Andreas Lossius

Epstein-Barr Virus in Systemic Lupus Erythematosus, Rheumatoid Arthritis and Multiple Sclerosis—Association and Causation

Epidemiological data suggest that the Epstein-Barr virus (EBV) is associated with several autoimmune diseases, such as systemic lupus erythematosus, rheumatoid arthritis and multiple sclerosis. However, it is not clear whether EBV plays a role in the pathogenesis of these diseases, and if so, by which mechanisms the virus may contribute. In this review, we discuss possible viral and immunological mechanisms that might explain associations between EBV and autoimmune diseases and whether these associations represent causes or effects of inflammation and autoimmunity.

High‐throughput sequencing of TCR repertoires in multiple sclerosis reveals intrathecal enrichment of EBV‐reactive CD8+ T cells

Epstein‐Barr virus (EBV) has long been suggested as a pathogen in multiple sclerosis (MS). Here, we used high‐throughput sequencing to determine the diversity, compartmentalization, persistence, and EBV‐reactivity of the T‐cell receptor (TCR) repertoires in MS. TCR‐β genes were sequenced in paired samples of cerebrospinal fluid (CSF) and blood from patients with MS and controls with other inflammatory neurological diseases. The TCR repertoires were highly diverse in both compartments and patient groups. Expanded T‐cell clones, represented by TCR‐β sequences >0.1%, were of different identity in CSF and blood of MS patients, and persisted for more than a year. Reference TCR‐β libraries generated from peripheral blood T cells reactive against autologous EBV‐transformed B cells were highly enriched for public EBV‐specific sequences and were used to quantify EBV‐reactive TCR‐β sequences in CSF. TCR‐β sequences of EBV‐reactive CD8+ T cells, including several public EBV‐specific sequences, were intrathecally enriched in MS patients only, whereas those of EBV‐reactive CD4+ T cells were also enriched in CSF of controls. These data provide evidence for a clonally diverse, yet compartmentalized and persistent, intrathecal T‐cell response in MS. The presented strategy links TCR sequence to intrathecal T‐cell specificity, demonstrating enrichment of EBV‐reactive CD8+ T cells in MS.

Sun exposure and multiple sclerosis risk in Norway and Italy: The EnvIMS study.

Objectives: The objective of this paper is to estimate the association between multiple sclerosis (MS) and measures of sun exposure in specific age periods in Norway and Italy. Methods: A total of 1660 MS patients and 3050 controls from Italy and Norway who participated in a multinational case-control study (EnvIMS) reported sun habits during childhood and adolescence. Results: A significant association between infrequent summer outdoor activity and increased MS risk was found in Norway and in Italy. The association was strongest between the ages of 16 and 18 years in Norway (odds ratio (OR) 1.83, 95% confidence interval (CI) 1.30–2.59), and between birth and age 5 years in Italy (OR 1.56, 95% CI 1.16–2.10). In Italy a significant association was also found during winter (OR 1.42, 95% CI 1.03–1.97). Frequent sunscreen use between birth and the age of 6 years was associated with MS in Norway (OR 1.44, 95% CI 1.08–1.93) after adjusting for outdoor activity during the same period. Red hair (OR 1.67, 95% CI 1.06–2.63) and blonde hair (OR 1.36, 95% CI 1.09–1.70) were associated with MS after adjusting for outdoor activity and sunscreen use. Conclusion: Converging evidence from different measures underlines the beneficial effect of sun exposure on MS risk.

Body size and the risk of multiple sclerosis in Norway and Italy: The EnvIMS study

Background: Obesity may be a risk factor for developing multiple sclerosis (MS). Objective: We examined if body size influences the risk of MS in a population-based, case control study. Methods: A total of 953 cases and 1717 controls from Norway and 707 cases and 1333 controls from Italy reported their body size by choosing a silhouette 1 to 9 (largest) every fifth year from age 5 to 30 and at time of study. The body size-related MS risk was defined by odds ratios (ORs) in logistic regression analyses adjusting for age, smoking and outdoor activity. Results: In Norway a large body size (silhouettes 6–9) compared to silhouette 3 increased the risk of MS, especially at age 25 (OR 2.21; 95% CI 1.09–4.46 for men and OR 1.43; 95% CI 0.90–2.27 for women). When comparing silhouette 9 to 1, we found a significant dose-response from age 10 until age 30 peaking at age 25 (sex-adjusted OR 2.83; 95% CI 1.68–4.78). The association was present for at least 15 years prior to disease onset. No significant associations were found in Italy. Conclusions: Obesity from childhood until young adulthood is a likely risk factor for MS with a seemingly stronger effect in Norway than in Italy.

Differential effects of levetiracetam, carbamazepine, and lamotrigine on reproductive endocrine function in adults.

Animal studies have shown endocrine changes after levetiracetam treatment. The present study investigated reproductive and sexual function in patients with epilepsy (aged 18-45) treated with levetiracetam (LEV: 30 men/26 women), carbamazepine (CBZ: 63 men/30 women), or lamotrigine (LTG: 37 men/40 women) monotherapy and in healthy controls (36 men/44 women). In women, no endocrine changes were observed during LEV treatment, whereas steroid hormone-binding globulin levels were greater and progesterone levels lower in women using CBZ. Dehydroepiandrosterone sulfate levels were higher and androstenedione levels lower in LTG-treated women. Arizona Sexual Experience Scale scores, which were significantly lower in females using LTG or LEV, suggesting they have better sexual function than CBZ users and controls. In men, no drug-specific hormonal pattern was observed after LEV treatment. Male patients in all treatment groups had lower androstenedione and free testosterone. Those using CBZ had lower free androgen indices and dehydroepiandrosterone sulfate levels, and higher steroid hormone-binding globulin, follicle-stimulating hormone, and luteinizing hormone levels. Arizona Sexual Experience Scale scores for men were similar in all groups. In conclusion, LEV treatment apparently has no drug-specific sexual or endocrine side effects in men or women in this age group.

