitive T-cell lines with peptic-tryptic digested barley hordein (PTH) and rye secalin (PTS). Synthesised candidate peptides were deamidated with tissue transglutaminase (tTG). Gluten-sensitive T-cell lines were generated by culturing small intestinal biopsies from CD patients with peptic-tryptic gluten (PTG), PTH or PTS, along with autologous PBMCs for antigen presentation. The stimulation indices were determined by measuring the relative cellular proliferation via incorporation of 3 H-thymidine. The majority of T-cell lines reacted to the peptides studied. There was also cross-reactivity between wheat gluten-sensitive T-cell lines and the hordein, gliadin and secalin peptides. PTH, PTS, barley hordein and rye secalin-derived CD antigen-sensitive T-cell lines showed positive stimulation with PTG. ω-gliadin/C-hordein peptide and rye-derived peptide are immunogenic to gluten-sensitive T-cell lines and potentially present in wheat, rye and barley. Additional CD toxic peptides may be shared.

“Wilms Tumor Protein 1” (WT1) Peptide Vaccination-induced Complete Remission in a Patient With Acute Myeloid Leukemia Is Accompanied by the Emergence of a Predominant T-cell Clone Both in Blood and Bone Marrow

Within the last few years, the first peptide vaccination trials for treatment of acute myeloid leukemia (AML) have been initiated. Athough the presence of epitope-specific T cells could be seen both in bone marrow (BM) and peripheral blood (PB), nothing is known about their clonal composition. In this study, we analyzed material from a patient with recurrent AML vaccinated with "Wilms Tumor Protein 1" (WT1) peptide, who achieved a complete remission (CR) lasting for 12 months. For identification of expanded WT1-specific T-cell clones, enrichment by tetramer and IFNγ secretion were followed by comparative quantitative reverse transcribed PCR (qRT PCR) quantification of all TCR Vβ-families. Vβ-families with increase in the enriched fraction were cloned and sequenced. A predominant clone was quantified by clonotypic qRT PCR from PB and BM. Quantity and functionality of WT1-specific cells were assessed by tetramer analyses and intracellular IFNγ staining. A specific predominant clone was identified during clinical remission. Clone-specific qRT PCR showed an increase both in PB and BM after 8 vaccinations. Six months after achieving CR, the transcript levels in BM decreased. Relapse was accompanied by secondary rise of the WT1-specific clone in PB but not in BM. In parallel, a lack of vaccine-induced WT1 specific IFNγ production was observed at that timepoint. In conclusion, we provide first data regarding evolution and compartmentalization of a peptide vaccine-induced T-cell clone in PB and BM of an AML patient. At the time of relapse, the same clone reappeared spontaneously in PB but not in BM showing impaired functionality.

Evolution of Clinical and Molecular Responses to Bexarotene Treatment in Cutaneous T-Cell Lymphoma

Background: The mechanisms of action of bexarotene are not well understood. Methods: A retrospective study on patients with cutaneous T-cell lymphoma (CTCL) treated with bexarotene was performed to see if bexarotene could act on the dominant T-cell clones. Thirty-five patients were included. Twenty-three were treated with bexarotene for more than 3 months (300 mg/m²). In 7 patients, phototherapy was given with bexarotene. Results: Dominant T-cell clones were observed in 11 patients in peripheral blood and in 19 patients in skin. Our results demonstrate no significant evolution of T-cell clones either in skin or peripheral blood. Furthermore, the detection of T-cell clones in peripheral blood before starting bexarotene was significantly associated with the progression of the disease. UV therapy given with bexarotene significantly improved therapeutic response without any correlation with T-cell clones. Conclusion: This is the first study on the evolution of the T-cell clone in blood and skin in CTCL patients during bexarotene therapy.

'Idiopathic' Eosinophilia with an Occult T-Cell Clone: Prevalence, FIP1L1-PDGFRA Status, and Clinical Course.

