Phenotypic and genotypic characteristics of cryopyrin-associated periodic syndrome: a series of 136 patients from the Eurofever Registry

Inherited Autoinflammatory Syndromes

Autoinflammation describes a collection of diverse diseases caused by indiscriminate activation of the immune system in an antigen-independent manner. The rapid advancement of genetic diagnostics has allowed for the identification of a wide array of monogenic causes of autoinflammation. While the clinical picture of these syndromes is diverse, it is possible to thematically group many of these diseases under broad categories that provide insight into the mechanisms of disease and therapeutic possibilities. This review covers archetypical examples of inherited autoinflammatory diseases in five major categories: inflammasomopathy, interferonopathy, unfolded protein/cellular stress response, relopathy, and uncategorized. This framework can suggest where future work is needed to identify other genetic causes of autoinflammation, what types of diagnostics need to be developed to care for this patient population, and which options might be considered for novel therapeutic targeting. Expected final online publication date for the Annual Review of Pathology: Mechanisms of Disease, Volume 17 is January 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Anti-Myelin Oligodendrocyte Glycoprotein Encephalomyelitis and Extensive Longitudinal Transverse Myelitis Associated with Compound Heterozygous NLRP3 Missense Mutations in a Young Child

Acute disseminated encephalomyelitis in association with extensive longitudinal transverse myelitis is reported in a young child with positive anti-myelin oligodendrocyte glycoprotein (MOG) antibody with heterozygous NLRP3 missense mutations; p.(Arg488Lys) and p.(Ser159Ile). This case may well present an exceptional coincidence, but may describe a yet unrecognized feature of the spectrum of childhood onset cryopyrinopathies that contribute to the understanding of the genetic basis for anti-MOG antibody positive encephalomyelitis. Based on this observation, a larger scale study investigating the role of NLRP3 and other inflammasomes in this entity would provide important pathophysiological insights and potentially novel avenues for treatment.

Colchicine - an effective treatment for children with a clinical diagnosis of autoinflammatory diseases without pathogenic gene variants

BACKGROUND

Autoinflammatory diseases (AID) are rare chronic conditions with high disease burden, affecting children and adults. Clinically and genetically confirmed, AID can be effectively treated with targeted cytokine inhibition. In contrast, for patients with clinical AID symptoms without pathogenic gene variants, no treatment recommendations are available. Colchicine is approved and established as effective, safe and low-cost first-line therapy in Familial Mediterranean Fever. Up to now, efficacy data for colchicine in children with a clinical AID diagnosis without pathogenic gene variants are rare. This pilot study was performed to evaluate the effectiveness of colchicine in children with a clinical diagnosis of AID without pathogenic gene variants.

METHODS

A pilot cohort study of consecutive children with active clinical AID without pathogenic gene variants treated with colchicine monotherapy was performed between 01/2009 and 12/2018. Demographics, clinical and laboratory characteristics were determined serially. Colchicine dosing and safety were documented. Physician estimate of disease activity was captured on visual analogue scales (VAS).

PRIMARY OUTCOME

Complete response (PGA ≤2 plus CRP ≤0.5 mg/dL and/or SAA ≤10 mg/L) at last follow-up.

SECONDARY OUTCOMES

partial/no response, flare characteristics and requirement for rescue therapies.

ANALYSIS

Nonparametric comparison of disease activity measures.

RESULTS

A total of 33 children were included; 39% were female. Median age at colchicine start was 3.8 years, median follow-up was 14.1 months. Clinical AID diagnoses included CAPS (24%), FMF (27%), PFAPA (43%) and unclassified AID (6%). At baseline, overall disease activity was moderate (PGA 4), inflammatory markers were elevated (CRP 12.1 mg/dL; SAA 289.2 mg/L), and 97% reported febrile flares.

OUTCOME

55% achieved complete response, 35% showed partial response and 58% had no febrile flares at last follow-up. Inflammatory markers (SAA: p < 0.0001, CRP: p < 0.005) and disease activity (p < 0.0001) decreased significantly. Overall, 93% of children experienced improvement of flare characteristics.

CONCLUSION

Colchicine was found to be effective and safe in children with a clinical AID diagnosis in the absence of pathogenic gene variants. Colchicine is a low-cost treatment option for non-organ threatening AID.

Ocular involvement in monogenic autoinflammatory disease

OBJECTIVE

Monogenic Autoinflammatory diseases (AIDs) are a broad spectrum of rare hereditary diseases whose ocular involvement has not been well characterized yet. This systematic review aims to provide an overview of the current knowledge about ocular findings in AIDs.

