Pulmonary function tests in extremely low gestational age infants at one year of age

RATIONALE

Identifying neonatal and post-discharge exposures among extremely low gestational age newborns (ELGANs) that drive increased pulmonary morbidity and abnormal lung function at 1 year of age proves challenging.

OBJECTIVE

The NIH-sponsored Prematurity and Respiratory Outcomes Program (PROP), evaluated infant pulmonary function tests (iPFTs) at 1 year corrected age to determine which demographic and clinical factors are associated with abnormal lung function.

METHODS

iPFTs were performed on a PROP subcohort of 135 participants following Institutional Review Board (IRB)-approved written consent. Demographic data, Neonatal Intensive Care Unit (NICU) clinical care, and post-NICU exposures were analyzed for association with iPFTs.

MAIN RESULTS

A significant decrease in forced expiratory volume at 0.5 s (FEV_0.5 ) and/or forced expiratory flows at 75% of forced vital capacity (FEF₇₅ ), were associated with male sex and African American race. Clinical factors including longer duration of ventilatory support, exposure to systemic steroids, and weight less than the 10th percentile at 36 weeks postmenstrual age were also associated with airflow obstruction, whereas supplemental oxygen requirement and bronchopulmonary dysplasia were not. Additionally, the need for respiratory medications, technology, or hospitalizations during the first year, ascertained by a quarterly survey, were the only post-NICU factors associated with decreased FEV_0.5 and FEF₇₅ . Only 7% of infants had reversible airflow obstruction.

CONCLUSIONS

Neonatal demographic factors, respiratory support in the NICU, and a history of greater post-NICU medical utilization for respiratory disease had the strongest association with lower lung function at 1 year in ELGANs.

Bronchopulmonary dysplasia-A historical perspective

Bronchopulmonary dysplasia (BPD) was first described by Northway et al in 1967. This article describes the evolution of our understanding of the pathophysiology of BPD and the approaches to treatments of this illness developed over the past fifty years. These interventions had their roots in the understanding of the principles of the surface tension present at air-liquid interfaces, which were developed over 150 years before BPD's initial description. Improving outcomes in neonatal care have led to greater survival of preterm and very preterm infants, and to an evolution of the pathogenesis and pathology of BPD, from an illness caused primarily by barotrauma and oxygen toxicity to one of interruption of lung development. While the incidence of BPD has remained about the same in recent decades, this is because survival of infants born at lower gestational ages is increasing. Understanding of molecular, genetic and physiologic mechanisms has led to newer treatments that have mitigated some of the harmful effects of prolonged mechanical ventilation. Recognition of BPD as a chronic multi-system disease has resulted in further improvements in care after discharge from neonatal intensive care. Since many of the origins of chronic obstructive lung disease in adults are based in childhood respiratory illnesses, improving outcomes of BPD in infancy and childhood will undoubtedly lead to improved respiratory outcomes in the adults that these children will become.

Predicting neonatal outcomes in infants with giant omphalocele using prenatal magnetic resonance imaging calculated observed-to-expected fetal lung volumes

OBJECTIVE

To examine the association between prenatal magnetic resonance imaging (MRI) based observed/expected total lung volume (O/E TLV) and outcome in neonates with giant omphalocele (GO).

METHODS

Between 06/2004 and 12/2019, 67 cases with isolated GO underwent prenatal and postnatal care at our institution. MRI-based O/E TLVs were calculated based on normative data from Meyers and from Rypens and correlated with postnatal survival and morbidities. O/E TLV scores were grouped based on severity into <25% (severe), between 25% and 50% (moderate), and >50% (mild) for risk stratification.

RESULTS

O/E TLV was calculated for all patients according to Meyers nomograms and for 49 patients according to Rypens nomograms. Survival for GO neonates with severe, moderate, and mild pulmonary hypoplasia based on Meyers O/E TLV categories was 60%, 92%, and 96%, respectively (p = 0.04). There was a significant inverse association between Meyers O/E TLV and risk of neonatal morbidities (p < 0.05). A similar trend was observed with Rypens O/E TLV, but associations were less often significant likely related to the smaller sample size.

CONCLUSION

Neonatal outcomes are related to fetal lung size in isolated GO. Assessment of Meyers O/E TLV allows identification of GO fetuses at greatest risk for complications secondary to pulmonary hypoplasia.

Tolerability and efficacy of two doses of aerosolized albuterol in ventilated infants with BPD: A randomized controlled crossover trial

RATIONALE

Aerosolized albuterol is widely used, but its tolerability and efficacy in infants with severe bronchopulmonary dysplasia (sBPD) is not well established.

OBJECTIVES

To compare the tolerability and efficacy of two dose levels of aerosolized albuterol to saline placebo in infants with sBPD.

METHODS

Single-center, multiple-crossover trial in 24 ventilated very preterm infants with sBPD. Albuterol (1.25 mg, 2.5 mg) and 3 ml of normal saline were administered every 4 h during separate 24-h treatment periods assigned in random order with a 6-h washout phase between periods. The primary outcome was the absolute change (post and pretherapy) in expiratory flow at 75% of exhalation (EF75). Secondary endpoints were changes in ventilator parameters, vital signs, and heart arrhythmia.

RESULTS

Average within subject EF75 values improved with each therapy: saline placebo ( + 0.45 L/min ± 2.5, p = .04), 1.25 mg of albuterol ( + 0.70 L/min ± 2.4, p < .001), and 2.5 mg of albuterol ( + 0.38 L/min ± 2.4, p = .06). However, 1.25 mg of albuterol (0.26 L/min; 95% CI -0.19, 0.72) and 2.5 mg (-0.10 L/min; 95% CI -0.77, 0.57) produced similar changes in EF75 when compared to saline. All secondary outcomes were similar between saline and 1.25 mg of albuterol. Peak inspiratory pressure needed to deliver goal tidal volumes (7.5% relative decrease, 95% CI 2.6, 12.3) and heart rate (6.5% increase, 95% CI 2.2, 10.8) differed significantly between albuterol 2.5 mg and saline.

