Plasmapheresis in a patient with severe asthma associated with auto-antibodies to platelets

Immunoglobulin E and G autoantibodies against eosinophil proteins in children and adults with asthma and healthy subjects

Background

Autoimmune IgG response has been described in the pathogenesis of asthma in adults, but IgE autoimmunity has been little explored. Considering high levels of blood eosinophils and immunoglobulin E in asthmatic patients, the possibility of IgE autoantibody response to eosinophil proteins arises.

Objective

To explore the presence of IgE and IgG autoantibodies against Eosinophil peroxidase (EPX) and Eosinophil cationic protein (ECP).

Methods

Three steps were followed: 1) The frequency of IgE and IgG autoantibodies against EPX and ECP was investigated among asthmatic and healthy subjects. 2) The ability of IgE autoantibodies to induce an inflammatory response (basophil activation) was performed. 3) The capacity of autoantibodies to identify patients with severe asthma was evaluated.

Results

Asthmatic and healthy subjects had IgE and IgG autoantibodies against EPX and ECP. Anti-EPX IgE was significantly higher in asthmatic patients. Severe asthmatic patients had a higher frequency and higher levels of IgE and IgG autoantibodies compared to healthy subjects. There was not a correlation between autoantibodies and blood eosinophils. Children younger than 14 years of age had IgE and IgG autoantibodies against to EPX and ECP. IgE autoantibodies to EPX and ECP induced basophil activation in asthmatic patients.

Conclusion

In this study, we identify for the first time IgE autoantibodies against EPX and ECP in adults and children patients with asthma; IgE and IgG autoantibodies against EPX and ECP could serve as a predictive biomarker of the clinical severity.

Immunoglobulin E-Mediated Autoimmunity

The study of autoimmunity mediated by immunoglobulin E (IgE) autoantibodies, which may be termed autoallergy, is in its infancy. It is now recognized that systemic lupus erythematosus, bullous pemphigoid (BP), and chronic urticaria, both spontaneous and inducible, are most likely to be mediated, at least in part, by IgE autoantibodies. The situation in other conditions, such as autoimmune uveitis, rheumatoid arthritis, hyperthyroid Graves’ disease, autoimmune pancreatitis, and even asthma, is far less clear but evidence for autoallergy is accumulating. To be certain of an autoallergic mechanism, it is necessary to identify both IgE autoantibodies and their targets as has been done with the transmembrane protein BP180 and the intracellular protein BP230 in BP and IL-24 in chronic spontaneous urticaria. Also, IgE-targeted therapies, such as anti-IgE, must have been shown to be of benefit to patients as has been done with both of these conditions. This comprehensive review of the literature on IgE-mediated autoallergy focuses on three related questions. What do we know about the prevalence of IgE autoantibodies and their targets in different diseases? What do we know about the relevance of IgE autoantibodies in different diseases? What do we know about the cellular and molecular effects of IgE autoantibodies? In addition to providing answers to these questions, based on a broad review of the literature, we outline the current gaps of knowledge in our understanding of IgE autoantibodies and describe approaches to address them.

miRNA meets plasma cells "How tiny RNAs control antibody responses"

We review the importance of small non-coding microRNAs for the generation of germinal center B cells and their differentiation in antibody-secreting plasma cells. In the last part, we briefly elucidate the role of microRNAs in some plasma cell disorders.

Histologic Findings of Severe/Therapy-Resistant Asthma From Video-assisted Thoracoscopic Surgery Biopsies

The histologic changes occurring in severe/therapy-resistant asthma (SA) as defined by the European Respiratory Society/American Thoracic Society guidelines, particularly at the level of the distal airways are unknown. This study describes the clinical, radiologic, and histologic characteristics of 29 SA patients who underwent video-assisted thoracoscopic surgery lung biopsy. Pathologic observations were correlated with clinical features, especially the presence of autoimmune disease (AID) (15/29, 51.7%). Ten biopsies (10/29, 34.5%) showed only small airway manifestations of asthma, whereas in 19 (65.5%) asthmatic granulomatosis, manifested by asthmatic bronchiolitis supplemented by an alveolar septal mononuclear infiltrates with non-necrotizing granulomas, was present. SA patients without asthmatic granulomatosis showed more striking small airway injury, subbasement membrane thickening, and neutrophilic infiltrates. Cases with concurrent AID had a tendency to more parenchymal eosinophilic inflammation, more bronchiolocentric granulomas, and a suggestion of increased responsivity to nonsteroidal immunosuppressive therapy. Histologic examination of video-assisted thoracoscopic surgery lung biopsies in SA demonstrates diverse pathologies including cases associated with granulomatous inflammation in addition to eosinophilic infiltrates. This spectrum of histologies may link to a high incidence of AID.

