Differential effects of disease modifying drugs on peripheral blood B cell subsets: A cross sectional study in multiple sclerosis patients treated with interferon-β, glatiramer acetate, dimethyl fumarate, fingolimod or natalizumab

Background

Several disease modifying drugs (DMDs) have been approved for the treatment of multiple sclerosis (MS), however, little is known about their differential impact on peripheral blood (PB) B cell subsets.

Methods

We performed a cross sectional study on PB B cells in MS patients treated with interferon-β (n = 25), glatiramer acetate (n = 19), dimethyl fumarate (n = 15), fingolimod (n = 16) or natalizumab (n = 22), untreated MS patients (n = 20), and in patients with non-inflammatory neurological diseases (n = 12). Besides analyzing routine laboratory data, flow cytometry was performed to analyze naïve B cells (CD19+CD20+CD27-IgD+), non-class switched (CD19+CD20+CD27+IgD+) and class-switched memory B cells (CD19+CD20+CD27+IgD-), double negative B cells (CD19+CD20lowCD27-IgD-) and plasmablasts (CD19+CD20lowCD27+CD38++).

Results

Treatment associated changes were found for the overall B cell pool as well as for all B cell subsets. Natalizumab increased absolute numbers and percentage of all B cells mainly by expanding the memory B cell pool. Fingolimod decreased absolute numbers of all B cell subsets and the percentage of total B cells. Fingolimod, dimethyl fumarate and interferon-β treatments were associated with an increase in the fraction of naïve B cells while class switched and non-class switched memory B cells showed decreased percentages.

Conclusion

Our results highlight differential effects of DMDs on the PB B cell compartment. Across the examined treatments, a decreased percentage of memory B cells was found in dimethyl fumarate, interferon-β and fingolimod treated patients which might contribute to the drugs’ mode of action in MS. Further studies are necessary to decipher the exact role of B cell subsets during MS pathogenesis.

Co-occurrence of two cases of progressive multifocal leukoencephalopathy in a natalizumab "infusion group"

We observed two cases of progressive multifocal leukoencephalopathy (PML) that occurred in the same "infusion group". The group consisted of four patients with relapsing-remitting multiple sclerosis (RRMS) who had been treated with natalizumab (NAT) in the same medical practice for more than four years at the same times and in the same room, raising concerns about viral transmission between members of the infusion group. DNA amplification and sequence comparison of the non-coding control region (NCCR) of JC virus (JCV) present in cerebrospinal fluid (CSF) samples from PML patients #1 and #2 revealed that the amplified JCV sequences differed from the JCV archetype. The NCRR of the viral DNA was unique to each patient, arguing against the possibility of viral transmission between patients. Statistical considerations predict that similar co-occurrences of PML are likely to happen in the future.

Familial Mediterranean fever-associated mutation pyrin E148Q as a potential risk factor for multiple sclerosis

BACKGROUND

Familial Mediterranean fever (FMF) is an inherited autoinflammatory disease caused by mutations in the MEFV gene and characterized by recurrent febrile polyserositis. A possible association of FMF and multiple sclerosis (MS) has been suggested in cohorts from Turkey and Israel.

OBJECTIVE

The objective of this study was to investigate the prevalence of MEFV mutations in subjects with MS and in controls in Germany.

METHODS

One-hundred and fifty seven MS patients with at least one symptom or without symptoms suggestive of FMF from our outpatient clinic were investigated for mutations in exons 2, 3, and 10 of the MEFV gene (group 1). 260 independent MS patients (group 2) and 400 unrelated Caucasian controls (group 3) were screened selectively for the low-penetrance pyrin mutations E148Q and K695R RESULTS: In group 1, 19 MS patients (12.1%) tested positive for a mutation in the MEFV gene, mainly the E148Q (n=7) substitution. Fifteen of the 19 mutation-positive individuals reported at least one symptom suggestive of FMF. In three cases, we could identify additional family members with MS. In these pedigrees, the E148Q exchange co-segregated with MS (p=0.026). Frequencies of the pyrin E148Q and K695R mutations were not statistically different between MS group 2 and controls but they occurred with a surprisingly high frequency in the German population.

CONCLUSION

The MEFV gene appears to be another immunologically relevant gene locus which contributes to MS susceptibility. In particular, the pyrin E148Q mutation, which co-segregated with disease in three MS families, is a promising candidate risk factor for MS that should be further explored in larger studies.