CONCLUSION

Albuterol at 1.25 mg and 2.5 mg, compared to aerosolized saline, did not affect EF75 in infants with sBPD receiving invasive ventilation. Greater improvement in peak inspiratory pressures with albuterol 2.5 mg suggests benefit, but close heart monitoring may be indicated.

An update on the post-NICU discharge management of bronchopulmonary dysplasia

Bronchopulmonary dysplasia (BPD) is a chronic lung disease which develops as a result of neonatal/perinatal lung injury. It is the commonest cause of chronic lung disease in infancy and the most frequent morbidity associated with prematurity. The incidence of BPD has continued to rise despite many advances in neonatal care and this increase has been attributed to the increased survival of younger and more premature babies. There have been many advances in the care of patients with early and evolving BPD, yet there is a paucity of data regarding outpatient management of patients with established BPD. There are limited adequately-powered high-quality studies/randomized controlled trials which assess commonly used therapies such as supplemental oxygen, bronchodilators, steroids and diuretics in patients with BPD, beyond short-term effects. Further research is needed to improve our understanding of the role of currently used treatments on the long-term outcomes of patients with established BPD, post-discharge from the neonatal intensive care unit.

Interobserver Reliability of the Respiratory Physical Examination in Premature Infants: A Multicenter Study

OBJECTIVE

To measure the inter-rater reliability of 7 visual and 3 auscultatory respiratory physical examination findings at 36-40 weeks' postmenstrual age in infants born less than 29 weeks' gestation. Physicians also estimated the probability that each infant would remain hospitalized for 3 months after the examination or be readmitted for a respiratory illness during that time.

STUDY DESIGN

Prospective, multicenter, inter-rater reliability study using standardized audio-video recordings of respiratory physical examinations.

RESULTS

We recorded the respiratory physical examination of 30 infants at 2 centers and invited 32 physicians from 9 centers to review the examinations. The intraclass correlation values for physician agreement ranged from 0.73 (95% CI 0.57-0.85) for subcostal retractions to 0.22 (95% CI 0.11-0.41) for expiratory abdominal muscle use. Eight (27%) infants remained hospitalized or were readmitted within 3 months after the examination. The area under the receiver operating characteristic curve for prediction of this outcome was 0.82 (95% CI 0.78-0.86). Physician predictive accuracy was greater for infants receiving supplemental oxygen (0.90, 95% CI 0.86-0.95) compared with those breathing in room air (0.71, 95% CI 0.66-0.75).

CONCLUSIONS

Physicians often do not agree on respiratory physical examination findings in premature infants. Physician prediction of short-term respiratory morbidity was more accurate for infants receiving supplemental oxygen compared with those breathing in room air.

Forced Expiratory Volume in 1 Second Variability Helps Identify Patients with Cystic Fibrosis at Risk of Greater Loss of Lung Function

OBJECTIVE

To evaluate several alternative measures of forced expiratory volume in 1 second percent predicted (FEV1 %pred) variability as potential predictors of future FEV1 %pred decline in patients with cystic fibrosis.

STUDY DESIGN

We included 13,827 patients age ≥6 years from the Epidemiologic Study of Cystic Fibrosis 1994-2002 with ≥4 FEV1 %pred measurements spanning ≥366 days in both a 2-year baseline period and a 2-year follow-up period. We predicted change from best baseline FEV1 %pred to best follow-up FEV1 %pred and change from baseline to best in the second follow-up year by using multivariable regression stratified by 4 lung-disease stages. We assessed 5 measures of variability (some as deviations from the best and some as deviations from the trend line) both alone and after controlling for demographic and clinical factors and for the slope and level of FEV1 %pred.

RESULTS

All 5 measures of FEV1 %pred variability were predictive, but the strongest predictor was median deviation from the best FEV1 %pred in the baseline period. The contribution to explanatory power (R(2)) was substantial and exceeded the total contribution of all other factors excluding the FEV1 %pred rate of decline. Adding the other variability measures provided minimal additional value.

CONCLUSIONS

Median deviation from the best FEV1 %pred is a simple metric that markedly improves prediction of FEV1 %pred decline even after the inclusion of demographic and clinical characteristics and the FEV1 %pred rate of decline. The routine calculation of this variability measure could allow clinicians to better identify patients at risk and therefore in need of increased intervention.

Prematurity and respiratory outcomes program (PROP): study protocol of a prospective multicenter study of respiratory outcomes of preterm infants in the United States

Background

With improved survival rates, short- and long-term respiratory complications of premature birth are increasing, adding significantly to financial and health burdens in the United States. In response, in May 2010, the National Institutes of Health (NIH) and the National Heart, Lung, and Blood Institute (NHLBI) funded a 5-year $18.5 million research initiative to ultimately improve strategies for managing the respiratory complications of preterm and low birth weight infants. Using a collaborative, multi-disciplinary structure, the resulting Prematurity and Respiratory Outcomes Program (PROP) seeks to understand factors that correlate with future risk for respiratory morbidity.

