MRI as a marker for disease heterogeneity in multiple sclerosis.

BACKGROUND: Whereas recent data from imaging studies challenge the prevailing notion that multiple sclerosis (MS) is purely an inflammatory disease, pathologic studies suggest differences in the disease processes between individual patients with MS. The ability to dissect the pathophysiologic disease heterogeneity, if it indeed exists, by methodologies that can be applied in vivo is important both for the development of new therapeutics and for the ability to identify the optimal therapy for an individual patient. OBJECTIVE: To design a stratification algorithm for patients with MS based on accepted MRI measurements reflective of inflammation and axonal damage/tissue loss and to assess if such MS subgroups retain their intergroup differences long term. METHODS: Mathematical modeling was used to select three discriminatory MRI measures for clinical outcome based on the cross-sectional analysis of 71 patients with untreated MS and tested general applicability of the stratification scheme on the independent longitudinal cohort of 71 MS patients. RESULTS: By consecutive employment of MRI measures reflective of inflammation and tissue loss, the authors were able to separate MS patients into four clinically meaningful subgroups. The analysis of the longitudinal confirmatory cohort demonstrated persistence of the intergroup differences in selected MRI measures for 8 years. CONCLUSIONS: The inflammatory activity and destructiveness of the multiple sclerosis process are to some degree independent of each other, and the successive evaluation of both of these variables can strengthen prediction of clinical outcome in individual patients.

Optimization of the safety and efficacy of interferon beta 1b and azathioprine combination therapy in multiple sclerosis.

We conducted an open-label pilot clinical trial to evaluate the safety and efficacy of adding oral azathioprine to the treatment regimen of 15 multiple sclerosis patients breaking through monotherapy with interferon beta-1b. There were no serious adverse events. Gastrointestinal side effects and leukopenia were the most common adverse events and limited dose escalation. There was a 65% reduction in the number of gadolinium-enhanced magnetic resonance imaging (MRI) lesions on combination therapy compared to the baseline values (P =0.003). A total WBC count less than 4800/mm3 was the best predictor of MRI response.

Methylprednisolone effect on brain volume and enhancing lesions in MS before and during IFNbeta-1b.

OBJECTIVE: To determine the effect of IV methylprednisolone (IVMP) on brain fraction volume (BFV), contrast-enhancing (CE) lesions, and white matter lesion load (WMLL) in patients with relapsing-remitting MS treated for acute exacerbations. BACKGROUND: MRI metrics of MS disease activity are being used as outcome measures in early phase treatment trials, however the short-term effects of IVMP treatment on cerebral atrophy are unknown. METHODS: Serial monthly MRI were performed in 26 patients enrolled in a baseline vs treatment trial with interferon beta-1b (IFNbeta-1b) who were followed for 3 months before and after IVMP. All 26 patients were evaluated while receiving IFNbeta-1b, and 12 patients were also studied during the baseline stage of the trial (NHx). Acute exacerbations were treated with IVMP (1 g/d) for 3 to 5 days. Precontrast and postcontrast T1-weighted and proton density T2-weighted fast spin-echo images were analyzed. RESULTS: Fifty-six acute exacerbations were evaluated. For the 3 months before IVMP, there was no difference in WMLL or BFV compared to month IVMP was administered. There was a significant decrease in BFV at month 1 after IVMP in the IFNbeta-1b and NHx groups. Compared to the month IVMP was administered, there was a difference in the CE lesions for months -3 and -1 prior (p < 0.039) in NHx patients. Following IVMP, CE lesions decreased (p < 0.0004) for months 1, 2, and 3 in both groups, but there was no effect on WMLL. CONCLUSIONS: BFV and CE lesions were significantly decreased for 1 month (BFV) and 3 months (CE lesions) following IVMP. Therefore, MRI studies should be delayed by probably at least 2 months following IVMP to avoid a possible confounding steroid effect in a clinical trial.

Interferon beta-1b and intravenous methylprednisolone promote lesion recovery in multiple sclerosis.

