MHC class I and class II genes in Tunisian patients with reactive and undifferentiated arthritis

OBJECTIVE

To study HLA class I and class II association in Tunisian patients with reactive (ReA) and undifferentiated arthritis (UA).

METHODS

The study included 17 patients with ReA defined according to the European Spondylarthropathy Study Group criteria for spondylarthropathy (SpA), 11 patients classified as having undifferentiated arthritis and 100 unrelated healthy controls. HLA class I antigens were typed serologically and HLA class II alleles were genotyped molecularly by the polymerase chain reaction with sequence-specific primers technique.

RESULTS

There was a major difference between HLA alleles in ReA and UA patients when compared separately with controls. Increased frequencies of HLA-B27 (p=7.76 10-12, OR=59.30), HLA-B51 (p=0.015, OR=4.91) and HLA-DRB1*04 (p=0.033, OR=2.90) alleles were found in patients with ReA but not in patients with UA. HLA-B27 was not expressed totally in our cohort of UA patients. A significant increase of HLA-B15 (p=0.002, OR=18.40) and a moderate increase of HLA-B7 (p=0.043, OR=5.15) was found in patients with UA, but not in patients with ReA. In the B27 negative patients, HLA-DRB1*04 association with ReA was found independently of B27.

CONCLUSION

Our data confirmed a significant association of HLA-B27 with ReA in the Tunisian population. Our results also suggested that some of the additional HLA antigens were associated with ReA including HLA-B51 and HLA-DRB1*04 alleles. UA seemed to have a genetic background different from ReA in Tunisian patients.

Animal models of acute and chronic graft-versus-host disease

Graft-versus-host disease (GVHD) represents a special situation in transplantation immunology in which immunocompetent donor cells are engrafted into recipients that are incapable of rejecting them due to tolerance, immaturity, or radiation- or chemotherapy-induced immune deficiency. Donor T cells encountering allogeneic stimulators become activated, secrete cytokines, proliferate, and differentiate into effectors; this in vivo immune response is known as the graft-versus-host reaction (GVHR). The systemic effects of this initial donor anti-host reaction comprise a multiorgan syndrome, graft-versus-host disease (GVHD). Murine GVHD experiments have been utilized to model the clinical disorders of acute and chronic GVHD (AGVHD and CGVHD) that occur after allogeneic bone marrow transplantation, and also to study T cell regulation, induction of tolerance, and autoimmune diseases. Presented in this unit are methods for generating and assessing both AGVHD and CGVHD in mice. While the two syndromes differ markedly in immunopathogenesis, both can be induced by the two main methods presented: transfer of allogenic donor lymphocytes and stem cells into irradiated hosts, and transfer of parental strain lymphocytes and stem cells into unirradiated, immune-competent F1 strain hosts. Several endpoints of AGVHD and CGVHD should be evaluated in experimental mice, with comparisons made to the syngeneic transplant control or the T cell-depleted allogeneic control. To this end, protocols are provided for the assessment of survival rates, weight loss, chimerism, donor-host cytotoxicity, and cytokine and proliferative responses to mitogenic or allogeneic stimuli. Histopathology and assays of B cell immune function are also described for evaluation of the pathogenesis of GVHD.

Host T cells affect donor T cell engraftment and graft-versus-host disease after reduced-intensity hematopoietic stem cell transplantation

Mixed chimerism in the T cell compartment (MCT) after reduced-intensity stem cell transplantation (RIST) may influence immune repopulation with alloreactive donor T cells. We examined effects of host T cell numbers on donor T cell engraftment and recovery and on acute graft-versus-host disease (aGVHD) in a relatively homogeneous patient population with respect to residual host T cells through quantified immune depletion prior to RIST and to donor T cells by setting the allograft T cell dose of 1x10(5) CD3+ cells/kg. In this setting, 2 patterns of early donor T cell engraftment could be distinguished by day +42: (1) early and complete donor chimerism in the T cell compartment (FDCT) and (2) persistent MCT. FDCT was associated with lower residual host CD8+ T cell counts prior to transplant and aGVHD. With persistent MCT, subsequent development of aGVHD could be predicted by the direction of change in T cell donor chimerism after donor lymphocyte infusion, and no aGVHD occurred until FDCT was established. MCT did not affect recovery of donor T cell counts. These observations suggest that the relative number and alloreactivity of donor and host T cells are more important than the absolute allograft T cell dose in determining donor engraftment and aGVHD after RIST.

