A247 VIRAL LOAD OF EPSTEIN-BARR VIRUS IN PEDIATRIC PATIENTS WITH NEW ONSET IBD AT DIAGNOSIS AND ON FOLLOW UP: AN OBSERVATIONAL STUDY

Background

Patients with Inflammatory Bowel Disease are at increased risk for complications associated with Epstein-Barr Virus, such as uncontrolled infection, colitis mimicking IBD, and lymphoproliferative disease. These complications may be due to inherent immune dysfunction or effects of immunomodulating therapies used. We have previously identified that the seroprevalence of EBV in our cohort of IBD patients at time of diagnosis was 44.2%, with prevalence stratified by age as follows: 0 to <10 years 36%, 10 to <17 years 46%, and 17 + years 50%.

Aims

Our objective is to assess the risk of EBV reactivation in this population, to determine whether patients treated with immunomodulators should be more closely monitored for EBV viral load.

Methods

Retrospective chart review was done for all patients with new-onset IBD diagnosed at CHU Sainte-Justine over a two-year period, from Jan. 2016 to Dec. 2017. Serum from time of diagnosis was retrieved from the microbiology laboratory for patients with positive EBV serology, and quantitative PCR was performed to assess viral load at diagnosis. 47 of 53 seropositive patients had available serum at time of retrieval. EBV PCR was subsequently performed on serum drawn one to two years after start of immunosuppressants.

Results

53 patients were EBV positive at time of diagnosis (EBNA/VCA IgG). Two patients were IgM positive, suggesting recent or active infection. The viral load as measured by quantitative PCR on serum drawn at diagnosis was negative in all retroactively tested patients. Of the two IgM-positive patients, one had known positive quantitative PCR at time of diagnosis. PCR previously tested in clinical follow-up of two seropositive, PCR-negative patients became positive at 7 and 17 months from diagnosis, suggesting viral reactivation. Both patients had received anti-TNF’s and systemic corticosteroids. Viral loads on follow-up are to be assessed for the rest of the cohort. Overall, therapies started within 6 months of diagnosis were similar in the seropositive and seronegative groups, the majority receiving some form of immunosuppression. Within the seropositive group: 66% received corticosteroids, 32.1% Infliximab, 5.7% Adalimumab, and 5.7% Azathioprine.

Conclusions

Only one patient had active EBV infection with positive PCR at time of diagnosis. All other patients had no sign of active infection based on retroactive PCR’s. While a majority of patients, regardless of EBV serology, receive immunomodulating agents, we currently do not routinely screen for seroconversion in seronegative patients, or for viral load in seropositive patients. We will be assessing viral loads after start of immunomodulation to better understand the potential impact of these agents on disease progression.

Funding Agencies

None

ICRP Publication 135: Diagnostic Reference Levels in Medical Imaging

Abstract –

The International Commission on Radiological Protection (ICRP) first introduced the term ‘diagnostic reference level’ (DRL) in 1996 in Publication 73. The concept was subsequently developed further, and practical guidance was provided in 2001. The DRL has been proven to be an effective tool that aids in optimisation of protection in the medical exposure of patients for diagnostic and interventional procedures. However, with time, it has become evident that additional advice is needed. There are issues related to definitions of the terms used in previous guidance, determination of the values for DRLs, the appropriate interval for re-evaluating and updating these values, appropriate use of DRLs in clinical practice, methods for practical application of DRLs, and application of the DRL concept to newer imaging technologies. This publication is intended as a further source of information and guidance on these issues. Some terminology has been clarified. In addition, this publication recommends quantities for use as DRLs for various imaging modalities, and provides information on the use of DRLs for interventional procedures and in paediatric imaging. It suggests modifications in the conduct of DRL surveys that take advantage of automated reporting of radiation-dose-related quantities, and highlights the importance of including information on DRLs in training programmes for healthcare workers. The target audience for this publication is national, regional, and local authorities; professional societies; and facilities that use ionising radiation for medical purposes, and responsible staff within these facilities. A full set of the Commission’s recommendations is provided.

Partial correlation analysis reveals abnormal retinotopically organized functional connectivity of visual areas in amblyopia

Amblyopia is a prevalent developmental visual disorder of childhood that typically persists in adults. Due to altered visual experience during critical periods of youth, the structure and function of adult visual cortex is abnormal. In addition to substantial deficits shown with task-based fMRI, previous studies have used resting state measures to demonstrate altered long-range connectivity in amblyopia. This is the first study in amblyopia to analyze connectivity between regions of interest that are smaller than a single cortical area and to apply partial correlation analysis to reduce network effects. We specifically assess short-range connectivity between retinotopically defined regions of interest within the occipital lobe of 8 subjects with amblyopia and 7 subjects with normal vision (aged 19–45). The representations of visual areas V1, V2, and V3 within each of the four quadrants of visual space were further subdivided into three regions based on maps of visual field eccentricity. Connectivity between pairs of all nine regions of interest in each quadrant was tested via correlation and partial correlation for both groups. Only the tests of partial correlation, i.e., correlation between time courses of two regions following the regression of time courses from all other regions, yielded significant differences between resting state functional connectivity in amblyopic and normal subjects. Subjects with amblyopia showed significantly higher partial correlation between para-foveal and more eccentric representations within V1, and this effect associated with poor acuity of the worse eye. In addition, we observed reduced correlation in amblyopic subjects between isoeccentricity regions in V1 and V2, and separately, between such regions in V2 and V3. We conclude that partial correlation-based connectivity is altered in an eccentricity-dependent pattern in visual field maps of amblyopic patients. Moreover, results are consistent with known clinical and psychophysical vision loss. More broadly, this provides evidence that abnormal cortical adaptations to disease may be better isolated with tests of partial correlation connectivity than with the regular correlation techniques that are currently widely used.

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Cortical functional connectivity abnormalities exist in amblyopia at a scale finer than previously reported.

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Connectivity changes within primary visual cortex are consistent with known loss of function.

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Connectivity changes between visual areas are consistent with concept of deafferentation.

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Partial correlation differentiates patients from controls, whereas correlation does not.

The use of fenbendazole in the treatment of commercial turkeys infected with Ascaridia dissimilis

Birds on a commercial turkey Farm were treated with fenbendazole on two separate occasions. For each treatment, fenbendazole was administered in the feed for 3 days at 30 mg/kg. Mean Ascaridia dissimilis total counts in randomly selected birds were 14.4 and 33.0 prior to the first and second treatments, respectively, whilst post-treatment counts averaged only 0.1 and 0.3, respectively. Anthelmintic effectiveness as demonstrated by both treatments was >99.0%. No untoward effects were noted with either fenbendazole treatment. After fenbendazole withdrawal, routine treatments with piperazine dihydrochloride were commenced with no apparent anthelmintic effectiveness. Mean total nematode burdens rose to 153.9 with a high individual count of 451. The potential for severe ascaridiasis when effective anthelmintic intervention is precluded was demonstrated.

Meningioma after radiotherapy for Hodgkin's disease

The most common second primary tumors after treatment of childhood Hodgkin's disease are leukemia, lymphoma, breast cancer, soft tissue sarcoma, and thyroid cancer. Although intracranial meningioma has been reported after radiotherapy to the scalp for benign conditions and for intracranial primary brain tumors, this appears to be an extremely rare sequelae of treatment for Hodgkin's disease. The authors describe a 15-year-old boy who underwent radiotherapy for Hodgkin's disease and in whom a meningioma developed in the posterior fossa 27 years later.