METHODS

A systematic literature review was conducted using 2 electronic databases, according to the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines. A combination of AIDs and ophthalmology-related search terms were used. All articles were screened by 2 independent reviewers for title, abstract and full text level. We included solely studies that investigated ocular findings in AIDs.

RESULTS

198 papers of 4268 records were retained. Data about 1353 patients with a diagnosis of autoinflammatory disease and ocular involvement were collected (680 CAPS, 211 FMF, 138 TRAPS, 238 Blau, 32 MKD, 21 SIFD, 7 Aicardi Goutières, 3 CANDLE, 8 DADA2, 9 HA20, 6 APLAID). Conjunctivitis was significantly more frequent in CAPS (p < 0.00001), uveitis in Blau, MKD, HA20 and CANDLE (p < 0.00001), papillitis/papilledema in CAPS (p < 0.00001), optic neuritis in Aicardi and DADA2 (p < 0.008), retinal vasculitis in FMF (p < 0.00001), progressive reduction in choroidal thickness in FMF and DADA2 (p < 0.00001), periorbital oedema in TRAPS (p < 0.00001) and retinitis in SIFD (p < 0.00001). Among AIDs with uveitis, granulomatous inflammation was more common in Blau syndrome (p < 0.00001).

CONCLUSION

This systematic literature review characterized the ocular involvement of several AIDs, and the present data may encourage to consider a timely ophthalmological screening program for these rare diseases.

Visual loss with chronic meningeal and systemic inflammation

A 46-year-old man presented with worsening vision in the context of long-standing optic disc changes, bilateral sensorineural hearing loss, chronic aseptic meningitis, rash, arthralgia and raised inflammatory markers. The differential diagnoses of neoplasia, infection and inflammation are discussed. We highlight a condition that can present to adult neurologists, with successful diagnosis leading to targeted treatments that transform patient outcomes. This case was presented at the Association of British Neurologists Annual Meeting 2020 as a Clinicopathological Conference (CPC).

The combined prevalence of classified rare rheumatic diseases is almost double that of ankylosing spondylitis

BACKGROUND

Rare diseases (RDs) affect less than 5/10,000 people in Europe and fewer than 200,000 individuals in the United States. In rheumatology, RDs are heterogeneous and lack systemic classification. Clinical courses involve a variety of diverse symptoms, and patients may be misdiagnosed and not receive appropriate treatment. The objective of this study was to identify and classify some of the most important RDs in rheumatology. We also attempted to determine their combined prevalence to more precisely define this area of rheumatology and increase awareness of RDs in healthcare systems. We conducted a comprehensive literature search and analyzed each disease for the specified criteria, such as clinical symptoms, treatment regimens, prognoses, and point prevalences. If no epidemiological data were available, we estimated the prevalence as 1/1,000,000. The total point prevalence for all RDs in rheumatology was estimated as the sum of the individually determined prevalences.

RESULTS

A total of 76 syndromes and diseases were identified, including vasculitis/vasculopathy (n = 15), arthritis/arthropathy (n = 11), autoinflammatory syndromes (n = 11), myositis (n = 9), bone disorders (n = 11), connective tissue diseases (n = 8), overgrowth syndromes (n = 3), and others (n = 8). Out of the 76 diseases, 61 (80%) are classified as chronic, with a remitting-relapsing course in 27 cases (35%) upon adequate treatment. Another 34 (45%) diseases were predominantly progressive and difficult to control. Corticosteroids are a therapeutic option in 49 (64%) syndromes. Mortality is variable and could not be determined precisely. Epidemiological studies and prevalence data were available for 33 syndromes and diseases. For an additional eight diseases, only incidence data were accessible. The summed prevalence of all RDs was 28.8/10,000.

CONCLUSIONS

RDs in rheumatology are frequently chronic, progressive, and present variable symptoms. Treatment options are often restricted to corticosteroids, presumably because of the scarcity of randomized controlled trials. The estimated combined prevalence is significant and almost double that of ankylosing spondylitis (18/10,000). Thus, healthcare systems should assign RDs similar importance as any other common disease in rheumatology.

Persistent urticarial rash in a newborn

We presented the case of a 1-month-old girl with diffuse urticarial-like rash since birth. The initial evaluation showed elevated inflammatory markers. The response to treatment helped to narrow the diagnosis. In this case, we explored the differential diagnosis of rashes in this age group and the role of a therapeutic trial of medication as a diagnostic modality.

