Dysregulated Epstein-Barr virus infection in patients with CIDP.

Ubiquitous viruses have frequently been proposed as a cause or trigger of chronic immune-mediated diseases. Infections are reported to be temporally associated with clinical exacerbations in patients with chronic inflammatory demyelinating polyneuropathy (CIDP). We examined immunological parameters of herpesvirus infections in untreated patients with CIDP compared to demographically matched controls. Patients with CIDP were uniformly seropositive for EBV-specific IgG and the disease was associated with a moderately enhanced IgG reactivity to EBV-encoded antigens expressed during both B cell transformation and productive viral replication. Moreover, cellular EBV copy numbers were 3-fold increased in patients with CIDP. In contrast, humoral immune responses to other herpesviruses (HCMV, HSV) as well as virus-specific IgM responses were unchanged in CIDP. These data indicate that host-pathogen interactions during chronic EBV infection are dysregulated in treatment-naïve patients with CIDP.

A type I interferon signature in monocytes is associated with poor response to interferon-beta in multiple sclerosis.

The effect of interferon-beta in multiple sclerosis is modest and many patients do not respond to treatment. To date, no single biomarker reliably correlates with responsiveness to interferon-beta in multiple sclerosis. In the present study, genome-wide expression profiling was performed in peripheral blood mononuclear cells from 47 multiple sclerosis patients treated with interferon-beta for a minimum of 2 years and classified as responders and non-responders based on clinical criteria. A validation cohort of 30 multiple sclerosis patients was included in the study to replicate gene-expression findings. Before treatment, interferon-beta responders and non-responders were characterized by differential expression of type I interferon-induced genes with overexpression of the type interferon-induced genes in non-responders. Upon treatment the expression of these genes remained unaltered in non-responders, but was strongly upregulated in responders. Functional experiments showed a selective increase in phosphorylated STAT1 levels and interferon receptor 1 expression in monocytes of non-responders at baseline. When dissecting this type I interferon signature further, interferon-beta non-responders were characterized by increased monocyte type I interferon secretion upon innate immune stimuli via toll-like receptor 4, by increased endogenous production of type I interferon, and by an elevated activation status of myeloid dendritic cells. These findings indicate that perturbations of the type I interferon signalling pathway in monocytes are related to lack of response to interferon-beta, and type I interferon-regulated genes may be used as response markers in interferon-beta treatment.

Autophagy in CD4+ T-cell immunity and tolerance.

Autophagy is a homeostatic process that enables eukaryotic cells to deliver cytoplasmic constituents for lysosomal degradation, to recycle nutrients and to survive during starvation. In addition to these primordial functions, autophagy has emerged as a key mechanism in orchestrating innate and adaptive immune responses to intracellular pathogens. Autophagy restricts viral infections as well as replication of intracellular bacteria and parasites and delivers pathogenic determinants for TLR stimulation and for MHC class II presentation to the adaptive immune system. Apart from its role in defense against pathogens, autophagy-mediated presentation of self-antigens in the steady state could have a crucial role in the induction and maintenance of CD4(+) T-cell tolerance. This review describes the mechanisms by which the immune system utilizes autophagic degradation of cytoplasmic material to regulate adaptive immune responses.

Classifications and treatment responses in chronic immune-mediated demyelinating polyneuropathy.

BACKGROUND: Chronic immune-mediated demyelinating polyneuropathy (CIP) represents a heterogeneous pool of motor, sensory, sensorimotor, symmetric, or asymmetric syndromes. OBJECTIVE: To evaluate published diagnostic classifications and characterize predictors of treatment response. METHODS: One hundred two of 158 patients with a working diagnosis of CIP were included and clinically characterized because they had electrophysiologic and/or histologic evidence of demyelination. The biostatistical profile of patients with symmetric clinical manifestation was analyzed using three proposed classifications (American Academy of Neurology [AAN] criteria, modified AAN criteria, European Federation of Neurological Societies/Peripheral Nerve Society [EFNS/PNS] criteria). Treatment responses to IV immunoglobulins (IVIg) and their positive predictors were investigated. RESULTS: Sensitivities (0.52 [AAN] vs 0.83 [modified AAN] vs 0.95 [EFNS/PNS]) and negative predictive values (0.68 vs 0.85 vs 0.92) differed markedly, whereas specificities (0.94 vs 0.90 vs 0.96) and positive predictive values (0.89 vs 0.89 vs 0.97) were similar. In CIP patients treated with IVIg, a positive response was found in 62 of 76 (82%). Patients with a monophasic or relapsing-remitting course or a more than twofold CSF protein increase had the highest probability to respond to IVIg, most evident when using the modified AAN criteria. CONCLUSIONS: The European Federation of Neurological Societies/Peripheral Nerve Society criteria for chronic inflammatory demyelinating polyneuropathy improve treatment of patients with chronic immune-mediated demyelinating polyneuropathy, particularly with respect to diagnostic issues. To predict IV immunoglobulin treatment response, the modified American Academy of Neurology criteria are the most valuable classification provided an increased CSF protein level.

Multiple sclerosis coinciding with Machado-Joseph disease.