Retention of adoptively transferred interleukin-2-activated natural killer cells in tumor tissue

BACKGROUND

Adoptively transferred interleukin-2 activated natural killer (A-NK) cells are capable of selectively infiltrating tumor, however, only at low efficiency. The aim of this study was to investigate the intratumoral A-NK cell retention using an ex-vivo tissue-isolated tumor preparation.

METHODS

R3230AC mammary adenocarcinoma and CSE fibrosarcoma were implanted in the ovarian fat pad of Fisher 344 rats. The tumors were perfused ex vivo 14 to 15 days post-implant with a known number of fluorescent labelled A-NK cells, and the effluent collected serially over time. Non stimulated splenocytes (N-SS) were used as controls.

RESULTS

In group 1, tumors were perfused with either A-NK (n = 16) or N-SS (n = 7) cells. The mean number of the cells which remained intratumorally at the completion of the perfusion was 48.37% +/- 14.94 for A-NK cells and 34.68% +/- 13.20 of N-SS (p = 0.048). In group 2, tumors were perfused with a suspension containing both A-NK and N-SS cell (n = 11). The difference in tumor retention between A-NK cells and N-SS was 22.5% (p = 0.0053) for R3230AC tumors (retention of intratumoral A-NK cells was 45.1% +/- 6.47 vs. 22.6% +/- 19.09 for N-SS) and 15.88% (p = 0.028) for the fibrosarcomas (34.01% +/- 15.96 vs. 18.12 +/- 17.78 for A-NK and N-SS, respectively). No difference with respect to retention of A-NK cells or N-SS cells was observed between tumor types (p = 0.23 and p = 0.71, respectively).

CONCLUSIONS

The retention of A-NK cells in tumor tissues was significantly better than the retention of N-SS when administered directly. Since the retention of A-NK cells in tumor tissue was high (35-50%), this factor does not explain the low efficiency of adoptively transferred A-NK cells accumulating in tumors when administered systemically.

Effect of radiation on interstitial fluid pressure and oxygenation in a human tumor xenograft

Elevated interstitial fluid pressure (IFP) is a pathophysiological characteristic of most human and experimental tumors and may be responsible, in part, for the poor distribution of blood-borne therapeutic agents and low blood flow rate in tumors. Recent data in cervical carcinomas in patients suggest that fractionated radiation can lower tumor IFP and increase oxygen partial pressure (pO (2)) in some patients. The goals of this study were to find the minimum dose of radiation required to modulate IFP and pO(2) and to determine the time course of IFP changes due to radiation in a preclinical model. Xenografts of the LS174T human colon adenocarcinoma were grown in the right flank of nude (BALB/c) mice. IFP and pO(2) were measured before and 24 h after graded doses of irradiation. The mean +/- SD initial IFP in untreated tumors was 12.9 +/- 0.5 mm Hg (n=109), and the range was 3.0 to 40.3 mm Hg. The mean +/- SD and median initial pO(2) were 20.2 +/- 2.4 and 11.9 mm Hg, respectively (n=37). IFP and pO(2) were independent of tumor size. Fractionated radiation lowered IFP by 2.5 mm Hg when the total dose was 10 or 15 Gy (P<0.05), but IFP did not change in the controls or the 5-Gy radiation group (P>0.05). Irradiation increased the proportion of tumors at higher oxygen tensions when compared to control tumors. The IFP and tumor volumes were followed for up to 10 days after a single dose of 10, 20, or 30 Gy of irradiation. IFP decreased for all treatment groups. The decrease was most significant for the group receiving 30 Gy. On day five following irradiation, the IFP had decreased by 35%. The changes in IFP and pO(2) occurred before any macroscopic changes in tumor volume could be observed. The radiation-induced decrease in IFP could be, in part, responsible for the increased uptake of monoclonal antibodies following single or fractionated radiation that has been reported in the literature.

Inhibition of nitric oxide synthesis does not improve interleukin-2-mediated antitumor effects in vivo

Nitric oxide (NO) decreases cytotoxicity and proliferation of cytotoxic lymphocytes (CTLs) in vitro. Both can be prevented by inhibitors of the NO synthase (NOS). To elucidate whether inhibition of the IL-2-induced NOS could boost efficacy of IL-2-stimulated CTLs in vivo, we assessed lung metastases in mice injected with IL-2, the NOS inhibitor aminoguanidine (AG), their combination and the diluent. No improvement was observed for IL-2 + AG compared to IL-2 while NO production was normalized. Since NO causes one of the two major side effects of IL-2 treatment, hypotension, we further studied whether capillary leak could be attributed to NO, too. While IL-2-inducible NO was reduced to control levels by AG, pulmonary edema was unaffected. Thus a decrease in NO does not improve antitumor effects of IL-2-stimulated CTLs nor does it attenuate IL-2-associated capillary leak.

Addition of interleukin 12 to low dose interleukin 2 treatment improves antitumor efficacy in vivo

Interleukin 12 (IL-12) enhances lysis mediated by NK- and lymphokine activated killer (LAK) cells. It also causes proliferation of IL-2 stimulated T and NK cells in vitro. For these IL-2 complementing properties murine pulmonary metastases of a coloncarcinoma line were treated with IL-12 and IL-2 or with the individual agents. Results were compared to sham treated controls. IL-2 alone mediated significant tumor reduction but provoked pulmonary edema and concomittand toxicity, graded in three steps. IL-12 combined with an IL-2 dose reduced by 81% still resulted in significant antitumoral activity. Toxicity, however, was not discernable from sham treated controls. IL-12 thus appears as an attractive cytokine for combination with IL-2 in antitumor therapy. Particularly treatment of tumors, like gastrointestinal tract cancers, so far mainly resistant to cell mediated antitumor therapy, might profit from this approach.

Simulation of the upper gastrointestinal fluoroscopic examination for calculation of absorbed dose in tissue

In order to simulate the upper gastrointestinal fluoroscopic examination, modifications were made to the Monte Carlo radiation-transport code that uses the anthropomorphic, mathematical reference phantoms ADAM and EVA. A set of discrete x-ray field projections of the principal anatomy of clinical interest has been previously defined. This note describes the new features incorporated in the simulations--divergent beams in oblique irradiation geometries, an esophagus and a duodenum, a double contrast medium consisting of a BaSO4-H2O mixture and air in the esophagus, stomach, and duodenum, and clinically representative beam qualities. The absorbed doses in tissues per unit entrance exposure (free-in-air) computed with the modified code appeared in Department of Health and Human Services Publication FDA 92-8282, Handbook of Selected Tissue Doses for the Upper Gastrointestinal Fluoroscopic Examination. A minor correction is described for the previously reported results for the esophagus.

Role of gamma-glutamyltranspeptidase-mediated glutathione transport on the radiosensitivity of B16 melanoma variant cell lines

PURPOSE

To elucidate the role of gamma-glutamyltranspeptidase-mediated glutathione transport on the radiosensitivity of B16 melanoma variant cell lines.

METHODS AND MATERIALS

B16 melanoma variant cell lines were examined for their levels of gamma-glutamyltranspeptidase (GGTP; E.C. 2.3.2.2), a plasma membrane-associated ectoenzyme that is involved in the transport of extracellular glutathione, by flow cytometric and biochemical analysis. B16 cell lines were examined for rates of de novo glutathione synthesis from extracellular glutathione and for their sensitivity to gamma-irradiation and glutathione synthesis inhibition. The GGTP inhibitors were examined for their effect on the radiosensitivity of B16 melanoma cells.