Effects of rhIL-7 administration in humans on in vivo expansion of naïve, memory and effector subsets of CD4+ & CD8+ T-cells

2504

Background: IL-7 has a critical and non-redundant role in T-cell lymphopoiesis and peripheral T-cell homeostasis. IL-7 administration may prove clinically valuable in conditions of disease induced (HIV) or iatrogenic T-cell depletion and for modulation of vaccine immune responses. In the first phase I study in humans, recombinant human interleukin-7 (“CYT 99–007”, Cytheris Inc., Rockville, MD) was administered subcutaneously every other day for two weeks in adults with refractory malignancies at 3, 10, 30 and 60 μg/kg/dose. Biologic activity, defined as a 50% increase over baseline of peripheral blood CD3+ T-cells, was seen at and above the 10μg/kg/dose in all patients. The kinetics of proliferation and expansion of peripheral blood T-cell subsets were analyzed. Methods: Multicolor flow cytometry was performed at baseline, 1, 2 and 3 weeks. Among CD4+ cells, the most naïve were defined as CD45RA+ /CD31+. Among CD4+ & CD8+ cells, the main naïve, memory and effector populations were defined respectively as CD45RA+/CD27+, CD45RA-/CD27+ and CD45RA-/CD27-. Within each subset, the number of cells in cycle was defined by Ki67 staining. Results: Following IL-7 therapy, there was marked proliferation of all T-cells subsets, peaking at week 1, most striking for the naive subsets with 30–70% of circulating cells induced to cycle. Proliferation rates were halved by week 2 despite continuation of treatment, coincident with the observed down-regulation of the IL-7 receptor. Cycling returned to baseline by week 3. Significant proliferation was also induced in effector and memory CD4+ and CD8+ T-cells but to a lesser magnitude, resulting in a greater net expansion of the naïve subsets, still ongoing one week after the end of treatment. Conclusions: IL-7 administration induces marked expansion of naïve, memory and effector CD4+ & CD8+ T-cells in humans. Consistent with the known down-regulation of the IL-7 receptor upon IL-7 exposure, proliferation rates decrease during the second week of treatment. rhIL-7 induced T-cell expansion may prove clinically valuable in adoptive immunotherapy as an adjunct to tumor vaccination and / or immunorestorative agent.

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Evaluation of the microdilution, Etest and disk diffusion methods for antifungal susceptibility testing of clinical strains of Trichosporon spp

Trichosporon spp are well recognized as pathogens capable of causing invasive disease. Despite the increasing frequency and severity of trichosporonosis, data on the antifungal susceptibility of Trichosporon spp. are limited and recommendations for in vitro testing of this fungus are not included in the guidelines of the National Committee for Clinical Laboratory Standards. The purpose of this study was to determine the in vitro susceptibility of clinical Trichosporon isolates to systemic antifungals. We evaluated the in vitro activity of amphotericin B, fluconazole, itraconazole and voriconazole against 27 clinical isolates of Trichosporon spp. (14 T. mucoides and 13 T. asahii) using NCCLS M27-A2 reference microdilution, Etest and disk diffusion methods. In the microdilution and Etest methods Trichosporon spp. demonstrated relatively high minimum inhibitory concentrations (MICs) for fluconazole (MIC90 4 and 6 microg/ml, respectively) and relatively low MICs for voriconazole (MIC90 0.125 and 0.125 microg/ml, respectively). MICs for amphotericin B determined on antibiotic medium 3 were lower (MIC90 0.06 microg/ml) than those on RPMI (MIC90 1 microg/ml). Observed agreements were 81-100% according to these drugs. Disk diffusion zone diameters correlate inversely with MICs from dilution tests except for amphotericin B. Validation of the clinical significance of these observations demands determination of MIC breakpoints for Trichosporon and in vitro- in vivo correlation studies.

