Allogeneic gene-modified tumor cells (RCC-26/IL-7/CD80) as a vaccine in patients with metastatic renal cell cancer: a clinical phase-I study.

Despite novel targeted agents, prognosis of metastatic renal cell cancer (RCC) remains poor, and experimental therapeutic strategies are warranted. Transfection of tumor cells with co-stimulatory molecules and/or cytokines is able to increase immunogenicity. Therefore, in our clinical study, 10 human leukocyte antigen (HLA)-A(*)0201(+) patients with histologically-confirmed progressive metastatic clear cell RCC were immunized repetitively over 22 weeks with 2.5-40 × 10(6) interleukin (IL)-7/CD80 cotransfected allogeneic HLA-A(*)0201(+) tumor cells (RCC26/IL-7/CD80). Endpoints of the study were feasibility, safety, immunological and clinical responses. Vaccination was feasible and safe. In all, 50% of the patients showed stable disease throughout the study; the median time to progression was 18 weeks. However, vaccination with allogeneic RCC26/IL-7/CD80 tumor cells was not able to induce TH1-polarized immune responses. A TH2 cytokine profile with increasing amounts of antigen-specific IL-10 secretion was observed in most of the responding patients. Interferon-γ secretion by patient lymphocytes upon antigen-specific and non-specific stimulation was substantially impaired, both before and during vaccination, as compared with healthy controls. This is possibly due to profound tumor-induced immunosuppression, which may prevent induction of antitumor immune responses by the gene-modified vaccine. Vaccination in minimal residual disease with concurrent depletion of regulatory cells might be one strategy to overcome this limitation.

Binding of mitogenic plant lectins to human lymphocytes. Flow cytometric analysis.

Several plant lectins, such as phytohaemagglutinin (PHA), pokeweed mitogen (PWM), concanavalin A (ConA), Maclura pumifera (MPA) and Pisum sativum agglutinin (PSA), are potent mitogens for human lymphocytes. The pattern of activation induced, however, is not uniform for all mitogenic lectins. The different biological effects following lectin activation of human lymphocytes might be due at least in part to a differential binding of the various lectins to lymphocyte subsets. We have therefore studied the binding of five mitogenic plant lectins, namely PHA, PWM, ConA, MPA and PSA to three major human lymphocyte subsets as defined by anti-CD4, anti-CD8 and anti-CD16 monoclonal antibodies. Dual colour, flow cytometric analysis employing PE-conjugated monoclonal antibodies and FITC-conjugated lectins revealed that all subsets uniformly show high binding of PHA, whereas two different populations, one high binding and the other low binding, can be detected with PWM, ConA, MPA and PSA.

A novel HLA-DR13 allele (DRB1*1314) identified by single-strand conformation polymorphism analysis and confirmed by direct sequencing.

A novel variant of the HLA-DR13 group is described. The new allele was found in a DR10, 13 heterozygous patient of Turkish origin, two HLA genotypically identical children of the patient typed as DR11,13, and one child typed as DR13,13. DR13 subtyping of the patient was initially performed by SSCP analysis of PCR-amplified DNA, using the 11th OHWS primers DRBAMP-3 and DRBAMP-B. Due to an unusual SSCP banding pattern, the PCR product was subjected to solid-phase sequencing. The sequence of the new allele, DRB1*1314, is different from that of DRB1*1307 by a single nucleotide substitution in codon 47, with T replacing consensus A. This results in a single amino acid change of tryptophan to phenylalanine in the first domain of the DR beta chain.

Discrimination of HLA-B27 alleles by group-specific amplification followed by solid-phase sequencing.