RESULTS

B16-F10-BL6 (BL6) melanoma cells were shown to express a 20-fold higher level of GGTP than the B16-F1 melanoma variant cells. Cultures of BL6 and B16-F1 cells depleted extracellular glutathione at rates of 2.4 and < 0.1 nmol glutathione/10(6) cells/h, respectively, and BL6 cells exported glutathione at a rate 7.2-fold higher than B16-F1 cells (710 and 98 pmol glutathione/10(6) cells/h, respectively). BL6 melanoma cells replenished exhausted intracellular glutathione levels from an extracellular glutathione source at a rate of 1.21 nmol glutathione/h (18% basal glutathione/h); however, B16-F1 cells lacked the capacity to replenish intracellular glutathione despite the presence of exogenous glutathione in the culture medium. BL6 melanoma cells were radioresistant compared to the B16-F1 cell line, exhibiting extrapolation numbers (ñ) of 14.9 and 1.0, respectively, and a lower surviving fraction to a wide range of radiation doses. The GGTP inhibitor combination of L-serine and sodium borate blocked the repletion of intracellular glutathione and in the presence or absence of buthionine sulfoximine-mediated depletion of glutathione reverses the radiation resistance in BL6 melanoma cells to near baseline levels observed with the B16-F1 parent clone. Serine-borate treatment of low-GGTP expressing B16-F1 cells had no effect on the ñ value or the surviving fraction of cells to a range of ionizing irradiation doses.

CONCLUSIONS

These results suggest that GGTP plays an important role in the extracellular metabolism and transport of glutathione, which also provides radioresistance to BL6 melanoma cells in vitro.

Local IL-4 delivery enhances immune reactivity to murine tumors: gene therapy in combination with IL-2

Tumor cells transduced with the IL-4 gene demonstrate reduction of growth associated with macrophage and eosinophilic infiltrates, generation of cytotoxic T-cells, and protective immunity. Using murine IL-4 retroviral vectors, murine fibroblasts and tumors that produce from 50 to 5000 U of IL-4/10(6) cells per 24 hours as determined by ELISA and bioassay were successfully transduced. In blinded studies using C57BL/6 and BALB/c mice, we have shown that tumor growth can be inhibited (mean delay of 10 days compared with controls; P < .05) and in some cases, completely suppressed by the coinjection of viable tumor with IL-4-producing fibroblasts (tumor free > 100 days; P < .001). Animals that are able to reject an initial tumor inoculate can also completely reject subsequent parental tumor challenge of 10(5) cells (P < .001) while challenge of 10(6) parental tumor cells results in a significant delay of tumor induction (P < .05). In addition, immunization with IL-4 transduced fibroblasts and irradiated tumor cells resulted in complete suppression of parental tumor challenge in animals that received the high-dose IL-4 delivery. Finally coadministration of systemic IL-2 led to enhancement of IL-4 gene therapy resulting in a 20-day delay of preestablished tumor growth compared with controls (P < .05).

Treatment of brain metastases from bladder cancer

The records of 28 patients with transitional cell cancer who had brain metastases were retrospectively reviewed. Data from 19 patients were considered suitable for analysis and were included in this study. One patient was treated with surgery alone, 10 with radiation alone and 7 with radiation and surgery, while 1 received no treatment. Mean and median survival times, respectively, were 57 and 42 months from the initial diagnosis, and 11 and 4 months from diagnosis of central nervous system metastases. Patients treated with surgery and radiation demonstrated a mean survival time of 19 months compared to 6 months for patients treated with radiation alone (p = 0.03). There were 2 long-term survivors in the combined modality group at 50 and at 12 months. Enthusiasm for combined modality treatment should be tempered by the fact that selection bias favored the combined modality group; 13 patients with single lesions demonstrated a mean survival of 14 months compared to 3 months for 6 patients with multiple lesions (p = 0.009) and only patients with solitary lesions underwent surgical resection. Brain metastases have an ominous prognosis in patients with bladder cancer primaries. Considering the sum of the retrospective and prospective reports, we recommend that patients with solitary brain lesions and good performance status be aggressively managed with surgical resection and postoperative radiation therapy.

A reappraisal of the role of prophylactic cranial irradiation in limited small cell lung cancer

The use of prophylactic cranial irradiation in limited stage small cell lung cancer remains controversial. Prospective trials have demonstrated that PCI can reduce central nervous system relapse rates, but the impact on survival remains questionable except for the possible evidence of a beneficial effect for long term survivors. With higher rates of thoracic control now obtainable with hyperfractionated radiation and concomitant chemotherapy, it becomes important to analyze the benefit of PCI in that setting. Before 1982, we included PCI in the management of all patients with limited stage small cell lung cancer; thereafter, we discontinued its use. This report compares the outcome of the two treatment approaches and addresses the role of PCI among patients who achieve durable local control. There were 36 limited stage small cell lung cancer patients treated with PCI from 1979-1982 and 26 patients treated without PCI from 1985-1989. Induction chemotherapy was followed in both groups by thoracic irradiation (45 Gy). The PCI patients received 30 Gy to the whole brain in 10 fractions. Both groups received maintenance chemotherapy. Of complete responders, brain failure was the first failure in 18% (4/22) of PCI (+) versus 45% (10/22) of PCI (-) (p = .04). Survival at 2 years was 42% for PCI (+) versus 13% for PCI (-) (p less than .05). When the analysis was limited to those patients permanently controlled in the thorax; there were 25% (4/16) brain failures PCI (+) versus 70% (7/10) PCI (-) (p = .03). For this same subset the 2-year survival was 56% PCI (+) versus 14% PCI (-) (p less than .05). There were no 5 year survivors without PCI compared to 38% (6/16) with PCI. These data suggest that PCI appears to be effective in enhancing survival of patients who achieve durable thoracic control. Prospective trials are necessary to evaluate the use of PCI combined with therapeutic regimens with a documented ability to achieve high rates of sustained control of thoracic disease.

A new device to stabilize templates for transperineal I-125 implants

Transperineal Iodine-125 implants of the prostate are currently being performed at Memorial Sloan-Kettering Cancer Center with CT-based treatment planning and transrectal ultrasound for verification of proper needle placement in the prostate at the time of implantation. An adjustable device, the WIPI, has been designed to stabilize the perineal template and rectal obturator during planning and implementation of the procedure. The device is simple to use and is compatible with CT scanning, transrectal ultrasound, and the Mick applicator. Its design and key functional features are described here.

Tissue doses in the upper gastrointestinal fluoroscopy examination

A method was developed to estimate tissue doses from the upper gastrointestinal fluoroscopy examination. It involved measuring the technical parameters of the clinical examination, partitioning the dynamic examination into a set of discrete x-ray fields, and generating corresponding tissue does tables with an existing computer program. Knowledge of the radiation exposures associated with each of the fields enabled the calculation of tissue doses for the entire dynamic examination. In this limited sample (eight patients), fluoroscopy times ranged from 108 to 183 seconds. Radiation exposures ranged from 2.3 to 7.2 mC/kg (9.1-28 R), thyroid doses from 0.15 to 3.5 mGy (15-350 mrad), uterine doses from 0.16 to 1.0 mGy (16-100 mrad), lung doses from 0.90 to 4.2 mGy (90-420 mrad), and active bone marrow doses from 0.81 to 5.4 mGy (81-540 mrad).