Monogenic Autoinflammatory Diseases: State of the Art and Future Perspectives

Systemic autoinflammatory diseases are a heterogeneous family of disorders characterized by a dysregulation of the innate immune system, in which sterile inflammation primarily develops through antigen-independent hyperactivation of immune pathways. In most cases, they have a strong genetic background, with mutations in single genes involved in inflammation. Therefore, they can derive from different pathogenic mechanisms at any level, such as dysregulated inflammasome-mediated production of cytokines, intracellular stress, defective regulatory pathways, altered protein folding, enhanced NF-kappaB signalling, ubiquitination disorders, interferon pathway upregulation and complement activation. Since the discover of pathogenic mutations of the pyrin-encoding gene MEFV in Familial Mediterranean Fever, more than 50 monogenic autoinflammatory diseases have been discovered thanks to the advances in genetic sequencing: the advent of new genetic analysis techniques and the discovery of genes involved in autoinflammatory diseases have allowed a better understanding of the underlying innate immunologic pathways and pathogenetic mechanisms, thus opening new perspectives in targeted therapies. Moreover, this field of research has become of great interest, since more than a hundred clinical trials for autoinflammatory diseases are currently active or recently concluded, allowing us to hope for considerable acquisitions for the next few years. General paediatricians need to be aware of the importance of this group of diseases and they should consider autoinflammatory diseases in patients with clinical hallmarks, in order to guide further examinations and refer the patient to a specialist rheumatologist. Here we resume the pathogenesis, clinical aspects and diagnosis of the most important autoinflammatory diseases in children.

Ocular manifestations in Chinese adult patients with NLRP3-associated autoinflammatory disease

NLRP3-associated autoinflammatory disease (NLRP3-AID) is a rare autosomal dominant disorder involving multiple systems. We aim to assess the ocular manifestations of Chinese adult patients with NLRP3-AID. Twelve adult patients (> 18 years old) were diagnosed as NLRP3-AID at the Department of Rheumatology, Peking Union Medical College Hospital. All patients underwent ophthalmologic evaluation by an ophthalmologist. Clinical and genetic features of these patients were collected and compared with those from Caucasian population. A total of 7 NLRP3-AID patients (58%) 14 eyes had ocular manifestations. Five NLRP3 variants were identified, and 3 patients (43%) with severe ocular damages were all found to have the NLRP3 T348M variant. The incidences of papilledema and optic atrophy in the Chinese adult NLRP3-AID patients of moderate type were similar to those in the Caucasian NLRP3-AID patients of severe type. This is the first cohort of Chinese adult NLRP3-AID patients with ocular involvement. Ocular manifestations were diverse and even severe in NLRP3-AID, particularly in patients with the moderate phenotype, and may have relationship with genotypes. Awareness of these manifestations by rheumatologists and ophthalmologists could help to avoid the irreversible ocular damages.

A Case of Hearing Impairment with Renal Dysfunction

Hearing impairment in a patient with renal failure is an important clue towards etiologic diagnosis of kidney disease. Variety of hereditary diseases, developmental defects, and toxins involve these two organs. However, additional retinopathy is seen in quite a few diseases which include Alport's syndrome and Muckle–Wells syndrome (MWS). We are reporting a case of middle-aged woman with childhood-onset of hearing impairment who presented with renal failure and was diagnosed to have renal amyloidosis on kidney biopsy but without any light chain restriction. During evaluation for live donor kidney transplant, her brother was also found to have hearing impairment and retinopathy however with normal renal function and urinalysis. Genetic testing of both of them was done for panel of mutations related to hereditary amyloidosis which revealed NLRP3 mutation in both. This mutation is characteristic of MWS which can lead to secondary amyloidosis and renal failure.

Pharmacological targeting of NLRP3 deubiquitination for treatment of NLRP3-associated inflammatory diseases

Pharmacologically inhibiting nucleotide-binding domain and leucine-rich repeat-containing (NLR) family, pyrin domain-containing protein 3 (NLRP3) inflammasome activation results in potent therapeutic effects in a wide variety of preclinical inflammatory disease models. NLRP3 deubiquitination is essential for efficient NLRP3 inflammasome activity, but it remains unclear whether this process can be harnessed for therapeutic benefit. Here, we show that thiolutin (THL), an inhibitor of the JAB1/MPN/Mov34 (JAMM) domain-containing metalloprotease, blocks NLRP3 inflammasome activation by canonical, noncanonical, alternative, and transcription-independent pathways at nanomolar concentrations. In addition, THL potently inhibited the activation of multiple NLRP3 mutants linked with cryopyrin-associated periodic syndromes (CAPS). Treatment with THL alleviated NLRP3-related diseases in mouse models of lipopolysaccharide-induced sepsis, monosodium urate-induced peritonitis, experimental autoimmune encephalomyelitis, CAPS, and methionine-choline-deficient diet-induced nonalcoholic fatty liver disease. Mechanistic studies revealed that THL inhibits the BRCC3-containing isopeptidase complex (BRISC)-mediated NLRP3 deubiquitination and activation. In addition, we show that holomycin, a natural methyl derivative of THL, displays an even higher inhibitory activity against NLRP3 inflammasome than THL. Our study validates that posttranslational modification of NLRP3 can be pharmacologically targeted to prevent or treat NLRP3-associated inflammatory diseases. Future clinical development of derivatives of THL may provide new therapies for NLRP3-related diseases.