Establishing a platform for immunotherapy: clinical outcome and study of immune reconstitution after high-dose chemotherapy with progenitor cell support in breast cancer patients

Tumor vaccine after high-dose chemotherapy (HDC) and autologous stem cell transplantation (ASCT) aims at directing immune recovery toward tumor responses after optimizing minimal residual disease. We have characterized T-cell recovery and tumor response after a regimen devised as a platform for such immunotherapy. One hundred patients with high-risk or metastatic breast cancer received 3 to 7 cycles of paclitaxel and cyclophosphamide (overall response rate, 78%) and then HDC with melphalan and etoposide. Seventy-one patients received HDC and ASCT (no mortality at 100 days). At 24 months after transplantation, progression-free and overall survival probabilities for patients with stage IIIA, IIIB, and IV disease were 82%, 81%, and 42% and 100%, 94%, and 68%, respectively. The median progression-free and overall survivals from entry on study for stage IV patients were 15.3 and 38.1 months, respectively. CD3 + , CD8 + , and CD4 + cells were severely depleted after ASCT. Although total CD8 + T-cell numbers approached the normal range by 3 months, most of these cells were CD28 - . Naive CD45RA + CD4 + T cells approached the normal range only 18 months after ASCT and only in younger patients. The described observations provide the basis for devising a strategy for cancer vaccine administration after ASCT. Incorporating immune reconstitution enhancement after ASCT may be advantageous.

B-cell recovery following rituximab-based therapy is associated with perturbations in stromal derived factor-1 and granulocyte homeostasis

The occurrence of delayed neutropenia following rituximab is poorly defined and of unknown cause. We hypothesized it may be related to perturbations of stromal derived factor-1 (SDF-1) and granulocyte homeostasis. Late-onset neutropenia (LON) was investigated in 130 patients with untreated aggressive B-cell lymphoma receiving DA-EPOCH (dose-adjusted etoposide, prednisone, Oncovin [vincristine], cyclophosphamide, and hydroxydaunorubicin) chemotherapy with or without rituximab. All patients were in remission and had no known causes for neutropenia. LON occurred in 6 (8%) of 76 patients receiving rituximab and 0 of 54 patients not receiving rituximab (P = .04). The median onset was 175 days (range, 77-204 days) after treatment with a median duration of 14 days (range, 11-16 days). In a subset of 24 patients, a significant correlation was found between rapid B-cell recovery and granulocyte decline over the 6-month recovery period (R = -0.53; P = .04). Rapid B-cell recovery directly correlated with prerecovery SDF-1 levels (R = 0.65; P = .015) and SDF-1 decline (R = -0.67; P = .013) after recovery. Our results suggest that early B-cell lymphopoiesis is important for B-cell recovery following rituximab, and that perturbation of SDF-1 during B-cell recovery retards neutrophil egress from the bone marrow. These findings illustrate the dual role of SDF-1 in human B-cell and granulocyte homeostasis.

Prostate cancer chemoprevention agents exhibit selective activity against early stage prostate cancer cells

Preclinical models for the identification of prostate cancer chemoprevention agents are lacking. Based upon the notion that clinically useful chemoprevention agents should exhibit selective activity against early stage disease, studies were undertaken to assess whether chemoprevention agents selectively inhibited the growth of early stage prostate cancer, as compared to late stage cancer. First, a series of cell and molecular studies were performed, which, when taken together, validated the use of a panel of prostate cell lines as a model of the different stages of carcinogenesis. Next, therapeutic responsiveness to ten different cytotoxic or chemoprevention agents was evaluated. Chemoprevention agents exhibited selective activity against normal and early transformed prostate tissue, whereas cytotoxic agents were non-specific. Selective activity against early versus advanced prostate cancer cells is identified as a potential screening method for chemoprevention agents.Prostate Cancer and Prostatic Diseases (2001) 4, 81-91

