Prospective study on the relationship between infections and multiple sclerosis exacerbations

One of the characteristics of multiple sclerosis is the unpredictable occurrence of exacerbations and remissions. These fluctuations in disease activity are related to alterations in (auto-)immune activity. Exacerbations lead to short-term morbidity, but may also influence long-term disability. This longitudinal study in 73 patients with relapsing-remitting multiple sclerosis assessed the contribution of systemic infections to the natural course of exacerbations. In addition, we analysed whether infections lead to an increase in the number of gadolinium-enhancing lesions. A total of 167 infections and 145 exacerbations were observed during 6466 patient weeks. During a predefined at-risk period (ARP) of 2 weeks before until 5 weeks after the onset of a clinical infection (predominantly upper airway infections), there was an increased risk of exacerbations (rate ratio 2.1), which is in accordance with previous studies. Exacerbations with onset during the ARP led more frequently to sustained deficit [increase of > or =1 Expanded Disability Status Scale (EDSS) point or > or =0.5 above EDSS 5.5 for >3 months] than exacerbations with onset outside the ARP, with a rate ratio of 3.8. Minor and major exacerbations were equally distributed between the ARP and non-ARP onset groups. ARP exacerbations were associated with significantly higher plasma levels of the inflammatory marker soluble intracellular adhesion molecule 1 than non-ARP exacerbations, indicating relatively enhanced immune activation during ARP relapses. Three serial MRI scans were performed after the onset of an infection over a 6-week period. There was no difference in the number of gadolinium-enhancing lesions between the three time points. In conclusion, exacerbations in the context of a systemic infection lead to more sustained damage than other exacerbations. There is no indication that this effect occurs through enhanced opening of the blood-brain barrier.

Bacterial peptidoglycan and immune reactivity in the central nervous system in multiple sclerosis

Multiple sclerosis is believed to result from a CD4+ T-cell response against myelin antigens. Peptidoglycan, a major component of the Gram-positive bacterial cell wall, is a functional lipopolysaccharide analogue with potent proinflammatory properties and is conceivably a mediator of sterile inflammation. Here we demonstrate that peptidoglycan is present within antigen-presenting cells in the brain of multiple sclerosis patients. These cells have macrophage and dendritic cell characteristics, and are immunocompetent as evidenced by co-expression of inflammatory cytokines and co-stimulatory molecules. In addition, intrathecal plasma cells specific for peptidoglycan are present in multiple sclerosis brain tissue, and antibodies binding peptidoglycan are present in CSF during active disease. Peptidoglycan may thus contribute to T- and B-cell activity during brain inflammation without a requirement for local bacterial replication.

Self reported stressful life events and exacerbations in multiple sclerosis: prospective study

OBJECTIVE

To study the relation between self reported stressful life events not related to multiple sclerosis and the occurrence of exacerbations in relapsing-remitting multiple sclerosis.

DESIGN

Longitudinal, prospective cohort study.

SETTING

Outpatient clinic of department of neurology in the Netherlands.

PARTICIPANTS

Patients aged 18-55 with relapsing-remitting multiple sclerosis, who could walk with a cane or better (score of 0-6.0 on the expanded disability status scale), and had had at least two exacerbations in 24 months before inclusion in the study. Patients with other serious conditions were excluded.

MAIN OUTCOME MEASURE

The risk of increased disease activity as measured by the occurrence of exacerbations after weeks with stressful events.

RESULTS

Seventy out of 73 included patients (96%) reported at least one stressful event. In total, 457 stressful life events were reported that were not related to multiple sclerosis. Average follow up time was 1.4 years. Throughout the study, 134 exacerbations occurred in 56 patients and 136 infections occurred in 57 patients. Cox regression analysis with time dependent variables showed that stress was associated with a doubling of the exacerbation rate (relative risk 2.2, 95% confidence interval 1.2 to 4.0, P = 0.014) during the subsequent four weeks. Infections were associated with a threefold increase in the risk of exacerbation, but this effect was found to be independent of experienced stress.

CONCLUSION

Stressful events were associated with increased exacerbations in relapsing-remitting multiple sclerosis. This association was independent of the triggering effect of infections on exacerbations of multiple sclerosis.

Epstein-Barr virus and disease activity in multiple sclerosis

OBJECTIVES

To study in relapsing-remitting (RR) multiple sclerosis (MS) whether exacerbations and brain activity as measured by magnetic resonance imaging (MRI) are associated with plasma levels of anti-Epstein Barr (EBV) antibodies and EBV DNA.

METHODS

This was a prospective study with 73 RR MS patients followed for an average of 1.7 years with frequent neurological examination and blood sampling. Antibodies to various EBV proteins were measured by ELISA and plasma EBV DNA was measured by PCR.