Management of Monogenic IL-1 Mediated Autoinflammatory Diseases in Childhood

Monogenic Interleukin 1 (IL-1) mediated autoinflammatory diseases (AID) are rare, often severe illnesses of the innate immune system associated with constitutively increased secretion of pro-inflammatory cytokines. Clinical characteristics include recurrent fevers, inflammation of joints, skin, and serous membranes. CNS and eye inflammation can be seen. Characteristically, clinical symptoms are coupled with elevated inflammatory markers, such as C-reactive protein (CRP) and serum amyloid A (SAA). Typically, AID affect infants and children, but late-onset and atypical phenotypes are described. An in-depth understanding of autoinflammatory pathways and progress in molecular genetics has expanded the spectrum of AID. Increasing numbers of genetic variants with undetermined pathogenicity, somatic mosaicisms and phenotype variability make the diagnosis of AID challenging. AID should be diagnosed as early as possible to prevent organ damage. The diagnostic approach includes patient/family history, ethnicity, physical examination, specific functional testing and inflammatory markers (SAA, CRP) during, and in between flares. Genetic testing should be performed, when an AID is suspected. The selection of genetic tests is guided by clinical findings. Targeted and rapid treatment is crucial to reduce morbidity, mortality and psychosocial burden after an AID diagnosis. Management includes effective treat-to-target therapy and standardized, partnered monitoring of disease activity (e.g., AIDAI), organ damage (e.g., ADDI), patient/physician global assessment and health related quality of life. Optimal AID care in childhood mandates an interdisciplinary team approach. This review will summarize the current evidence of diagnosing and managing children with common monogenic IL-1 mediated AID.

Diagnosis and Management of the Cryopyrin-Associated Periodic Syndromes (CAPS): What Do We Know Today?

The cryopyrin-associated periodic syndromes (CAPS) are usually caused by heterozygous NLRP3 gene variants, resulting in excessive inflammasome activation with subsequent overproduction of interleukin (IL)-1β. The CAPS spectrum includes mild, moderate, and severe phenotypes. The mild phenotype is called familial cold autoinflammatory syndrome (FCAS), the moderate phenotype is also known as Muckle-Wells syndrome (MWS), and the neonatal-onset multisystem inflammatory disease (NOMID)/chronic infantile neurologic cutaneous articular syndrome (CINCA) describes the severe phenotype. The CAPS phenotypes display unspecific and unique clinical signs. Dermatologic, musculoskeletal, ocular, otologic, and neurologic disease symptoms combined with chronic systemic inflammation are characteristic. Nevertheless, making the CAPS diagnosis is challenging as several patients show a heterogeneous multi-system clinical presentation and the spectrum of genetic variants is growing. Somatic mosaicisms and low-penetrance variants lead to atypical clinical symptoms and disease courses. To avoid morbidity and to reduce mortality, early diagnosis is crucial, and a targeted anti-IL-1 therapy should be started as soon as possible. Furthermore, continuous and precise monitoring of disease activity, organ damage, and health-related quality of life is important. This review summarizes the current evidence in diagnosis and management of patients with CAPS.

Evolution of Our Understanding of XIAP Deficiency

X-linked inhibitor of apoptosis (XIAP) deficiency is a rare inborn error of immunity first described in 2006. XIAP deficiency is characterised by immune dysregulation and a broad spectrum of clinical manifestations, including haemophagocytic lymphohistiocytosis (HLH), inflammatory bowel disease (IBD), hypogammaglobulinemia, susceptibility to infections, splenomegaly, cytopaenias, and other less common autoinflammatory phenomena. Since the first description of the disease, many XIAP deficient patients have been identified and our understanding of the disease has grown. Over 90 disease causing mutations have been described and more inflammatory disease manifestations, such as hepatitis, arthritis, and uveitis, are now well-recognised. Recently, following the introduction of reduced intensity conditioning (RIC), outcomes of allogeneic haematopoietic stem cell transplantation (HSCT), the only curative treatment option for XIAP deficiency, have improved. The pathophysiology of XIAP deficiency is not fully understood, however it is known that XIAP plays a role in both the innate and adaptive immune response and in immune regulation, most notably through modulation of tumour necrosis factor (TNF)-receptor signalling and regulation of NLRP3 inflammasome activity. In this review we will provide an up to date overview of both the clinical aspects and pathophysiology of XIAP deficiency.

