Aiden Haghikia

TNF receptor 1 genetic risk mirrors outcome of anti-TNF therapy in multiple sclerosis.

Although there has been much success in identifying genetic variants associated with common diseases using genome-wide association studies (GWAS), it has been difficult to demonstrate which variants are causal and what role they have in disease. Moreover, the modest contribution that these variants make to disease risk has raised questions regarding their medical relevance. Here we have investigated a single nucleotide polymorphism (SNP) in the TNFRSF1A gene, that encodes tumour necrosis factor receptor 1 (TNFR1), which was discovered through GWAS to be associated with multiple sclerosis (MS), but not with other autoimmune conditions such as rheumatoid arthritis, psoriasis and Crohn’s disease. By analysing MS GWAS data in conjunction with the 1000 Genomes Project data we provide genetic evidence that strongly implicates this SNP, rs1800693, as the causal variant in the TNFRSF1A region. We further substantiate this through functional studies showing that the MS risk allele directs expression of a novel, soluble form of TNFR1 that can block TNF. Importantly, TNF-blocking drugs can promote onset or exacerbation of MS, but they have proven highly efficacious in the treatment of autoimmune diseases for which there is no association with rs1800693. This indicates that the clinical experience with these drugs parallels the disease association of rs1800693, and that the MS-associated TNFR1 variant mimics the effect of TNF-blocking drugs. Hence, our study demonstrates that clinical practice can be informed by comparing GWAS across common autoimmune diseases and by investigating the functional consequences of the disease-associated genetic variation.

Treatment of Progressive Multifocal Leukoencephalopathy Associated with Natalizumab

We describe the clinical and therapeutic course of a 52-year-old patient with multiple sclerosis in whom progressive multifocal leukoencephalopathy (PML) developed after 12 months of therapy with natalizumab. The patient was hospitalized 2 months after the onset of neurologic and psychiatric symptoms and was treated with plasma exchange and immunoadsorption to eliminate natalizumab. After a brief improvement, he became critically ill with an apparent episode of immune reconstitution inflammatory syndrome. Steroid-pulse therapy led to stabilization of the patients condition and clinically significant recovery. This case illustrates that prompt diagnosis and treatment may improve the outcome in patients with severe PML associated with natalizumab therapy.

Dietary Fatty Acids Directly Impact Central Nervous System Autoimmunity via the Small Intestine

Growing empirical evidence suggests that nutrition and bacterial metabolites might impact the systemic immune response in the context of disease and autoimmunity. We report that long-chain fatty acids (LCFAs) enhanced differentiation and proliferation of T helper 1 (Th1) and/or Th17 cells and impaired their intestinal sequestration via p38-MAPK pathway. Alternatively, dietary short-chain FAs (SCFAs) expanded gut T regulatory (Treg) cells by suppression of the JNK1 and p38 pathway. We used experimental autoimmune encephalomyelitis (EAE) as a model of T cell-mediated autoimmunity to show that LCFAs consistently decreased SCFAs in the gut and exacerbated disease by expanding pathogenic Th1 and/or Th17 cell populations in the small intestine. Treatment with SCFAs ameliorated EAE and reduced axonal damage via long-lasting imprinting on lamina-propria-derived Treg cells. These data demonstrate a direct dietary impact on intestinal-specific, and subsequently central nervous system-specific, Th cell responses in autoimmunity, and thus might have therapeutic implications for autoimmune diseases such as multiple sclerosis.

Anti-JC virus antibodies in a large German natalizumab-treated multiple sclerosis cohort

Objective: To investigate the rate of seropositivity of anti-JC virus (JCV) antibodies in a German multiple sclerosis (MS) cohort treated with natalizumab in the postmarketing setting and to assess anti-JCV serostatus in samples obtained before diagnosis of progressive multifocal leukoencephalopathy (PML). Methods: This was a blinded, retrospective cross-sectional and longitudinal analysis for anti-JCV antibodies using a confirmatory 2-step ELISA on 2,782 blood samples obtained from 2,253 patients nationwide for routine testing for anti-natalizumab antibodies during open-label treatment between 2007 and 2010. Results: Of the natalizumab-treated patients with MS, 58.8% tested positive for anti-JCV antibodies. The rate of seropositivity was higher in males and increased with age, with a plateau between age intervals 20–29 and 30–39 years. In longitudinal analyses, 19 of 194 (9.8%) patients converted from anti-JCV antibody-negative to seropositive status over 7.7 months; 4.7% reverted from antibody-positive to seronegative status over 7.9 months. Antibody levels, especially in the latter group, were low, indicating fluctuations around the lower cut point of the assay. Neither anti-JCV serostatus nor antibody levels were associated with immunosuppressive pretreatment, duration of natalizumab treatment, or anti-natalizumab antibodies. All samples obtained from 10 patients who developed PML were seropositive (13 samples before PML diagnosis [2.0–37.6 months]; 2 samples at diagnosis). Antibody levels in these samples were higher than those in samples from seropositive patients who did not develop PML. Conclusions: These data argue for the potential clinical utility of JCV serology for PML risk stratification. However, further investigations of fluctuations in serostatus and of antibody levels for a more precise understanding of the predictive value are warranted.