Season of infectious mononucleosis and risk of multiple sclerosis at different latitudes; the EnvIMS Study.

Background: Seasonal fluctuations in solar radiation and vitamin D levels could modulate the immune response against Epstein-Barr virus (EBV) infection and influence the subsequent risk of multiple sclerosis (MS). Methods: Altogether 1660 MS patients and 3050 controls from Norway and Italy participating in the multinational case-control study of Environmental Factors In Multiple Sclerosis (EnvIMS) reported season of past infectious mononucleosis (IM). Results: IM was generally reported more frequently in Norway (p=0.002), but was associated with MS to a similar degree in Norway (odds ratio (OR) 2.12, 95% confidence interval (CI) 1.64–2.73) and Italy (OR 1.72, 95% CI 1.17–2.52). For all participants, there was a higher reported frequency of IM during spring compared to fall (p<0.0005). Stratified by season of IM, the ORs for MS were 1.58 in spring (95% CI 1.08–2.31), 2.26 in summer (95% CI 1.46–3.51), 2.86 in fall (95% CI 1.69–4.85) and 2.30 in winter (95% CI 1.45–3.66). Conclusions: IM is associated with MS independently of season, and the association is not stronger for IM during spring, when vitamin D levels reach nadir. The distribution of IM may point towards a correlation with solar radiation or other factors with a similar latitudinal and seasonal variation.

Intrathecal levels of vitamin D and IgG in multiple sclerosis

Holmøy T, Lossius A, Gundersen TE, Moen SM, Castellazzi M, Fainardi E, Casetta I. Intrathecal levels of vitamin D and IgG in multiple sclerosis. 
Acta Neurol Scand: 2012: 125: e28–e31. 
© 2011 John Wiley & Sons A/S.

Vitamin D sensitive EBNA-1 specific T cells in the cerebrospinal fluid of patients with multiple sclerosis

The pathogenesis of multiple sclerosis (MS) may involve intrathecal Epstein-Barr virus nuclear antigen-1 (EBNA-1) specific T cells susceptible to modulation by vitamin D. We established EBNA-1 reactive T cell lines from the cerebrospinal fluid (CSF) and blood of three MS patients and cloned EBNA-1 specific CD4+ T cells from two of these. T cell clones from CSF and blood displayed Th1 or Th17 phenotypes and were restricted by HLA-DR molecules, in one patient encoded by the DRB1*0403 or DRB1*1501 haplotypes. 1,25-dihydroxyvitamin D inhibited proliferation and suppressed secretion of IFN-γ and IL-17, irrespective of T cell origin and HLA restriction.

Effect of high-dose vitamin D3 supplementation on antibody responses against Epstein–Barr virus in relapsing-remitting multiple sclerosis:

Background: Elevated antibody levels against Epstein–Barr virus (EBV) and a poor vitamin D status are environmental factors that may interact in relapsing-remitting multiple sclerosis (RRMS) aetiology. Objectives: To examine effects of high-dose oral vitamin D3 supplementation on antibody levels against EBV nuclear antigen 1 (EBNA1) in RRMS. Methods: Serum 25-hydroxyvitamin D3 (25(OH)D) and immunoglobulin G antibody levels against EBNA1 (whole protein and amino acid 385–420 fragment), EBV viral capsid antigen (VCA), cytomegalovirus (CMV) and varicella zoster virus (VZV) were measured in 68 RRMS patients enrolled in a 96-week randomised double-blinded placebo-controlled clinical trial of oral vitamin D3 supplementation (20,000 IU/week) (NCT00785473). Results: The mean 25(OH)D level more than doubled in the vitamin D group and was significantly higher than in the placebo group at study conclusion (123.2 versus 61.8 nmol/L, p < 0.001). Compared to the placebo group, both anti-EBNA1 protein and fragment antibody levels decreased in the vitamin D group from baseline to week 48 (p = 0.038 and p = 0.004, respectively), but not from baseline to week 96. Vitamin D3 supplementation did not affect antibodies against VCA, CMV or VZV. Conclusion: The results indicate that high-dose oral vitamin D3 supplementation can affect humoral immune responses against the latent EBV antigen EBNA1 in RRMS.

Intrathecal BCR transcriptome in multiple sclerosis versus other neuroinflammation: Equally diverse and compartmentalized, but more mutated, biased and overlapping with the proteome

The mechanisms driving the intrathecal synthesis of IgG in multiple sclerosis (MS) are unknown. We combined high-throughput sequencing of transcribed immunoglobulin heavy-chain variable (IGHV) genes and mass spectrometry to chart the diversity and compartmentalization of IgG-producing B cells in the cerebrospinal fluid (CSF) of MS patients and controls with other neuroinflammatory diseases. In both groups, a few clones dominated the intrathecal IGHV transcriptome. In most MS patients and some controls, dominant transcripts matched the CSF IgG. The IGHV transcripts in CSF of MS patients frequently carried IGHV4 genes and had more replacement mutations compared to controls. In both groups, dominant IGHV transcripts were identified within clusters of clonally related B cells that had identical or related IGHV transcripts in the blood. These findings suggest more pronounced affinity maturation, but an equal degree of diversity and compartmentalization of the intrathecal B-cell response in MS compared to other neuroinflammatory diseases.