Clinical and psychological phenomenology of pain in autoinflammatory diseases

BACKGROUND

Pain is the clinical hallmark of patients in patients with autoinflammatory diseases (AID) caused by variants of the NLRP3-, MEFV- or TNFRSF1A gene. However, no systematical analysis of the clinical and psychological presentation of pain has been performed to date.

METHODS

Twenty-one symptomatic patients with variants in the NLRP3-, MEFV- and TNFRSF1A gene and clinical signs suggestive of an AID were retrospectively included in this monocentric cross-sectional case-series study. Patients were examined and interviewed using the German pain questionnaire. The hospital anxiety and depression scale (HADS) was applied to screen patients for anxiety and depression.

RESULTS

Twenty out of 21 AID patients (95%) reported pain at the time of examination. Mean current pain intensity in all AID patients comprised 3.6 ± 1.3 and mean maximum pain intensity was 7.0 ± 1.6 on a 11-point numeric ranging scale (NRS). In 15 patients (71%), pain was present for more than 60 months. Ten patients (48%) experienced recurrent attacks with asymptomatic intervals and 7 patients (33%) suffered from constant pain, while 4 patients (19%) experienced both. Nociceptive pain including musculoskeletal and visceral affection was the most prominent type of pain (n = 20; 95%). Pain symptoms were treated continuously with analgesic or co-analgesic drugs in 10 patients (48%). Five patients (24%) have been positively screened for concomitant depression or anxiety.

CONCLUSIONS

Early and prompt diagnosis is necessary to provide multimodal pain treatment and to avoid the development of chronic pain in patients with AID.

Genetic panel screening in patients with clinically unclassified systemic autoinflammatory diseases

OBJECTIVE

Systemic autoinflammatory diseases (SAIDs) may not always present with typical clinical findings of a monogenic disease. We aimed to genetically screen and diagnose these clinically unclassified patients by next-generation sequencing (NGS) analysis.

METHOD

A total of 64 patients who had clinical findings of a periodic fever syndrome but did not meet the clinical diagnostic criteria for any SAID or had clinical findings for more than one monogenic SAID were identified as "clinically unclassified SAIDs." NGS panel analysis, including 16 genes, was performed in these patients. Patients, who could not be classified as one of the defined SAID after the result of the NGS gene analysis, were identified as "undefined SAID."

RESULTS

The most common autoinflammatory symptoms in unclassified SAID patients were abdominal pain (60.9%), arthralgia (48.4%), urticarial rash (43.8%), myalgia (40.6%), oral aphthae (28.1%), and conjunctivitis (20.3%), respectively. In the result of the NGS gene panel screening, pathogenic, likely pathogenic variants, or VUS (variants of uncertain significance) were detected in 36 of 64 patients in at least one gene in the NGS panel. A total of 15 patients were diagnosed with a monogenic SAID according to both phenotypic and genotypic data; 12 patients as FMF, two patients as FCAS, and one patient as TRAPS, respectively. A total of 49 patients who did not meet the classification criteria including genetic results for a monogenic SAID were followed as undefined SAID.

CONCLUSIONS

The classification criteria described for SAIDs so far unfortunately do not cover all patients with signs of periodic fevers. The NGS gene panel appears to be a useful diagnostic tool for some of the patients with clinically unclassified SAID findings. Key Points • The classification criteria described for SAIDs do not cover all patients with signs of periodic fevers • The use of the undefined SAID nomenclature will benefit clinicians for diagnosis and initiating early treatment • The NGS panel appears to be a useful diagnostic tool in patients with clinically unclassified SAIDs.

Paediatric autoimmune and autoinflammatory conditions associated with uveitis

Childhood uveitis comprises a collection of heterogenous ocular phenotypes which are associated with a diverse range of childhood autoimmune and autoinflammatory disorders. Of these genetic and/or acquired disorders, juvenile idiopathic arthritis is the most common, affecting 30-80% of children with uveitis. Up to a third of children with uveitis have 'isolated' idiopathic disease and do not have an associated systemic disease which manifests in childhood. However, uveitis may be the presenting manifestation of disease; thus, the apparently well child who presents with uveitis may have isolated idiopathic disease, but they may have an evolving systemic disorder. The diagnosis of most of the associated disorders is reliant on clinical features rather than serological or genetic investigations, necessitating detailed medical history taking and systemic examination. Adequate control of inflammation is key to good visual outcomes, and multidisciplinary care is key to good broader health outcomes.

