Improving Complex Brachytherapy Efficiency in the Current Financial Climate

PURPOSE/OBJECTIVE(S)

To optimize multidisciplinary collaboration in the setting of limited resources to increase the efficiency of complex brachytherapy workflow for patients with locally advanced cervical cancer.

MATERIALS/METHODS

High Dose Rate (HDR) brachytherapy is a critical component in the treatment of women with locally advanced cervical cancer. The completion of HDR brachytherapy to provide a complete treatment of concurrent chemoradiation and brachytherapy of <56 days has been well established. A quality improvement (QI) initiative was born out of the need to accommodate an increasing volume of patients with locally advanced cervical cancer. The challenges addressed were: different location of the operating room (OR), HDR brachytherapy suite, MR scanner; Inconsistent OR days; Post-Anesthesia Care Unit (PACU)/transportation delays; Anesthesiology staffing constraints. The QI initiative required multidisciplinary collaboration. A new protocol was finalized which provided protected OR time, and changed analgesia from general anesthesia requiring prolonged monitoring in PACU, to a pre-procedural epidural with moderate sedation. Additionally, a dedicated anesthesiologist was assigned to discuss process improvement, and the medical history for these complex patients as it relates to anesthesia safety. The streamlined process allows the patients' physical time in PACU to be bypassed; a dedicated brachytherapy nurse competent in moderate sedation recovery accompanies the patient to CT simulation. An MR protocol was established with tentative slots secured. The primary metric was the change in the number of interstitial cases performed. Additional metrics included: total case time, anesthesiology delay, MR delay, and number of OR days where 2 complex cases are performed.

RESULTS

Prior to initiation of QI initiative, from 01/2022-09/2022 there were 27 cases, average 3.0/month. After implementation of QI project, from 10/2022-02/2023 there were 32 cases, average 6.4/month, a 113.3% increase. Total case time decreased from baseline 9.3 hours to average 6 hours (Range: 3.8-10.6). Anesthesiology related delays were on average 18.5 minutes (Range: -15-35). MR related delays were on average 87.6 minutes (Range: 35-275). These changes now permit the flexibility of performing 2 complex interstitial cases per day, instead of one. The average days per month where two interstitial cases are performed increased from 0.4 to 1.4.

CONCLUSION

As hospital systems continue to face economic constraints, it is critical that we leverage our existing resources in order to provide timely care to our patients. This QI initiative shows that despite the limitation in brachytherapy operations, systems can be changed through multidisciplinary collaboration to improve efficiencies and increase capacities while working within financial workforce constraints to provide optimal patient care.

Manganese-Enhanced MRI in Patients with Multiple Sclerosis

BACKGROUND AND PURPOSE

Cellular uptake of the manganese ion, when administered as a contrast agent for MR imaging, can noninvasively highlight cellular activity and disease processes in both animals and humans. The purpose of this study was to explore the enhancement profile of manganese in patients with multiple sclerosis.

MATERIALS AND METHODS

Mangafodipir is a manganese chelate that was clinically approved for MR imaging of liver lesions. We present a case series of 6 adults with multiple sclerosis who were scanned at baseline with gadolinium, then injected with mangafodipir, and followed at variable time points thereafter.

RESULTS

Fourteen new lesions formed during or shortly before the study, of which 10 demonstrated manganese enhancement of varying intensity, timing, and spatial pattern. One gadolinium-enhancing extra-axial mass, presumably a meningioma, also demonstrated enhancement with manganese. Most interesting, manganese enhancement was detected in lesions that formed in the days after mangafodipir injection, and this enhancement persisted for several weeks, consistent with contrast coming from intracellular uptake of manganese. Some lesions demonstrated a diffuse pattern of manganese enhancement in an area larger than that of both gadolinium enhancement and T2-FLAIR signal abnormality.

CONCLUSIONS

This work demonstrates the first use of a manganese-based contrast agent to enhance MS lesions on MR imaging. Multiple sclerosis lesions were enhanced with a temporal and spatial profile distinct from that of gadolinium. Further experiments are necessary to uncover the mechanism of manganese contrast enhancement as well as cell-specific uptake.

A pilot study of recombinant insulin-like growth factor-I in seven multiple sclerosis patients

The purpose of this open-label, crossover study was to determine the safety and efficacy of recombinant insulin-like growth factor-I (rhIGF-I) using magnetic resonance imaging (MRI) and clinical measures of disease activity in seven multiple sclerosis (MS) patients. Monthly clinical and MRI examinations were performed during a 24-week baseline and a 24-week treatment period with rhIGF-I. The primary outcome measure was contrast enhancing lesion (CEL) frequency on treatment compared to baseline. Secondary outcome measures included clinical and MRI measures of disease activity including. white matter lesion load (WMLL), magnetization transfer ratio (MTR), TI-Hypointensity volume, cervical spine cross-sectional area and proton magnetic resonance spectroscopic (MRS) imaging for determining regional metabolite ratios. rhIGF-I (Cephalon) was administered at a dose of 50 mg subcutaneously twice a day for 6 months. rhIGF-I was safe and well tolerated with no severe adverse reactions. There was no significant difference between baseline and treatment periods for any MRI or clinical measures of disease activity. Although rhIGF-I did not alter the course of disease in this small cohort of MS patients, the drug was well tolerated. Further studies using rhIGF-I alone or in combination with other therapies may be of value because of the proposed mechanism of action of this growth factor on the oligodendrocyte and remyelination. Multiple Sclerosis (2002)8,24-29

Intrathecal effects of daclizumab treatment of multiple sclerosis

OBJECTIVES

We previously reported that daclizumab, a humanized monoclonal antibody against CD25, reduced contrast-enhancing lesions (CEL) in patients with multiple sclerosis (MS) who were suboptimal responders to interferon-β and that this response correlated with expansion of CD56(bright) NK cells. These data have been reproduced in a placebo-controlled multicenter trial (CHOICE study). The current study investigates whether daclizumab monotherapy reduces CEL in untreated patients with relapsing-remitting MS (RRMS) and the effects of daclizumab on the intrathecal immune system.

