Autoinflammatory diseases in childhood, part 1: monogenic syndromes

Autoinflammatory diseases constitute a family of disorders defined by aberrant stimulation of inflammatory pathways without involving antigen-directed autoimmunity. They may be divided into monogenic and polygenic types. Monogenic autoinflammatory syndromes are those with identified genetic mutations, such as familial Mediterranean fever, tumor necrosis factor receptor-associated periodic fever syndrome (TRAPS), mevalonate kinase deficiency or hyperimmunoglobulin D syndrome, cryopyrin-associated periodic fever syndromes (CAPS), pyogenic arthritis pyoderma gangrenosum and acne (PAPA) syndrome, interleukin-10 and interleukin-10 receptor deficiencies, adenosine deaminase 2 deficiency and pediatric sarcoidosis. Those without an identified genetic mutation are known as polygenic and include systemic-onset juvenile idiopathic arthritis, idiopathic recurrent acute pericarditis, Behçet syndrome, chronic recurrent multifocal osteomyelitis and inflammatory bowel disease among others. Autoinflammatory disorders are defined by repeating episodes or persistent fever, rash, serositis, lymphadenopathy, arthritis and increased acute phase reactants, and thus may mimic infections clinically. Most monogenic autoinflammatory syndromes present in childhood. However, because of their infrequency, diverse and nonspecific presentation, and the relatively new genetic recognition, diagnosis is usually delayed. In this article, which is Part 1 of a two-part series, the authors update monogenic autoinflammatory diseases in children with special emphasis on imaging features that may help establish the correct diagnosis.

Colchicine as an anti-inflammatory and cardioprotective agent

INTRODUCTION

Colchicine has been successfully used for the treatment of neutrophilic disorders such as familial Mediterranean fever (FMF), Behçet disease (BD) and gout. There is a growing interest in its cardiovascular effects.

AREAS COVERED

A MEDLINE/PubMed search for English articles published from January 1972 to June 2015 was completed using the following terms: therapy, pharmacokinetics, efficiency, side effects, toxicity, heart, colchicine, inflammation, FMF, amyloidosis, BD, gout, cardiovascular disorders, pericarditis, arrhythmias, inflammation, neutrophils, platelets.

EXPERT OPINION

By targeting neutrophils, endothelial cells and platelets, inhibiting mitosis, vascular hyperplasia and fibrosis, colchicine improves outcomes of pericarditis, myocardial ischemia and coronary interventions. Studies in neutrophilic rheumatic diseases and cardiovascular disorders demonstrated that oral colchicine at doses of 0.5 - 2.5 mg/daily is useful for treating pericarditis, myocardial ischemia and coronary occlusion. In rheumatic and cardiovascular disorders, therapeutic doses of the drug reduce C-reactive protein to levels below 2 mg/L, prevent myocardial damage and preserve normal values of atrial and ventricular impulse generation. One of the drug's frequent side effects is diarrhea, which is treated by diet modification or temporary discontinuation of the therapy. Certain drugs (macrolides, statins), comorbidities and certain genetic factors increase risk of colchicine toxicity.

The Role of the NLRP3 Inflammasome in Fibrosis

Fibrosis leads to the deposition of collagens in organs and tissues. The resulting pathology induces a loss of function in the organ it is manifested in and this loss of function modulates the morbidity and mortality in that individual. Indeed, approximately 45% of all deaths in the Western world can be attributed to fibrosis and there are no FDA approved drugs for the treatment of fibrosis. The recent discovery of the inflammasome has led to a plethora of studies investigating this inflammatory signaling pathway in a wide variety of pathogen associated diseases. Many studies have focused on the NLRP3 inflammasome and this inflammasome is activated by a wide variety of cellular alarm signals. Once activated, caspase-1 is cleaved, inducing the secretion of IL-1β and IL-18 that signal to aid in the clearance of invading organisms. However, as the knowledge of the inflammasome has expanded, it was found that it can directly control collagen synthesis, leading to the increased deposition of collagens in the tissues such as the lung, liver, heart, and skin. Mice lacking the inflammasome adaptor protein, ASC, failed to become fibrotic when exposed to bleomycin. Inhibition of caspase-1 activity in fibroblasts from patients with the fibrotic disease systemic sclerosis, decreased collagen synthesis and reduced α-smooth muscle actin expression in myofibroblasts. Taken together, these observations suggest that the inflammasome can drive the fibrotic response and paves the way for novel therapeutics to be identified.