Long-term follow-up of patients with neuromyelitis optica after repeated therapy with rituximab

BACKGROUND

Neuromyelitis optica (NMO) is a severe autoimmune disease targeting optic nerves and spinal cord. The monoclonal anti-CD20 B-cell antibody rituximab is an emerging therapeutic option in NMO. However, neither long-term efficacy or safety of rituximab, nor the correlation between B-cell counts, B-cell fostering cytokines, aquaporin-4 antibodies (AQP4-ab), and disease activity in NMO, have been investigated prospectively.

METHODS

We performed a prospective long-term cohort study of 10 patients with NMO who were treated up to 5 times with rituximab as a second-line therapy. Clinical examinations, B-cell counts, and serum concentrations of BAFF (B-cell activating factor of the TNF family; also called TNFSF13b), APRIL (a proliferation-inducing ligand; also called TNFSF13), AQP4-ab, and immunoglobulin levels were measured every 3 months.

RESULTS

Repeated treatment with rituximab led to sustained clinical stabilization in most patients with NMO. Disease activity correlated with B-cell depletion, but not clearly with AQP4-ab or levels of APRIL. BAFF levels increased after application of rituximab and indicated persisting efficacy of the drug but did not correlate with disease activity. Overall, rituximab was well-tolerated even after up to 5 consecutive treatment courses; however, we observed several severe adverse reactions.

CONCLUSION

Our data indicate that long-term therapy with rituximab is effective in NMO as a second-line therapy and has an acceptable safety profile. Retreatment with rituximab should be applied before reappearance of circulating B cells.

CLASSIFICATION OF EVIDENCE

This study provides Class IV evidence that repeated doses of rituximab result in stabilization in most patients.

Headache in patients with a meningioma correlates with a bone-invasive growth pattern but not with cytokine expression

We included 58 patients with meningioma in a prospective study to analyse the prevalence of and risk factors for different types of meningioma-associated headache. Twenty-three patients (40%) had meningioma-associated headache. Of these, the pain was migraine-like in five (22%) and tension-type headache (TTH)-like in 13 (57%). Sixteen of 21 (76%) experienced relief of pain intensity of at least 50% after 18–24 months. Univariate analysis revealed bone-invasive growth pattern ( P = 0.007) as a risk factor for headache and intake of antiepileptic drugs ( P = 0.04) or large surrounding oedema ( P = 0.04) as possible protective parameters. For migraine-like headache, risk factors were a positive history of migraine ( P = 0.009) and bone-invasive growth pattern ( P = 0.046) and, for TTH-like headache, only bone-invasive growth pattern ( P = 0.009). Binary logistic regression analysis added to assess predictability and interaction effects could not identify a single factor predicting the occurrence of headache in the presence of a meningioma (correct prediction in 74% by a model consisting of bone-invasive growth pattern, history of head surgery, intake of antiepileptic drugs, temporal tumour location and moderate and large surrounding oedema). Analysis of 38 tumour specimens could not confirm the hypothesis that the occurrence of headache correlates with the expression magnitude of signal substances known to be present in meningiomas [stroma cell-derived factor 1, interleukin (IL)-1β, IL-6, vascular endothelial growth factor A] or thought to be relevant to headache/pain pathophysiology [prostaglandin-endoperoxide synthase 2, calcitonin-related polypeptide alpha, nitric oxide synthase (NOS) 1, NOS2A, NOS3, transforming growth factor-alpha, tumour necrosis factor, tachykinin, vasoactive intestinal peptide]. The affection of bone integrity and the expression of molecules thought to be relevant to headache pathophysiology might be important for meningioma-associated headache in predisposed individuals.

Natalizumab disproportionately increases circulating pre-B and B cells in multiple sclerosis

BACKGROUND

Natalizumab, a humanized anti-alpha4 integrin monoclonal antibody, reduces relapses and disease progression in patients with multiple sclerosis (MS). Whereas its presumed mode of action is inhibition of T cell/monocyte entry into the brain, little is known about its specific effect on B cells, which are increasingly recognized to participate in MS pathogenesis.

METHODS

We obtained serial blood samples from 17 patients before and during natalizumab therapy for relapsing-remitting MS for up to 16 months, and blood samples from 10 untreated patients with MS and 13 healthy donors. We determined numbers of mature and immature lymphocyte subsets by flow cytometry for CD3, CD4, CD8, CD19, CD138, and CD10 in 111 samples. We analyzed marker transcripts for immature hematopoietic cells by quantitative PCR for CD34, Vprebeta1 (pre-B lymphocyte gene 1), and DNTT (terminal deoxynucleotidyltransferase) in 65 samples.