HLA-B27 is known to be highly associated with ankylosing spondylitis. Until now, nine B27 subtypes have been sequenced and may contribute in different fashions to ankylosing spondylitis. Additionally, the divergent subtypes may be of clinical importance in bone marrow transplantation with alternative donors. The purpose of this study was to determine the different subtypes of HLA-B27 by a direct sequencing approach. The typing strategy is based on a group-specific amplification of the second and third exon followed by automated fluorescence sequencing of the polymorphic regions. The extensive sharing of sequence motifs between the different B alleles made it impossible to specifically amplify the B27 group under the precondition of including all sequence variations necessary for a postamplification specificity step. Therefore, for setting up a direct sequencing approach of B27, co-amplified B alleles had to be taken into account. In order to get unambiguous sequencing chromatograms without any heterozygous positions, nested sequencing primers were used which selectively matched sequence motifs only present in the second and third exon of the amplified B27 alleles. This strategy allowed in all cases investigated a clear separation of the haplotypes, revealing unequivocal sequencing results. Using this method, we have investigated 93 B27-positive individuals. Sequencing identified the alleles B*2702, 2703, 2704, 2705, and 2707. B*2701, 2706, 2708, and 2709 were not represented in the population studied.

Two subsets of peripheral blood plasma cells defined by differential expression of CD45 antigen.

The purpose of this study was to optimize the flow cytometric determination of circulating normal and malignant plasma cells (PC). We investigated peripheral blood (PB) samples of 65 patients with multiple myeloma or monoclonal gammopathy of unknown significance and 47 control subjects using CD38, CD45, B-B4, CD56, VLA-4, VLA-5 and CD19 monoclonal antibodies (MoAbs). Mono- or polyclonality was determined by staining of intracellular kappa and lambda light chains. Two subpopulations of PBPC were distinguished by differential expression of CD45. CD45 positive (CD45+) PC showed a more immature morphology and were detected in all groups. They were polyclonal in the control subjects and either poly- or monoclonal in the myeloma patients. In contrast, CD45 negative (CD45-) PBPC only occurred in myeloma patients and were consistently monoclonal, their presence being significantly associated with high disease activity (P < 0.001). Although detection of CD45- PBPC using CD38 or B-B4 MoAbs lead to similar results. CD45+ PBPC often were recognized to a lesser extent by B-B4 than by CD38 MoAbs. In conclusion, normal and malignant circulating PC can reliably be identified using CD38 and CD45 MoAbs. CD45 expression separates PBPC into two subsets of which the CD45- one only occurs in myeloma patients.

Quantitative fluorescence flow cytometry: a comparison of the three techniques for direct and indirect immunofluorescence.

Three types of microbead calibrators available for quantitative fluorescence flow cytometry have been studied in parallel using a variety of monoclonal antibodies (MoAbs). The QIFI kit is designed for indirect immunofluorescence (IF), and both the Quantum Simply Cellular (QSC) assay and the Quanti-BRITE assay are designed for direct IF. Because of the different nature of the respective ligands, epitopes on cells versus F'ab-portions on QSC beads, large differences in titration curves for a large number of CD MoAbs were noted between QSC beads and cells. Use of the QSC assay and fluorescein isothiocyanate (FITC) and phycoerythrin (PE) conjugates of the same CD reagent revealed substantially different numbers of cellular binding sites. Numbers of cellular binding sites as determined by direct IF using the Quanti-BRITE assay and by indirect IF using the QIFI kit were similar. We also found that erythrocyte (RBC)-lysing reagents cause varying and sometimes substantial reduction in the fluorescence intensity (FI) of cells stained directly with CD34 MoAb conjugates, but the RBC-lysing reagents had no effect on the FI of cells stained indirectly with the same CD34 MoAbs. This report defines a number of variables critical for standardized quantitative flow cytometry. We conclude that the choice of calibrators, fluorochrome conjugates, staining methods, and modes of sample processing can effect the determination of cellular binding sites to MoAbs. Direct immunofluorescence using the Quanti-BRITE assay and indirect IF using the QIFI kit appear to yield comparable results for the standardized determination of numbers of cellular binding sites to MoAbs.