Tissue doses from radiotherapy of cancer of the uterine cervix

For use in an epidemiologic study of subsequent tumors, absorbed doses from brachytherapy and external beam radiotherapy were measured and calculated for various tissues of patients treated for cancer of the uterine cervix. External beams included orthovoltage x rays (1.9 and 3.0 mm Cu half-value layer), cobalt-60 gamma rays, 2 MV x rays, and 25 MV X rays. The brachytherapy sources were encapsulated radium. Measurements were made in an Alderson anthropomorphic phantom and a water phantom; calculations were made using a Monte Carlo technique or standard radiotherapy methods. Depending upon stage of disease and radiation energy, the absorbed doses (cGy) from typical treatment regimes to tissues of interest were: ovaries, 1400-5200; stomach, 130-320; kidneys, 120-310; pancreas, 100-260; lungs 22-48; breasts, 19-52; thyroid, 6-17; salivary glands, 4-11; brain, 2-7, and total active bone marrow, 320-1100. The lower values of each range were for stage I of the disease.

Breast cancer after multiple chest fluoroscopies: second follow-up of Massachusetts women with tuberculosis

A second follow-up was conducted of 1742 women with tuberculosis who were treated in one of two sanatoria in Massachusetts between 1930 and 1956. One hospital treated only children under the age of 17. Patient follow-up was extended from 1975 through 1980, and an additional 18 breast cancers were identified from hospital records, death certificates, and responses to a mailed questionnaire. Vital status was established for 97% of the subjects. Among 1044 women who were examined an average of 101 times with X-ray fluoroscopies during lung collapse therapy, 55 breast cancers were observed in contrast to 35.8 expected, based on incidence rates from the general population. No excess was found for 698 women treated by other means (19 observed versus 22.8 expected). Excess breast cancer risk did not appear until 15 years after initial exposure and was present at the end of 50 years of observation. Risk appeared to decrease with increasing age at exposure. Estimates of radiation dose to the breast for individuals (mean = 96 rad) were based on the most current information for the numbers of fluoroscopies, reconstruction of exposure conditions, and absorbed dose calculations. The relation between dose and breast cancer risk was consistent with linearity up to 400 rads (4 Gy). For 10-year survivors, the absolute excess risk was 5.5/1 million woman-year-rad, the excess relative risk per rad was 0.73%, and the relative risk at 100 rad was 1.7. These data indicate that a woman's lifetime risk of breast cancer is influenced by events occurring in early reproductive life, that low-dose fractionated exposures are as effective as single exposures of the same total dose in inducing breast cancer, and that risk of radiogenic breast cancer persists for many years, and perhaps for life.

Thyroid, parathyroid, and salivary gland evaluations in patients exposed to multiple fluoroscopic examinations during tuberculosis therapy: a pilot study

The prevalence of thyroid, parathyroid, and salivary abnormalities was determined in 91 women who received an average of 112 fluoroscopic chest examinations during pneumothorax treatment for tuberculosis more than 40 yr previously and in 72 women treated for tuberculosis by other modalities. Thyroid abnormalities were determined by physical examination, scintiscans, and measurements of serum free T4 index, TSH, and thyroid microsomal antibodies. Thyroid nodules were diagnosed in 7.7% of the exposed and 4.2% of the comparison group (prevalence ratio, 1.8; 90% confidence interval 0.6-5.7). Autoimmune thyroid disease was diagnosed in 15.2% of the exposed and 6.9% of the comparison group (prevalence ratio, 2.2; 95% confidence interval, 0.8-6.2). No salivary tumors were detected. Two exposed women and 1 comparison woman had primary hyperparathyroidism. Although absorbed dose to the thyroid could not be precisely determined, approximately 60 rads would be expected to yield the observed excess of thyroid nodules. While the prevalence ratios were not significantly increased in the exposed group, the results suggest that susceptibility of the thyroid to nodules from cumulative radiation doses of this magnitude could be increased even when the doses are accumulated over years and that such x-ray exposure of the thyroid gland may predispose the patient to the development of autoimmune disease.

Efficacy in turkeys of spray vaccination with a temperature-sensitive mutant of Bordetella avium (Art Vax)

Broad-breasted white turkeys were vaccinated with a temperature-sensitive mutant of Bordetella avium (Art Vax) at 2 and 15 days of age and challenged at 22 days of age by contact with infected birds. Necropsy was performed at 35 days of age. Two vaccination protocols (eyedrop/oral and spray cabinet/spray bottle) and two challenge isolates (Arkansas 105 and North Carolina [NC] isolates) were used. Neither the spray nor the eyedrop/oral methods of vaccination prevented infection of the anterior trachea with either of the virulent challenge strains. The spray and eyedrop/oral methods of vaccination were equally effective in reducing the severity of gross lesions in the trachea. The vaccine reduced the severity of gross lesions in the tracheas of turkeys challenged with the NC isolate to a level approximately equal to that observed in unchallenged vaccinated controls, but the vaccine only moderately reduced the severity of lesions in birds challenged with the 105 isolate.

Extravasation of intravascular fluid mediated by the systemic administration of recombinant interleukin 2

Adoptive immunotherapy with lymphokine-activated killer cells and recombinant interleukin 2 (IL 2) can produce significant reduction of visceral metastases in tumor-bearing mice and, as shown recently, in humans with disseminated cancer. Because further dose escalations of IL 2 have been prevented by the development of a vascular leak syndrome (VLS) in both mice and humans, we investigated this VLS in mice undergoing the systemic administration of high-dose IL 2. A model for quantitating capillary permeability was used in which 125I-bovine serum albumin was injected i.v., and 2 hr later, tissues were counted in a gamma analyzer. A permeability index (PI) was calculated by dividing the mean counts per minute (cpm) of tissues from IL 2-treated mice by those from control animals. The injection of IL 2 produced increases in vascular permeability that were most pronounced in the thymus, spleen, lungs, liver, and kidneys (PI = 18.0, 10.0, 9.7, 6.7, and 6.3, respectively, on day 6). The development of the VLS was highly dependent on the number of days of IL 2 treatment (for example, the lungs contained 638, 1382, 3350, and 6187 cpm after 0, 1, 3, and 6 days of IL 2, respectively). Moreover, the degree of the VLS was directly related to the dose of IL 2 administered. Measurement of the wet and dry weights of lungs from IL 2-treated mice demonstrated that IL 2 produced a dramatic increase in their water weight (from 0.10 g at base line to 0.22 g after 200,000 U of IL 2 for 6 days). The injection of the IL 2 excipient failed to induce capillary leakage in tissues. Immunosuppression of mice by pretreatment irradiation (500 rad) or by injection of cyclophosphamide or by concurrent use of cortisone acetate markedly reduced or eliminated the development of the VLS. Similarly, the VLS was not observed in nude mice receiving IL 2. Thus, the administration of IL 2 produces a dose-limiting VLS that may be mediated, directly or indirectly, by host lymphoid elements.