Pregnancy and natalizumab: results of an observational study in 35 accidental pregnancies during natalizumab treatment

Background: Natalizumab, a therapeutic monoclonal antibody approved for the treatment of relapsing–remitting multiple sclerosis (RRMS), is recommended to be withdrawn 3 months prior to a planned pregnancy. Our aim was to analyse the safety and impact of natalizumab exposure on course of disease and pregnancy outcome. Objectives: Prospective follow-up of women with MS who became accidentally pregnant during natalizumab treatment in comparison with pregnancies of women with MS not exposed to disease-modifying treatments (DMT). Method: 35 women with MS who became accidentally pregnant while treated with natalizumab, and 23 women with MS who became pregnant devoid of any DMT as a control group, were chosen. Results: All pregnancies except one were followed in a prospective fashion. Of the women exposed to natalizumab during pregnancy, 29 women gave birth to 28 healthy children; one child was born with hexadactyly. Five pregnancies ended in an early miscarriage and one woman decided to undergo an elective termination of pregnancy. MS activity did not rebound during pregnancy or post partum after natalizumab was withdrawn, and no significant differences were observed when compared with the non-DMT-exposed control group. Conclusion: Our data may support the notion that an elective termination of pregnancy due to natalizumab exposure may not be necessary, but rather requires careful monitoring. Women should still be advised to stop natalizumab in the course of planned pregnancy until more data on long-term outcomes are available.

Regulated microRNAs in the CSF of patients with multiple sclerosis A case-control study

ABSTRACT Objective: MicroRNAs (miRNAs) are small noncoding RNAs that regulate gene expression and serve as promising therapeutic targets in many diseases. MiRNAs are also present in biological fluids and may be of use as disease biomarkers. We evaluated whether miRNAs are differentially regulated in the CSF of patients with multiple sclerosis (MS). Methods: The CSF of 53 patients with MS and 39 patients with other neurologic diseases (OND) was analyzed. First, global miRNA profiling was assessed to screen for reported miRNAs, followed by quantitative reverse transcriptase PCR to validate candidate miRNAs. Results: After global miRNA profiling, we quantitatively confirmed miR-922 (p = 0.0001), miR-181c (p = 0.0007), and miR-633 (p = 0.0014) to be differentially regulated in patients with MS as compared with OND. Importantly, miR-181c and miR-633 differentiated relapsing-remitting from secondary progressive MS courses with specificity up to of 82% and a sensitivity of 69%. Conclusion: CSF-based miRNAs were differentially regulated in patients with MS as compared with OND and in different MS disease courses. Despite the preliminary character of our case-control study, the results provide rationale for a confirmation study in larger MS cohorts.

Signal transducer and activator of transcription 3-mediated regulation of miR-199a-5p links cardiomyocyte and endothelial cell function in the heart: a key role for ubiquitin-conjugating enzymes.

AIMS Mice with a cardiomyocyte (CM)-restricted knockout of signal transducer and activator of transcription 3 (STAT3-KO) develop spontaneous heart failure. We investigated the impact of STAT3-mediated regulation of microRNAs for pathophysiological alterations in the heart. METHODS AND RESULTS MicroRNAchip and qRT-PCR analysis revealed elevated cardiac expression of miR-199a in STAT3-KO mice. Lentiviral shRNA-mediated STAT3-knock-down in neonatal rat CMs markedly increased miR-199a promoter activity and miR-199a levels indicative of a suppressive effect of STAT3 on miR-199a transcription. Up-regulated miR-199a in CM by pre-miR-199a transfection (pre-miR-199a-CM) reduced expression of components of the ubiquitin-proteasome system (UPS), i.e. the ubiquitin-conjugating enzymes Ube2g1 (mRNA and protein) and Ube2i (protein). Pre-miR-199a-CM or CM with siRNA-mediated down-regulation of Ube2i and Ube2g1 (siRNA-Ube2i/2g1-CM) displayed massive down-regulation of α- and β-myosin heavy chain expression associated with disrupted sarcomere structures. In addition, protein arginine methyltransferase I (PRMT-I) expression and asymmetric dimethylarginine (ADMA) synthesis were increased in pre-miR-199a-CM or in siRNA-Ube2i/2g1-CM. Increased ADMA in cell culture supernatant (SN) from pre-miR-199a-CM or siRNA-Ube2i/2g1-CM lowered nitric oxide (NO) bioavailability of rat cardiac endothelial cells while lowering ADMA concentration in CM SNs by the PRMT inhibitor arginine methyltransferase inhibitor 1 (AMI-1) (100 µM) improved NO bioavailability. In STAT3-KO hearts Ube2i and Ube2g1 expression were markedly reduced. Human terminal failing hearts harbouring low STAT3 protein levels displayed increased miR-199a levels and decreased Ube2g1 expression. CONCLUSION This study identifies a novel pathophysiological circuit in the heart between reduced STAT3 protein levels, increased miR-199a expression, and subsequent impairment of the UPS that disrupts CM sarcomere structure and impairs via the release of ADMA endothelial cell function.