METHODS

Sixteen patients with RRMS with high inflammatory activity were enrolled in an open-label, baseline-vs-treatment, phase II trial of daclizumab monotherapy for 54 weeks and followed by serial clinical and MRI examinations and immunologic biomarkers measured in the whole blood and CSF.

RESULTS

The trial achieved predefined outcomes. There was an 87.7% reduction in brain CEL (primary) and improvements in Multiple Sclerosis Functional Composite (secondary), Scripps Neurologic Rating Scale, and Expanded Disability Status Scale (tertiary) outcomes. There was significant expansion of CD56(bright) NK cells in peripheral blood and CSF, with resultant decrease in T cells/NK cells and B cells/NK cells ratios and IL-12p40 in the CSF. Surprisingly, CD25 Tac epitope was equally blocked on the immune cells in the CSF and in peripheral blood.

CONCLUSIONS

Daclizumab monotherapy inhibits formation of MS plaques in patients with RRMS and immunoregulatory NK cells may suppress activation of pathogenic immune responses directly in the CNS compartment.

CLASSIFICATION OF EVIDENCE

The study provides Class III evidence that daclizumab reduces the number of contrast-enhancing lesions in treatment-naive patients with RRMS over a 54-week period.

Phase 1 pharmacokinetic and pharmacodynamic study of the histone deacetylase inhibitor MS-275 in combination with 13-cis retinoic acid in patients with advanced solid tumors

3055

Background: Preclinical studies suggest that histone deacetylase (HDAC) inhibitors may restore tumor sensitivity to retinoids. The objective of this study was to determine the maximum-tolerated dose (MTD), the dose-limiting toxicity (DLT), and the pharmacokinetic (PK)/pharmacodynamic (PD) profiles of the HDAC inhibitor MS-275 in combination with 13-cis retinoic acid (CRA). Methods: Patients (pts) with advanced solid tumors were treated with MS-275 orally once weekly and CRA orally twice daily x 3 weeks every 4 weeks. The starting dose for MS-275 was 4 mg/m2 and the dose was escalated based on toxicity assessments. The fixed dose for CRA was 1 mg/kg/day. PK concentrations of MS-275 and CRA were determined by LC/MS/MS. Western Blot analysis on peripheral-blood mononuclear cells (PBMCs) and tumor samples (when feasible) were performed to evaluate target inhibition. Results: To date thirteen pts have been enrolled. Tumor types include prostate (4 pts), bladder and renal cell (2 pts), and others. The MTD was exceeded at the 5 mg/m2 dose level (G3 hyponatremia, neutropenia and anemia). Fatigue (G1 or G2) is a common side effect. MS-275 peak concentrations were 141.6±75.7ng/mL at 4mg/m2 and 139.5±30.9 ng/mL at 5mg/m2. MS-275 half-life and clearance were 108.2±47.9h and 9.4±6.0L/h/m2, which is consistent with prior reports for MS-275 as single agent. Median CRA steady-state trough levels were 182.4 ng/mL. The MTD was 4 mg/m2 MS-275 and 1 mg/kg CRA. Five pts remained on treatment for ≥ 4 months including pts with prostate cancer (3), pancreatic cancer (6 months) and a pt with renal cell carcinoma (12 months) who presented a partial response in the lungs. Histones isolated from PBMCs showed transient but consistent protein acetylation post-therapy. Tumor biopsy of a liver lesion from prostate carcinoma revealed post-therapy induced histone acetylation and decreased phosphorylated ERK and STAT3 protein expression consistent with HDAC inhibitory activity. Conclusions: Combination of MS-275 with CRA is reasonably well tolerated and 4 mg/m2 is the Phase II recommended dose for MS-275 in combination with CRA. Tumor response and PD data suggest clinical and biological activity for this combination strategy.

[Table: see text]

Interferon beta-1b in secondary progressive MS: a combined analysis of the two trials

BACKGROUND

A European (EU) and a North American (NA) placebo-controlled study with interferon beta-1b (IFNB-1b) in secondary progressive multiple sclerosis (SPMS) showed divergent results with regard to their primary outcome of sustained Expanded Disability Status Scale (EDSS) progression, while effects were similar on relapse and MRI-related endpoints. Reasons for this discrepancy were explored in the combined dataset.

METHODS

Baseline characteristics and variability in EDSS assessments were compared. Retrospective combined analyses for time to confirmed progression were performed to assess treatment effects overall and in subgroups defined by pre-study disease activity criteria and other key baseline variables.

RESULTS

The variance of EDSS measurements was 6.5% higher in the NA-SPMS study. The EU study included patients in an earlier phase of SPMS and with more active disease both pre-study (relapses, MRI) as well as on study (EDSS, relapses, and MRI variables as assessed in the placebo groups). The pooled analysis showed an overall risk reduction by about 20% in patients treated with 8 MIU (250 mcg) IFNB-1b for EDSS progression confirmed at 6 months (p = 0.008). Risk reduction by 30% to 40% was found for patients with at least one relapse or change in EDSS by >1 in the 2 years prior to study entry. No other consistent across-studies relation of clinical and MRI variables at baseline to potential treatment response was found.

CONCLUSIONS

Although post hoc, this combined analysis of the two large studies with IFNB-1b in secondary progressive multiple sclerosis suggests that both pronounced disability progression and continuing relapse activity might help in identifying those patients in the secondary progressive phase of the disease who are more likely to benefit from treatment.