Extravasation of intravascular fluid mediated by the systemic administration of recombinant interleukin 2

Adoptive immunotherapy with lymphokine-activated killer cells and recombinant interleukin 2 (IL 2) can produce significant reduction of visceral metastases in tumor-bearing mice and, as shown recently, in humans with disseminated cancer. Because further dose escalations of IL 2 have been prevented by the development of a vascular leak syndrome (VLS) in both mice and humans, we investigated this VLS in mice undergoing the systemic administration of high-dose IL 2. A model for quantitating capillary permeability was used in which 125I-bovine serum albumin was injected i.v., and 2 hr later, tissues were counted in a gamma analyzer. A permeability index (PI) was calculated by dividing the mean counts per minute (cpm) of tissues from IL 2-treated mice by those from control animals. The injection of IL 2 produced increases in vascular permeability that were most pronounced in the thymus, spleen, lungs, liver, and kidneys (PI = 18.0, 10.0, 9.7, 6.7, and 6.3, respectively, on day 6). The development of the VLS was highly dependent on the number of days of IL 2 treatment (for example, the lungs contained 638, 1382, 3350, and 6187 cpm after 0, 1, 3, and 6 days of IL 2, respectively). Moreover, the degree of the VLS was directly related to the dose of IL 2 administered. Measurement of the wet and dry weights of lungs from IL 2-treated mice demonstrated that IL 2 produced a dramatic increase in their water weight (from 0.10 g at base line to 0.22 g after 200,000 U of IL 2 for 6 days). The injection of the IL 2 excipient failed to induce capillary leakage in tissues. Immunosuppression of mice by pretreatment irradiation (500 rad) or by injection of cyclophosphamide or by concurrent use of cortisone acetate markedly reduced or eliminated the development of the VLS. Similarly, the VLS was not observed in nude mice receiving IL 2. Thus, the administration of IL 2 produces a dose-limiting VLS that may be mediated, directly or indirectly, by host lymphoid elements.

Adoptive immunotherapy of a syngeneic murine leukemia with a tumor-specific cytotoxic T cell clone and recombinant human interleukin 2: correlation with clonal IL 2 receptor expression

The successful adoptive immunotherapy of the syngeneic Friend virus-induced murine leukemia FBL-3 was mediated by a proliferative MHC-restricted, tumor-specific CTL clone in combination with recombinant human IL 2. This clone was previously shown to express the L3T4-, Lyt-1+, Lyt-2+ surface phenotype. Activation of the clone for 48 hr in vitro with irradiated tumor cells induced the expression of IL 2 receptors and markedly increased clonal proliferation in response to recombinant IL 2. Intravenous injection of 2 X 10(7) 48 hr in vitro-activated cloned cells, followed by 6 days of systemic (i.p.) administration of IL 2 resulted in the complete regression of tumors and the cure of 50% of the treated mice. IL 2 alone had no effect on tumor growth, whereas the injection of nonactivated (resting) clone plus IL 2 or activated clone without IL 2 had small but insignificant effects on tumor growth and survival. These results indicated that the in vivo effector functions of cloned T cells may be markedly enhanced by the concurrent systemic administration of recombinant IL 2 and by the induction of optimal IL 2 receptor expression on the cloned T cells at the time of cell administration.

Risk of extrathyroid tumors following radiation treatment in infancy for thymic enlargement

Two thousand eight hundred and fifty-six individuals who received X-ray treatments in infancy for an enlarged thymus gland and their 5053 nonirradiated siblings have been followed prospectively since 1953 to evaluate the risk of radiation-induced neoplastic disease. The health status of the entire cohort has been ascertained periodically by mail questionnaire survey. Based on the cumulative experience of five surveys of this cohort, the irradiated group has a statistically significant increased risk for both benign and malignant extrathyroid tumors, the age-adjusted relative risks being 2.0 and 2.2, respectively. Benign tumors of the bone, nervous system, salivary gland, skin, and breast (females only) and malignant tumors of the skin and breast (females only) account for the excess incidence of extrathyroid tumors among the thymic-irradiated individuals. Although a radiation-induced excess of extrathyroid tumors was suggested in an earlier survey of this cohort, small numbers restricted attribution of this excess to specific sites. The implications of these findings are discussed. Thyroid tumors are addressed in a separate paper.

Curative intravenous adoptive immunotherapy of Meth A murine sarcoma. A histologic and immunohistochemical assessment

Intravenous administration of 1.5 X 10(8) syngeneic spleen cells from immune animals resulted in the complete eradication of established Meth A soft tissue sarcomas in (C57BL/6 X BALB/c) F1 mice. In mice receiving a single injection of immune spleen cells 4 days after tumor implantation in the abdominal wall, the tumors continued to grow for approximately 1 week before undergoing regression. This delay before adoptive immunity is expressed is thought to represent the time needed for the passively transferred cells to give rise to a host response of sufficient magnitude to destroy the tumor. None of the mice receiving a similar number of control spleen cells were cured of their sarcomas. Successful therapy was dependent upon the transfer of viable, immune T lymphocytes and required prior irradiation of the tumor-bearing host in order to remove suppressor T cells. Utilizing sequential histologic and immunohistochemical techniques, we attempted to characterize the cellular events of tumor regression. The earliest histologic difference between animals treated with immune and nonimmune lymphocytes was in the number of lymphocytes detected at the perimeter of the tumor in specifically immunized mice on day 6. There was also a striking difference between animals treated with immune versus nonimmune lymphocytes in the intensity and timing of the acute inflammatory response beginning on day 8. The "front" of immunologically mediated tumor destruction appeared at the lateral and deep borders of the implanted sarcomas and progressed inward. During the period of active tumor regression T lymphocytes reactive with a biotinylated mouse anti-Thy 1.2 monoclonal antibody were increased in frozen sections of tumors in mice receiving immune cells relative to the controls. During the first 3 weeks following adoptive transfer of lymphocytes, T cells reactive with Lyt-1 biotinylated mouse monoclonal antibody (helper/inducer phenotype) outnumbered their Lyt-2 (suppressor/cytotoxic) counterparts in frozen sections of tumor from both specifically immunized and control mice. By the end of the 4th week of the experiment, the sarcomas were completely eradicated in all mice receiving immune cells. The previous tumor beds were occupied by collections of lipid-laden macrophages, lymphocytes, plasma cells, and fibroblasts. Despite vigorous but delayed acute and chronic inflammatory responses at the tumor perimeters in the control mice, these tumors all progressed.(ABSTRACT TRUNCATED AT 400 WORDS)

Eradication of a disseminated syngeneic mouse lymphoma by systemic adoptive transfer of immune lymphocytes and its dependence upon a host component(s)

We have studied the in vivo effects of carrageenan and trypan blue on the adoptive immunotherapy of an established local and disseminated syngeneic mouse FBL-3 lymphoma. Mice receiving 500 rads total-body irradiation before injection of FBL-3 tumor into the footpad were treated 4 to 5 days later when a palpable local tumor and disseminated metastases were present. Injection of in vivo immune lymphocytes i.v. caused complete regression of footpad tumor and cured 96% of all mice (greater than 60 days mean survival; p less than 0.0005). Carrageenan or trypan blue treatment of the tumor-bearing host abrogated the therapeutic effect of adoptively transferred cells. Cure rates were significantly reduced to 27% (p less than 0.004) and 0% (p less than 0.0001) and mean survival times to 40.2 days (p less than 0.0005) and 15.2 (p less than 0.005) days for mice treated with carrageenan and trypan blue, respectively, in addition to immune cells. In vivo treatment of the immune spleen cell donors with carrageenan or trypan blue had no significant effect on the ability of those splenocytes to mediate cure when adoptively transferred into tumor-bearing hosts, indicating that the inhibitory activity of these agents cannot be attributed to direct toxicity to immune lymphoid cells. These results demonstrate that a recipient component(s), possibly macrophages, sensitive to carrageenan and to trypan blue but relatively resistant to radiation (500 rads), plays a vital role in the cure of tumor-bearing mice that receive the adoptive transfer of immune splenocytes.