Methods/Design

The PROP is an observational prospective cohort study performed by a consortium of six clinical centers (incorporating tertiary neonatal intensive care units [NICU] at 13 sites) and a data-coordinating center working in collaboration with the NHLBI. Each clinical center contributes subjects to the study, enrolling infants with gestational ages 23 0/7 to 28 6/7 weeks with an anticipated target of 750 survivors at 36 weeks post-menstrual age. In addition, each center brings specific areas of scientific focus to the Program. The primary study hypothesis is that in survivors of extreme prematurity specific biologic, physiologic and clinical data predicts respiratory morbidity between discharge and 1 year corrected age. Analytic statistical methodology includes model-based and non-model-based analyses, descriptive analyses and generalized linear mixed models.

Discussion

PROP incorporates aspects of NICU care to develop objective biomarkers and outcome measures of respiratory morbidity in the <29 week gestation population beyond just the NICU hospitalization, thereby leading to novel understanding of the nature and natural history of neonatal lung disease and of potential mechanistic and therapeutic targets in at-risk subjects.

Trial registration

Clinical Trials.gov NCT01435187.

Electronic supplementary material

The online version of this article (doi:10.1186/s12887-015-0346-3) contains supplementary material, which is available to authorized users.

Continuous long-term immunomodulatory therapy in relapsing multiple sclerosis: results from the 15-year analysis of the US prospective open-label study of glatiramer acetate

The ongoing US Glatiramer Acetate (GA) Trial is the longest evaluation of continuous immunomodulatory therapy in relapsing-remitting multiple sclerosis (RRMS). The objective of this study was to evaluate up to 15 years of GA as a sole disease-modifying therapy. Two hundred and thirty-two patients received at least one GA dose since study initiation in 1991 (mITT cohort), and 100 (43%, Ongoing cohort) continued as of February 2008. Patients were evaluated every 6 months using the Expanded Disability Status Scale (EDSS). Mean GA exposures were 8.6 +/- 5.2, 4.81 +/- 3.69, and 13.6 +/- 1.3 years and mean disease durations were 17, 13, and 22 years for mITT, Withdrawn and Ongoing cohorts, respectively. For Ongoing patients, annual relapse rates (ARRs) maintained a decline from 1.12 +/- 0.82 at baseline to 0.25 +/- 0.34 per year; 57% had stable/improved EDSS scores (change < or = 0.5 points); 65% had not transitioned to secondary progressive multiple sclerosis (SPMS); 38%, 18%, and 3% reached EDSS 4, 6, and 8. For all patients on GA therapy (the mITT cohort), ARRs declined from 1.18 +/- 0.82 to 0.43 +/- 0.58 per year; 54% had stable/improved EDSS scores; 75% had not transitioned to SPMS; 39%, 23%, and 5% reached EDSS 4, 6, and 8. In conclusion, multiple sclerosis patients with mean disease duration of 22 years administering GA for up to 15 years had reduced relapse rates, and decreased disability progression and transition to SPMS. There were no long-term safety issues.

Serial combination therapy: is immune modulation in multiple sclerosis enhanced by initial immune suppression?

Background

Although the concept that an initial course of immune-suppression facilitates subsequent immune-modulation (such as Th1 to Th2 deviation) is attractive for several autoimmune diseases, such a mechanism for serial-combination therapy has never been formally demonstrated. Recently, brief mitoxantrone induction-chemotherapy followed by immune-modulation with glatiramer acetate (GA) was significantly more effective at reducing multiple sclerosis disease activity than with GA alone.

Objective

To examine whether the benefit of initial immune suppression with mitoxantrone before GA treatment is associated with more efficient immune modulation.

Methods

IgG1/IgG4 GA-reactive antibody profiles, previously established as markers of GA-induced Th2 immune-deviation, were prospectively measured in vivo in patients treated with GA alone or with mitoxantrone induction therapy followed by GA.

Results

Significant and sustained increase in IgG4 antibodies (and the anticipated reversal of the IgG1/IgG4 ratio) was seen in patients treated with GA alone. Combination therapy resulted in lesser IgG4 induction (and no reversal of IgG1/IgG4 ratio). Thus, the enhanced efficacy of mitoxantrone–GA combination regimen was associated with decreased, rather than increased, efficiency of shifting the GA-reactive IgG1/IgG4 antibody profile.

Conclusion

These results provide important insights into mechanisms of combination therapy and therapeutic strategies for autoimmune diseases.

Glatiramer acetate after mitoxantrone induction improves MRI markers of lesion volume and permanent tissue injury in MS

BACKGROUND

Glatiramer acetate (GA) therapy following brief, low-dose induction with mitoxantrone was safe and more effective than GA alone in suppressing inflammatory disease activity, as determined by a significant reduction in gadolinium (Gd)- enhancing MRI lesions, in a 15- month, randomized, single-blind study of relapsing-remitting multiple sclerosis (RRMS) patients.

OBJECTIVE

To determine whether effects on MRI markers of disease burden and tissue damage support and extend data on the benefits of mitoxantrone induction therapy before initiation of long-term GA therapy.

DESIGN/METHODS

40 RRMS patients, aged 18 to 55 years, with 1-15 Gd-enhancing lesions on screening MRI and EDSS score 0-6.5 were randomized to receive GA (20 mg/d SC), starting 2 weeks after the last of 3 monthly mitoxantrone infusions (36 mg/m2 total; n = 21), or to GA alone (20 mg/d SC; n = 19), for a total of 15 months. MRIs were obtained at baseline and months 6, 9, 12, and 15.

RESULTS

At baseline, mean (+/- SD) age was 37.2 +/- 9.7 years; disease duration, 3.5 +/- 4.8 years; EDSS score, 2.3 +/- 1.1; and number of Gd-enhancing lesions, 3.75 +/- 3.95. Reductions in Gd-enhancing lesions (RR = 0.30, 95 % CI, 0.11-0.86, p = 0.0147) and relapse activity favoring mitoxantrone- GA were accompanied by significant differences in changes in T2w lesion volume (p = 0.0139), T1w hypointense lesion volume (p = 0.0303), and proportion of Gdenhancing lesions that evolved into black holes (p = 0.0023) compared with GA alone.