Transcatheter closure of single muscular ventricular septal defects using the amplatzer muscular VSD occluder: initial results and technical considerations

Surgical closure of multiple muscular ventricular septal defects (MVSDs) is associated with mortality and morbidity; therefore, both surgeons and cardiologists welcome a nonsurgical safe approach. We report our initial results of catheter closure of MVSD using the new Amplatzer muscular VSD occluder delivered via the venous or arterial routes. Eight patients with MVSD underwent closure of their VSDs using the Amplatzer VSD occluder under general endotracheal anesthesia. The mean +/- SD of age was 5.4 +/- 3.1 years (2-10 years) and mean weight was 18.4 +/- 6.5 kg (11.5-29 kg). All patients had left ventricular volume overload with mean Qp/Qs ratio of 1.7 +/- 0.6 (1.4-3). The location of the VSD was mid muscular in four, anterior in two, apical in one, and posterior in one. The systolic pulmonary artery pressure ranged from 25 to 85 mm Hg (mean, 39.9 +/- 18.8 mm Hg). The device was implanted successfully in all eight patients. In five patients (four mid muscular and one apical), the deployment of the device was anterograde from the right internal jugular vein and in three patients (two anterior and one posterior VSD), the initial attempt at anterograde deployment was unsuccessful due to kinking in the delivery sheath; therefore, retrograde deployment was attempted successfully. The size of the device used ranged from 6 to 14 mm (the size of the connecting waist). In patients with elevated pulmonary artery pressure, repeat measurements immediately after closure revealed normalization in all. There was immediate complete closure of the defect in two patients and six patients had trivial residual shunt (foaming through the device), which disappeared completely within 24 hr in five and at 6-month follow-up in the sixth patient. The mean fluoroscopy time was 37.1 +/- 13 min (11.7-55 min). Complications encountered included transient junctional rhythm in one patient. No blood transfusion was required. On follow-up evaluation, there has been no episode of endocarditis, thromboembolism, hemolysis, or wire disruption. we conclude that the Amplatzer MVSD occluder is a safe and effective device for closure of MVSDs up to 12 mm in diameter. Further clinical trials with this device are underway. Cathet. Cardiovasc. Intervent. 49:167-172, 2000.

Simultaneous stent implantation for coarctation of the aorta and closure of patent ductus arteriosus using the Amplatzer duct occluder

We report on a 13-year-old girl with coarctation of the aorta and patent ductus arteriosus who underwent successful simultaneous stent implantation for the coarctation and catheter closure of the ductus using an Amplatzer duct occluder.

Transcatheter closure of a large coronary arteriovenous fistula using the new Amplatzer Duct Occluder

A 9-year-old patient with a large coronary arteriovenous fistula (circumflex-right atrium) underwent successful complete percutaneous closure, using the new Amplatzer Duct Occluder (ADO) inserted via a 6 Fr sheath.

Prostate cancer cell growth inhibition by tamoxifen is associated with inhibition of protein kinase C and induction of p21(waf1/cip1)

BACKGROUND

Inhibition of protein kinase C (PKC) and modulation of transforming growth factor-beta (TGF-beta) are both associated with tamoxifen treatment, and both appear to be important in the regulation of prostate cancer cell growth. Investigations were performed which sought to measure the efficacy, and to elucidate the mechanism of growth inhibition by tamoxifen, in hormone-refractory prostate cancer.

METHODS

Growth assays were performed on PC3, PC3-M, and DU145 prostate cancer cells. TGF-beta was measured by ELISA; p21(waf1/cip1) and retinoblastoma (Rb) protein levels were measured by Western blot; PKC activity was measured by kinase assay; and effects upon cell cycle were measured by flow cytometric analysis.