OBJECTIVE: To determine whether lesion evolution in relapsing-remitting multiple sclerosis (RRMS) patients is altered by treatment with interferonbeta1b (IFNbeta-1b) or by intravenous methylprednisolone (IVMP) as measured by magnetization transfer imaging. METHODS: Magnetization transfer ratios (MTR) of 225 contrast enhancing lesions (CEL), in four RRMS patients were serially determined for 12 months before and 12-18 months after contrast enhancement in a baseline vs treatment trial with IFNbeta-1b. During the baseline period, 185 new CEL were identified: 76 were treated with IVMP (1 g/day x 5 days) and designated steroid CEL (S-CEL); the remaining 109 were considered baseline lesions (BCEL). During IFNbeta-1b treatment, 40 CEL (IFN-CEL) were identified. After image co-registration, regions of interest (ROIs) defining new CEL were transferred to the MTR image set to determine the mean lesion MTR on each monthly exam. The lesion MTR was compared to MTR of normal appearing white matter (NAWM) on the same exam. RESULTS: As early as 12 months prior to enhancement, the MTR of CEL was reduced compared to NAWM (mean 9.43 +/- 3.2%; P<0.001). The further reduction in MTR (28% +/- 4.0) at the time of contrast enhancement was not significantly different for BCEL, S-CEL or IFN-CEL Following enhancement, lesion recovery for IFN-CEL (P=0.02) and S-CEL (P=0.002) was significantly higher than BCEL CONCLUSION: IFNbeta-1b and IVMP reduce tissue damage and promote lesion recovery in RRMS patients. The additional benefit of IVMP compared to IFNbeta-1b may be related to its inhibitory effect on demyelination.

MRI and clinical activity in MS patients after terminating treatment with interferon beta-1b.

Monthly MRI activity and clinical disability were evaluated in two relapsing-remitting multiple sclerosis (RRMS) patients for 4 years during a cross-over treatment trial with IFNbeta-1b, and for a mean of 21 months after terminating treatment with IFNbeta-1b. Post-treatment MRI activity was compared to baseline activity in these patients. Although contrast enhancing lesions (CEL) and the bulk white matter lesion load (BWMLL) on T2-weighted images eventually returned to baseline values, there was a refractory period of 6 - 10 months after terminating treatment, before baseline MRI activity was restored. Although the mechanism for a sustained effect of IFNbeta-1b is unclear at this time, these results have important implications for enrollment of such patients into new treatment protocols that rely on contrast enhancing lesion frequency as an outcome measure.

Serial whole-brain magnetization transfer imaging in patients with relapsing-remitting multiple sclerosis at baseline and during treatment with interferon beta-1b.

BACKGROUND AND PURPOSE: To determine whether occult disease fluctuates with macroscopic lesions during the natural history of multiple sclerosis (MS) and whether therapeutic interventions affect occult disease, we performed serial monthly magnetization transfer (MT) imaging in patients with relapsing-remitting MS in a crossover trial with interferon beta-lb. METHODS: Serial whole-brain magnetization transfer ratios (MTRs) in eight patients with relapsing-remitting MS and in four control subjects were plotted as normalized histograms, and MTR parameters were compared with contrast-enhancing lesions and bulk white matter lesion load. RESULTS: In patients with relapsing-remitting MS, the histographic peak of 0.25+/-0.01 and the histographic mean of 0.21+/-0.01 were statistically lower than corresponding values in control subjects, in whom the histographic peak was 0.27+/-0.01 and the histographic mean was 0.23+/-0.01. When histograms (with MTRs ranging from 0.0 to 0.5) were analyzed by quartiles (quartile 1 to quartile 4) based on histographic area, voxels with low MTRs in quartile 1 (0 to 0.12) increased during the baseline period and corresponded to bulk white matter lesion load. Interferon beta-lb reduced enhancing lesions by 91% and mean bulk white matter lesion load by 15%, but had no effect on MTR in this patient cohort. CONCLUSION: Occult disease in normal-appearing white matter of patients with relapsing-remitting MS measured by MTR parallels the waxing and waning pattern of enhancing lesions and bulk white matter lesion load during the baseline period. MTR is not altered by interferon beta-lb, which raises the possibility of ongoing disease in normal-appearing white matter (not detected by conventional MR sequences).

ELI-spot of Th-1 cytokine secreting PBMC's in multiple sclerosis: correlation with MRI lesions.