Background: Blood eosinophilia results either from autonomous expansion of a myeloid stem/progenitor cell, or as a response to cytokines that promote growth and differentiation of eosinophil progenitors. A subset of patients with hypereosinophilic syndrome/idiopathic eosinophilia (HES/IE) display abnormal T-cell immunophenotype and/or clonal rearrangements of the T-cell receptor (TCR), operationally assigned the term “lymphocyte variant” HES/IE. Information on the prevalence, FIP1L1-PDGFRA status, and clinical course of such patients is limited.Methods: Consecutive patients with eosinophilia were identified by querying our institutional electronic database from 1995 to 2004. Clonal rearrangements of the γchain of the TCR were identified by polymerase chain reaction followed by gel electrophoresis in all cases, and confirmed by Southern Blot analysis of the gene coding for the β chain of the TCR, using standard methods. FIP1L1-PDGFRA was screened by fluorescence in situ hybridization.Results: We studied a total of 205 consecutive patients with eosinophilia defined as an absolute eosinophil count (AEC) of > 600/μL, who also had a bone marrow study performed. Of these, TCR gene rearrangements studies were performed in 99 patients (AEC range of 650 to 38,000/μL) including 3 children and 96 adults (age range 18 to 88 years; 58 males). Among these 99 patients, 14 (~14%) had a demonstrable T-cell clone in peripheral blood, bone marrow aspirate, lymph node, and/or skin. Six of the 14 patients with a demonstrable T-cell clone were found to have a concurrent T-cell malignancy at the time of evaluation including T-cell large granular lymphocytic (T-LGL) leukemia - 1 case and peripheral T-cell lymphoma - 5 cases. The other 8 (~8%) patients otherwise fulfilled the working diagnosis of “lymphocyte variant” HES/IE (median AEC=2045/μL, range 720/μL to 9600/μL). The median duration of eosinophilic prodrome, prior to identification of the occult T-cell clone was 5 years (range 3 months to 11 years), and virtually all had dominant skin involvement presenting as dermatitis (5 cases) or episodic angioedema with eosinophilia (EAE) (2 cases). Five of 7 patients tested had an elevated serum IgE level, and a similar proportion displayed an abnormal T-cell immunophenotype (most commonly, aberrant CD5 and/or CD7 expression). Six of the 8 patients with an occult T-cell clone were evaluated for FIP1L1-PDGFRA and tested negative. Two patients were effectively treated with low-dose oral cyclophosphamide or methotrexate (follow-up duration of 3+ and 6+ years, respectively) whereas imatinib treatment was ineffective in another 2 patients. Two patients (25%) transformed into cutaneous T-cell lymphoma after 3 to 8 years of eosinophilic prodrome.Conclusion: The current study suggests that the presence of a T-cell clone in idiopathic eosinophilia is a marker/harbinger of a primarily skin-based peripheral T-cell lymphoma that responds to T cell-directed therapy but not imatinib therapy, which is consistent with the absence of FIP1L1-PDGFRA in such cases.

The presence of dominant T-cell clones in peripheral blood of patients with collagen vascular disorders: a prospective study of 97 cases

T-lymphocyte dysfunction has been seldom investigated in collagen vascular disorders. The search for dominant T-cell clones has been scarcely reported, although the presence of such clones might be expected in disorders showing immune responses directed against a variety of autoantigens. We conducted a systematic search for dominant T-cell clones in peripheral blood in patients with collagen vascular disorders. Patients and methods Ninety-seven patients with collagen vascular disorders were studied (7 cutaneous and 38 systemic lupus erythematosus; 8 multiple morphea; 12 regional scleroderma; 32 systemic sclerosis of the CREST type). A dominant T-cell clone was searched for in peripheral blood by polymerase chain reaction targeting the T-cell receptor gamma chain followed by a size analysis of amplified fragments. Peripheral blood from patients with nonlymphocyte-dependent disorders and matched by age and sex was assessed in the same conditions. Results in both groups were compared using nonparametric statistical tests. Overall, a circulating dominant T-cell clone was found in 52% of patients compared with 16.9% in controls. More precisely, such a dominant clone was present in 43% and 37% of cutaneous and systemic lupus erythematosus, respectively, in 75% of multiple morphea, 75% of regional scleroderma and 60% of CREST syndrome patients. The percentages in all subsets of patients were significantly higher than in the control group. The presence of a dominant T-cell clone in peripheral blood is significantly more frequent in collagen vascular disorders than in controls, especially in patients with scleroderma, whatever the clinical subset, which suggests T-cell involvement in the immune response dysfunction in these diseases classically characterized by disturbances of B lymphocytes. The relevance of such a dominant clone regarding diagnosis, pathomechanisms, long-term outcome and visceral prognosis of these diseases as well as therapeutic decisions remains to be evaluated.

