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H Mellstedt

Publications and source records attributed to H Mellstedt.

At least 19 recordsLinked to original sources
PubMed2001

Incidence of GM-CSF antibodies in cancer patients receiving GM-CSF for immunostimulation.

We have assessed the immunogenicity profile of GM-CSF in patients with either colorectal carcinoma (CRC) at different stages of disease or with multiple myeloma who were given recombinant human GM-CSF (Escherichia coli-derived) combination therapy. Metastatic CRC patients received a colon carcinoma-reactive antibody and high doses of GM-CSF (425--500 microg/day for 10 days), while other CRC patients and those with myeloma received low doses of GM-CSF (75--80 microg/day for 4 days) as an adjuvant along with appropriate tumor antigens. We found that 55% of the patients (11/20) given high doses of GM-CSF developed GM-CSF-reactive antibodies in comparison with an incidence of only 16% (4/25) in patients given low doses of GM-CSF. None of the patients developed neutralizing antibodies and so the biological effects of GM-CSF were not compromised. A majority of patients (80%) (36/45) also developed antibodies to E. coli proteins that were present as trace contaminants in the GM-CSF product. Treatment with recombinant GM-CSF products, therefore, may induce antibodies against this cytokine depending on the regimen and the amounts used. In this study, multiple immunizations with low doses of GM-CSF was associated with a low incidence of GM-CSF antibodies, which did not neutralize the effect of the cytokine. This therapeutic strategy was effective in inducing adjuvant-type effects and needs to be explored in further clinical trials with this cytokine.

Antibodies↗
PubMed2001

Increased serum levels of soluble Fas in progressive B-CLL.

Clinical progression of B-cell chronic lymphocytic leukemia (B-CLL) depends on survival and accumulation of leukemic cells, regulated in part by physical cell contact and soluble molecules. Here we have studied the Fas/FasL system in relation to clinical progression in B-CLL. Serum levels of soluble Fas (sFas) and FasL (sFasL) were determined by ELISA in 43 progressive and 40 non-progressive B-CLL patients and in 21 control individuals. Correlation between sFas serum levels and clinical progression, stage and survival were statistically analyzed. We found high levels of sFas in B-CLL sera correlated with disease progression (p<0.01). In addition, higher sFas levels were found in patients in stages II, III and IV in comparison to patients in stage 0 (p<0.05, p<0.01, p<0.03, respectively). Survival was significantly shorter for patients with > or =6 ng/ml sFas serum levels, although a multivariate analysis did not show sFas to be a significant independent prognostic factor. Fresh B-CLL cells showed only low levels of membrane expression, which were not correlated to sFas levels in serum. In vitro activation of B-CLL cells increased Fas expression, as reported earlier, and induced cells to release sFas into the supernatant. In conclusion, our results indicate that sFas in serum may be a useful parameter for the prediction of clinical progression in B-CLL.

Adult↗
PubMed2001

Interleukin 4 therapy for patients with chronic lymphocytic leukaemia: a phase I/II study.

Interleukin 4 (IL-4) is a pleiotropic type II cytokine which has been shown to have a direct killing effect on lymphoma and B-cell chronic lymphocytic leukaemia (B-CLL) cells in vitro. The clinical effects and toxicity of IL-4 treatment in patients with B-CLL were evaluated. Fourteen patients with B-CLL who were in partial remission after chemotherapy received one, two or three 8-week cycles of escalating doses (2, 4 or 6 microg/kg/d s.c.) of IL-4 for 3 d/week. Clinical response was analysed after each treatment cycle and toxicity was monitored continuously. Ten patients (71%) had progressive disease (PD) during IL-4 treatment. This was mainly attributable to an increase (two- to fourfold) of the blood lymphocyte count during IL-4 therapy. After cessation of IL-4 treatment, the lymphocytosis decreased spontaneously in 8 out of 12 evaluable patients. Splenomegaly remained unchanged in 7/7 patients, whereas enlarged lymph nodes were reduced by > 50% in 1/13 patients and by 25-50% in 4/13 patients. None of the patients achieved an objective tumour regression (complete or partial remission). A temporary increase (16-60%) of the platelet count was observed during IL-4 treatment. The platelet count decreased in 8/11 patients after the end of IL-4 therapy. World Health Organization (WHO) grade I/II fever, arthralgia and fatigue was observed in one-third of the patients and was more commonly seen with the highest dose (6 microg/kg/d). One patient developed pulmonary oedema and WHO grade III neutropenia was recorded in three patients. IL-4 was well tolerated by most patients in an outpatient setting. The anti-tumour activity observed in previous in vitro studies was not verified by the present in vivo trial which showed that IL-4 may instead increase the number of CLL cells in blood, indicating that IL-4 may have induced a stimulatory or antiapoptotic effect on the CLL cells in blood. These results may have important implications for the development of immunotherapy of CLL. In addition, the potential platelet-stimulatory effect of IL-4 warrants further studies.