RESULTS

IC50s for growth inhibition ranged from 5.5-10 microM, and were not affected by estrogen. Tamoxifen-mediated growth inhibition was not associated with induction of TGF-beta. However, tamoxifen treatment was associated with inhibition of PKC, which was followed by induction of p21(waf1/cip1), Rb dephosphorylation, and G1/S phase cell cycle arrest. Similar effects were observed with the known PKC inhibitor, Ro31-8220.

CONCLUSIONS

These data suggest that micromolar concentrations of tamoxifen inhibit prostate cancer cell growth by inhibition of PKC, resulting in induction of the p21(waf1/cip1) protein.

Transcatheter closure of secundum atrial septal defect in a patient with dextrocardia using the amplatzer septal occluder

Transcatheter closure of secundum atrial septal defects (ASD) in patients with levocardia is performed routinely using various investigational devices. A 6-yr-old child with dextrocardia, situs inversus, and secundum ASD measuring 13 mm by TEE underwent successful transcatheter closure using a 15 mm Amplatzer Septal Occluder with complete closure of the defect.

A phase I study of topotecan followed sequentially by doxorubicin in patients with advanced malignancies

Inhibitors of topoisomerase I and topoisomerase II have demonstrated synergy when administered sequentially in several tumor models while having a diminished antitumor effect when given concurrently. To explore the potential for clinical sequence-dependent synergy, we instituted a Phase I study of topotecan (a topoisomerase I inhibitor) followed by doxorubicin (a topoisomerase II inhibitor) in patients with advanced malignancies. Thirty-three patients with advanced malignancies or malignancies for whom no standard therapy exists were entered into the study. Topotecan was administered in escalating doses by 72-h continuous infusion on days 1, 2, and 3, followed by a bolus of doxorubicin given on day 5. To explore the hematological toxicity associated with this sequence, bone marrow aspirates were obtained both prior to the topotecan infusion and immediately prior to the doxorubicin in 10 patients to determine by fluorescence-activated cell sorting analysis whether CD34+ cell synchronization was occurring using this sequential schedule. Dose-limiting hematological toxicity occurred at the first dose-level in three of six patients. Therefore, we defined the maximum-tolerated dose (MTD) below our starting dose-level. Further dose-escalation and a new MTD were defined with the addition of granulocyte-colony stimulating factor (G-CSF). The MTD was, therefore, topotecan 0.35 mg/m2/day continuous i.v. infusion on days 1, 2, and 3, followed by doxorubicin 45 mg/m2 on day 5 without G-CSF, whereas the MTD with G-CSF was topotecan 0.75 mg/m2/day by 72-h continuous i.v. infusion, followed by doxorubicin 45 mg/m2 i.v. bolus on day 5. Ten patients with paired bone marrow aspirates obtained before topotecan and before doxorubicin administrations were available for evaluation. In 7 of 10 patients, there was an increase (16.6 +/- 2.9% to 25.0 +/- 3.5%; P < 0.02) in the proportion of CD34+ cells in S-phase 24 h after the topotecan infusion and prior to doxorubicin compared to the pretreatment values, whereas 1 patient had a decrease in the proportion of CD34+ cells in S phase and 2 patients had no change. Topotecan and doxorubicin with this sequence and schedule can be given safely; the dose-limiting toxicity is hematological toxicity. Alterations in the fraction of hematopoietic progenitor CD34+ cells in S-phase may account for the increased granulocytopenia and thrombocytopenia observed at relatively low dose levels of the combination with and without G-CSF.

Initial characterization of the dosimetry and radiology of a device for administering interstitial stereotactic radiosurgery

OBJECTIVE

We report the design and initial characterization of the dosimetry and radiobiology of a novel device for interstitial stereotactic radiosurgery.

INSTRUMENTATION

The device is lightweight, handheld, and battery-powered, and it emits x-ray radiation from the tip of a probe 3 mm in diameter by 10 cm in length.

