Mucus obstruction and inflammation in early cystic fibrosis lung disease: Emerging role of the IL‐1 signaling pathway

Mucus plugging constitutes a nutrient‐rich nidus for a bacterial infection that has long been recognized as a potent stimulus for neutrophilic airway inflammation driving progressive lung damage in people with cystic fibrosis (CF). However, mucus plugging and neutrophilic inflammation are already present in many infants and young children with CF even in the absence of detectable bacterial infection. A series of observational studies in young children with CF, as well as investigations in animal models with CF‐like lung disease support the concept that mucus plugging per se can trigger inflammation before the onset of airways infection. Here we review emerging evidence suggesting that activation of the interleukin‐1 (IL‐1) signaling pathway by hypoxic epithelial cell necrosis, leading to the release of IL‐1α in mucus‐obstructed airways, may be an important mechanistic link between mucus plugging and sterile airway inflammation in early CF lung disease. Furthermore, we discuss recent data from preclinical studies demonstrating that treatment with the IL‐1 receptor (IL‐1R) antagonist anakinra has anti‐inflammatory as well as mucus modulating effects in mice with CF‐like lung disease and primary cultures of human CF airway epithelia. Collectively, these studies support an important role of the IL‐1 signaling pathway in sterile neutrophilic inflammation and mucus hypersecretion and suggest inhibition of this pathway as a promising anti‐inflammatory strategy in patients with CF and potentially other muco‐obstructive lung diseases.     

Functional relevance of NLRP3 inflammasome-mediated interleukin (IL)-1β during acute allergic airway inflammation

Overall asthmatic symptoms can be controlled with diverse therapeutic agents. However, certain symptomatic individuals remain at risk for serious morbidity and mortality, which prompts the identification of novel therapeutic targets and treatment strategies. Thus, using an adjuvant-free T helper type 2 (Th2) murine model, we have deciphered the role of interleukin (IL)-1 signalling during allergic airway inflammation (AAI). Because functional IL-1β depends on inflammasome activation we first studied asthmatic manifestations in specific inflammasome-deficient [NACHT, LRR and PYD domains-containing protein 3 (NLRP3^−/−) and apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC^−/−)] and IL-1 receptor type 1^−/− (IL-1R1^−/−) mice on the BALB/c background. To verify the onset of disease we assessed cellular infiltration in the bronchial regions, lung pathology, airway hyperresponsiveness and ovalbumin (OVA)-specific immune responses. In the absence of NLRP3 inflammasome-mediated IL-1β release all symptoms of AAI were reduced, except OVA-specific immunoglobulin levels. To address whether manipulating IL-1 signalling reduced asthmatic development, we administered the IL-1R antagonist anakinra (Kineret®) during critical immunological time-points: sensitization or challenge. Amelioration of asthmatic symptoms was only observed when anakinra was administered during OVA challenge. Our findings indicate that blocking IL-1 signalling could be a potential complementary therapy for allergic airway inflammation.     

Immune mechanism–targeted treatment of experimental epidermolysis bullosa acquisita

Epidermolysis bullosa acquisita (EBA) is an autoimmune bullous dermatosis characterized by chronic mucocutaneous blistering caused by autoantibodies directed against type VII collagen. EBA causes a high morbidity and is difficult to treat. Model systems have significantly broadened our understanding of EBA pathogenesis, leading to the identification of numerous therapeutic targets. Of these, so far, a few have been evaluated for their therapeutic potential in preclinical models. In mice, EBA can be induced by transfer of anti-type VII collagen antibodies or by immunization with the protein. The latter model, immunization-induced EBA, is ideal to test drugs for their therapeutic efficacy. Here, mice with already established disease can be treated for prolonged periods. Albeit time consuming, results from immunization-induced EBA will pave the way for clinical application in patients. As the key pathogenic principle, that is, autoantibody-induced, leukocyte-mediated tissue injury and inflammation, is shared by other diseases, these findings may have translational applications beyond EBA.     