Therapeutic options for patients with rare rheumatic diseases: a systematic review and meta-analysis

BACKGROUND

Rare diseases (RDs) in rheumatology as a group have a high prevalence, but randomized controlled trials are hampered by their heterogeneity and low individual prevalence. To survey the current evidence of pharmacotherapies for rare rheumatic diseases, we conducted a systematic review and meta-analysis. Randomized controlled trials (RCTs) of RDs in rheumatology for different pharmaco-interventions were included into this meta-analysis if there were two or more trials investigating the same RD and using the same assessment tools or outcome parameters. The Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, and PUBMED were searched up to April 2nd 2020. The overall objective of this study was to identify RCTs of RDs in rheumatology, evaluate the overall quality of these studies, outline the evidence of pharmacotherapy, and summarize recommended therapeutic regimens.

RESULTS

We screened 187 publications, and 50 RCTs met our inclusion criteria. In total, we analyzed data of 13 different RDs. We identified several sources of potential bias, such as a lack of description of blinding methods and allocation concealment, as well as small size of the study population. Meta-analysis was possible for 26 studies covering six RDs: Hunter disease, Behçet's disease, giant cell arteritis, ANCA-associated vasculitis, reactive arthritis, and systemic sclerosis. The pharmacotherapies tested in these studies consisted of immunosuppressants, such as corticosteroids, methotrexate and azathioprine, or biologicals. We found solid evidence for idursulfase as a treatment for Hunter syndrome. In Behçet's disease, apremilast and IF-α showed promising results with regard to total and partial remission, and Tocilizumab with regard to relapse-free remission in giant cell arteritis. Rituximab, cyclophosphamide, and azathioprine were equally effective in ANCA-associated vasculitis, while mepolizumab improved the efficacy of glucocorticoids. The combination of rifampicin and azithromycin showed promising results in reactive arthritis, while there was no convincing evidence for the efficacy of pharmacotherapy in systemic sclerosis.

CONCLUSION

For some diseases such as systemic sclerosis, ANCA-associated vasculitis, or Behcet's disease, higher quality trials were available. These RCTs showed satisfactory efficacies for immunosuppressants or biological drugs, except for systemic sclerosis. More high quality RCTs are urgently warranted for a wide spectrum of RDs in rheumatology.

Cutaneous clues to diagnose autoinflammatory diseases

Systemic autoinflammatory diseases (AIDs) are a group of disorders characterized by recurrent episodes of systemic inflammation. Suspecting the diagnosis can be difficult and many of the clinical manifestations are common to different diseases. Although most of the cutaneous manifestations are non-specific, it is important to know them because sometimes they can lead to the diagnosis. The purpose of this review was to synthesize the main cutaneous lesions of autoinflammatory diseases to aid in their diagnosis.

Schnitzler Syndrome in a 27-Year-Old Man: Diagnostic and Therapeutic Dilemma in Adult Auto-Inflammatory Syndromes A Case Report and Literature Review

A 32-year-old-man, with a history of chronic urticaria from the age of 27, diagnosed with an adult-onset Still’s disease and received a low dose of glucocorticoids, methotrexate and tocilizumab. Despite the long-term combined treatments, he suffered from chronic urticaria, low-grade fever and bone pain. He was found to have high inflammatory markers, hypogammaglobulinemia, monoclonal IgM – kappa light chain in serum and increased radiotracer uptake in the whole bone scintigraphy. No pathological variants for monogenic autoinflammatory diseases were present in the genome exome sequencing. These investigations confirmed the diagnosis of Schnitzler syndrome, which is an exception before the age of 35. Switching from tocilizumab to interleukin 1 receptor inhibitor, anakinra led to a full clinical response and normalisation of inflammatory markers. Patients with a history of fever and chronic urticaria are routinely tested for monoclonal gammopathy in the context of malignancy, but it should also be considered as a sign of the autoinflammatory syndrome. The Schnitzler syndrome and the adult-onset Still’s disease share common features, so the diagnosis requires a thorough investigation to establish an optimal treatment. In the diagnostic algorithm, monoclonal gammopathy is usually considered red flag for malignancy but might be overlooked as a criterion of Schnitzler syndrome, particularly in young adults. We confirm that the interleukin 1 inhibitor should be the first line of therapy in Schnitzler syndrome, and in the presented case we found it more effective than the interleukin 6 blockade. The main goal of this paper is to increase awareness of Schnitzler syndrome among health care professionals. We aim to present features which can be helpful in differential diagnosis.