Gene expression analysis of the CD4+ T‐cell clones derived from gingival tissues of periodontitis patients

The function of T cells infiltrating periodontitis lesions is complex and has not been fully elucidated. Here, we established T-cell clones from the gingival tissues of periodontitis patients and examined their gene expression. A total of 57 and 101 T-cell clones were established by means of immobilized anti-CD3 antibody and IL-2 from gingival tissues and peripheral blood, respectively. The gingival T-cell clones were derived from three patients, and the peripheral blood T-cell clones from two of these patients and a further patient whose gingival T-cell clones were not established. Gingival tissues were also obtained from a further 19 periodontitis patients. The expression of cytokines and molecules related to both regulatory function and tissue destruction were examined by means of reverse-transcription polymerase chain reaction. All the gingival T-cell clones expressed mRNA for TGF-beta1, CTLA-4, and CD25, and all the T-cell clones from peripheral blood expressed IFN-gamma and TGF-beta1 mRNAs. Most but not all the T-cell clones from gingival tissues and peripheral blood expressed mRNA for IFN-gamma and, CD25 and CTLA-4, respectively. The frequency of T-cell clones and gingival tissues expressing FOXP3, a possible master gene for mouse CD4(+)CD25(+) regulatory T cells, was very high (97%, 93%, and 100% for gingival T-cell clones, peripheral blood T-cell clones, and gingival tissues, respectively). Whereas the frequency of IL-4-expressing T-cell clones was lower for gingival T-cell clones (70% vs. 87%), the frequency of the gingival T-cell clones expressing IL-10 and IL-17 was higher than peripheral blood T-cell clones (75% vs. 62% for IL-10, 51% vs. 11% for IL-17). A similar expression profile was observed for gingival T-cell clones compared with gingival tissue samples with the exception of IL-4 expression, where the frequency of positive samples was lower in the gingival tissues (70% vs. 11%). These results suggest that the individual T cells infiltrating gingival lesions can express mRNA for both Th1 and Th2 cytokines as well as regulatory cytokines simultaneously.

Monoclonal T-Cell Dyscrasia of Undetermined Significance Associated With Recalcitrant Erythroderma

Erythroderma is a diffuse, inflammatory skin reaction that, in rare instances, is associated with hematologic malignancies such as cutaneous T-cell lymphoma (erythrodermic mycosis fungoides) or T-cell leukemia (Sezary syndrome or adult T-cell leukemia/lymphoma). We screened 30 patients with erythroderma (20 patients with erythroderma of known etiology and 10 patients with idiopathic erythroderma) for the presence of circulating monoclonal T-lymphocyte populations using T-cell receptor (TCR)-gamma gene-specific polymerase chain reaction and automated capillary DNA electrophoresis. Moreover, the phenotypic analysis of peripheral blood CD4+ lymphocytes was performed using the following surface markers: CD3, CD7, CD8, CD25, CD26, CD27, CD28, CD29, CD30, CD45RO, CD45RA, CD56, CD134, HLA-DR, TCRalphabeta, TCRgammadelta, and cutaneous lymphocyte antigen (CLA). In 5 patients with idiopathic erythroderma we detected T-cell clones in peripheral blood (in 1 case, associated with the presence of the same clone in the skin) and a 2-fold increase in the proportion of CD3+ CD4+ CD7- CD26- cells. Cell depletion studies indicated that the monoclonal T cells were present within the CD4+ CD7- cell population. Clinically, all patients had chronic, recalcitrant erythroderma but none developed any hematological malignancy during their lifetimes or fulfilled the criteria for cutaneous lymphoma or Sezary syndrome. A proportion of patients with chronic erythroderma present with the monoclonal expansion of CD4+ CD7- CD26- lymphocytes in their blood. This condition represents a probably benign T-cell dyscrasia, or one of very low malignancy. Alongside monoclonal gammapathy of undetermined significance (MGUS) and monoclonal (B-cell) lymphocytosis of undetermined significance (MLUS), we propose using monoclonal T-cell dyscrasia of undetermined significance (MTUS) to underline a conceptual similarity between this disorder and the more common types of lymphocytic dyscrasia.