The role of radiotracer imaging in Parkinson disease

Radiotracer imaging (RTI) of the nigrostriatal dopaminergic system is a widely used but controversial biomarker in Parkinson disease (PD). Here the authors review the concepts of biomarker development and the evidence to support the use of four radiotracers as biomarkers in PD: [18F]fluorodopa PET, (+)-[11C]dihydrotetrabenazine PET, [123I]beta-CIT SPECT, and [18F]fluorodeoxyglucose PET. Biomarkers used to study disease biology and facilitate drug discovery and early human trials rely on evidence that they are measuring relevant biologic processes. The four tracers fulfill this criterion, although they do not measure the number or density of dopaminergic neurons. Biomarkers used as diagnostic tests, prognostic tools, or surrogate endpoints must not only have biologic relevance but also a strong linkage to the clinical outcome of interest. No radiotracers fulfill these criteria, and current evidence does not support the use of imaging as a diagnostic tool in clinical practice or as a surrogate endpoint in clinical trials. Mechanistic information added by RTI to clinical trials may be difficult to interpret because of uncertainty about the interaction between the interventions and the tracer.

Estimating cerebral atrophy in multiple sclerosis patients from various MR pulse sequences

PURPOSE

The purpose of this study was to determine how measures reflecting cerebral atrophy (CA) are influenced by pulse sequence (PS) and segmentation algorithm (SA) used in multiple sclerosis (MS) patients and healthy control (HC)s.

METHODS

Magnetic resonance imaging (MRI) scans from 10 relapsing-remitting MS (RRMS) patients and five HCs were used to determine the change in brain fractional volume (BFV) over a two-year period. T1-weighted, fluid-attenuated inversion recovery (FLAIR), and proton density (PD)/T2-weighted sequences were analysed Image segmentation to determine brain volume was performed using the following a histogram SA, an adaptive fuzzy c-means algorithm (AFCM), and an adaptive Bayesian segmentation with a K-means clustering.

RESULTS

Combinations of the SA and PS in MS patents demonstrated significant differences in the per cent change in BFV from baseline. For the combination of PS and SA the per cent change in BFV for year one and year two varied from +2.05% to - 1.6% and +0.79% to -3.11%, respectively. Analysis of the HCs data revealed fluctuations in BFV varying from +0.26% to -0.29%.

CONCLUSIONS

MRI estimates of CA are dependent on both the type of PS and SA; therefore, the choice of SA technique and PS should be consistent during an MS treatment trial. The progression of CA in MS should only be used as a secondary or tertiary outcome measure in treatment trials until a better understanding of how this measurement is affected by the disease, the image acquisition and analysis techniques.

A pilot study of recombinant insulin-like growth factor-1 in seven multiple sderosis patients

The purpose of this open-label, crossover study was to determine the safety and efficacy of recombinant insulin-like growth factor-1 (rhIGF-1) using magnetic resonance imaging (MRI) and clinical measures of disease activity in seven multiple sderosis (MS) patients. Monthly clinical and MPI examinations were performed during a 24-week baseline and a 24-week treatment period with rhIGF-1. The primary outcome measure was contrast enhancing lesion (CEL) frequency on treatment compared to baseline. Secondary outcome measures included dinical and MRI measures of disease activity including: white matter lesion load (WMLL), magnetization transfer ratio (MTR), T1-Hypointensity volume, cervical spine cross-sectional area and proton magnetic resonance spectroscopic (MRS) imaging for determining regional metabolite ratios. rhIGF-1 (Cephalon) was administered at a dose of 50 mg subcutaneously twice a day for 6 months. rhIGF-1 was safe and well tolerated with no severe adverse reactions. There was no significant difference between baseline and treatment periods for any MRI or clinical measures of disease activity. Although rhIGF-1 did not alter the course of disease in this small cohort of MS patients, the drug was well tolerated. Further studies using rhIGF-1 alone or in combination with other therapies may be of value because of the proposed mechanism of action of this growth factor on the oligodendrocyte and remyelination.

Contrast-enhanced magnetic resonance activity in relapsing remitting multiple sclerosis patients: a short term natural history study

Magnetic resonance imaging (MRI) has been used to study the history of multiple sclerosis (MS). We analyze the relationship between MRI activity in the first scan compared to the subsequent five scans, and we evaluate whether a shorter observation period of 3 months may predict the subsequent 3 months. Monthly enhanced MRI was performed in 103 relapsing remitting (RR) MS patients for 6 months. Thirty-five per cent of patients had an inactive scan on the initial examination. More than 80% of them developed MRI activity during the following 5 months. Eighteen per cent of patients had three consecutive inactive scans; 65% of them had at least one active scan on the subsequent 3 monthly MRI's. The relationship between the first scan and all subsequent scans demonstrates a clear weakening over time. Eighty-two per cent of patients had at least one active scan during the initial 3 consecutive months, the chance of becoming inactive decreased from 23% to 0% over the subsequent 3 months, according with the mean number of enhancing lesions during the first 3 months. These results suggest that neither a single scan nor a short baseline of 3 months may adequately describe the natural history of disease in an individual RRMS patient.

Therapeutic potential of phosphodiesterase-4 and -3 inhibitors in Th1-mediated autoimmune diseases

Phosphodiesterase-4 (PDE4) inhibitors have the potential to modulate immune responses from the Th1 toward the Th2 phenotype and are considered candidate therapies for Th1-mediated autoimmune disorders. However, depending on the model and cell types employed, studies of atopic individuals have come to the opposite conclusion, i.e., that PDE inhibitors may be beneficial in asthma. Using in vitro immunopharmacologic techniques we analyzed the effects of PDE4 and PDE3 inhibitors on human immune cells to address these discrepancies and broaden our understanding of their mechanism of action. Our results indicate that PDE inhibitors have complex inhibitory effects within in vivo achievable concentration ranges on Th1-mediated immunity, whereas Th2-mediated responses are mostly unaffected or enhanced. The Th2 skewing of the developing immune response is explained by the effects of PDE inhibitors on several factors contributing to T cell priming: the cytokine milieu; the type of costimulatory signal, i.e., up-regulation of CD86 and down-regulation of CD80; and the Ag avidity. The combination of PDE4 and PDE3 inhibitors expresses synergistic effects and may broaden the therapeutic window. Finally, we observed a differential sensitivity to PDE inhibition in autoreactive vs foreign Ag-specific T cells and cells derived from multiple sclerosis patients vs those derived from healthy donors. This suggests that PDE inhibition weakens the strength of the T cell stimulus and corrects the underlying disease-associated cytokine skew in T cell-mediated autoimmune disorders. These new findings broaden the understanding of the immunomodulatory actions of PDE inhibitors and underscore their promising drug profile for the treatment of autoimmune disorders.