Secondary Intracranial Hypertension in Pediatric Patients With Cryopyrin-Associated Periodic Syndrome

BACKGROUND

Cryopyrin-associated periodic syndrome is characterized by periodic fever, rash, and joint pain. Papilledema rarely occurs. We present our series of patients with cryopyrin-associated periodic syndrome who clinically met the diagnostic criteria for Muckle-Wells syndrome and our experience with secondary intracranial hypertension.

METHODS

Retrospective review of all patients with cryopyrin-associated periodic syndrome at Nationwide Children's Hospital from October 2015 to September 2017.

RESULTS

Eighteen children met inclusion criteria: 15 females and three males, aged 1.5 to 16.2 years. Fifteen had periodic fever genetic testing; three had a known genetic defect identified, eight had a defect identified not currently known to be associated with cryopyrin-associated periodic syndrome, and four had no defect identified. Six patients (30%) developed headaches and were diagnosed with secondary intracranial hypertension. Lumbar puncture opening pressures ranged from 28 to 45 cm H₂O. Only one patient had papilledema. Initial treatment was medical in all cases, by increasing interleukin-1 inhibitor dose and/or acetazolamide. One patient required a ventriculoperitoneal shunt for headache management. No visual acuity loss was detected. All six patients with secondary intracranial hypertension had a known genetic mutation or genetic variant of unknown significance; five involved the NLRP3 gene.

CONCLUSIONS

In our series of 18 patients with cryopyrin-associated periodic syndrome, secondary intracranial hypertension occurred at a higher than expected rate. We suspect that genetic defects involving the NLRP3 gene may be a risk factor. Papilledema was present in only one patient. Physicians treating cryopyrin-associated periodic syndrome should be aware of this vision-threatening association and potential therapeutic approach.

Familial Mediterranean Fever and COVID-19: Friends or Foes?

Familial Mediterranean Fever (FMF) and COVID-19 show a remarkable overlap of clinical symptoms and similar laboratory findings. Both are characterized by fever, abdominal/chest pain, elevation of C-reactive protein, and leukocytosis. In addition, colchicine and IL-1 inhibitors treatments that are effective in controlling inflammation in FMF patients have recently been proposed for off-label use in COVID-19 patients. Thus, FMF may resemble a milder recapitulation of the cytokine storm that is a hallmark of COVID-19 patients progressing to severe disease. We analyzed the sequence of the MEFV-encoded Pyrin protein - whose mutations cause FMF- in mammals, bats and pangolin. Intriguingly, although Pyrin is extremely conserved in species that are considered either a reservoir or intermediate hosts for SARS-CoV-2, some of the most common FMF-causing variants in humans are present as wildtype residues in these species. We propose that in humans, Pyrin may have evolved to fight highly pathogenic infections.

The systemic autoinflammatory disorders for dermatologists. Part 2: disease examples

The systemic autoinflammatory disorders (SAIDS) or periodic fever syndromes are disorders of innate immunity, which can be inherited or acquired. They are almost all very rare and easily overlooked; typically, patients will have seen multiple specialities prior to diagnosis, so a high level of clinical suspicion is key. It is important to note that these are 'high-value' diagnoses as the majority of these syndromes can be very effectively controlled, dramatically improving quality of life and providing protection against the development of irreversible complications such as AA amyloidosis. In Part 1 of this review, we took an overview of SAIDS and described the common features; in this article, we take a more in-depth look at the better recognized or more dermatologically relevant conditions.

Novel mutation in the NRLP3 manifesting as an intermediate phenotype of cryopyrinopathies

Cryopyrin-associated periodic syndromes (CAPS) are a group of autoinflammatory diseases associated with NLRP3 gain of function mutations. CAPS associated mutations are found predominantly in exon 3. The objective of this study is to describe a new variant on NRLP3 gene and its phenotype. Case report description of a new NRLP3 pathogenic variant and literature case-based search through INFEVERS database. A 21-year old male who presented multiple tonic-clonic seizures on his 3rd day of life. At age 2, he had recurrent central facial palsy, high fever (40 °C), painful and persistent oral ulcers, abdominal pain, nausea and vomiting, and delayed neuropsychomotor development, with polyarthritis in wrists and knees. Over the years, several symptoms were observed: livedo reticularis, Raynaud's phenomenon, positive pathergy test, heat allodynia, extremely painful genital ulcers, and sporadic conjunctivitis. Laboratory studies revealed persistently elevated inflammatory markers and serum amyloid protein A (30 μg/l). The genetic panel for autoinflammatory diseases revealed heterozygous mutation in the NLRP3, (c.2068G > C, p.E690Q) with 0% of frequency in the general population. The patient denies rash and did not have frontal bossing or patellar overgrowth. We found a positive familial history on mother and brother, who carried the same mutation. The patient was started on canakinumab which controlled his symptoms. Currently, 241 missense variants in the NLRP3 have been described. We presented a new mutation in exon 3 of the NRLP3 gene in a patient that fulfills clinical criteria for CAPS who had complete clinical response to Canakinumab, supporting the idea that this mutation is pathogenic.