Familial Mediterranean fever presenting as anti-cyclic citrullinated peptide antibody negative palindromic rheumatism

A 64-year-old Egyptian man who resides in the United States presented to the rheumatology clinic with 6 months history of episodic recurrent pauci--arthritis along with constitutional symptoms. His Mediterranean ancestry, anti-cyclic citrullinated peptide negativity, and cyclical palindromic rheumatism prompted an investigation for familial Mediterranean fever gene mutation. He was found to have heterozygous 694I gene mutation during MEFV analysis. He also met Liveneh 1 major and 1 minor criteria for the diagnosis of familial Mediterranean fever.

Familial Mediterranean Fever as an Emerging Clinical Model of Atherogenesis Associated with Low-Grade Inflammation

Numerous inflammatory and innate immune pathways are involved in atherogenesis. Elaboration of clinical models of inflammation-induced atherogenesis may further advance our knowledge of multiple inflammatory pathways implicated in atherogenesis and provide a useful tool for cardiovascular prevention. Familial Mediterranean fever (FMF) is a chronic inflammatory disorder with profiles of inflammatory markers close to that seen in the general population. In a few recent studies, it has been shown that endothelial dysfunction, increased atherosclerotic burden and activation of platelets accompany attack-free periods of FMF. Colchicine is proved to be useful in suppression of inflammation in FMF. Preliminary basic and clinical studies suggest that this relatively safe drug may be useful for cardiovascular protection in patients with FMF and in the general population. Multinational prospective studies are warranted to further elaborate clinical model of inflammation-induced atherosclerosis associated with FMF.

Familial mediterranean Fever as an emerging clinical model of atherogenesis associated with low-grade inflammation

Numerous inflammatory and innate immune pathways are involved in atherogenesis. Elaboration of clinical models of inflammation-induced atherogenesis may further advance our knowledge of multiple inflammatory pathways implicated in atherogenesis and provide a useful tool for cardiovascular prevention. Familial Mediterranean fever (FMF) is a chronic inflammatory disorder with profiles of inflammatory markers close to that seen in the general population. In a few recent studies, it has been shown that endothelial dysfunction, increased atherosclerotic burden and activation of platelets accompany attack-free periods of FMF. Colchicine is proved to be useful in suppression of inflammation in FMF. Preliminary basic and clinical studies suggest that this relatively safe drug may be useful for cardiovascular protection in patients with FMF and in the general population. Multinational prospective studies are warranted to further elaborate clinical model of inflammation-induced atherosclerosis associated with FMF.

The role of inflammatory cytokines and NF-kappaB/MAPK signaling pathways in the evolution of familial Mediterranean fever: current clinical perspectives and potential therapeutic approaches

Familial Mediterranean fever (FMF) is one of the social and health care problems for several populations that is known as a historically endemic disease of inflammatory nature. FMF, albeit a rare disorder, is characterized by recurrent fevers and painful inflammation of various body parts, especially the abdomen, lungs, and joints. FMF is typically characterized by inflammation of the abdominal lining (peritonitis), inflammation of the lining surrounding the lungs (pleurisy), painful, swollen joints (arthralgia and occasionally arthritis), and a characteristic ankle rash, a condition that is referred to as recurrent polyserositis, or familial paroxysmal polyserositis. Moreover, FMF is an inherited inflammatory disorder usually occurring in people of Mediterranean origin - including Sephardic Jews, Arabs, Armenians, and Turks; but it may ostensibly affect any other ethnic group, however, rarely. While there's no cure for this disorder, FMF is typically diagnosed during childhood, and signs and symptoms are treatable - or even preventable - by specialized medical attrition. The inflammatory signaling pathways associated with the evolution of FMF are currently being unraveled has that has therapeutic repercussions. In this review, I recap major concepts associated with the cellular and molecular immunology of FMF, especially shedding light on the likely roles of inflammatory cytokines, the transcription factor nuclear factor (NF)-kappaB, and the superfamily of mitogen-activated protein kinases (MAPKs). Furthermore, I summarize current advances for the clinical treatments available for FMF.