Gene-marked autologous hematopoietic stem cell transplantation of autoimmune disease

In phase I (safety) trials, we have demonstrated the feasibility of autologous hematopoietic stem cell transplantation (HSCT) for patients with autoimmune diseases. Although this review comments on results of our phase I trials, the focus is on phase II (efficacy) trials using gene-marked autologous stem cells.

Cerebrospinal fluid somatostatin, mood, and cognition in multiple sclerosis

BACKGROUND

Cerebrospinal fluid (CSF) somatostatin (SS) levels have been shown to be decreased in multiple sclerosis (MS) during relapse as well as in disorders characterized by depression or cognitive impairment. Since MS is often associated with depression and cognitive impairment, we examined both the effect of course of illness on CSF SS as well as the variance in SS attributable to associated features (e.g., depression or cognitive impairment).

METHODS

Fifteen patients with chronic progressive MS participating in a 2-year cyclosporine trial underwent lumbar punctures for CSF SS at baseline and at 12 and 24 months. Additionally, patients were evaluated by neuropsychological testing, and physical disability and mood ratings. Baseline CSF SS levels were also obtained in a group of control subjects (n = 10).

RESULTS

At baseline, CSF SS levels were lower in MS patients than control subjects (p < .001). Decreased CSF SS at 24 months was correlated with decreased cognitive performance on several measures and was best and significantly predicted by cognitive deterioration at 24 months.

CONCLUSIONS

Our data support those from previous studies that found lower levels of CSF SS in MS during relapse and suggest that changes in CSF SS are related to the process responsible for diminished cognitive function in MS.

Monitoring relapsing remitting MS patients

The availability of safe and partially effective disease modifying therapies necessitates changes in how neurologists monitor patients with relapsing remitting multiple sclerosis (RRMS). Neurologists need to make the diagnosis of MS as soon as possible to be able to initiate therapy early in the course of disease. In deciding whom to treat, neurologists should consider information on disease activity and burden acquired from the neurologic history and examination and magnetic resonance imaging (MRI). Patients not on a disease modifying therapy should undergo yearly clinical assessments and periodic cerebral MRI to monitor for changes in disease activity. Patients on disease modifying therapy should undergo regular clinical assessments to monitor for side-effects and disease activity. Cerebral MRI scanning may also be useful in assessing patients on therapy, particularly when considering changes in therapy.

Mature T lymphocyte apoptosis--immune regulation in a dynamic and unpredictable antigenic environment

Apoptosis of mature T lymphocytes preserves peripheral homeostasis and tolerance by countering the profound changes in the number and types of T cells stimulated by diverse antigens. T cell apoptosis occurs in at least two major forms: antigen-driven and lymphokine withdrawal. These forms of death are controlled in response to local levels of IL-2 and antigen in a feedback mechanism termed propriocidal regulation. Active antigen-driven death is mediated by the expression of death cytokines such as FasL and TNF. These death cytokines engage specific receptors that assemble caspase-activating protein complexes. These signaling complexes tightly regulate cell death but are vulnerable to inherited defects. Passive lymphokine withdrawal death may result from the cytoplasmic activation of caspases that is regulated by mitochondria and the Bcl-2 protein. The human disease, Autoimmune Lymphoproliferative Syndrome (ALPS) is due to dominant-interfering mutations in the Fas/APO-1/CD95 receptor and other components of the death pathway. The study of ALPS patients reveals the necessity of apoptosis for preventing autoimmunity and allows the genetic investigation of apoptosis in humans. Immunological, cellular, and molecular evidence indicates that throughout the life of a T cell, apoptosis may be evoked in excessive, harmful, or useless clonotypes to preserve a healthy and balanced immune system.

Molecular genetic studies in lymphocyte apoptosis and human autoimmunity

Using a genetic approach, we have studied the molecular basis of human autoimmunity with special emphasis on a disease that is due to defective lymphocyte apoptosis. Recently, we and our collaborators have found that the autoimmune/lymphoproliferative syndrome (ALPS), an inherited disease of children comprising marked lymphoid hyperplasia and autoimmune manifestations, is due to abnormalities in the CD95 gene that cause defective lymphocyte apoptosis. Our recent investigations have shown that the mutations in most families with ALPS cause either global or local changes in the structure of a cytoplasmic portion of the molecule called the 'death domain'. These death domain alterations impair binding of the adapter protein FADD/MORT1 and result in a failure to activate apoptotic caspases after CD95 (Fas/APO-1) cross-linking. Mutations in apoptotic caspases may also contribute to the pathogenesis of ALPS in individuals that have no CD95 gene mutations.

Magnetic resonance techniques to monitor the long term evolution of multiple sclerosis pathology and to monitor definitive clinical trials

Magnetic resonance has provided a literal window on the brain to visualise the actual pathology of MS as it evolves in the living patient. Natural history studies disclosed that MRI visualised pathological activity was seen at 5 to 10x the rate of clinical relapses. Utilising that knowledge, systematic MRI monitoring has been used to supplement clinical monitoring to show the treatment effect in several clinical trials. This chapter explains how MR techniques can be used to further explore the evolution of in vivo pathology both in clinical trials and natural history studies.