Aged↗
PubMed2001

Alteration of interleukin 2 (IL-2) pharmacokinetics and function by IL-2 antibodies induced after treatment of colorectal carcinoma patients with a combination of monoclonal antibody 17-1A, granulocyte macrophage colony-stimulating factor, and IL-2.

In this study, we have assessed the development of neutralizing and non-neutralizing interleukin 2 (IL-2) antibodies in metastatic colorectal carcinoma patients receiving a colon carcinoma reactive monoclonal antibody (17-1A) in combination with granulocyte macrophage colony-stimulating factor and IL-2 therapy. Before treatment, no IL-2 antibodies were detected in any of the patients. After therapy, 10 of the 19 patients tested developed antibodies that bound to the IL-2 product used for therapy, but only one developed antibodies that neutralized the biological activity of IL-2 as assessed using an in vitro bioassay. We found that the induction of IL-2 antibodies in some patients irrespective of their neutralizing potential had a significant impact on IL-2 pharmacokinetics. A significant reduction of the area under the concentration-time curve and maximum concentration (C(max)) and increased IL-2 distribution and clearance were observed in IL-2 antibody-positive patients in comparison with IL-2 antibody-negative patients. A significant decrease in IL-2-mediated expansion of lymphocytes was also evident in patients positive for IL-2 antibodies in comparison with those negative for these antibodies. Further characterization of sera from patients with antibodies showed that, in most cases, the antibodies recognized different IL-2 preparations. Results also showed that serum IL-2 concentration at initiation of therapy in patients was significantly higher relative to healthy control donors. The endogenous production of IL-2 gradually increased during the treatment cycles. To conclude, induction of neutralizing and non-neutralizing antibodies in cytokine-treated patients should be carefully monitored in terms of their clinical significance.

Adult↗
PubMed2000

Autologous T lymphocytes recognize the tumour-derived immunoglobulin VH-CDR3 region in patients with B-cell chronic lymphocytic leukaemia.

We have previously shown that autologous T cells recognize leukaemic cells from patients with chronic lymphocytic leukaemia (B-CLL) in an MHC class I- and/or II-restricted manner. A candidate recognition structure might be the tumour cell-derived Ig VH complementarity-determining region (CDR)3. Three patients with B-CLL were analysed for the presence of autologous T cells recognizing the tumour-specific VH-CDR3 region. The VH region was shown to be mutated in all three patients. In two patients, a VH-CDR3-specific T-cell response was detected by proliferation assay, as well as by gamma-interferon (IFN) production. The responses could be inhibited by monoclonal antibodies against MHC class II, but not MHC class I. In the third patient, a VH-CDR3 proliferative response was detected, which could be inhibited by an anti-MHC class I monoclonal antibody, but not by anti-MHC class II antibodies. No gamma-IFN response could be detected in this patient. In no patient was an interleukin (IL)-4 response noted. Thus, in patients with B-CLL, naturally occurring T cells recognizing the tumour-unique VH-CDR3 region are present.

Aged↗
PubMed2000

Autologous T lymphocytes may specifically recognize leukaemic B cells in patients with chronic lymphocytic leukaemia.