Although inflammatory demyelination is considered to be the key feature in multiple sclerosis (MS) pathogenesis, histopathological investigations and MRI studies recently highlighted the extent of neuronal damage that occurs even in the early stages of the disease. We report the unusual case of a patient with Machado-Joseph disease (MJD; spinocerebellar ataxia (SCA) III) and discuss this coincidence in light current pathogenetic paradigms of CNS autoimmunity.

[Immunotherapy of chronic inflammatory demyelinating polyneuropathy]. / Immuntherapie der chronisch inflammatorischen demyelinisierenden Polyneuropathie.

Chronic inflammatory demyelinating polyneuropathy (CIDP) is an acquired immune-mediated disease of the peripheral nervous system with an estimated prevalence of 1-2/100,000. The clinical presentation is heterogeneous, but the most common form causes symmetrical progressive or relapsing weakness affecting proximal and distal muscles. CIDP is among the most treatable peripheral nerve disorders and corticosteroids, plasmapheresis and intravenous immunoglobulin have been shown to be effective in short-term prospective, randomized controlled trials. Data however indicate that approximately one-third of patients do not respond to these treatment modalities, nor do they provide equivalent evidence for a durable clinical response. There is a lack of good quality controlled trials of any other immunosuppressive agent, but cyclophosphamide and cyclosporin may be of value in patients with poor response to first-line modalities. Alternatively, the use of combination therapy may increase the efficacy in unresponsive patients. This review highlights the current status of CIDP treatment trials and discusses the significance of any therapeutic option in terms of efficacy, tolerability and cost-effects.

[Heterogeneity of Borrelia burgdorferi: etiopathogenetic relevance and clinical implications]. / Heterogenität von Borrelia burgdorferi: Atiopathogenetische Relevanz und klinische Implikationen.

Of the ten different species of Borrelia (B.) burgdorferi sensu lato which have been characterized to date, only B. burgdorferi sensu stricto, B. garinii and B. afzelii have been identified as pathogenic in humans. It was suggested that different species possess different organotropisms and may preferentially cause distinct clinical manifestations of Lyme disease. Molecular analyses revealed a strong association of B. afzelii with the late cutaneous manifestation acrodermatitis chronica atrophicans, whereas B. garinii was predominantly identified in clinical samples from patients with neuroborreliosis. PCR-based analyses of samples from European patients with Lyme arthritis had given controversial results, but B. burgdorferi sensu stricto appears to be the major pathogen. The identity of the infecting species seems to be a major determinant in the pathogenesis of Lyme arthritis, although its complex immunopathological background and its clinical heterogeneity clearly indicate concomitant factors. Thus, characterization of the infecting organism at the species level on the one hand and linkage of clinical data with pathogenetically relevant immune parameters on the other, shall lead to a more precise understanding of the pathogenesis and the individual clinical course of Lyme borrelioses.

Downregulation of transforming growth factor-beta1 in interferon-beta1a-treated MS patients.

The authors report an intense downregulation of transforming growth factor-beta1 (TGF-beta1) serum levels 4 weeks from start of interferon-beta1a (IFN-beta1a) treatment at 44 microg/week in 271 patients with relapsing-remitting MS, which was still present after 1 year (p < 0.001). In line with previous data, interleukin-10 serum levels did not vary significantly. These results indicate that the immunomodulatory effects of IFN-beta might not be restricted to the postulated anti-inflammatory mechanisms and address the role of TGF-beta in the pathogenesis of MS.

Rapid typing of Borrelia burgdorferi sensu lato species in specimens from patients with different manifestations of Lyme borreliosis.

To further investigate the pathogenic potential of different Borrelia burgdorferi genospecies, specimens from 27 patients with different manifestations of Lyme borreliosis were analyzed by PCR and reverse line blotting (RLB). In samples from Lyme arthritis patients, B. burgdorferi sensu stricto was predominantly identified, while in patients with neuroborreliosis or acrodermatitis, Borrelia garinii and Borrelia afzelii, respectively, were exclusively detected. The results demonstrate that PCR-RLB is a valuable tool for epidemiological and pathogenetic studies of Lyme borreliosis.

Norepinephrine inhibits energy metabolism of human peripheral blood mononuclear cells via adrenergic receptors.

Previous studies demonstrated that the adaptive response to stressors and inflammatory signals involves the activation of the autonomous [corrected] nervous system. Catecholamines have been shown to modulate the activity of various immune effector cells directly via membrane adrenergic receptors. Here, we investigated immediate effects of norepinephrine on energy metabolism of immune cells. Norepinephrine inhibits oxygen consumption of human peripheral blood mononuclear cells at concentrations that are relevant to its physiological range. The beta-adrenoreceptor antagonist propranolol, but not the alpha-adrenoreceptor antagonist phentolamine reversed the norepinephrine induced inhibition in quiescent cells. Conversely, phentolamine but not propranolol is capable of blocking norepinephrine mediated effects in mitogen activated human peripheral blood mononuclear cells. Our data indicate that the sensitization of alpha- and beta-adrenoreceptors on immune cells is differentially regulated, and that these processes depend on the activation state of these cells. These findings have important implications for the understanding of stress-induced suppression of immune function and may contribute to the elucidation of the pathogenesis of immunologically mediated diseases.