Identification of high potency microbial and self ligands for a human autoreactive class II-restricted T cell clone

CD4+ class II-restricted T cells specific for self antigens are thought to be involved in the pathogenesis of most human autoimmune diseases and molecular mimicry between foreign and self ligands has been implicated as a possible mechanism for their activation. In this report we introduce combinatorial peptide libraries as a powerful tool to identify cross-reactive ligands for these T cells. The antigen recognition of a CD4+ T cell clone (TCC) specific for myelin basic protein peptide (MBP) (86-96) was dissected by the response to a set of 220 11-mer peptide sublibraries. Based on the results obtained with the libraries for each position of the antigen, artificial peptides were found that induced proliferative responses at much lower concentrations than MBP(86-96). In addition stimulatory ligands derived from protein sequences of self and microbial proteins were identified, some of them even more potent agonists than MBP(86-96). These results indicate that: (a) for at least some autoreactive CD4+ T cells antigen recognition is highly degenerate; (b) the autoantigen used to establish the TCC represents only a suboptimal ligand for the TCC; (c) a completely random and unbiased approach such as combinatorial peptide libraries can decrypt the spectrum of stimulatory ligands for a T cell receptor (TCR).

Modifications of peptide ligands enhancing T cell responsiveness imply large numbers of stimulatory ligands for autoreactive T cells

In this report, we demonstrate for autoreactive T cell clones that single amino acid modifications of the antigenic ligand can result in not only abrogated, decreased, or unmodified, but also increased, T cell responsiveness (superagonist ligands). We further studied the effects of combinations of multiple substitutions with different effects in single peptides. Experiments with peptides carrying multiple amino acid exchanges revealed that the final outcome of TCR ligation by a given ligand is the integration of negative, neutral, and positive effects of each single residue. In addition, the introduction of superagonist substitutions together with nonconservative modifications of primary and secondary TCR contacts resulted in stimulatory ligands. These findings indicate that: 1) the specificity of a single TCR is highly degenerate; 2) ligands exist for autoreactive T cells that have higher agonist activity than the autoantigen itself; 3) the rules to search for cross-reactive epitopes in autoimmunity should take into account that amino acids at certain positions within an antigenic peptide may exert superagonist activity and compensate for the negative effects of residues at other positions that would otherwise not be tolerated.

Modifications of peptide ligands enhancing T cell responsiveness imply large numbers of stimulatory ligands for autoreactive T cells

In this report, we demonstrate for autoreactive T cell clones that single amino acid modifications of the antigenic ligand can result in not only abrogated, decreased, or unmodified, but also increased, T cell responsiveness (superagonist ligands). We further studied the effects of combinations of multiple substitutions with different effects in single peptides. Experiments with peptides carrying multiple amino acid exchanges revealed that the final outcome of TCR ligation by a given ligand is the integration of negative, neutral, and positive effects of each single residue. In addition, the introduction of superagonist substitutions together with nonconservative modifications of primary and secondary TCR contacts resulted in stimulatory ligands. These findings indicate that: 1) the specificity of a single TCR is highly degenerate; 2) ligands exist for autoreactive T cells that have higher agonist activity than the autoantigen itself; 3) the rules to search for cross-reactive epitopes in autoimmunity should take into account that amino acids at certain positions within an antigenic peptide may exert superagonist activity and compensate for the negative effects of residues at other positions that would otherwise not be tolerated.

Clinical safety of serial monthly administrations of gadopentetate dimeglumine in patients with multiple sclerosis: implications for natural history and early-phase treatment trials

Serial contrast magnetic resonance imaging (MRI) has played an increasingly important role in understanding natural-history and early-treatment trials of multiple sclerosis patients. The purpose of this study is to determine whether the serial administration of gadopentetate dimeglumine at the conventional dose has any demonstrable effect on routine hematologic or serum chemistries. This study followed 56 patients with multiple sclerosis in a longitudinal natural-history trial using contrast-enhanced MRI scans over a four-year period between 1988 and 1993. Patients received between 3 and 53 doses of gadopentetate dimeglumine at 0.1 mmol/kg intravenously. A retrospective review of regular blood screening tests over this period identified no significant effect either on routine hematologic studies, as defined by complete blood count (hemoglobin, hematocrit, platelet and white blood cell counts, and mean corpuscular volume); standard serum chemistry studies, including electrolytes (sodium, potassium, chloride) and renal and liver function tests; or serum iron profiles. We conclude, therefore, that serial contrast-enhanced MRIs can be used safely as an outcome measure for Phase I/II evaluations of new therapies for multiple sclerosis.

A novel population of CD4+CD56+ myelin-reactive T cells lyses target cells expressing CD56/neural cell adhesion molecule

CD56 is a member of the neural cell adhesion molecule family expressed on cells of the central nervous system and also on NK cells. Previous studies suggest the involvement of CD56 in effector-to-target cell conjugation mediated by NK cells. It was shown recently that CD56 is also expressed by subpopulations of CD8+ and CD4+ T cells. The present study describes the functional characteristics of CD4+CD56+ T cell lines established from blood of multiple sclerosis patients by stimulation with myelin basic protein (MBP). CD4+CD56+, MBP-specific T cell lines were able to lyse MBP-pulsed target cells in an HLA class II-restricted fashion. At the same time, they mediated MHC-unrestricted lysis of CD56+ target cells such as CD56+ lymphoid or glial tumor cells, but not of the typical NK target, K562. A number of experimental results including separation of CD4+CD56+ T cells into CD56 high and low expressing populations, cold target inhibition, as well as killing of CD56-transfected cells indicate that homotypic CD56 interactions are involved in the MHC-unrestricted lysis. CD56 interactions are not sufficient but are required for effector/target interaction. Our findings raise the possibility that CD4+CD56+ T cells sharing properties of both typical Ag-specific Th0-like T cells and NK cells might be involved in damage of tissues expressing CD56/neural cell adhesion molecule, such as the central nervous system. Thus, we provide evidence for a novel mechanism that could lead to organ-specific autoreactivity.