A randomized cross-over study to compare PUVA and extracorporeal photopheresis in the treatment of plaque stage (T2) mycosis fungoides

PUVA is a well-established and effective treatment for plaque stage mycosis fungoides (MF) but its use is limited on a long-term basis because of the risk of cutaneous carcinogenesis. A further disadvantage is that nonexposed areas (sanctuary sites) often develop persistent disease. Therefore it is important to find alternative methods of treatment. Extracorporeal photopheresis (ECP) is a form of photochemotherapy that involves exposure of white blood cells to UVA with psoralens and can be effective in Sézary syndrome and erythrodermic cutaneous T-cell lymphoma. The aim of this study was to compare the efficacy of PUVA and ECP in the treatment of patients with T2 plaque stage (Stage 1B) MF who had a detectable peripheral blood T-cell clone. The study was of a cross-over design. Sixteen patients were randomized to receive either PUVA twice weekly for 3 months followed by ECP once monthly for 6 months at relapse, or vice-versa. Response was assessed by monthly skin scores and peripheral blood T-cell clonality. Ten patients received PUVA initially and six ECP initially. Eight patients completed the study. Skin scores taken at the completion of each treatment arm in patients who completed the study were 113 units better (confidence interval, 42-184 units) following 3 months PUVA than 6 months ECP (P = 0.002). Peripheral blood T-cell clones were detectable in all patients post-treatment. This study indicates that ECP is not effective in the treatment of plaque stage (1B/T2) MF even in patients with molecular evidence of a peripheral blood T-cell clone. Although PUVA was more effective than ECP, neither treatment modality cleared malignant T-cells from the peripheral blood.

Rare occurrence of CD30+ circulating cells in patients with cutaneous CD30+ anaplastic large cell lymphoma: a study of nine patients.

The presence of a significant percentage of circulating atypical lymphocytes in peripheral blood has already been demonstrated in systemic CD30+ anaplastic large cell lymphoma (ALCL), which implies that a leukaemic component may be present in this subset of lymphomas. However, no similar data are available for the cutaneous counterpart of this particular lymphoproliferation. To assess the presence of atypical cells, CD30+ lymphocytes and of a dominant T-cell clone in peripheral blood in a series of patients with cutaneous CD30+ ALCL. Nine patients with either primary (four) or secondary (five) cutaneous CD4+ CD30+ ALCL were selected. The percentage of CD30+ CD4+ lymphocytes among peripheral blood mononuclear cells (PBMC) was determined by flow cytometry and the presence of a dominant circulating T-cell clone was assessed by polymerase chain reaction targeting the T-cell receptor gamma chain. A control group composed of apparently healthy individuals was similarly studied at the same time. The mean percentage of CD30+ cells in PBMC was slightly higher in patients than in controls (3.9% vs. 2.7%) but the difference was not statistically significant. Only two patients displayed more than 5% CD30+ cells, both of whom had a minor tumour burden. A dominant circulating T-cell clone was detected in only three cases, including these two latter patients. The occurrence of a significant percentage of CD30+ CD4+ circulating cells is rare in active cutaneous CD30+ ALCL, either primary or secondary. This percentage is not related to the apparent skin tumour burden but a significant figure appeared to be correlated with the detection of a dominant T-cell clone in peripheral blood. Overall, these data show that, unlike mycosis fungoides, peripheral blood involvement seems infrequent in cutaneous CD30+ ALCL. The hypothesis that a high percentage of CD30+ circulating cells might be related to the presence of a cryptic systemic disease cannot be ruled out.

Diagnostic value of dominant T-cell clones in peripheral blood in 363 patients presenting consecutively with a clinical suspicion of cutaneous lymphoma

AbstractIt is now widely accepted that polymerase chain reaction (PCR) analysis of cutaneous T-cell clonality is of diagnostic value in cutaneous T-cell lymphomas (CTCLs) and most helpful in the diagnosis of mycosis fungoides (MF). However, the diagnostic and prognostic value of circulating clonal T cells remains unclear. We studied T-cell clonality in the peripheral blood (PB) and the cutaneous lesion, sampled at the same time, in 363 consecutively seen patients with a clinical suspicion of cutaneous lymphoma. Using a PCR technique providing a specific imprint of T-cell clones (PCRγ–denaturing gradient gel electrophoresis), we found that detection of identical circulating and cutaneous T-cell clones was associated with the diagnosis of CTCL (P < .001). Detection of circulating tumor cells in patients with MF was infrequent (12.5%), except in those with erythrodermic MF (42%; P = .003). Moreover, among the 46 patients who had identical circulating and cutaneous T-cell clones, 25 (56%) had erythroderma. The finding of a dominant clone in the PB but not in the skin was frequent, regardless of the clinicohistologic classification; it occurred in 30% of patients with CTCL, 41% with non-CTCL malignant infiltrates, and 34% with benign infiltrates. This pattern was significantly more frequent in patients over 60 years of age (P < .002), even in the CTCL group (P < .01). In conclusion, dominant T-cell clones detected in the PB of patients with MF by using a routine PCR technique are rarely tumoral and are more often related to age. A multicenter prospective study is under way to establish the prognostic value of circulating tumor cells.