CONCLUSIONS

Longterm continuous GA after brief, low-dose mitoxantrone induction is safe and more effective than GA alone. A trend toward decreased clinical disease activity was accompanied by major effects on MRI measures of disease burden and severe tissue injury.

Glatiramer acetate after mitoxantrone induction improves MRI markers of lesion volume and permanent tissue injury in MS

BACKGROUND

Glatiramer acetate (GA) therapy following brief, low-dose induction with mitoxantrone was safe and more effective than GA alone in suppressing inflammatory disease activity, as determined by a significant reduction in gadolinium (Gd)- enhancing MRI lesions, in a 15- month, randomized, single-blind study of relapsing-remitting multiple sclerosis (RRMS) patients.

OBJECTIVE

To determine whether effects on MRI markers of disease burden and tissue damage support and extend data on the benefits of mitoxantrone induction therapy before initiation of long-term GA therapy.

DESIGN/METHODS

40 RRMS patients, aged 18 to 55 years, with 1-15 Gd-enhancing lesions on screening MRI and EDSS score 0-6.5 were randomized to receive GA (20 mg/d SC), starting 2 weeks after the last of 3 monthly mitoxantrone infusions (36 mg/m2 total; n = 21), or to GA alone (20 mg/d SC; n = 19), for a total of 15 months. MRIs were obtained at baseline and months 6, 9, 12, and 15.

RESULTS

At baseline, mean (+/- SD) age was 37.2 +/- 9.7 years; disease duration, 3.5 +/- 4.8 years; EDSS score, 2.3 +/- 1.1; and number of Gd-enhancing lesions, 3.75 +/- 3.95. Reductions in Gd-enhancing lesions (RR = 0.30, 95 % CI, 0.11-0.86, p = 0.0147) and relapse activity favoring mitoxantrone- GA were accompanied by significant differences in changes in T2w lesion volume (p = 0.0139), T1w hypointense lesion volume (p = 0.0303), and proportion of Gdenhancing lesions that evolved into black holes (p = 0.0023) compared with GA alone.

CONCLUSIONS

Longterm continuous GA after brief, low-dose mitoxantrone induction is safe and more effective than GA alone. A trend toward decreased clinical disease activity was accompanied by major effects on MRI measures of disease burden and severe tissue injury.

Differential diagnosis of suspected multiple sclerosis: a consensus approach

BACKGROUND AND OBJECTIVES

Diagnosis of multiple sclerosis (MS) requires exclusion of diseases that could better explain the clinical and paraclinical findings. A systematic process for exclusion of alternative diagnoses has not been defined. An International Panel of MS experts developed consensus perspectives on MS differential diagnosis.

METHODS

Using available literature and consensus, we developed guidelines for MS differential diagnosis, focusing on exclusion of potential MS mimics, diagnosis of common initial isolated clinical syndromes, and differentiating between MS and non-MS idiopathic inflammatory demyelinating diseases.

RESULTS

We present recommendations for 1) clinical and paraclinical red flags suggesting alternative diagnoses to MS; 2) more precise definition of "clinically isolated syndromes" (CIS), often the first presentations of MS or its alternatives; 3) algorithms for diagnosis of three common CISs related to MS in the optic nerves, brainstem, and spinal cord; and 4) a classification scheme and diagnosis criteria for idiopathic inflammatory demyelinating disorders of the central nervous system.

CONCLUSIONS

Differential diagnosis leading to MS or alternatives is complex and a strong evidence base is lacking. Consensus-determined guidelines provide a practical path for diagnosis and will be useful for the non-MS specialist neurologist. Recommendations are made for future research to validate and support these guidelines. Guidance on the differential diagnosis process when MS is under consideration will enhance diagnostic accuracy and precision.

Glatiramer acetate after induction therapy with mitoxantrone in relapsing multiple sclerosis

Forty relapsing multiple sclerosis patients with 1-15 gadolinium (Gd)-enhancing lesions on screening brain magnetic resonance imaging (MRI) and Expanded Disability Status Scale (EDSS) scores 0-6.5 were randomized to receive short-term induction therapy with mitoxantrone (three monthly 12 mg/m(2) infusions) followed by 12 months of daily glatiramer acetate (GA) therapy 20 mg/day subcutaneously for a total of 15 months (M-GA, n = 21) or daily GA 20 mg/day for 15 months (GA, n = 19). MRI scans were performed at months 6, 9, 12 and 15. The primary measure of outcome was the incidence of adverse events; secondary measures included number of Gd-enhanced lesions, confirmed relapses and EDSS changes. Except age, baseline demographic characteristics were well matched in both treatment arms. Both treatments were safe and well tolerated. M-GA induction produced an 89% greater reduction (relative risk (RR) = 0.11, 95% confidence interval (CI): 0.04-0.36, p = 0.0001) in the number of Gd-enhancing lesions at months 6 and 9 and a 70% reduction (RR = 0.30, 95% CI: 0.11-0.86, p = 0.0147) at months 12 and 15 versus GA alone. Mean relapse rates were 0.16 and 0.32 in the M-GA and GA groups, respectively. Short-term immunosuppression with mitoxantrone followed by daily GA for up to 15 months was found to be safe and effective, with an early and sustained decrease in MRI disease activity.