A novel population of CD4+CD56+ myelin-reactive T cells lyses target cells expressing CD56/neural cell adhesion molecule

CD56 is a member of the neural cell adhesion molecule family expressed on cells of the central nervous system and also on NK cells. Previous studies suggest the involvement of CD56 in effector-to-target cell conjugation mediated by NK cells. It was shown recently that CD56 is also expressed by subpopulations of CD8+ and CD4+ T cells. The present study describes the functional characteristics of CD4+CD56+ T cell lines established from blood of multiple sclerosis patients by stimulation with myelin basic protein (MBP). CD4+CD56+, MBP-specific T cell lines were able to lyse MBP-pulsed target cells in an HLA class II-restricted fashion. At the same time, they mediated MHC-unrestricted lysis of CD56+ target cells such as CD56+ lymphoid or glial tumor cells, but not of the typical NK target, K562. A number of experimental results including separation of CD4+CD56+ T cells into CD56 high and low expressing populations, cold target inhibition, as well as killing of CD56-transfected cells indicate that homotypic CD56 interactions are involved in the MHC-unrestricted lysis. CD56 interactions are not sufficient but are required for effector/target interaction. Our findings raise the possibility that CD4+CD56+ T cells sharing properties of both typical Ag-specific Th0-like T cells and NK cells might be involved in damage of tissues expressing CD56/neural cell adhesion molecule, such as the central nervous system. Thus, we provide evidence for a novel mechanism that could lead to organ-specific autoreactivity.

Experimental immunotherapies for multiple sclerosis

Multiple sclerosis (MS) is a chronic demyelinating disease affecting the central nervous system (CNS) principally in young adults. Although its etiology is as yet unknown current evidence suggests that tissue damage is mediated by autoimmune T cells. The examination of an experimental animal model for MS, experimental allergic encephalomyelitis (EAE), has demonstrated that myelin basic protein (MBP)- or proteolipid protein (PLP)-specific T cells mediate the destruction of CNS myelin. In recent years, elegant studies in EAE have shown that encephalitogenic T cells recognize short peptides of MBP or PLP in the context of MHC/HLA-class II molecules, express a restricted number of T cell receptor (TCR) molecules and secrete interferon-gamma and tumor necrosis factor-alpha/beta. Understanding the pathogenetic steps in lesion development at the molecular level led to highly specific immunotherapies for EAE targeting each individual molecule. It has been the hope of many investigators that immunological events resembling those in EAE can be found in patients with MS and that the specific immunotherapies effective in EAE could also be applied to MS. However, to date, the evidence for a unique immunological abnormality in MS is not strong. Although MBP- and PLP-specific T cells with properties similar to those that are encephalitogenic in animals can be isolated from patients, they are not specific for MS and occur with similar frequency in controls. In addition, the variability in specificity and TCR usage has raised questions regarding the relevance of these cells in patients. The importance of the T cell responses to myelin antigens in MS may not be established until the effects of abrogating their activity through specific therapies targeting the trimolecular complex (TMC) have been demonstrated. Consequently, attention has begun to focus on modifying the biology of the MS lesion rather than targeting the initiating event at the level of the TMC, and the success of this approach is reflected by the effect of interferon-beta on lesion development in MS. The recent approval for the use of interferon-beta for the treatment of relapsing-remitting MS has raised great interest in examining novel strategies for immunotherapies in MS. The basic concepts as well as the current candidates for such new immunotherapies will be outlined in this short review.

Autocrine feedback death and the regulation of mature T lymphocyte antigen responses

Antigen-induced T cell death is an important regulatory mechanism in the peripheral immune system. Evidence suggests that this process depends on T cell growth-inducing lymphokines such as IL-2 and occurs in proportion to the degree of T cell receptor occupancy. Strong T cell receptor stimulation leads to the synthesis of death molecules such as Fas ligand and tumor necrosis factor that cause T cell suicide. We propose that T cell death under these circumstances is the culmination of a feedback control mechanism termed propriocidal regulation or autocrine feedback death that regulates the expansion of specific T cell clones under conditions of high lymphokine and antigen load. In a quasi-stochastic system such as the antigen receptor repertoire, feedback information may be essential for the appropriate regulation of peripheral immune responses. Our understanding of this feedback mechanism affords a means to manipulate antigen-specific T cell death in vivo. The application of this approach to the therapy of T cell-medicated immunological diseases is discussed.

Mattress evaluation for long-term care facilities

Patients spend more than a third of their hospital time in bed and considerably more than that if they are residents in a long-term care facility. When our facility, Fair Acres Geriatric Center, a 911-bed long-term care facility in Lima, PA, noticed increasing losses of our standard mattresses, we decided to evaluate new products. We listed very important criteria (bacteria resistance, flame retardation, self-deodorization and comfort and resiliency) and important criteria (stain resistance, cost and warranty) and then brought in three standard mattresses for our staff to evaluate. We were able to procure a mattress that met our criteria and halved our costs in the process.

Clinical and pathological features of an autosomal dominant, adult-onset leukodystrophy simulating chronic progressive multiple sclerosis

OBJECTIVE

To study the clinical and pathological features of a kindred with an adult-onset autosomal dominant leukodystrophy.

PATIENTS

Five symptomatic and nine asymptomatic at-risk members of the kindred.

INTERVENTIONS

Subjects underwent detailed histories and general and neurologic examinations. Further evaluation included electroencephalography, evoked potentials, electromyography, autonomic testing, and analysis of serum, urine, and cerebrospinal fluid. One patient underwent sural nerve biopsy and analysis. Another, previously studied patient, underwent a limited autopsy.

RESULTS

Cerebellar and pyramidal dysfunction began in the fourth and fifth decades of life; subtle autonomic symptoms were often present years earlier. Frontal lobe dysfunction and abnormalities of the central visual pathways were mild and of late onset. Sensorineural hearing loss was common. The peripheral nervous system was spared. Autopsy results of one patient revealed severe degeneration of the white matter at all levels of the neuraxis, but most prominent in the frontoparietal and cerebellar regions, with sparing of the subcortical U fibers. Histological and ultrastructural examinations failed to show evidence of a specific pathogenetic mechanism or etiology.

CONCLUSION

This disorder seems to be a distinct type of hereditary leukodystrophy, but its exact nature remains unknown.