The Th1-like cytokines, interleukin 2 (IL-2), interferon gamma (IFN-gamma), and lymphotoxin alpha (LT-alpha) have been implicated in the immunopathogenesis of multiple sclerosis (MS) and experimental allergic encephalomyelitis (EAE), an animal model of immune mediated demyelination. These cytokines have been associated with opening of the blood brain barrier (BBB) in EAE and in vitro, but not in MS. We used an enzyme-linked immunospot (ELI-spot) assay to measure relative numbers of cytokine-secreting peripheral blood mononuclear cells (PBMC) from eight MS patients who were followed with serial monthly contrast-enhanced head magnetic resonance imagings (MRI) and phlebotomy. We found a significant positive correlation between changes in IL-2 secreting cells and MRI lesions over a 6-month time period. There was a weaker association between contrast-enhancing MRI lesions and IFN-gamma or LT-alpha secreting cells. These data are the first to show a significant positive correlation between any cytokine and serial gadolinium (Gd-) MRI disease activity in MS patients. The association between IFN-gamma and LT-alpha secretion and MRI lesions is less clear.

Increased serum levels of soluble CD95 (APO-1/Fas) in relapsing-remitting multiple sclerosis.

CD95/CD95 ligand interactions are critically involved in the negative regulation of peripheral T-cell responses. Here, we report that serum levels of soluble CD95 are significantly elevated in patients with relapsing remitting multiple sclerosis. In a transectional study, CD95 levels did not correlate with clinical disability or lesion formation on magnetic resonance imaging. Longitudinally, Expanded Disability Status Scale changes were associated with high CD95 levels. Interferon-beta (IFNbeta) treatment led to an initial increase and subsequent decline of serum CD95 levels. Interestingly, patients generating neutralizing antibodies to the drug had significantly higher baseline CD95 levels before IFNbeta treatment than those without neutralizing antibodies.

Characterization of MRI response to treatment with interferon beta-1b: contrast-enhancing MRI lesion frequency as a primary outcome measure.

MRI is a valuable tool to examine the pathophysiology and natural history of multiple sclerosis (MS), and several large multicenter trials have utilized MRI as a secondary outcome measures. We previously examined the effect of interferon beta-1b on contrast-enhancing lesions on MRI using a baseline versus treatment design, and found that on treatment there is a reduction in mean frequency of enhancing lesions over the group. Using an expanded number of patients and the same trial design, we examined the individual response to treatment more extensively. We find that the effect seen previously is still present, and that there is heterogeneity in the amount of decrease in contrast-enhancing lesions. This expanded number of patients and trial design allows for the discussion of new criteria for individual response to treatment, which are applied in the current trial. These approaches may be useful in the examination, early testing, and comparison of experimental therapeutic agents in MS as well as in the characterization of patients who do or do not have a response seen on MRI.

Seasonality and pituitary volume.

Pituitary volume in humans has been reported to change size in response to experimental manipulations of photoperiod, and to be increased during an episode of non-seasonal major depression. We wanted to determine whether pituitary volume changes either across the seasons or during an episode of winter depression. Nineteen patients with winter-seasonal affective disorder and 19 sex-, age-, height-, and weight-matched controls underwent magnetic resonance imaging of the pituitary gland in both winter and summer. Images were obtained using 0.7-mm contiguous slices and the areas of all slices were summed to compute the final volume for each gland. We found no main effects or interactions involving either diagnosis or season in our primary analysis. In a post-hoc analysis, we found a trend towards a season x gender effect (P = 0.06), such that pituitary volume increased slightly (+4.0%) across seasons in women, whereas it decreased slightly (-4.3%) across seasons in men. The results suggest that neither winter depression nor the change of seasons is associated with a significant change in pituitary size.

Interferon beta results in immediate reduction of contrast-enhanced MRI lesions in multiple sclerosis patients followed by weekly MRI.

Interferon beta-1a and -1b reduce the frequency and severity of clinical exacerbations, and reduce both T2-weighted and contrast-enhanced MRI activity in patients with multiple sclerosis (MS). Several recent reports suggest that at the initiation of treatment there may be transient worsening of symptoms associated with the induction of interferon gamma-secreting cells. We studied eight MS patients with weekly brain MRI's after starting interferon beta treatment, and found immediate reduction in the number of contrast-enhancing lesions. Several patients did experience recurrence of previous symptoms without concomitant opening of the blood brain barrier on contrast-enhanced MRI. These data suggest that the symptoms described after the initiation of interferon beta are not associated with new disease activity, but rather may be related to preexisting lesions. This has implications for both understanding the immunopathogenesis of the disease and for its treatment.