[Effect of the method on the results of determining T-cell subpopulations]. / Einfluss der Methode auf das Ergebnis der Bestimmung von T-Zellsubpopulationen.

Two methods of determining lymphocyte subpopulations were compared on samples obtained from 18 healthy blood donors and 16 HIV-positive patients. In the whole-blood method directly marked monoclonal antibodies were used, whereas Ficoll-separated mononuclear cells were assayed indirectly. The number of CD4-positive helper cells was significantly lower in both groups in the whole-blood test, but that of CD8-positive suppressor cells significantly increased after Ficoll separation. In HIV-infected patients the values for CD8-positive lymphocytes were even further apart than in the healthy donors. As a result the difference in the ratio CD4/CD8 was higher in HIV-infected patients (0.3 vs 0.65; P less than 0.001) than in the healthy donors (1.35 vs 1.8; P less than 0.001).

[Measures for reducing the use of homologous blood. Effects on blood coagulation during total endoprosthesis]. / Fremdblutsparende Massnahmen. Auswirkungen auf die plasmatische Gerinnung bei totalendoprothetischen Eingriffen.

The influence of two different methods of autologous transfusion, preoperative donor plasmapheresis (Abbott Autotrans) and postoperative autotransfusion (intraoperative blood salvage, Dideco Autotrans), on the intravascular hemostatic system was investigated. Forty-two patients undergoing total hip surgery and preoperative donor plasmapheresis were prospectively randomized into three groups. For substitution of blood loss, patients in group 1 (control group, n = 12) received in addition to cristalloids and colloids only homologous blood, group 2 (n = 14) autologous blood, and group 3 (n = 16) additionally intra- and postoperative autologous fresh frozen plasma (FFP). The investigation included blood parameters (hemoglobin, hematocrit, thrombocytes), clotting status (prothrombin time, plasma thromboplastin time, thrombin time, fibrinogen, plasminogen, and antithrombin III), and immunological methods such as fibrinopeptide A (FPA), thrombin-antithrombin III (TAT), and protein C. No significant difference was found with respect to total amount of infusion, intraoperative blood loss, autologous transfusion, and blood parameters. Excellent quality of the autologous FFP was demonstrated by investigation of the specimens before administration. The autologous packed red cells showed high levels of TAT and FPA as an indicator of thrombin generation. Their administration caused a significant increase in TAT and FPA levels in groups 2 and 3 compared to group 1.(ABSTRACT TRUNCATED AT 250 WORDS)

Circulating CD4+ T lymphocytes with intracellular but no surface CD3 antigen in five of seven patients consecutively diagnosed with angioimmunoblastic T-cell lymphoma.

Angioimmunoblastic T-cell lymphoma (AITL) accounts for less than 1% of all lymphatic malignancies. Oligoclonality or monoclonality for any of the T-cell receptor (TCR) chain genes can be demonstrated in the majority of the cases. During systematic screening for the presence of circulating lymphocytes with atypical coexpression of differentiation antigens in patients with T-cell lymphomas, we have discovered a minor population (accounting for 0.2% to 10.% of all lymphocytes) of atypical lymphocytes in the blood of five of seven patients consecutively diagnosed in 1997/1998 by lymph node histology to have AITL. The major distinguishing feature of these cells consists of the lack of the surface expression of the CD3 antigen, but not of the intracellular expression. These cells express the T-cell antigens CD2 and CD5 on their surface, but not CD7, and they express CD4 and CD45 at numbers of molecules per cell typical for T lymphocytes. Gene scan analyses for the TCR gamma chain revealed oligoclonality of these flow-sorted cells in one patient and monoclonality in two patients, the same patterns of TCR gamma chain gene as determined processing the respective diagnostic lymph nodes. Circulating CD4-expressing T lymphocytes with exclusively cytoplasmic expression of CD3 appear to represent the malignant population in patients with histologically diagnosed AITL.