RESULTS

Natalizumab therapy increased CD19(+) mature B cells more than other lymphocytes/monocytes in blood (2.8-fold versus 1.3-1.8-fold increase in cells/microL; p < 0.01). Even greater was the increase of immature CD19(+)CD10(+) pre-B cells (7.4-fold; p < 0.01). This pattern remained stable during treatment for up to 16 months. Transcripts of lymphocyte precursors (Vprebeta1 and DNTT) were elevated more than transcripts for CD34.

CONCLUSIONS

Circulating B cells and especially pre-B cells are most prominently elevated among the studied immune cell subsets, raising the possibility that the effects and side effects of natalizumab are partly mediated by actions on B cells.

Anti-Ma and anti-Ta associated paraneoplastic neurological syndromes: 22 newly diagnosed patients and review of previous cases

BACKGROUND

Paraneoplastic neurological syndromes (PNS) are indirect remote effects of cancer on the nervous system, often associated with the presence of specific serum antibodies. The most recently described PNS defining reactivity is anti-Ma/anti-Ta. Here we present 22 newly diagnosed patients with anti-Ma or anti-Ta reactivity, refine the associated clinical picture and review all published patients to date.

PATIENTS AND METHODS

Patients were identified by testing for PNMA1 and PNMA2 antibodies by western blotting and indirect immunofluorescence. Clinical data were obtained either by referral of the patient or from the referring physicians.

RESULTS

Analysis of 22 new patients (14 anti-Ma, eight anti-Ta) confirmed that anti-Ta are usually found in young men with limbic encephalitis and testicular germ cell tumours who stabilise neurologically with long term survival after tumour treatment. Patients with anti-Ma were of either sex, middle-aged, presented with a range of tumours and neurological symptoms and had a limited response to treatment. Furthermore, we expanded the range of associated clinical features: (1) the peripheral nervous system may be involved; (2) an overlap with anti-Hu is possible; and (3) testicular tumour manifestation can be extragonadal or detectable only at orchiectomy.

CONCLUSION

Refining and expanding the range of anti-Ma/anti-Ta associated neurological presentations and tumours clearly demonstrated that the distinction between anti-Ma and anti-Ta associated PNS is of high clinical relevance.

Interferon-beta increases BAFF levels in multiple sclerosis: implications for B cell autoimmunity

B cells are increasingly recognized as major players in multiple sclerosis pathogenesis. The BAFF/APRIL system is crucial for B cell homoeostasis and may drive B cell-dependent autoimmunity. We asked whether this system is affected by Interferon (IFN)-beta therapy. We analysed transcription of the ligands (BAFF, APRIL, TWE-PRIL) and the corresponding receptors (BAFF-R, TACI and BCMA) by TaqMan-PCR ex vivo in whole blood and in immune cell subsets purified from IFN-beta-treated multiple sclerosis patients. Serum BAFF concentrations were determined by ELISA. This cross-sectional study involved 107 donors. IFN-beta therapy strongly induced BAFF transcription proportionally to the IFN-beta biomarker MxA in monocytes and granulocytes in vivo. BAFF serum concentrations were elevated in IFN-beta-treated multiple sclerosis patients to a similar level as observed in SLE patients. In cultured PBMC, neutrophils, fibroblasts and astrocytes, BAFF was induced by IFN-beta concentrations similar to those reached in vivo in treated multiple sclerosis patients. BAFF turned out to be the main regulated element of the BAFF/APRIL system. In untreated multiple sclerosis patients, there was no BAFF increase as compared to healthy controls. Our study reveals a complex situation. We show that IFN-beta therapy induces a potent B cell survival factor, BAFF. However, B cell depletion would be desirable at least in some multiple sclerosis patients. The systemic induction of BAFF by IFN-beta therapy may facilitate the production of various autoantibodies and of IFN-neutralizing antibodies. Individual MS/NMO patients who have major B cell involvement may benefit less than others from IFN-beta therapy, thus explaining interindividual differences of the therapeutic response.