Preemie abandonment? Multidisciplinary experts consider how to best meet preemies needs at "preterm infants: a collaborative approach to specialized care" roundtable

In June 2006, the Institute of Medicine (LoM), released a comprehensive study, Preterm Birth: Causes, Consequences, and Prevention. The report was a result of the IoM's efforts, in particular the Committee on Understanding Premature Birth and Assuring Healthy Outcomes, to better understand and prevent preterm birth and improve care for babies born prematurely. After its publication, a group of health care professionals came together in a roundtable session, "Preterm Infants: A Collaborative Approach to Specialized Care," to discuss the implications of the report. The following article captures the group's April 2007 discussion about the clinical and societal problems of preterm birth. It should be of interest to hospital administrators, pediatricians, third-party payers, policy makers, public health officials, academic researchers, funding agencies, allied health professionals, and others with a vested interest in curbing healthcare costs as well as what needs to be understood and done to safeguard the short- and long-term health of a most vulnerable population.

Interferon-beta-1a induces increases in vascular cell adhesion molecule: implications for its mode of action in multiple sclerosis

We investigated soluble vascular cell adhesion molecule-1 (sVCAM) levels and MRI lesions over 24 weeks in 15 Relapsing Remitting MS (RRMS) patients randomized prospectively to receive once-weekly (qw) IFN-beta-1a 30 mug intramuscularly (IM) (Group I, 8 patients) or three-times-weekly (tiw) IFN-beta-1a 44 mug subcutaneously (SC) (Group II, 7 patients). Both groups demonstrated a significant increase in sVCAM during treatment when compared to pre-treatment levels. Patients on IFN-beta-1a 44 mug SC tiw had a significant (p<0.0001) mean increase in sVCAM of 321.9 ng/ml which was significantly greater (p<0.0001) than with IFN-beta-1a 30 mug IM qw (68.6 ng/ml). There was a negative correlation between combined unique (CU) MRI lesions and sVCAM levels within the IFN-beta-1a 44 mug SC tiw group (slope=-0.00106, p=0.009). We postulate that the mode of action of IFN-beta therapy in MS may involve the induction of an increase in sVCAM. sVCAM could bind VLA-4 on T-cells and intercept their adhesion to the blood brain barrier (BBB). This mechanism is consistent with the observed clinical effect of IFN-beta in reducing MRI contrast enhancing lesions.

Effect of combined IFNbeta-1a and glatiramer acetate therapy on GA-specific T-cell responses in multiple sclerosis

The combined treatment with interferon beta (IFNbeta) and glatiramer acetate (GA) is of current interest in multiple sclerosis (MS). The therapeutic effect of GA in MS is believed to be mediated by GA-specific Th2 cells. IFNbeta has a significant anti-proliferative effect on GA-induced lymphoproliferation in vitro. Therefore, we examined the possibility that IFNbeta may interfere with the generation and phenotype of GA T-cell responses in MS patients receiving combined therapy. Sixty-six GA-specific T-cell lines (TCL) were generated ex vivo from five MS patients enrolled in an open-label dinical trial of combined IFNbeta/GA treatment. Controls included 83 pretreatment and 131 on-treatment GA-TCL from 11 MS patients treated with GA only, and five GA-TCL generated from four patients receiving IFNbeta-1a monotherapy. IFNgamma and IL-5 (markers of Th1 and Th2 responses, respectively) were assayed by ELISA in GA-TCL supematants. Th1/Th2 bias was defined by the IFNgamma/IL-5 level ratio ( >2 = Th1 bias, <0.5 = Th2 bias, and 0.5-2 = Th0 bias). The frequency with which GA-reactive TCL were generated was 37.0% for the patients in the combination trial compared to 33.3% in the patients receiving GA alone. The mean stimulation index of the GA-TCL was 8.41 (range 2-42) for the combination compared to a mean of 6.29 (range 2-37) for the GA-treated group--a nonsignificant difference. Mean GA-TCL IFNgamma production was significantly lower in all treatment groups compared to pretreatment IL-5 levels were enhanced in all treatment groups compared to pretreatment levels, but the change was not statistically significant. The Th1/Th0/Th2 distribution of GA-TCL was 7%/30%/63% for the GA+IFNbeta group, 8%/9%/83% for the GA group, compared to 48%/21%/31% pre-GA treatment. All five GA-TCL from the IFNbeta-1a monotherapy patients were Th2-biased. We conclude that IFNbeta-1a does not affect the generation of GA-reactive T cells in vivo. Although more Th0 G4-TCL occurred with combination therapy than with G4 treatment alone, both groups shared an overall Th2 bias. Therefore, we speculate that combined therapy is unlikely to reduce the efficacy of GA treatment in MS.

Randomized, comparative study of interferon beta-1a treatment regimens in MS: The EVIDENCE Trial

BACKGROUND

Interferon beta (IFNbeta) reduces relapses and MRI activity in relapsing-remitting MS (RRMS), with variable effects on disability. The most effective dose regimen remains controversial.

METHODS

This randomized, controlled, multicenter trial compared the efficacy and safety of IFNbeta-1a (Rebif) 44 micro g subcutaneously three times weekly (tiw), and IFNbeta-1a (Avonex) 30 micro g IM once weekly (qw) in 677 patients with RRMS. Assessors blinded to treatment performed neurologic and MRI evaluations. The primary endpoint was the proportion of patients who were relapse free at 24 weeks; the principal MRI endpoint was the number of active lesions per patient per scan at 24 weeks.