Successful treatment of macrophage activation syndrome complicating adult Still disease with anakinra

A previously healthy 20‐year‐old man presented with adult Still disease (ASD). He developed life‐threatening macrophage activation syndrome (MAS), which was refractory to standard immunosuppression but responded dramatically to the IL‐1 receptor antagonist anakinra. Subsequent immunological investigations included assessment of the perforin expression of natural killer (NK) cells and CD8+ T cells, which confirmed MAS.     

Successful use of subcutaneous anakinra in hemophagocytic lymphohistiocytosis precipitated by candidiasis in a patient with systemic lupus erythematosus: A case report and description of a novel therapeutic regimen

Hemophagocytic lymphohistiocytosis (HLH) is a rare and often fatal condition characterized by inappropriate immune system activation leading to a “cytokine storm”, and ultimately resulting in end-organ damage. Causes include primary defects in genes involved in immune-mediated cytolytic pathways, or secondary triggers such as infection or malignancy. We describe a case of HLH precipitated by fungal infection which occurred as a consequence of immunosuppression for management of systemic lupus erythematosus (SLE) and necrotizing myopathy. The patient presented with immune-mediated disease of the muscles and lung which was treated with high-dose corticosteroids and aggressive immunosuppression. HLH emerged in the context of confirmed candidiasis and features of severe sepsis. The patient responded rapidly to antifungal therapy and high-dose anakinra, which was administered subcutaneously and progressively weaned over 4 weeks. She completed HLH treatment as an outpatient and remains well at 12 months with controlled SLE and no recurrence of HLH.     

Anakinra: an inhibitor of IL-1 for the treatment of rheumatoid arthritis

Anakinra (Amgen, Inc.) is a specific receptor antagonist of IL-1 that differs from naturally occurring IL-1 receptor antagonist by the presence of a methionine group. Anakinra has been shown to be of benefit in patients with active rheumatoid arthritis, either when given alone or in combination with methotrexate, as assessed by improvement in clinical signs and symptoms, decreased radiographic progression and improvement in patient function, pain and fatigue, although it appears to be effective in fewer patients than anti-TNF agents. It has a favourable safety profile as demonstrated in clinical trials. The physician and patient must be cognizant of serious infectious episodes. Many of the rare side effects seen with TNF blockers, such as tuberculosis, other opportunistic infections, worsening of congestive heart failure and the development of demyelinating disease, have not been seen in patients treated with anakinra. Anakinra should not be given in combination with anti-TNF agents.     

Review of Biologic Therapies

The emergence of biologic therapy as treatment for autoimmune and inflammatory diseases is rapidly changing the face of medicine. From fusion proteins to monoclonal antibodies, biologic therapies encompass a variety of agents that target distinct pathways involved in autoimmunity and inflammation. In this review, a survey of available and emerging biologic therapies detailing their current indications, mechanism of action, dosing, side effects, and recommended drug monitoring will be summarized so as to aid clinicians in making treatment decisions regarding their usage.     

Chronic urticaria of neonatal onset: A potential sign of autoinflammation

We present a 6 year old boy with chronic urticaria of neonatal onset associated in childhood with features of neurological and joint inflammation. Genetic analysis confirmed the diagnosis of neonatal onset multi‐inflammatory disorder (NOMID). Daily subcutaneous anti‐IL‐1 receptor antagonist therapy resulted in a dramatic and sustained amelioration of systemic inflammation. NOMID must be considered in any child with chronic urticaria of neonatal/infantile onset, particularly if associated with joint and/or neurological inflammation.     

Anakinra (Interleukin-1 Receptor Antagonist) has positive effects on function and quality of life in patients with rheumatoid arthritis

Rheumatoid arthritis (RA) has severe and lasting effects on quality of life. This review (1) describes the disease progression, disability, and joint destruction that seriously alter a patient’s quality of life, and (2) explains how the interleukin-1 receptor antagonist (IL-1Ra), anakinra, retards the progress of disease, thereby improving outcomes. Relevant articles were reviewed with a focus on RA, anakinra, and functional and quality-of-life outcomes. In randomized, controlled trials, the IL-1 Ra anakinra provided meaningful benefits for patients with active RA, such as decreased signs and symptoms of disease, slower radiographic disease progression, reduced disability, and improved health-related quality of life. The biologic agent, anakinra, provides to patients with RA a valuable treatment option that has a positive impact on both function and quality of life.