Measles immunity in a population of healthcare workers

OBJECTIVES

To evaluate measles seroprevalence among cohorts of new employees and to evaluate vaccine responses of susceptible adult healthcare workers.

DESIGN

New employees were screened for measles susceptibility as part of employee evaluations. Anti-IgG measles antibody tests were completed on 2,473 workers. Demographic, measles history, and measles vaccination information was collected using a short questionnaire. Susceptible workers were vaccinated and screened for vaccine responses following vaccination.

RESULTS

Ninety-three workers (4%) were seronegative, and 56 (2%) were equivocal. Individuals in the youngest cohort (born after 1956) were significantly more likely to be susceptible than those in the middle cohort (born 1951 to 1956) and those in the oldest cohort (born before 1951) (P < 0.01). The middle cohort included eight (5%) of the 149 seronegative or equivocal workers. Among the members of the youngest cohort, those from the United States were more likely to be susceptible (P < 0.01) than those from outside the United States. Of the 106 vaccinated susceptible workers whose follow-up serologies were determined, 90 (85%) developed positive IgG serologies, six had equivocal results, and 10 were seronegative. Eleven of the 16 non- or hyporesponders were revaccinated and re-evaluated; nine developed low positive IgG antimeasles levels, one exhibited an equivocal response, and one failed to respond.

CONCLUSIONS

A small but important proportion of healthcare workers are susceptible to measles. Whenever feasible, measles immunity programs for healthcare workers should include workers born before 1957. Of workers born after 1956, those from outside the United States are more likely to be immune than workers from inside the United States. Using the currently available vaccine, revaccination of initial non- or hyporesponders appears to be effective.

Heat shock proteins in multiple sclerosis and other autoimmune diseases

Because of the abundance of the highly conserved heat shock proteins (hsp) in microbial pathogens and in mammalian cells, hsps have been considered candidates as target antigens in autoimmune disorders such as multiple sclerosis (MS). Consequently, this workshop examined the current understanding of the biology of hsps and discussed the evidence that they may contribute to autoimmune disease processes. This article reports the outcome of the discussion.

Measles virus-specific cellular immunity in patients with vaccine failure

The cytotoxic T-lymphocyte (CTL) response to measles virus (MV) was studied in blood samples from 13 acute- and early convalescent-phase patients with measles infection despite previous vaccination with the live-MV vaccine. MV CTL responses were also measured in six healthy peer controls who had live-MV vaccination during childhood and in five healthy adults who had a remote history of natural measles. All patients recovered from illness without complication. Acute MV infection was diagnosed on the basis of the Centers for Disease Control criteria and by measuring MV-specific immunoglobulin G (IgG) and IgM antibodies. Elevated IgG titers occurred in 80% of the patients at 1 to 2 weeks and in 100% at 4 weeks postinfection. IgM antibodies were detectable in all patient tested and were elevated in 60% of the patients at 1 to 2 weeks postinfection. The MV-specific CTL response was enhanced in 10 of the 13 patients tested, with a mean maximal lysis of 48.5% +/- 13.3%, compared with that of healthy peer controls who had had live-MV vaccinations during childhood (mean lysis, 14.6% +/- 12.9%; n = 6) and healthy adults with a remote history of natural measles (mean, 30.8% +/- 12.2%; n = 5). Three patients had low MV CTL levels at two time points following measles, with a mean lysis of 12% +/- 1.7%. It is concluded that while there is no evidence for a deficiency in the generation of cellular immunity to MV in the majority of patients with MV vaccine failure, a small number of individuals may fail to develop an enhanced T-cell response following infection.

Hydrated clearance of gadolinium-DTPA as a measurement of glomerular filtration rate

Technetium (99mTc)-diethylene triamine pentaacetic acid (DTPA) hydrated clearance studies are accurate for determining GFR but require special facilities for handling and measuring samples. We investigated the potential of a non-radioactive paramagnetic analog, Gadolinium (Gd)-diethylene triamine pentaacetic acid (DTPA), an approved NMR contrast agent, as a glomerular filtration marker. Instead of relying on the radioactivity of technetium, this test is based on the fact that gadolinium induces alterations in the NMR T1 relaxation times in blood and urine samples. Ninety patients underwent simultaneous determinations of GFR using 1 mCi of Tc-DTPA and 0.05 mmol/kg Gd-DTPA (Berlex Labs) IV. The patients were hydrated with oral and intravenous fluid. Following a one hour equilibrium period, three or four consecutive urine collections were obtained; plasma samples were acquired at the beginning and end of each approximately 20-minute interval. 99mTc-DTPA radioactivity was determined with a scintillation counter. T1 relaxation times were measured on a 10 MHz NMR spectrometer. These were converted to Gd-DTPA concentration by comparison with standard solutions. The Gd-DTPA derived GFR closely approximated the 99mTc-DTPA derived GFR which ranged from 15 to 147 ml/min. The equation and correlation coefficient of the regression line is y = 1.04 x -2.2, r = 0.94. Thus, Gd-DTPA is a safe, non-radioactive indicator of GFR that may provide an alternative renal clearance method for clinical studies of progressive renal disease and nephrotoxicity.

Copolymer-1-induced inhibition of antigen-specific T cell activation: interference with antigen presentation

Copolymer-1 (Cop-1) has been shown to inhibit in vivo development of experimental allergic encephalomyelitis (EAE) in animals and has been reported to have some therapeutic benefit in relapsing/remitting multiple sclerosis (MS). The mechanism by which Cop-1 acts in vivo is not known. The present study demonstrates that Cop-1 inhibits the in vitro response of several antigen-specific murine T cell hybridomas restricted to I-A, and to a lesser extent, I-E. The ability of human myelin basic protein (MBP)-specific T cell lines (TCL) to lyse targets in the context of three HLA-DR types associated with MS was also impaired by Cop-1. The results suggest that the observed inhibition was due to competition between Cop-1 and nominal antigen for the class II major histocompatibility complex (MHC) peptide binding site.