Diagnostic value of dominant T-cell clones in peripheral blood in 363 patients presenting consecutively with a clinical suspicion of cutaneous lymphoma

It is now widely accepted that polymerase chain reaction (PCR) analysis of cutaneous T-cell clonality is of diagnostic value in cutaneous T-cell lymphomas (CTCLs) and most helpful in the diagnosis of mycosis fungoides (MF). However, the diagnostic and prognostic value of circulating clonal T cells remains unclear. We studied T-cell clonality in the peripheral blood (PB) and the cutaneous lesion, sampled at the same time, in 363 consecutively seen patients with a clinical suspicion of cutaneous lymphoma. Using a PCR technique providing a specific imprint of T-cell clones (PCRγ–denaturing gradient gel electrophoresis), we found that detection of identical circulating and cutaneous T-cell clones was associated with the diagnosis of CTCL (P &lt; .001). Detection of circulating tumor cells in patients with MF was infrequent (12.5%), except in those with erythrodermic MF (42%; P = .003). Moreover, among the 46 patients who had identical circulating and cutaneous T-cell clones, 25 (56%) had erythroderma. The finding of a dominant clone in the PB but not in the skin was frequent, regardless of the clinicohistologic classification; it occurred in 30% of patients with CTCL, 41% with non-CTCL malignant infiltrates, and 34% with benign infiltrates. This pattern was significantly more frequent in patients over 60 years of age (P &lt; .002), even in the CTCL group (P &lt; .01). In conclusion, dominant T-cell clones detected in the PB of patients with MF by using a routine PCR technique are rarely tumoral and are more often related to age. A multicenter prospective study is under way to establish the prognostic value of circulating tumor cells.

T-cell expansions in patients with multiple myeloma have a phenotype of cytotoxic T cells.

The presence of T-cell clones in peripheral blood has been previously shown to be associated with a survival advantage in patients with multiple myeloma and suggests that the expanded T-cell populations may be involved in an anti-tumour response. We studied the T-cell receptor (TCR) repertoire of 38 patients with myeloma to identify and characterize the expanded T-cell populations by flow cytometry. T-cell expansions were found in 79% of the patients. The expansions occurred randomly among the 21 variable regions of the TCR beta chain (Vbeta) studied, representing 62% of the V-beta repertoire, and were stable during an 18-month follow-up. The phenotype of the expanded V-beta populations was predominantly CD8+, CD57+, CD28- and perforin+, which differed significantly from the other non-expanded Vbeta populations. The expression of the apoptosis markers Fas (CD95) and bcl-2 were similar between the expanded and non-expanded Vbeta populations. In conclusion, expanded T-cell populations were frequent in patients with myeloma, they remained unchanged during follow-up and had phenotypic characteristics of cytotoxic T cells. These data add further support to the concept that the T-cell expansions may have an immunoregulatory role in myeloma.

Accumulation of interferon gamma-producing TH1 helper T cells in nasal polyps.

We investigated the mechanisms involved in the formation of nasal polyps by examining T-cell clones and their production of soluble mediators in nasal polyps. Recently, the allergic origin of nasal polyps has been challenged. To study this question we characterized T cells from polyp tissue of allergic individuals in terms of their cytokine pattern. Nasal polyp T cells were cloned from allergic individuals undergoing polypectomy. Polyp tissue was dispersed enzymatically, and T cells were stimulated with mitogen and interleukin-2. Control T cells were obtained from peripheral blood of nonallergic donors. Cytokine production of interleukin-4 and interferon was then determined by indirect enzyme-linked immunosorbent assay tests. Polyp T-cell clones were found to produce high interferon but low interleukin-4 levels that were not significantly different from control peripheral blood T-cell clones. In addition, immunoglobulin production by dispersed polyp tissue was investigated. Immunoglobulin levels were higher in polyp tissues than in serum with immunoglobulin A predominating. These results suggest that the inflammatory reaction in nasal polyps is different than that seen in a typical type I hypersensitivity response.