RESULTS

After 24 weeks, 74.9% (254/339) of patients receiving IFNbeta-1a 44 micro g tiw remained relapse free compared with 63.3% (214/338) of those given 30 micro g qw. The odds ratio for remaining relapse free was 1.9 (95% CI, 1.3 to 2.6; p = 0.0005) at 24 weeks and 1.5 (95% CI, 1.1 to 2.1; p = 0.009) at 48 weeks, favoring 44 micro g tiw. Patients receiving 44 micro g tiw had fewer active MRI lesions (p < 0.001 at 24 and 48 weeks) compared with those receiving 30 micro g qw. Injection-site reactions were more frequent with 44 micro g tiw (83% vs 28%, p < 0.001), as were asymptomatic abnormalities of liver enzymes (18% vs 9%, p = 0.002) and altered leukocyte counts (11% vs 5%, p = 0.003) compared with the 30 micro g qw dosage. Neutralizing antibodies developed in 25% of 44 micro g tiw patients and in 2% of patients receiving 30 micro g qw.

CONCLUSIONS

IFNbeta-1a 44 micro g subcutaneously tiw was more effective than IFNbeta-1a 30 micro g IM qw on all primary and secondary outcomes investigated after 24 and 48 weeks of treatment.

Induction of a non-encephalitogenic type 2 T helper-cell autoimmune response in multiple sclerosis after administration of an altered peptide ligand in a placebo-controlled, randomized phase II trial. The Altered Peptide Ligand in Relapsing MS Study Group

In this 'double-blind', randomized, placebo-controlled phase II trial, we compared an altered peptide ligand of myelin basic protein with placebo, evaluating their safety and influence on magnetic resonance imaging in relapsing-remitting multiple sclerosis. A safety board suspended the trial because of hypersensitivity reactions in 9% of the patients. There were no increases in either clinical relapses or in new enhancing lesions in any patient, even those with hypersensitivity reactions. Secondary analysis of those patients completing the study showed that the volume and number of enhancing lesions were reduced at a dose of 5 mg. There was also a regulatory type 2 T helper-cell response to altered peptide ligand that cross-reacted with the native peptide.

Effect of propranolol and IFN-beta on the induction of MHC class II expression and cytokine production by IFN-gamma IN THP-1 human monocytic cells

This study was undertaken to investigate the effects of propranolol, IFN-beta, and the protein kinase modulators on IFN-gamma induction of MHC class II antigen expression and cytokine production in THP-1 human monocytic cells. IFN-gamma induced expression of HLA-DR and DQ molecules and secretion of the monokines IL-1 beta and TNF-alpha in THP-1 cells in a time and dose-dependent manner. The effect of INF-gamma on class II HLA antigens was dose-dependently inhibited by IFN-beta. H-7, phloretin, staurosporine as well as GF 109203X are selective enzyme inhibitors of protein kinase C (PKC), down-regulating IFN-gamma induced MHC class II expression and cytokine production. Stimulators of PKC, like PMA, replaced IFN-gamma in the induction of monokines in THP-1 cells, whereas the addition of HA 1004 or arachidonic acid to the culture had no effect on IFN-gamma mediated changes. Blocking of phospholipase D (PLD)-derived diacylglycerol (DAG) formation by propranolol abrogated IFN-gamma increased HLA class II expression and IL-1 beta secretion, but had little effect on IFN-gamma induced TNF-alpha production. These findings appear to suggest that PLD-derived phosphatidate is not the primary source of DAG production in IFN-gamma-induced TNF-alpha secretion, but may be necessary for IFN-gamma-mediated MHC class II induction and IL-1 beta production in human monocytes, whereas phospholipase A2 may not be required for IFN-gamma activation of PKC in the process.

Glatiramer acetate blocks the activation of THP-1 cells by interferon-gamma

Glatiramer acetate (previously known as copolymer 1) is a synthetic copolymer of four amino acids that has been approved for use in the treatment of multiple sclerosis. It has been shown to suppress myelin antigen specific T cell activation by competing with these antigens at the major histocompatibility complex class II binding site and by inducing antigen specific suppressor T cells. In this study we investigated the effects of glatiramer acetate on the human monocytic cell line, THP-1, activated by lipopolysaccharide and interferon-gamma as a model for macrophages. At non-toxic concentrations of glatiramer acetate there were dose dependent reductions in the percentage of cells expressing human leukocyte DR and DQ antigen as well as in mean fluorescence intensity by flow cytometry. Production of tumor necrosis factor-alpha and the lysosomal cysteine proteinase cathepsin B were markedly inhibited, but production of interleukin-1 increased. These results suggest that glatiramer acetate might alter macrophage effector function and suggest that further studies in human monocytes and macrophages are warranted.

Effect of sinus surgery on pulmonary function in patients with cystic fibrosis

The impact of sinus surgery on the pulmonary status of cystic fibrosis patients is unknown. This retrospective study reviewed the charts of the cystic fibrosis patients presenting to our institution's cystic fibrosis center with nasal obstruction, recurrent sinusitis, and nasal polyposis. This group subsequently underwent endoscopic ethmoidectomy and antrostomy. Fourteen of the 15 patients, ages 5-24 years, received preoperative and postoperative pulmonary function testing obtained by spirometry. The data were compiled and analyzed statistically. Our results suggested no significant improvement in the pulmonary function of cystic fibrosis patients after sinus surgery.

Tracheobronchography in children

Tracheobronchography (TBG) can provide anatomic information supplementing endoscopy in evaluating complex congenital and acquired tracheal abnormalities. With the use of modern non-ionic contrast agents and flexible fiberoptic bronchoscopes, TBG can be performed safely and comfortably in children. As some tracheal lesions have a significant risk of mortality, obtaining maximum definition of the abnormality is imperative prior to attempting surgical management. Twenty-two patients underwent TBG at St. Christopher's Hospital for Children (Philadelphia) from July 1990 through June 1995. With the use of iohexol as a contrast agent, flexible bronchoscopes and adequate sedation and analgesia, without the need for intubation or general anesthesia, there were no significant complications or discomfort during or after the procedure. Techniques and illustrative radiographs are presented. TBG provides a useful adjunct to endoscopy.