This study analysed a naturally occurring specific cellular immunity against tumour cells in chronic lymphocytic leukaemia (CLL) patients. Five out of eight patients had blood T lymphocytes able to recognize spontaneously and specifically the autologous tumour B cells (proliferation assay). In these five patients, detection of cytokines by real-time reverse transcription polymerase chain reaction (RT-PCR) revealed that granulocyte-macrophage colony-stimulating factor (GM-CSF) was the most abundant cytokine gene expressed by the T cells that recognized the autologous tumour B cells. Other activated cytokine genes were gamma-interferon (IFN), interleukin (IL)-2 and tumour necrosis factor (TNF)-alpha, but not IL-4. This profile suggests a type 1 anti-B-CLL T-cell response. CD80 and CD54 were relatively downregulated on the native tumour B cells compared with control normal B cells. Upregulation of CD80 on the leukaemic cells was mandatory for the induction of such a specific T-cell response. CD80 and CD54 monoclonal antibodies inhibited the specific T-cell DNA synthesis proliferation. The proliferative T-cell response was either MHC class I or class II restricted (inhibition by monoclonal antibodies). The specific cytokine gene expression could be found in isolated CD4, as well as CD8, T-cell subsets. This study demonstrated the presence of a potential natural specific CD4, as well as a CD8 type 1 T-cell immunity against the leukaemic CLL tumour B cells in CLL. A further detailed analysis of the spontaneous anti-CLL T-cell immunity is warranted that may facilitate the development of effective anti-tumour vaccines in CLL.

Adult↗
PubMed2000

Idiotype immunity (natural and vaccine-induced) in early stage multiple myeloma.

Idiotypic structures expressed on the myeloma immunoglobulin (Ig) protein (M-component) might be regarded as tumor-specific antigens. Naturally occurring, idiotype-specific type I T-cell immunity has been observed preferentially in patients with early stage myeloma. The idiotypic structures on the clonal myeloma B-cells (B lymphocytes and plasma cells) may serve as targets for active immunization. Vaccination using the autologous monoclonal Ig as a vaccine has conferred resistance to tumor cell challenge in murine myeloma. The autologous myeloma Ig protein was used for immunization in patients with progressive stage I and early stage II multiple myeloma. When the idiotype (emulsified in aluminium phosphate) was used alone for immunization, a weak and transient idiotype-specific T-cell response was observed with no clinical effects. In our second series, the idiotype (in alum) was combined with GM-CSF. In all five patients, a specific T-cell response was induced consisting preferentially of MHC class I restricted (CD8+) T-cells. Ig-specific CD4+ T-cells were also induced. A clinical response ( > 50% reduction of the M-component concentration) was observed in one patient. These results indicate that idiotype-specific T-cell immunity may be induced or enhanced by idiotype Ig vaccination in patients with early stage multiple myeloma, in which the tumor load is relatively low and the immune system is functionally less compromized than in patients with chemotherapy-treated, advanced stages of the disease. The use of GM-CSF seems to be mandatory for the frequency and magnitude of the induced T-cell response. The optimal route, schedule and cytokine combination for idiotype immunization remains to be established.

Clone Cells↗
PubMed2000

Ga733/EpCAM as a target for passive and active specific immunotherapy in patients with colorectal carcinoma.

GA733/EpCAM is an oncofetal antigen abundantly expressed in colorectal carcinoma. This antigen can spontaneously induce a humoral and cellular antitumor immunity and may therefore be a suitable target structure for immunotherapy. Patients with advanced colorectal carcinoma have been treated with monoclonal antibodies (MAb17-1A) against this structure. The data indicate that the chimeric variant was not superior to the original mouse MAb. Addition of cytokines and chemotherapeutics may improve the therapeutic effect of the MAb. A particularly interesting regimen is a combination of MAb17-1A/GM-CSF/alpha-IFN/5-Fu. The GA733 protein antigen can also be used as a vaccine. Patients with colorectal carcinoma stages B and C were vaccinated with this protein antigen in combination with GM-CSF as an adjuvant cytokine. A strong type I T cell response was induced that seemed to be MHC class I as well as class II restricted. No systemic side effects were noted.

Animals↗
PubMed1999

Induction of CD4(+) and CD8(+) Bordetella pertussis toxin subunit S1 specific T cells by immunization with synthetic peptides.

In this study two synthetic peptides from the Bordetella pertussis toxin subunit S1 were conjugated to human anti-idiotypic antibodies and used as an immunogen in cancer patients to induce immunity. The aims of the present report are to explain why no carrier or adjuvant effect of the conjugated pertussis peptides could be established regarding induction of responses against the anti-idiotype and to explore the type and quality of induced anti-pertussis immune responses. The lack of carrier and adjuvant effect of the peptides might be related to the fact that the anti-idiotypic antibodies by themselves include helper epitopes and that none of the patients had a detectable T cell response against any of the selected peptides before immunization, which might be a requirement for an adjuvant effect. However, three of four immunized patients mounted a humoral as well as cellular response against the pertussis peptides used. The induced T cell immunity was restricted to one of the two peptides in responding patients. Established T cell lines and MHC blocking studies indicated that the T cell epitopes of the two peptides had a different MHC restriction. The type of T cell response induced seemed to govern the humoral response. The only durable antibody response was accompanied by the presence of a CD4(+) T cell response against the same peptide. Immunization with an anti-idiotype conjugated to synthetic peptides might thus induce both a B and a T cell response against the peptides and the type of induced T cells (CD4 or CD8) governs the quality of the humoral response. Moreover, the possibility of boosting or inducing a response against the antigen from which the peptide sequences were deduced also seemed feasible.