Computed tomography and magnetic resonance imaging in adult-onset leukodystrophy

Five clinically affected and nine at-risk members of a kindred with an autosomal dominant adult-onset leukodystrophy simulating chronic progressive multiple sclerosis were studied with computed tomography (CT) and magnetic resonance imaging (MRI). Computed tomographic scans showed white matter lucencies occurring earliest and most prominently in the frontoparietal region. The lesions were nondiscrete, diffuse, and bilaterally symmetric. These changes were more clearly visualized as areas of increased signal intensity with T2-weighted MRI. Magnetic resonance imaging also showed increased signal intensity in the brain stem, cerebellar white matter, or both of four patients. Both MRI and CT differentiated this entity from multiple sclerosis, but MRI was superior to CT in detailing the extent of white matter involvement.

Adrenergic dysfunction in hereditary adult-onset leukodystrophy

We studied the pressor response to norepinephrine infusion in patients with an autosomal dominant adult-onset leukodystrophy. We also examined cardiovascular and catecholamine responses to insulin-induced hypoglycemia. A parallel shift to the left of the norepinephrine dose response curve, in conjunction with low baseline plasma norepinephrine levels, was consistent with denervation supersensitivity, suggesting a distal lesion of sympathetic noradrenergic neurons. Absence of the epinephrine response to insulin-induced hypoglycemia indicated that autonomic neuropathy was attended by severe adrenal medullary dysfunction.

Viral antibodies in twins with multiple sclerosis

Viral antibodies to measles, rubella, corona, vaccinia, and mumps viruses in serum and CSF (and to Epstein-Barr virus in serum only) were studied in 24 twin pairs, both discordant and concordant for clinical MS. In pairs, CSF antibody titers for rubella in MS monozygotic and dizygotic twins and for vaccinia in dizygotic twins were higher than for unaffected twins. Increased CSF titers among MS twins existed for measles, rubella, and vaccinia when pairing was ignored. Among MS twins, serum rubella and measles and CSF measles antibody titers, and CSF:serum ratios for measles virus, were higher in those who were DW2 positive.

Hereditary adult-onset leukodystrophy simulating chronic progressive multiple sclerosis

We studied a large kindred with a chronic progressive neurologic disorder affecting at least 10 men and 11 women in four generations in a pattern compatible with autosomal dominant inheritance. In 20 of the affected subjects, evaluated before the availability of computerized tomography and without regard to family history, the diagnosis was multiple sclerosis. Symptoms of the neurologic disorder begin in the fourth and fifth decades and include cerebellar, pyramidal, and autonomic abnormalities. The autonomic symptoms, which involve bowel and bladder regulation and orthostatic hypotension, may be the earliest changes but are frequently disregarded. Survival for 20 years after onset is common. The CT scan is striking and shows a symmetrical decrease in white-matter density, beginning in the frontal lobes but extending to all of the centrum ovale and the cerebellar white matter. Limited pathological observation reveals gross white-matter degeneration with microscopic vacuolation, preservation of U fibers and cortical structures, and no inflammatory changes or reactive gliosis. Because of its hereditary basis, the disorder should be susceptible to genetic definition and ultimately to treatment or prevention.

Multiple sclerosis in twins

We studied 30 sets of twins in whom one or both was suspected of having multiple sclerosis (MS). In 24 pairs, a firm clinical diagnosis was made on each twin. Among these 24 pairs, 6 of 12 monozygotic twins were concordant for clinical MS, compared with 2 of 12 dizygotic twins. Of those over the age of 50, two of three monozygotic pairs were concordant, but neither of the two dizygotic twin pairs were concordant. Because ascertainment was primarily through public announcement, this series may be biased in favor of twins concordant for MS. The individuals within monozygotic concordant twin pairs exhibited wide differences in severity and age at onset of disease; the more recently affected twin tended to have a lower cerebrospinal fluid (CSF) IgG and a higher IgM level. Although the frequency of HLA-B7 and Dw2 in this twin population was high, the HLA makeup did not differ appreciably between concordant and discordant MS twins. Furthermore, the two DZ-concordant twins were HLA-nonidentical. Unexplained neurologic signs were found in three asymptomatic twins, and a high proportion of clinically normal twins had abnormalities of CSF immunoglobulins. These latter findings suggest a high incidence of subclinical MS in this population.

Familial multiple sclerosis: clinical, histocompatibility, and viral serological studies

Evaluation of presumed "multiple sclerosis families" and comparison with recently reported families has led us to the following observations: (1) Seven of our original fourteen presumptive multiple sclerosis families had to be eliminated after personal clinical evaluation of family members failed to confirm the diagnosis in a second close relative. (2) No segregation of HLA type was noted between affected and unaffected individuals in our seven bona fide multiple sclerosis families, and no consistent segregation was noted in the twenty-eight families reported elsewhere. This supports other genetic evidence that there is not a single, major gene mapping in the HLA complex which predisposes to multiple sclerosis. (3) The DW2 antigen was increased in frequency among affected members of our families, and the A3 B7 haplotype was more frequent among affected members of other families reported. But unaffected members also tended to have an increased frequency of these same antigens. (4) No relationship was noted between HLA type and antimeasles antibody titer within our families.

Protein A-peroxidase: a valluable tool for the localization of antigens

Protein A of Staphylococcus aureus has been conjugated to horseradish peroxidase and used in an indirect immunolabeling technique to visualize membrane and viral antigens. The same Protein A-peroxidase conjugate was used with antisera from five different species. Using this indirect test, membrane markers for T and B lymphocytes were labeled with a greater specificity than when peroxidase conjugated anti-immunoglobulin was used in the second step. Viral antigens on cells infected with measles, vesicular stomatitis, herpes or visna virus, respectively, were also stained in the protein A-peroxidase indirect test with a greater specificity than indirect method using anti-immunoglobulin. Paired preparations were examined in the light and electron microscope. Ultrastructural analysis showed that the protein A-peroxidase conjugate penetrated well through fixed viral membranes and resulted in fine resolution of antigenic sites.