METHODS

The dosimetry was characterized by two independent methods: thermoluminescent dosimeters and radiochromic film. The radiobiology was characterized by in vivo irradiation of rat liver, dog liver, and dog brain. The animals were killed at varying intervals of time, and histological examinations were performed. Heat transfer from the probe to dog brain was studied in vivo by placing thermocouple sensors around the probe tip before irradiating.

RESULTS

Both dosimetric methods showed a steep dose-distance fall-off relationship (proportional to the reciprocal of the cube of the distance from the probe tip). Rats and dogs that were killed weeks to months after liver irradiation tended to have sharply demarcated lesions. Liver enzyme levels, measured serially in the dogs, did not give evidence of chronic inflammation. Histological examination of the brains of dogs that were killed acutely after irradiation did not show evidence of inflammation, edema, or hemorrhage. The tissue temperature elevation 1 cm from the tip never exceeded 0.5 degree C, thereby excluding hyperthermia as a significant contributor to the formation of lesions.

CONCLUSIONS

Because this device requires relatively few supporting resources, has sharp dosimetric properties, and seems to be safe, it may be useful as a clinical tool for interstitial stereotactic radiosurgery.

Electroporation of synthetic oligodeoxynucleotides: a novel technique for ex vivo bone marrow purging

Recent data suggest that tumor cells contaminating reinfused bone marrow may contribute to relapse in patients undergoing autologous bone marrow transplantation. Purging strategies that are able to remove these contaminating tumor cells need to be developed. This study describes how electroporation (EP) can be used to improve intracellular delivery of synthetic antisense oligodeoxynucleotides (ODNs), thereby enhancing their ability to suppress a target protein. Antisense ODNs that were introduced into cells by EP led to immediate suppression of targeted c-myc protein; this was associated with rapid cell death in the diffuse histiocytic lymphoma, U937; Burkitt's lymphoma, ST486; breast carcinoma, MCF-7; and Ewing's sarcoma, CHP-100, cell lines. Electroporation was found to have little or no detrimental effect on cells responsible for murine hematopoietic long-term reconstitution as determined from in vivo competitive repopulation studies. Using human c-myc-directed antisense ODNs as a model for the application of this approach to bone marrow purging, selective killing of human lymphoma U937 cells relative to normal human bone marrow cells was shown in cell mixing studies. In vivo studies were performed in which a survival advantage was shown for athymic mice that were inoculated with antisense-treated U937 cells as opposed to control cells. These studies suggest that EP of bone marrow may be of use in enhancing intracellular delivery of a variety of molecular/pharmaceutical agents. Taken together, these data suggest that the use of electroporation to enhance delivery of antisense ODNs is a promising new approach towards ex vivo bone marrow purging.

Early suppressive effects of chemotherapy and cytokine treatment on committed versus primitive haemopoietic progenitors in patient bone marrow

These studies investigated the effectiveness of in vivo administration of cytokines in ameliorating potential marrow damage induced by chemotherapy. Breast cancer patients received 5-fluorouracil, leucovorin, doxorubicin and cyclophosphamide (FLAC) followed by either GM-CSF, PIXY321, or no cytokine. Marrow was obtained before and after one or two cycles of FLAC once blood cell counts had recovered. Colony-forming units for granulocytes and macrophages (CFU-GM) were used to indicate the effect of therapy on recovery of committed progenitor cells responsible for early blood cell recovery. The frequency and number of CFU-GM in marrow obtained after FLAC + PIXY321 were significantly lower than in marrow obtained after FLAC+GM-CSF or FLAC without cytokine. CD34+ cell numbers were also reduced after FLAC + PIXY321. CFU-GM production in marrow long-term cultures (LTC) was used to assess the effect of therapy on primitive progenitors. After 5 weeks the number of CFU-GM in LTC of post-therapy marrow from all three treatment arms was < 15% of the number in pre-therapy LTC. Suppressive effects of FLAC on primitive progenitors were observed even when committed progenitors and CD34+ cells had recovered to pre-therapy levels. These results demonstrate that cytokine treatment did not ameliorate suppressive or toxic effects of FLAC on the functional integrity of the marrow.