Lymphokine-activated killer cells: lysis of fresh syngeneic natural killer-resistant murine tumor cells by lymphocytes cultured in interleukin 2

Normal splenocytes that are cultured in the lymphokine, interleukin 2 (IL-2), for as short as 2 days develop lytic activity for fresh syngeneic natural killer-resistant tumor cells as well as natural killer-sensitive YAC cells in a 4-hr 51Cr release assay. Lymphokine-activated killer (LAK) cells do not lyse syngeneic fresh lymphocytes but do lyse syngeneic concanavalin A-induced lymphocyte blasts. Lysis is not due to the presence of lectin or xenogeneic serum and appears to be an intrinsic property of lymphocytes activated in IL-2. The activation appears universal in that lymphocytes from all strains of mice activated in this manner exhibited similar patterns of lysis for fresh tumor target cells. To characterize the cells responsible for this lysis, we analyzed the phenotypic expression of surface markers on these cells with depletion techniques using monoclonal antibody and complement. These studies indicate that the precursor of the LAK cell is Thy-1+ and nonadherent to plastic or nylon wool. Lysis of syngeneic tumor was inhibited when LAK cells were treated with an anti-Thy-1.2, or anti-Lyt-2.2 monoclonal antibody and complement but not with anti-Lyt-1.2 monoclonal antibody and complement, indicating that the observed lytic activity was due to a Thy-1+ Lyt-1-2+ cell. Furthermore, LAK cell-mediated lysis could be inhibited by the addition of anti-Lyt-2 or LFA-1 monoclonal antibody to cytotoxicity assays. Cold target inhibition analysis revealed that the syngeneic tumor cells were lysed by recognition of a determinant not present on normal lymphocytes or lymphocyte blasts. This lysis of fresh solid tumor cells by lymphoid cells grown in IL-2 may be of value in the study of tumor-host immunological interactions. The biological significance of tumor lysis by IL-2-activated cells requires further study.

Generation of lytic and proliferative lymphoid clones to syngeneic tumor: in vitro and in vivo studies

T-cell clones that exhibited both lytic and proliferative activity for the syngeneic FBL-3 lymphoma were isolated from in vitro sensitization cultures. These clones were Lyt-2+ and proliferated specifically to the FBL-3 lymphoma but not to other tumors of C57BL/6 origin, allogeneic tumor, or C57BL/6 normal lymphocytes. Adoptive transfer of clones exhibiting both proliferative and cytotoxic activity prolonged survival and occasionally cured the animals of disseminated FBL-3 lymphomas, while T-cell clones exhibiting lytic but no proliferative activity conferred no survival benefit compared to the survival seen among animals receiving no treatment.

In vivo administration of purified Jurkat-derived interleukin 2 in mice

Pure human interleukin 2 (IL-2), produced by the T-cell lymphoma Jurkat, was injected in mice to study the serum half-life, toxicity, and in vivo immunological effects of IL-2. The serum half-life (t1/2) of Jurkat IL-2 in mice appeared to have two components: (a) a rapid initial phase with t1/2 of approximately 2 min during which most of the exogenous IL-2 was cleared from the serum; and (b) a second, slower component with t1/2 of about 9 min. Mice given injections i.p. or i.v. with pure Jurkat IL-2, at doses comparable on a microgram/kg basis to contemplated doses for humans, showed no signs of toxicity on the basis of serial measurements of weight, serum liver and kidney chemistries, or histology of lymphoid and vital organs. Jurkat IL-2 had no effect on the rate of growth or survival of mice with an established s.c. methylcholanthrene-induced fibrosarcoma, but Jurkat IL-2 used in conjunction with in vitro-resensitized and IL-2-expanded specific immune splenocytes prolonged survival of mice with disseminated FBL-3 tumor. This survival prolongation was highly significant when compared to treatment with Jurkat IL-2 alone (p = less than 0.001) or an equivalent number of in vitro-resensitized and expanded cells alone (p = 0.004). Treatment of mice with i.p. Jurkat IL-2 subsequent to secondary immunization with allogeneic tumor enhanced by more than 5-fold the splenocyte cytotoxicity for alloantigen measured 7 days later. Thus, purified human IL-2 derived from the Jurkat cell line has a short half-life in mice with no apparent toxicity at large doses. In vivo efficacy of human IL-2 was demonstrated in increasing alloantigen responsiveness and in increasing the efficacy of transferred expanded immune lymphocytes in the FBL-3 lymphoma model.

Adoptive immunotherapy of established syngeneic solid tumors: role of T lymphoid subpopulations

We have investigated the subpopulations of T cells necessary to mediate the cure of established tumors in two models of successful adoptive immunotherapy. In C57BL/6 mice bearing palpable and disseminated FBL-3 lymphoma, both Lyt-1+ and Lyt-2+ cells played a major role in mediating the regression and permanent cure of mice, whereas in BALB/c mice bearing the Meth A sarcoma the adoptive transfer of Lyt-1+2+ cells played a major role in mediating the regression of tumors and the curing of disease. Identical experiments performed in hybrid (BALB/c X C57BL/6) mice yielded similar results, further supporting our initial observation and indicating that in these two adoptive transfer model systems it is the tumor and not the variable expression of Lyt antigens by the host that determines which T cell subpopulation is required to cure mice of tumors.

The systemic administration of purified interleukin 2 enhances the ability of sensitized murine lymphocytes to cure a disseminated syngeneic lymphoma

Significant serum titers of interleukin 2 (IL 2) can be maintained in mice for 12 h after i.p. injection in a 15% gelatin solution. We have tested the ability of IL 2 administered systemically in this fashion to enhance the therapeutic effect of adoptively transferred specifically sensitized lymphoid cells that were expanded in IL 2. Mice with established local and disseminated FBL-3 lymphoma, induced by intrafootpad injection of 10(7) cells after 500 rad total body irradiation, were treated with a combination of i.v. injected murine splenocytes and either murine supernatants containing IL 2 or pure human IL 2 in gelatin. Splenocytes from immune mice were resensitized to irradiated tumor in vitro and were expanded for 7 days in lectin-free IL 2 supernatants. Treatment with these murine splenocytes administered with murine IL 2 supernatants prolonged mean survival to 33.6 days compared with mean survival times of 16.9 days (p less than 0.001) and 23.4 days (p = 0.007) for mice treated with IL 2 alone or splenocytes alone. Human IL 2, purified to homogeneity from the Jurkat cell line, was also capable of improving the therapeutic efficacy of transferred cells in mice. Mean survival was significantly prolonged to 32.1 days when cells and purified human IL 2 were administered, whereas mean survival times of 18.1 days (p = less than 0.001) and 21.5 (p = less than 0.001) were seen for mice treated with IL 2 alone or expanded immune cells alone. Cure rates in this model were also significantly enhanced with the combined treatment of IL 2 and expanded immune cells. Combined immunotherapy utilizing IL 2 and immune cells was thus significantly better than either component used alone. The systemic administration of IL 2 in conjunction with sensitized expanded lymphoid cells may be a useful approach to the immunotherapy of other murine and human tumors.