Adenocarcinoma↗
PubMed1999

Oligoclonal TCRBV gene usage in B-cell chronic lymphocytic leukemia: major perturbations are preferentially seen within the CD4 T-cell subset.

TCRBV (T-cell receptor B variable) gene usage and CDR3 size distribution were analyzed using reverse transcription polymerase chain reaction (RT-PCR) to assess the T-cell repertoire of 10 patients with B-cell chronic lymphocytic leukemia (B-CLL) and in nine age-matched healthy control donors. When the usage of each TCRBV gene within the CD8(+) T cells of the patients was compared with that of the controls, no statistically significant difference was noted except for BV 6S1-3. In contrast, within the CD4(+) T cells of the CLL patients, a statistically significant overexpression for four BV families (2, 3, 5S1, 6S1-3) was seen while an underrepresentation was noted for five BV families (10, 11, 15, 16, 19). Based on the criterion that a value of any BV higher than the mean + 3 standard deviation (SD) of healthy controls indicated an overexpression, individual patients were shown to overexpress several TCRBV genes compared with the controls. Analyses of the CDR3 length polymorphism showed a significantly higher degree of restriction within CD4(+) and CD8(+) T cells of the patients, as compared with the corresponding control T-cell population. There was a significant difference in the CDR3 size distribution pattern with a more polymorphic CDR3 length pattern in the age-matched controls as compared with CLL patients, suggesting different mechanisms driving the T cells towards a clonal/oligoclonal TCRBV usage in patients and controls, respectively. The results show major perturbations of T cells in CLL patients, more frequently seen in the CD4(+) T-cell subset, indicating that nonmalignant CD4(+) T cells may be involved in the pathogenesis of CLL, but also CD8(+) T cells.

Adult↗
PubMed1999

T-cell-epitope mapping of the idiotypic monoclonal IgG heavy and light chains in multiple myeloma.

The idiotypic structures of the myeloma protein might be regarded as tumor-specific antigens. The present study was designed to map T-cell epitopes of the idiotypic myeloma protein to prove the existence of naturally occurring major-histocompatibility-complex-dependent idiotype (peptide)-specific T cells in multiple myeloma. The fine specificity of idiotype-reactive, interferon-gamma-producing blood T cells of a patient with multiple myeloma stage I was characterized by identification of idiotype (heavy and light chains)-derived MHC-restricted T-cell epitopes. T cells specifically reacting with peptides corresponding to each of the 3 complementarity-determining regions (CDRs) of the heavy-chain variable part (V(H)) of the autologous idiotype were found. In contrast, none of the peptides corresponding to the 3 CDRs of the light chain (V(L)) induced a specific T-cell response. The idiotype amino-acid sequence corresponding to the junction of the V(H), diversity (D), and joining (J) gene segments of the VH appeared to be an important target for T cells, since the sequence expressed MHC-class-I- as well as MHC-class-II-restricted epitopes. The study provides further support for the existence of MHC-restricted idiotype-specific T cells, which may target immunogenic CDR peptides in multiple myeloma. Such T cells could be an important part of the specific anti-tumor immune responses induced in idiotype vaccination protocols.

Aged↗
PubMed1999

Cytokine expression in B-CLL in relation to disease progression and in vitro activation.