Presence in sputum of functional dust mite-specific IgE antibodies in intrinsic asthma

RATIONALE

Intrinsic asthma was described by Rackemann as asthma without allergy. Local IgE production has been documented in intrinsic asthma, but antigen specificity of this response remains elusive.

OBJECTIVES

We investigated (1) the presence of dust mite-specific IgE in sputum of patients with intrinsic asthma, (2) their clinical/immunological relevance, and (3) their functionality.

METHODS

Specific IgE to Dermatophagoides pteronyssinus (Der p) and to recombinant major allergens (rDer p1 and rDer p2) were assayed by ELISA in sputum samples from patients with intrinsic versus atopic asthma and control subjects. Whole-lung challenge was performed with Der p for clinical and inflammatory readouts. Functionality of local IgE to trigger effector cells was assessed using basophil activation test (surface expression of CD203c).

MEASUREMENTS AND MAIN RESULTS

Both total IgE and Der p-specific IgE levels are increased in patients with intrinsic asthma compared with healthy nonatopic patients. However, no immediate asthmatic responses were observed in patients with intrinsic asthma after Der p exposure. These sputum Der p-specific IgE do, however, recognize major allergens Der p1 and Der p2 and are able to trigger activation of blood basophils from atopic donors.

CONCLUSIONS

We confirm that IgE production occurs in intrinsic asthma and show that part of this IgE recognizes Der p antigens. However, this IgE reactivity does not translate into clinical responses to Der p exposure, despite specificity to major allergens and functionality to activate effector cells in vitro. We postulate that a second signal that promotes IgE-mediated asthmatic responses through FcεRI is lacking in intrinsic asthma.

Asthma and autoimmunity: a complex but intriguing relation

Asthma and autoimmune diseases apparently have little to share except for the involvement of the immune system in both types of disorder. However, epidemiological studies have shown that asthma and Type 1 diabetes, a typical autoimmune disease, are associated at the population level, and some experimental findings have suggested that autoimmune mechanisms might be operating in asthma as well. Female preponderance, increased incidence of antinuclear autoantibodies and detection of autoantibodies against either bronchial epithelial antigens or endothelial antigens in patients with nonallergic asthma suggest that the disease may have an autoimmune basis. Approximately 50% of patients with nonallergic asthma react to intradermal injection of autologous serum, indicating the presence of circulating vasoactive factors and suggesting an autoreactive mechanism. Recent findings in experimental animals support the involvement of an autoreactive mechanism in allergic asthma as well, indicating that human alpha-nascent polypeptide-associated complex, identified as an IgE-reactive autoantigen, has the potential to sensitize and induce immediate skin reactions and airway inflammation. In summary, asthma is a heterogeneous disorder characterized by chronic inflammation of the respiratory airways that can be triggered by allergen exposure or by other mechanisms, possibly autoreactive/autoimmune. The autoimmune hypothesis is further, indirectly, supported by the response to immunosuppressive drugs.

Linking allergy to autoimmune disease

Type I allergy is a classical Th2-driven hypersensitivity disease based on IgE recognition of environmental allergens. Exposure of allergic individuals to exogenous allergens leads to immediate type inflammation caused by degranulation of mast cells via IgE-allergen immune complexes and the release of inflammatory mediators, proteases and pro-inflammatory cytokines. However, allergic inflammation can occur and persist in the absence of exposure to exogenous allergens and might paradoxically resemble a Th1-mediated chronic inflammatory reaction. We summarize evidence supporting the view that autoimmune mechanisms might contribute to these processes. IgE recognition of autoantigens might augment allergic inflammation in the absence of exogenous allergen exposure. Moreover, autoantigens that activate Th1-immune responses could contribute to chronic inflammation in allergy, thus linking allergy to autoimmunity.

Plasmapheresis in the treatment of steroid-dependent bronchial asthma

BACKGROUND

Can plasmapheresis improve disease severity and lung function and reduce steroid doses in severe asthma patients dependent on oral corticosteroids?