The systemic administration of purified interleukin 2 enhances the ability of sensitized murine lymphocytes to cure a disseminated syngeneic lymphoma

Significant serum titers of interleukin 2 (IL 2) can be maintained in mice for 12 h after i.p. injection in a 15% gelatin solution. We have tested the ability of IL 2 administered systemically in this fashion to enhance the therapeutic effect of adoptively transferred specifically sensitized lymphoid cells that were expanded in IL 2. Mice with established local and disseminated FBL-3 lymphoma, induced by intrafootpad injection of 10(7) cells after 500 rad total body irradiation, were treated with a combination of i.v. injected murine splenocytes and either murine supernatants containing IL 2 or pure human IL 2 in gelatin. Splenocytes from immune mice were resensitized to irradiated tumor in vitro and were expanded for 7 days in lectin-free IL 2 supernatants. Treatment with these murine splenocytes administered with murine IL 2 supernatants prolonged mean survival to 33.6 days compared with mean survival times of 16.9 days (p less than 0.001) and 23.4 days (p = 0.007) for mice treated with IL 2 alone or splenocytes alone. Human IL 2, purified to homogeneity from the Jurkat cell line, was also capable of improving the therapeutic efficacy of transferred cells in mice. Mean survival was significantly prolonged to 32.1 days when cells and purified human IL 2 were administered, whereas mean survival times of 18.1 days (p = less than 0.001) and 21.5 (p = less than 0.001) were seen for mice treated with IL 2 alone or expanded immune cells alone. Cure rates in this model were also significantly enhanced with the combined treatment of IL 2 and expanded immune cells. Combined immunotherapy utilizing IL 2 and immune cells was thus significantly better than either component used alone. The systemic administration of IL 2 in conjunction with sensitized expanded lymphoid cells may be a useful approach to the immunotherapy of other murine and human tumors.

Adoptive immunotherapy of established syngeneic solid tumors: role of T lymphoid subpopulations

We have investigated the subpopulations of T cells necessary to mediate the cure of established tumors in two models of successful adoptive immunotherapy. In C57BL/6 mice bearing palpable and disseminated FBL-3 lymphoma, both Lyt-1+ and Lyt-2+ cells played a major role in mediating the regression and permanent cure of mice, whereas in BALB/c mice bearing the Meth A sarcoma the adoptive transfer of Lyt-1+2+ cells played a major role in mediating the regression of tumors and the curing of disease. Identical experiments performed in hybrid (BALB/c X C57BL/6) mice yielded similar results, further supporting our initial observation and indicating that in these two adoptive transfer model systems it is the tumor and not the variable expression of Lyt antigens by the host that determines which T cell subpopulation is required to cure mice of tumors.

Lysis of fresh natural killer-resistant tumor cells by lectin-activated syngeneic and allogeneic murine splenocytes

This paper demonstrates that lectin-activated lymphocytes of selected mouse strains can lyse fresh autologous or allogeneic tumor cells but not the fresh normal cells tested in short-term 51Cr release assays. Murine splenocytes, incubated with concanavalin A for 3 days, lysed tumor cells from fresh syngeneic P815 mastocytoma, 102 methylcholanthrene sarcoma, and FBL3 lymphoma; fresh allogeneic 3LL lung carcinoma and MethA sarcoma; and tissue-cultured YAK cells in 18-hr51Cr release assays. Natural killer cells in fresh splenocyte preparations only lysed tissue-cultured YAK cells and not the other targets. Syngeneic and allogeneic lymphoblasts, lung, or liver cells were not lysed by the concanavalin A-activated killer (CAK) cells. The induction of cytotoxicity by concanavalin A incubation was abrogated by alpha-methylmannoside in the 3-day incubation, but not in cytotoxicity assay. Radiosensitive cells and adherent cells were necessary for the generation of CAK cells. The CAK effectors themselves were radioresistant, nonadherent, and mostly Thy 1+ and Ly 2+. The CAK phenomenon may be mediated by lymphokine production by an Ly 1+ cell, since depletion of Ly 1+ cells prior to activation abrogates CAK induction, and the ability of numerous mouse strains (and nude mice) to generate CAK cells correlated with their ability to produce Interleukin 2. The biological and therapeutic role of these cells is currently being investigated in murine syngeneic primary and metastatic tumor models.

Clonal analysis of the lymphoid cells mediating skin allograft rejection. Mediation of graft rejection in vivo by cloned Lyt-1+2- proliferative, noncytotoxic long-term cell lines

Studies were undertaken to elucidate the cellular basis of skin allograft rejection mediated by long-term cultured cell lines and clones. The adoptive transfer, in vivo, of in-vitro-sensitized cells, from B6AF1 anti B10.BR or from C57BL/6 anti DBA/2 cultures, and expanded eight-fold to ten-fold for one week in lectin-free interleukin 2 (LF-IL-2) were able to mediate specific skin allograft rejection. These same cells lost the ability to mediate accelerated skin graft rejection when they were expanded more than 100-fold during three weeks of culture in LF-IL-2 even though these cultures mediated high levels of specific in vitro cytotoxicity for the appropriate allosensitizing cells. When Lyt-2+ cells were depleted using monoclonal antibodies and complement prior to in vitro sensitization and expansion in LF-IL-2, these cells lines retained the ability to mediate skin allograft rejection in vivo when expanded more than 100-fold for three culture generations in vitro. These latter lines were greatly enriched for Lyt-1+2- cells and had little or no cytolytic activity, but they retained specific in vitro proliferative responses to the sensitizing alloantigen. Several Lyt-1-2+ cloned long-term lymphoid cell lines with high levels of specific cytolytic activity against the sensitizing alloantigen were derived and none was capable of mediating the accelerated rejection of skin grafts in vivo. However, cloned lymphoid cell lines that were phenotypically Lyt-1+2- and were capable of proliferating when in contact with specific alloantigen, but were not cytolytic, were capable of mediating the accelerated rejection of skin grafts in vivo both in irradiated mice and in nude mice. These studies demonstrate that skin allograft rejection can be mediated by Lyt-1+2- cell lines with specific in vitro proliferative activity to alloantigen although Lyt-1-2+ cell lines with cytolytic but not proliferative activity to alloantigen in vitro are ineffective in mediating graft rejection in vivo. Specific proliferative activity and no cytolysis appears to be a good in vitro correlate of the in vivo activity of long-term cultured cell lines.

Simplified techniques for the isolation of alloreactive cell lines and clones with specific cytotoxic or proliferative activity

A rapid method is described for the isolation of alloantigen specific proliferative and cytotoxic clones from primary mixed lymphocyte cultures (MLC). To raise cell lines and clones with specific alloantigenic proliferative activity in vitro, responder splenocytes were depleted of Lyt-2+ cells by monoclonal antibody and complement prior to in vitro sensitization. This procedure resulted in cultures highly proliferative to alloantigen with little or no lytic activity after expansion in interleukin-2 (IL-2). Subsequent cloning of lymphocytes from Lyt-1+ enriched allosensitized cultures by limiting dilution led to proliferative clones in extremely high yield, while cloning from nondepleted allosensitized cultures led to cytotoxic clones in high yield. Furthermore, conditions of high antigen and low IL-2 concentration favor the growth of proliferative cells while high IL-2 concentrations favored the growth of cytotoxic cells. These experiments indicate that selection for cytotoxic or proliferative clones may be enhanced by specific depletion of T cell subpopulations and by alteration of culture conditions.