Earlier, we reported an association between low in vitro and in vivo IL-1 and IL-6 production, decreased IL-1beta and IL-10 mRNA expression and B cell chronic lymphocytic leukemia (B-CLL) disease progression. We have now further investigated cytokine mRNA transcription in B-CLL cells and cytokine serum levels in B-CLL patients. Reverse transcriptase polymerase chain reaction (RT-PCR) amplification of tumor necrosis factor (TNFalpha), IFNgamma, IL-6 and BCGF was equally often seen in non-progressive and progressive patients. However, 4 out of 23 non-progressive cases expressed mRNA for IL-12 while no IL-12 expression was seen in 15 progressive patients. No IL-12 was found in sera or supernatants from in vitro stimulated B-CLL cells, whereas TNFalpha and IL-10 were detected in sera from 51 and 31 of 65 B-CLL patients, respectively. TNFalpha values were significantly high in sera from patients in stages III and IV with disease progression. TNFalpha and IL-10 were also detected in culture supernatants from in vitro stimulated B-CLL cells, whereas IFNgamma was undetectable in these cultures and rarely positive in serum. Although further investigations are required, our data and that from previous reports indicate that B-CLL-derived cytokines are involved in B-CLL disease progression.

Adult↗
PubMed1999

Autoantibodies against the tumour-associated antigen GA733-2 in patients with colorectal carcinoma.

The tumour-associated antigen (TAA) GA733-2 is expressed as a non-secreted surface molecule on the majority of human colorectal carcinoma cells. The antigen has been used as a target for passive and active immunotherapy during the last decade. To determine the incidence of autoantibodies against this antigen, sera from 1068 patients with colorectal carcinoma were analysed for naturally occurring IgG antibodies against the baculovirus-produced GA733-2E protein. A total of 14.5% of the patients had IgG antibodies against the antigen. In 519 patients, sera were collected at the time of diagnosis and 15% of those patients had anti-GA733-2E IgG antibodies. There was a tendency to a higher frequency of patients with antibodies among those in the advanced Dukes stages: 11% in stage A and 32% in stage D respectively (P = 0.06). Antibodies could be detected for up to 10 years after the diagnosis. Patients with Crohn's disease or colitis ulcerosa (n = 20) did not elicit anti-GA733-2E antibodies. No healthy control donor (n = 45) had detectable antibodies against the antigen. The specificity of GA733-2E-reactive serum IgG was indicated by significant inhibition of mAb17-1A (originally used to define GA733-2) binding to the GA733-2E antigen. Sera of positive patients bound to the GA733-2-expressing human colorectal carcinoma cell line, SW948. No significant correlation was found between the presence of antibodies and survival in the present patient population. However, the high incidence of autoantibodies against this tumour antigen in colorectal carcinoma patients confirms its antigenicity in humans and supports the use of the GA733-2 antigen as a target for immunotherapy.

Adult↗
PubMed1999

Clinical effects of monoclonal antibody 17-1A combined with granulocyte/macrophage-colony-stimulating factor and interleukin-2 for treatment of patients with advanced colorectal carcinoma.

Granulocyte/macrophage-colony-stimulating factor (GM-CSF) has previously been indicated to enhance the therapeutic effect of the anti-colorectal carcinoma mAb17-1A as well as to augment in vivo immune effector functions. In vitro interleukin-2 (IL-2) augmented GM-CSF-induced antibody-dependent cellular cytotoxicity, a mechanism considered to be of significance for the therapeutic effect of mAb. A treatment regimen was elaborated that combined mAb17-1A (400 mg at day 3 of a 10-day treatment cycle) with the simultaneous administration of GM-CSF (250 microgram/m(2) once daily) and IL-2 (2.4 x 10(6) U/m(2) twice daily) for 10 days. The treatment cycle was repeated once a month. Twenty patients with advanced colorectal carcinoma were included in the study. One patient obtained a partial remission and 2 patients stable disease for 7 and 4 months respectively. The median survival time from the start of mAb therapy was 8 months. Owing to allergic reactions, the planned mAb17-1A dose had to be reduced by repeated infusions. At the fourth treatment cycle only 25% received the planned mAb dose. In 3 patients the GM-CSF and IL-2 dose was reduced because of side-effects. The subjective tolerability of the treatment was considered good or acceptable in more than 80% of the patients. The increment in white blood cell subsets induced by the cytokines decreased by increasing number of courses. This particular regimen did not augment the therapeutic effect of mAb17-1A anticipated from in vitro data but rather hampered the clinical effect of the antibody. The reason for this is not clear but a possibility might be the induction of immune suppression in vivo resulting from an impaired human anti-(mouse Ab) and anti-idiotypic antibody response as well as antibody-dependent cellular cytotoxicity, on the basis of a comparison of mAb17-1A/GM-CSF/IL-2- and mAb17-1A/GM-CSF-treated patients.

Adult↗