CCL19 is constitutively expressed in the CNS, up-regulated in neuroinflammation, active and also inactive multiple sclerosis lesions

CCL19 and CCL21 bind to CCR7, which is crucial for both inducing an immune response and establishing immunological tolerance. We report that in the normal human brain CCL19, but not CCL21, is transcribed, and detectable as a protein in tissue lysates and in cerebrospinal fluid. In both active and inactive multiple sclerosis (MS) lesions CCL19 transcripts were elevated. In cerebrospinal fluid from MS and OIND patients CCL19 protein was increased. In relapsing-remitting and secondary progressive MS patients CCL19 correlated with intrathecal IgG production. This study suggests that CCL19 plays a role in both the physiological immunosurveillance of the healthy CNS and the pathological maintenance of immune cells in the CNS of MS patients.

Cellular localization of 17 natural mutant variants of ALADIN protein in triple A syndrome - shedding light on an unexpected splice mutation

The triple A syndrome is a complex and multisystemic autosomal recessive disease with the 3 main symptoms of adrenal insufficiency, alacrima, and achalasia accompanied by neurological impairment. Mutations in the AAAS gene on chromosome 12q13 are responsible for the disorder. AAAS encodes a protein named ALADIN, which belongs to the family of WD-repeat-containing proteins and has been shown to localize to nuclear pore complexes. The function of the protein is not clear. It is supposed that ALADIN plays an important role in RNA and (or) protein trafficking between the nucleus and cytoplasm. With transfection experiments, we analyzed the cellular localization of the wild-type and 17 natural mutant variants (9 missense, 5 nonsense, 3 frameshift mutations) of ALADIN. We show that most mutations cause mislocalization of the mutant ALADIN proteins in the cytoplasm. In contrast, some variants with mutations located at the N-terminus (Q15K, L25P) and 3 artificial C-terminus mutations (Q490X, R493X, and V497X) remain at the nuclear pore. Using a patient cell line, we show that the mutation 43C>A in exon 1 does not cause a missense mutation Q15K but, rather, results in aberrant splicing.

Implementing Enterprise Resource Planning Packages in Different Corporate and National Cultures

ERP (enterprise resource planning) packages provide generic off-the-shelf business and software solutions for customers. However, these packages are implemented in companies with different corporate and national cultures and there is growing evidence that failure to adapt ERP packages to fit these cultures leads to projects which are expensive and overdue. This paper describes research which synthesizes social science theories of culture in order to be able to model and predict the impact of culture on ERP package implementation. It describes a knowledge meta-schema for modelling the surface and deeper manifestations of culture and predictions of ERP implementation problems based on national culture differences. It reports on an empirical study into the implementation of ERP packages in a large pharmaceuticals organization in Scandinavia and the UK. The results provide evidence for an association between corporate culture and ERP implementation problems but no direct evidence for an association between national culture and implementation problems. Furthermore, the results demonstrate that these diverse implementation problems can be caused by a mismatch between a small set of core values which are indicative of a customer's corporate culture. The paper concludes with revisions to the design of our extended method for ERP package implementation to the design of the meta-model and to rules that codify culture constraints that are applied in order to analyse instances of the meta-model.

Efficient expression of the tumor-associated antigen MAGE-3 in human dendritic cells, using an avian influenza virus vector

Dendritic cells (DCs) are the most potent inducers of immune reactions. Genetically modified DCs, which express tumor-associated antigens (TAA), can efficiently induce antitumor immunity and thus have a high potential as tools in cancer therapy. The gene delivery is most efficiently achieved by viral vectors. Here, we explored the capacity of influenza virus vectors to transduce TAA genes. These viruses abortively infect DCs without interfering with their antigen-presenting capacity. In contrast to other viruses used for DC transduction, influenza viruses can be efficiently controlled by antiviral pharmaceuticals, lack the ability to integrate into host chromosomes, and fail to establish persistent infections. Genes encoding a melanoma-derived TAA (MAGE-3), or the green fluorescence protein (GFP), were introduced into a high-expression avian influenza virus vector. Monocyte-derived mature DCs infected by these recombinants efficiently produced GFP or MAGE-3. More than 90% of the infected DCs can express a transduced gene. Importantly, these transduced DCs retained their characteristic phenotype and their potent allogeneic T cell stimulatory capacity, and were able to stimulate MAGE-3-specific CD8(+) cytotoxic T cells. Thus influenza virus vectors provide a highly efficient gene delivery system in order to transduce human DCs with TAA, which consequently stimulate TAA-specific T cells.