Additive effects of copolymer-1 and interferon beta-1b on the immune response to myelin basic protein

Copolymer-1 (Cop-1) inhibits the T cell response to myelin basic protein (MBP), suppresses experimental autoimmune encephalomyelitis in many animal species, and was recently shown to be effective in the treatment of multiple sclerosis (MS). Interferon beta-1b (IFN-beta), an immune modulator with no antigenic specificity, is already approved for treatment of relapsing-remitting MS. We investigated the combined effect of these two agents on the cellular immune response to MBP. Antigen-specific Th1-like cell lines were generated from two healthy individuals with different MHC phenotypes. Cop-1 inhibited the proliferation of all MBP-specific lines but had no suppressive effect on tuberculin (PPD) or tetanus toxoid (TT)-specific T cell lines from either donor, while IFN-beta non-specifically reduced proliferation of all T cell lines. When combined in vitro, Cop-1 and IFN-beta had additive suppressive effects on proliferation of MBP-specific T cell lines, with 70-100% inhibition depending on the concentration of antigen. Synthesis of the pro-inflammatory cytokines interleukin-2 and IFN-gamma by MBP-specific lines was also inhibited additively (up to 100%). When antigen-presenting cells (APC) were pretreated with Cop-1, IFN-beta or both, T cell proliferation was inhibited in the same additive pattern, even though the inhibitors were not present in culture, indicating that they acted primarily through modulation of APC function. Additive effects were not found with PPD- or TT-specific cell lines. Pretreatment of APC with IFN-beta resulted in dose-dependent reduction in HLA-DR and HLA-DQ expression, which paralleled inhibition of T cell proliferation.(ABSTRACT TRUNCATED AT 250 WORDS)

Interferon beta-1b reduces interferon gamma-induced antigen-presenting capacity of human glial and B cells

Interferon (IFN) beta-1b has been shown to alter the course of multiple sclerosis and to inhibit MHC class II expression, but its effect on antigen presentation has not been examined in a functional assay (Neurology 43 (1993) 655-661). The effect of IFN beta-1b on alloantigen presentation by human antigen-presenting cells (APC) including human fetal astrocytes (HFA) and microglia was examined. The effect of IFN beta-1b on the ability of B cells to present tetanus toxoid (TT) to TT-specific T cell lines was also examined. APC were pre-treated with IFN gamma (100 units/ml), IFN beta-1b (10-2000 units/ml), or a combination of IFN gamma and IFN beta-1b for 3 days and washed thoroughly prior to culture with allogeneic peripheral blood lymphocytes (PBL) for a period of 6 days. Lymphocyte proliferation was then measured by tritiated thymidine uptake. Treatment of the APC with IFN beta-1b resulted in a reduction in the IFN gamma-enhanced alloantigen-induced T cell responses. This reduction ranged between 50 and 70%, was associated with a 30-50% reduction in HLA class II (DR) and 35-40% reduction in ICAM-1 expression on the HFA used as APC. IFN beta-1b pretreatment of B cells reduced their constitutive and IFN gamma enhanced capacity to present TT to TT-specific T cell lines by 50-80%. This was associated with a 30 +/- 11% mean reduction in class II (DR) expression and approximately 50 +/- 1% reduction in ICAM-1 expression in IFN beta-1b + IFN gamma-treated B cells compared to IFN gamma-treated B cells (mean of three experiments).(ABSTRACT TRUNCATED AT 250 WORDS)

Sulfogalactocerebroside and bis-(monoacylglyceryl)-phosphate as activators of spleen glucocerebrosidase

Sequential extraction of human spleen membranes with sodium cholate and n-butanol removes endogenous lipids and renders glucocerebrosidase activity dependent upon exogenous acidic lipids (e.g., phosphatidylserine, gangliosides) and a heat-stable activator protein (HSF). In the present report, we show that two previously untested lysosomal acidic lipids, namely sulfogalactocerebroside and bis-(monoacylglyceryl)-phosphate (BMP), also activate normal human glucocerebrosidase. In addition, sulfogalactocerebroside also markedly enhanced the activity of glucocerebrosidase isolated from a patient with type 1 (non-neuronopathic) Gaucher's disease, resulting in a specific activity which was 60-80% that of control glucocerebrosidase. Furthermore, when the sulfolipid was used as the activator, glucocerebrosidase from the type 1 patient was 30 times more active than the corresponding glucocerebrosidase from a person with type 2 (neuronopathic) Gaucher's disease. In contrast, the two BMPs, one rich in C26 saturated fatty acid and another rich in C18 unsaturated fatty acids, were relatively poor activators of both mutant glucocerebrosidases while providing excellent reconstitution of control activity.

Monoclonal gammopathy and neuropathy: myelin-associated glycoprotein reactivity and clinical characteristics

Immunoblot analysis was performed on the serum from 29 patients with polyneuropathy and monoclonal gammopathy. Nine patients had IgM spikes, and six of the nine had reactivity against myelin-associated glycoprotein (MAG) associated with a slowly progressive, predominantly sensory neuropathy. In contrast, 23 patients who lacked anti-MAG reactivity had more severe sensory motor neuropathy. Thus, IgM monoclonal gammopathy with reactivity against MAG may define a distinct clinical entity.