Multiple sclerosis and pregnancy: experience from a nationwide database in Germany

Objective: The objective of this study was to evaluate exposure to disease-modifying therapies (DMTs) during pregnancy in 335 pregnancies of multiple sclerosis (MS) patients and to further determine whether exclusive breastfeeding of MS mothers has any relevant influence on postpartum relapse rate. Background: Only limited data are available on whether DMT exposure during pregnancy affects relapse rate during pregnancy or after birth. Currently, findings on beneficial effect of exclusive breastfeeding on MS disease course are controversially discussed. Methods: We enrolled pregnant women with MS who contacted us directly or via their treating physicians to be included in our nationwide MS and pregnancy database. Results: We identified 78 pregnancies under interferon-beta (IFNβ) preparations, 41 under glatiramer acetate (GLAT), and 216 pregnancies without DMT exposure during pregnancy. As expected, annualized relapse rate (ARR) decreased continuously during pregnancy in nonexposed mothers (p < 0.001) to then increase after birth. In IFNβ- or GLAT-exposed women this typical pattern was not as obvious. Congenital anomalies were within normal ranges in exposed pregnancies. In total, 170 women were identified who exclusively breastfed (EBF). Significantly reduced postpartum relapse rate during the first 3 months after birth were registered in the EBF group as compared with nonexclusively breastfeeding (NEBF) or nonbreastfeeding women (NBF) women with MS (p < 0.0001). Relapse rate (RR) in the year before pregnancy had been similar throughout all groups. We did not observe any significant differences in RR of NEBF and NBF women. Conclusion: Exclusive breastfeeding showed some beneficial effects on postpartum relapse rate in our cohort. Our data support that IFNβ and GLAT do not seem to represent a major teratogenic risk in pregnancy.

Therapies for multiple sclerosis: translational achievements and outstanding needs

In recent years, multiple sclerosis (MS) research has progressed on several fronts, prompting numerous clinical trials, primarily for immunotherapeutics. Although several new therapies have been disappointing and some were revealed to have devastating side effects, others have shown benefits and all have generated valuable knowledge about the progression of MS, the key contributors to pathogenesis, and on natural surveillance mechanisms for brain infections. This makes now a useful time to take stock of recent advances in developing MS treatments and consider new approaches for adding information where the gaps are greatest - mainly in understanding the degenerative processes responsible for most of the long-term disability. Here, we summarize currently accepted therapeutic principles and the drugs in late stages of development, as well as spotlighting potential novel openings for future research.

Natalizumab Use During the Third Trimester of Pregnancy

IMPORTANCE Natalizumab reduces multiple sclerosis relapses very effectively; however, severe disease activity may return once natalizumab treatment is withdrawn, as recommended during pregnancy. Sometimes restarting natalizumab treatment may be the best option for the mother, but the consequences for the infant are unknown. Except for a few single case reports, to our knowledge, comprehensive data about third-trimester natalizumab exposure are scant. OBSERVATIONS In a case series of 12 women with 13 pregnancies and highly active multiple sclerosis who were treated with natalizumab during their third trimester of pregnancy, we assessed the clinical and laboratory effects on the newborns. We observed mild to moderate hematologic alterations in 10 of 13 infants including thrombocytopenia and anemia. In a subsample of 5 mother-child pairs, we analyzed natalizumab levels in the umbilical cord blood. Natalizumab was detectable in all 5 newborns. CONCLUSION AND RELEVANCE Natalizumab can be a therapeutic option in patients with highly active multiple sclerosis during pregnancy. We recommend that a pediatrician be available at the time of delivery to evaluate for potential complications of anemia and thrombocytopenia in newborns exposed to natalizumab during the third trimester.