METHODS

A pilot study with four asthma patients was undertaken using PEF (peak expiratory flow) symptom score, number of puffs of beta2-agonist, and dose of systemic steroids as disease variables. After at least an 8-week run-in, the patients were randomized to a crossover treatment regimen consisting of either 10 days of plasmapheresis or placebo treatment. Each treatment was succeeded by an 8-26-week follow-up period.

RESULTS

No patients achieved a significant effect of plasmapheresis treatment according to the established criteria, nor did anyone experience deterioration.

CONCLUSIONS

Removing humoral factors extensively over a 10-day period did not significantly influence the clinical condition of the four steroid-dependent asthma patients studied. Circulating humoral factors seem to be of little importance for the maintenance of the established chronic allergic inflammation in these patients. Plasmapheresis does not seem to be a treatment option for this patient category.

T and B cell immune response to a 55-kDa endothelial cell-derived antigen in severe asthma

Current concepts on the pathogenesis of chronic asthma emphasize the role of several inflammatory cell populations and their respective mediators that interact in a complex network. However, beside inflammatory cells, lymphocytes are also present in asthmatic airways. Although little is known about their involvement in asthma, it has been suggested that lymphocytes may participate in the development of chronic inflammation either through lymphokine secretion or through antibody production. In this study, we describe circulating IgG autoantibodies, directed against a common 55-kDa antigen shared by platelets and cultured endothelial cells, and found in 34 out of 97 asthmatic patients. Among epidemiological, clinical and biological characteristics of these asthmatic patients, the anti-55-kDa antigen antibodies are mainly restricted to patients with negative cutaneous prick tests (p = 0.0014), and corticosteroid-dependent asthma (p = 0.0036). These antibodies were also detected in a few patients with autoimmune disorders like systemic lupus erythematosus (3/30) or rheumatoid arthritis (2/36). Both platelet and endothelial cell antigens were cross-reactive, had an isoelectric point between 8.0 and 9.0, were insensitive to reducing agents such as 2-mercaptoethanol, and were not present on either platelet or endothelial cell surface, as determined by immunostaining assay. [3H]Thymidine incorporation assay with peripheral blood mononuclear cells from patients in the presence or in the absence of 55-kDa antigen, purified from nitrocellulose sheets demonstrated a specific incorporation in 6 out of 13 patients with circulating anti-55-kDa antigen antibodies, with index values ranging from 12 to 3. Such a T cell reactivity has also been observed in 3 out to 17 patients without detectable serum anti-55-kDa antigen antibodies. Moreover, a significant correlation was found between index values of antigen-specific T cell reactivity and the forced expiratory volume in one second (r = 0.544, p = 0.003). Our data indicate that the detection of such antibodies allows to distinguish a subgroup of asthmatics in terms of severity and to suggest a relationship between clinical severity and T and B cell autoreactivity to the 55-kDa platelet/endothelial cell antigen.

Human endothelial cells transfected by SV40 T antigens: characterization and potential use as a source of normal endothelial factors

A putative role for the vascular endothelium as target for autoantibodies has been suggested in several autoimmune disorders and connective-tissue diseases. However, there are some difficulties linked to the use of cultured endothelial cells (EC) that limit considerably the extensive studies on the nature of endothelial target antigens involved. To overcome this problem, human EC, derived from umbilical veins, were transfected with recombinant plasmid pSV1 which contained the early genes of simian virus SV40. These transfected cells, called EC-pSV1, are able to grow without EC growth supplement and demonstrate a population doubling time of about 50 h. Among the EC properties, EC-pSV1 retain intracellular content of angiotensin-converting enzyme activity, exhibit constitutive production of interleukin 6 and of a growth-promoting activity on early passage EV, express intercellular adhesion molecule 1 (ICAM-1) and its up-regulation by tumor necrosis factor alpha, but have lost the expression of factor VIII-related antigen. Moreover, EC-pSV1 express a 55-kDa antigen found on EC and human platelets, and presumably acting as an antibody target in some cases of non-allergic asthma. However, at the 50-55th generation, morphological changes and altered growth behavior were visible. This work demonstrates that transfection of EC with SV40 T antigens may be of interest, particularly in areas of research including the study of EC targets involved in different human diseases.