Dose equivalent conversion factors for human organs and tissues from external radiation

The literature contains a number of tabulations of conversion factors that permit the direct computation of dose equivalent to organs and tissues of the human body for exposure from external radiation sources. Notable among these are conversion factors normalized to external field quantities for full body exposure to monoenergetic photons, full body exposure to photons and electrons from specific radionuclides, partial body exposure to X-ray photons and X-ray spectra used in diagnostic medical radiation, and full body exposure to neutrons. This article surveys the current literature and advises the reader on the scope and sources of more extensive data tabulations.

Regression of a disseminated syngeneic solid tumor by systemic transfer of lymphoid cells expanded in interleukin 2

We have studied the ability of immunized lymphoid cells expanded in IL-2 to mediate the cure of mice with localized and disseminated syngeneic lymphoma. Mice received 500 rad total-body irradiation before injection of tumor into the footpad. Mice were treated 5 d later when a palpable local tumor and disseminated metastases were present. Intravenous injection of in vivo immune lymphocytes cured 93% of all mice, significantly better than any control group (P less than 0.0005). Immune cells, secondarily sensitized to the FBL-3 tumor in vitro, also conferred significant survival benefit (P less than 0.005) when injected intravenously, curing 79% of the animals treated. When these in vitro sensitized cells were expanded in IL-2, 8-10-fold over 7 d, 93% of the animals thus treated were cured, (P less than 0.005). When these cells were grown for multiple generations in IL-2 they retained their ability to cure mice (56% cured, P less than 0.01). This is the first demonstration that intravenous injection of sensitized cells grown in long term culture in IL-2 is capable of curing mice of established local and disseminated syngeneic tumor.

Development of long-term cell lines and lymphoid clones reactive against murine and human tumors: a new approach to the adoptive immunotherapy of cancer

We have investigated the use of T-cell growth factor (TCGF) to isolate and grow, in long-term culture, lymphoid cells with immunologic reactivity directed against syngeneic murine and autologous human tumors. Splenocytes from mice immune to a methylcholanthrene-induced sarcoma were expanded in TCGF, both before and after in vitro mixed lymphocyte-tumor cultures, and expressed high levels of cytotoxicity for fresh syngeneic solid tumor cells. Cloned lines have been isolated with a high level of specific lysis for the immunizing tumor. Similar studies of cytotoxic reactivity to a syngeneic FBL-3 lymphoma have given rise to long-term cytotoxic cell lines growing in TCGF capable of curing mice with disseminated lymphoma in adoptive transfer studies. Exposure to TCGF, of human peripheral lymphoid cells from cancer-bearing patients, results in the development of cytotoxicity to autologous fresh tumor. We have used clonal analysis by limiting dilution techniques to isolate individual cloned cells with this autologous antitumor reactivity. Infusion to autologous cytotoxic cells expanded 10,000-fold in TCGF and labeled with 111In into three cancer patients resulted in cell localization initially to the lung and subsequently to the liver and spleen. The application of these techniques for the cloning and expansion of antitumor T-lymphoid cells in TCGF has offered a new approach to adoptive immunotherapy.

Generation of long-term T-lymphoid cell lines with specific cytotoxic reactivity for a syngeneic murine lymphoma

The long-term in vitro growth in T-cell growth factor (TCGF) of murine cytotoxic T-lymphoid cells directed against syngeneic tumor antigens was investigated. C57BL/6 mice were immunized to syngeneic FBL-3 lymphoma by two ip injections of irradiated FBL-3 lymphoma cells. Splenocytes from these animals were injected into mice with disseminated lethal FBL-3 tumor. The injection of cyclophosphamide (Cy) plus immunized lymphocytes significantly improved survival with cure of 53% of 38 animals. In comparison, treatment with Cy alone resulted in 0 of 31 cured and treatment with Cy plus unimmunized cells resulted in 0 of 40 cured (P less than 0.0005). These in vivo immunized lymphocytes were reexposed to FBL-3 tumor in vitro for 5 days in lectin-free TCGF (LF-TCGF). Although in vivo and in vitro sensitized lymphocytes exhibited no cytotoxicity toward fresh FBL-3 tumor cells in an 18-hour 51Cr release assay, expansion of appropriately sensitized cells in LF-TCGF resulted in significant lysis of fresh FBL-3 tumor cells. This significant lysis was specific and lysed syngeneic FBL-3 but not syngeneic MCA-103 fresh tumor targets. This maximal specific cytotoxicity was maintained for 2.5 months. A screening assay was developed that permitted rapid identification and isolation of low-frequency cytotoxic clones with reactivity specific for FBL-3 tumor. Several of these cloned cells were grown for almost 3 months with maintenance of high degrees of specific lysis (as much as 4,500 lytic U/10(6) cells). These cytotoxic lines and clones will be of value for the study of tumor-host immunologic interactions and perhaps for use in adoptive immunotherapy.

Adoptive chemoimmunotherapy of a syngeneic murine lymphoma with long-term lymphoid cell lines expanded in T cell growth factor

Recently techniques have been developed for the long-term growth of cytotoxic T-lymphoid cells in vitro with T cell growth factor (TCGF). We have investigated the use of these in vitro-expanded T cells for the immunotherapy of a disseminated syngeneic murine FBL-3 lymphoma. In this model, mice with disseminated tumor were treated on day 5 with 180 mg cytoxan/kg and then 5 h later were given lymphoid cells IP. In vivo-immunized lymphocytes resulted in significantly improved survival in three of three experiments, curing 52% of 38 animals, compared with treatment with cytoxan alone (0 of 31 cured) or cytoxan plus unimmunized cells (0 of 40 cured) (P<0.0005). In vivo-immunized lymphocytes were re-exposed to FBL-3 tumor in vitro for 5 days in complete medium (CM) or lectin-free TCGF (LF-TCGF). Both groups showed significantly improved survival in six of six experiments. Cytoxan cured 17% of 66 animals, while cytoxan plus normal lymphocytes after IVS cured 6% of 47 animals. In vivo-immunized cells resensitized in vitro to FBL-3 in CM or LF-TCGF cured 82% of 50 animals (P<0.001) and 72% of 61 animals (P<0.001), respectively. Cells from in vivo- and in vitro-sensitized lymphocytes exhibited no cytotoxicity in our in vitro 51Cr-release assay; expansion of these cells resulted in significant specific lysis of fresh FBL-3 targets. Adoptive transfer of immune lymphocytes resensitized to FBL-3 tumor in vitro and expanded in LF-TCGF conferred a significant survival benefit (P<0.001, curing 7 of 27 animals) compared with all controls. These expanded cells were then continuously grown in LF-TCGF for 2 1/2 months. Again, in vivo-immunized lymphocytes resensitized to FBL-3 tumor and expanded in LF-TCGF for 2 1/2 months cured 56% of the animals with disseminated tumor, significantly prolonging survival over that recorded in any control group (P<0.0002). Irradiation of these same cells totally abolished their efficacy. Clones were generated from IVS and continuously grown in LF-TCGF. Two of these clones were very cytotoxic for fresh FBL-3 (>4,000 lytic units/106 cells). When adoptively transferred to mice in this chemoimmunotherapy model these cytotoxic clones significantly enhanced survival over that recorded following treatment with cytoxan alone (P<0.00001), though prolongation of survival was small. Implications of these results for application of these techniques to other less antigenic tumors and human cancers are discussed.