RESULTS

All MS patients had IgG antibodies to EBV (viral capsid antigen (VCA) and/or EBV nuclear antigen (EBNA)), irrespective whether samples were taken at stable disease or exacerbation. A significantly elevated percentage of the patients (48%) had antibodies against EBV antigens (early antigen, EA) that indicate active viral replication, compared with the age matched healthy controls (25%). Antibodies against a control herpesvirus, cytomegalovirus, were similar between the two groups. The percentage of EA positive individuals and EA titres did not differ between stable disease or exacerbation. Anti-VCA IgM was positive in three cases, unrelated to disease activity. Using a highly sensitive PCR on 51 samples taken at exacerbation visits, only three patients were found to have one timepoint with viraemia, and this viraemia was unrelated to disease activity. Of special note was the fact that anti-EA seropositive patients remained seropositive during follow up, with stable titres over time. We hypothesised that these patients may constitute a subgroup with higher disease activity, due to the triggering effect of a chronic attempt of the virus to reactivate. The EA positive group did not differ from the EA negative with respect to clinical disease activity or other characteristics. However, in the EA positive group, analysis with gadolinium enhanced MRI indicated more MRI disease activity.

CONCLUSIONS

There was no evidence for increased clinical disease activity in the subgroup of MS patients with serological signs of EBV reactivation. However, the observation that chronic EBV reactivation may be associated with increased inflammatory activity as assessed by gadolinium enhanced MRI lesions should be reproduced in a larger and independent dataset.

Prediction of anxiety and distress following diagnosis of multiple sclerosis: a two-year longitudinal study

OBJECTIVE

To investigate the course of anxiety, depression and disease-related distress of patients with multiple sclerosis (MS) and their partners in the first years after diagnosis.

METHODS

The Hospital Anxiety and Depression Scale (HADS) and Impact of Event Scale (IES) were completed at baseline, six-month, one- and two-year follow-up in 101 recently diagnosed patients and 78 partners. The Expanded Disability Status Scale (EDSS) was assessed annually.

RESULTS

Mean time since diagnosis at baseline was 7.8 (SD 6.5) months. Mean anxiety scores of patients and partners did not change during the two years of follow-up and remained higher than that observed in the general population at all assessments (P < 0.05). The high levels of disease-related distress at baseline were lower at follow-up. Of the patients and partners with high anxiety scores at baseline (HADS anxiety > or = 8), 69% also had high scores at any time during follow-up, compared to 26% in those with low baseline anxiety scores. For severe distress at follow-up, these percentages were 41 and 14%. The sensitivity and specificity of baseline anxiety screening for the prediction of high anxiety or distress scores at follow-up were 55 and 85%.

CONCLUSION

MS patients and their partners continued to have high levels of anxiety and distress in the first years after diagnosis. Screening for anxiety after diagnosis can be used to predict levels of anxiety and distress during two-year follow-up.

The reliability and validity of the PALOC-s: a post-acute level of consciousness scale for assessment of young patients with prolonged disturbed consciousness after brain injury

The objective of the study was the validation of the Post-Acute Level of Consciousness scale (PALOC-s) for use in assessing levels of consciousness of severe brain injured patients in a vegetative state or in a minimally conscious state. A cohort of 44 successively admitted patients (between 2 and 25 years of age), who were treated in an early intensive neurorehabilitation programme, were included in the study. Each patient was examined, using the Western Neuro Sensory Stimulation Profile (WNSSP) and the Disability Rating Scale (DRS), once every two weeks resulting in 327 examinations (all videotaped). To determine the reliability of the PALOC-s, six observers rated one videotape of each patient. One of the observers rated the same tapes a second time, 3-4 months later. Validity was determined by correlating 100 ratings of one observer with the scores on the WNSSP and the DRS. To determine the responsiveness of the PALOC-s, the size of change between the scores of the first and last examinations was calculated. The inter-observer correlations and agreement scores varied between .82 and .95. The intra-observer correlation and agreement scores varied between .94 and .96. Correlations with the WNSSP varied between .88 and .93, and with the DRS between .75 and .88. The responsiveness was significantly high (t=8.2), with a standardised effect size of 1.30. It is concluded that the PALOC-s is a reliable, valid, and responsive observation instrument provided it is administered after a structured assessment by an experienced and trained clinician. The PALOC-s is feasible for use in clinical management, as well as in outcome research.

Space-time clustering of multiple sclerosis cases around birth

OBJECTIVES

To investigate whether infectious events around birth and during early infancy are likely to be of relevance in MS pathogenesis.

SUBJECTS AND METHODS

Data are available from two regions in The Netherlands: Groningen (n=320) and Rotterdam (n=226). Simultaneous clustering in birth date and birth location of MS cases is tested by the methods of Mantel, Knox and Jacquez.

RESULTS

No evidence was found for a space-time interaction between place and time of birth.

CONCLUSION

Perinatal infectious events are unlikely to be a major factor in determining MS susceptibility.