Induction of recurrent experimental allergic encephalomyelitis with myelin basic protein

Recurrent experimental allergic encephalomyelitis (EAE) was induced in Lewis rats by inoculation of human myelin basic protein (MBP) and complete Freund's adjuvant (CFA). The animals developed clinical disease characterized by unsteadiness, ataxic gait, and abnormal posturing of the limbs. Spontaneous remissions and relapses were noted for periods up to 120 days. Histologically there were perivascular infiltrates of mononuclear cells, especially prominent in the cerebellar white matter. There was little evidence of demyelination. This study demonstrates that relapsing EAE may be induced with MBP in the rat. Sensitization with other myelin antigens is not required, although immunity to such antigens may be necessary to induce demyelination. It is postulated that relapsing EAE may be associated with a defect in suppressor cell function.

The ultrastructure of early visna lesions

The ultrastructure of visna, a slowly progressive menigo-encephalomyelitis of sheep, was studied in animals sacrificed one month after intracerebral inoculation of visna virus. The major pathological changes, representative of those seen during the first year after infection, consist of inflammation and minor focal destructive lesions of grey and white matter. The inflammatory infiltrates, both subependymal and perivascular as well as of the choroid plexus, were composed mainly of lymphocytes and macrophages with varying numbers of plasma cells. The demyelination seen was of the secondary or Wallerian type. There was no evidence of primary demyelination. Visna virions were not seen in any of the CNS material studied. The ultrastructural findings are compatible with the view that lesions in visna may be induced by a cell-mediated immune response. However, changes characteristic of an autoimmune reaction to myelin antigens were not observed.

Pathogenesis of visna. II. Effect of immunosuppression upon early central nervous system lesions

It was hypothesized that the lesions of visna might represent an immunopathologic process. To test this hypothesis, a 1-month schedule of immunosuppressive treatment was devised, using horse anti-sheep thymocyte serum. In Hampshire sheep, this regime was shown to protect against experimental allergic encephalomyelitis, to inhibit development of tuberculin hypersensitivity, to retard rejection of skin homografts by 3 weeks, and to markedly reduce the number and mitogenic responsiveness of peripheral blood lymphocytes. Two groups of Icelandic sheep received intracerebral inoculations of visna virus, and one group was treated with horse antisheep thymocyte serum supplemented by a short terminal course of cyclophosphamide. Central nervous system lesions were seen in only one of eight suppressed animals at sacrifice 25 days after infection, whereas definite lesions were present in eight of eight infected control animals. The frequency of central nervous system virus isolation was similar in the two groups, indicating that treatment suppressed the cellular proliferative response without preventing the central nervous system phase of infection. Sheep receiving horse antisheep thymocyte serum had a reduced number of virus isolations from peripheral lymphoid tissue, presumably reflecting the lympholytic effect of treatment. These observations are consistent with the immunopathologic hypothesis and suggest several different ways in which suppression could modify the immune response to visna virus.

Pathogenesis of visna. III. Immune responses to central nervous system antigens in experimental allergic encephalomyelitis and visna

Experimental allergic encephalomyelitis (EAE) was induced in sheep in pursuit of the hypothesis that an immune response against central nervous system antigens might play a role in the pathogenesis of visna. Nine to 12 days after sensitization with whole sheep brain and complete Freund's adjuvant, approximately 50% of sheep developed a fulminating lethal form of EAE. Following a second sensitization, another 20% of animals developed EAE whereas a residual 30% failed to develop any signs or histologic evidence of disease. A histologic comparison of EAE and visna indicated considerable similarity in the nature of the pathologic process. However, the distribution of lesions was quite different, suggesting cellular responses to two different antigens, Cell-mediated immunity to myelin basic protein, as measured by lymphocyte blast transformation, was minimally elevated in sheep sensitized with whole brain suspension in complete Freund's adjuvant, whereas no response could be detected in visna-infected sheep. Complement-fixing antibody titers to basic protein and to a lipid antigen of brain, probably galactocerebroside, rose briskly after sensitization. In visna-infected sheep, on the other hand, there was no increase in either antibody. A large proportion of both Hampshire and Icelandic sheep had low levels of complement-fixing antibody to central nervous system antigens prior to induction of EAE or infection with visna virus. The origin of this antibody is undetermined, but it appeared to have no effect on the course of either disease. Immunosuppression of sheep with antilymphoid serum prevented induction of EAE. Acute EAE was, thus, successfully induced in sheep and used as a model to measure immune responses to central nervous system antigens and as an index of immunosuppression. However, these comparative studies did not provide any evidence for the role of an autoimmune response, to the two central nervous system antigens tested, in the pathogenesis of visna.

Pathogenesis of visna. I. Sequential virologic, serologic, and pathologic studies

A total of 56 Icelandic sheep were infected with visna virus by intracerebral injection of strain 1514 and the course of infection was followed for 12 months. Virus was isolated from more than 90 per cent of the animals, primarily from central nervous system and lymphoid tissues. However, titers of free infectious virus were minimal and virus isolation often required the use of tissue explants. All sheep raised serum-neutralizing and complement-fixing antibodies beginning 1 to 3 months after infection. Differences in neutralization titers against the infecting strain (1514) and a reference strain (796) suggested that antigenic drift might occur during prolonged infection. High cerebrospinal fluid neutralization titers in the spinal fluid indicated local antibody production in the central nervous system. Although the incidence of clinical disease during the 1st year of infection was less that 10 per cent, approximately 80 per cent of the sheep examined had central nervous system histologic lesions of variable severity, which were marked 1 month after infection with little progression during the subsequent year. There was a striking correlation between the severity of central nervous system lesions and the frequency of virus isolations from all tissues. These observations provide detailed base line data on visna infection, suggest some of the mechanisms responsible for the persistence of infection and for the slowness and irregularity of disease occurrence, and form the basis for further experiments on the role of immunologic mechanisms in the pathogenesis of this slow infection.