Increases in soluble VCAM-1 correlate with a decrease in MRI lesions in multiple sclerosis treated with interferon beta-1b.

Interferon beta-1b reduces clinical exacerbations and disease activity in multiple sclerosis as shown by magnetic resonance imaging, but the mechanism of action is unknown. We investigated the correlation between the levels of soluble adhesion molecules and a reduction in contrast-enhancing lesions on gadopentetate dimeglumine magnetic resonance images after treatment with interferon beta-1b. We determined levels of soluble vascular cell adhesion molecule-1, intercellular adhesion molecule-1, E-selectin, L-selectin, and tumor necrosis factor receptor (60 kd) in monthly serum samples from patients with definite multiple sclerosis before and during treatment with interferon beta-1b. The level of soluble adhesion molecules was correlated with the number of newly enhancing lesions on monthly contrast-enhanced images. Levels of soluble vascular cell adhesion molecule during treatment were significantly increased compared to control or pretreatment values. The median levels (ng/ml) of this adhesion molecule were 580.3 (range; 373.0-640.7) for the healthy subjects, and 551.4 (489.7-875.5) for patients prior to treatment and 847.9 (591.5-1,232.9) during treatment. Levels of the other soluble adhesion molecules and soluble tumor necrosis factor receptor were not significantly changed during treatment. The increase in soluble vascular cell adhesion molecule correlated with a decrease in the number of contrast-enhancing lesions on magnetic resonance images. These data suggest a novel mechanism of action for interferon beta-1b by direct interference with the adhesion cascade, which may prevent activated T cells from trafficking into the central nervous system.

MRI studies of multiple sclerosis: implications for the natural history of the disease and for monitoring effectiveness of experimental therapies.

The use of magnetic resonance imaging (MRI) in multiple sclerosis (MS) has increased in our understanding of the natural history of the disease course and has provided and important tool for the analysis of new experimental therapies. Studies using MRI as well as pathological studies of MS indicate that the first event in the development of a new MS lesion as seen on T2 weighted images is disruption of the blood brain barrier (BBBD) which can be demonstrated by areas of increased signal on T1 weighted images done after the administration of gadolinium DTPA. When GdDTPA enhanced MRIs are used to monitor disease activity in patients with mild relapsing remitting MS, a considerable degree of disease activity is observed in clinically stable patients. These findings indicate that MS is an active and progressive disease in most patients even during the earliest phases of the disease and before significant clinical disability has occurred. MRI is also an important tool in evaluating new therapies. Using simple baseline vs treatment designs evidence for an effect of a new treatment on MRI parameters such as Gd-DTPA enhanced measure of BBBD can be achieved using a small study cohort and over a short duration. Together these advances should lead to more rapid progress in the understanding of MS and in identifying new treatments.

Blood-brain barrier disruption on contrast-enhanced MRI in patients with mild relapsing-remitting multiple sclerosis: relationship to course, gender, and age.

MRI has provided insight into the pathophysiology and course of MS, particularly through the use of a paramagnetic contrast agent that allows visualization of blood-brain barrier (BBB) breakdown. Neither the overall frequency of BBB breakdown in MS patients nor the characteristics associated with BBB breakdown in MS are known. We studied 68 relapsing-remitting MS (RRMS) patients with three monthly MRIs to examine these questions. Seventy-eight percent of the RRMS patients studied had evidence of BBB breakdown on at least one MRI. While there was a great deal of variability among patients in terms of mean enhancing lesion frequency, BBB breakdown was associated with younger age at onset of disease, measured by age at first symptom or age at diagnosis, and more severe disease as measured by Expanded Disability Status Scale scores equal to or greater than 4.0. We found no relationship between BBB breakdown and duration of disease or gender. We conclude that BBB breakdown is a relatively common phenomenon in RRMS patients and may be most commonly found in patients with more aggressive disease and younger onset. These findings have implications for clinical trials that use MRI as an outcome measure.