NLRP3 Inflammasome Activation in Cancer: A Double-Edged Sword

Inflammation is involved in tumor development and progression as well as antitumor response to therapy. In the past decade, the crosstalk between inflammation, immunity, and cancer has been investigated extensively, which led to the identification of several underlying mechanisms and cells involved. The formation of inflammasome complexes leads to the activation of caspase-1, production of interleukin (IL)-1β, and IL-18 and pyroptosis. Multiple studies have shown the involvement of NLRP3 inflammasome in tumorigenesis. Conversely, other reports have indicated a protective role in certain cancers. In this review, we summarize these contradictory roles of NLRP3 inflammasome in cancer, shed the light on oncogenic signaling leading to NLRP3 activation and IL-1β production and outline the current knowledge on therapeutic approaches.

How to handle the main drugs to treat autoinflammatory disorders and how we treat common autoinflammatory diseases

This article provides an overview of the main drugs to treat autoinflammatory disorders focusing on the four emblematic diseases within this group which represent, to date, the vast majority of patients with monogenic SAID; i.e. familial Mediterranean fever, mevalonate kinase deficiency, TNF receptor 1 deficiency and cryopyrin-associated periodic syndrome. We will therefore resume the evolutionary risks of the four main IL-1 dependent SAID, there treatments and monitoring tools. After having exposed the general principles, we will detail specific guidelines for the management in everyday clinical practice of patients according to the four main pathologies based on both our expertise and international recommendations. We aim herein to guide practitioners in charge of patients with common SAID towards optimal follow-up with appropriate monitoring of anti-inflammatory drugs.

Next generation sequencing panel in undifferentiated autoinflammatory diseases identifies patients with colchicine-responder recurrent fevers

OBJECTIVES

The number of innate immune system disorders classified as systemic autoinflammatory diseases (SAID) has increased in recent years. More than 70% of patients with clinical manifestations of SAID did not receive a molecular diagnosis, thus being classed as so-called undifferentiated or undefined SAID (uSAID). The aim of the present study was to evaluate a next-generation sequencing (NGS)-based clinically oriented protocol in patients with uSAID.

METHODS

We designed a NGS panel that included 41 genes clustered in seven subpanels. Patients with uSAID were classified into different groups according to their clinical features and sequenced for the coding portions of the 41 genes.

RESULTS

Fifty patients were enrolled in the study. Thirty-four patients (72%) displayed recurrent fevers not consistent with a PFAPA phenotype. Sixteen patients displayed a chronic inflammatory disease course. A total of 100 gene variants were found (mean 2 per patient; range 0-6), a quarter of which affected suspected genes. Mutations with a definitive diagnostic impact were detected in two patients. Patients with genetically negative recurrent fevers displayed a prevalent gastrointestinal, skin and articular involvement. Patients responded to steroids on demands (94%) and colchicine, with a response rate of 78%.

CONCLUSION

Even with a low molecular diagnostic rate, a NGS-based approach is able to provide a final diagnosis in a proportion of uSAID patients with evident cost-effectiveness. It also allows the identification of a subgroup of genetically negative patients with recurrent fever responding to steroid on demand and colchicine.

Neurological phenotypes in patients with NLRP3-, MEFV-, and TNFRSF1A low-penetrance variants

Background

Neurological manifestations and the co-occurrence of multiple sclerosis (MS) have been reported in patients with autoinflammatory diseases (AID) and variants of the NLRP3-, MEFV-, or TNFRSF1A gene. However, type and frequency of neurological involvement are widely undetermined.

Methods

We assessed clinical characteristics of 151 (108 with MS) patients carrying NLRP3-, MEFV- and TNFRSF1A low-penetrance variants  from the Institute of Clinical Neuroimmunology. We evaluated demographic, genetic, and clinical features with a focus on central nervous system (CNS) involvement including magnetic resonance imaging (MRI) results and cerebrospinal fluid (CSF) data. The disease course of AID patients with MS was compared to a matched MS control group without mutations.

Results

The genetic distribution comprised 36 patients (23%) with NLRP3- and 66 patients (43%) with TNFRSF1A low-penetrance variants as well as 53 (34%) patients carrying pathogenic mutations or low-penetrance variants in the MEFV gene. MS patients displayed most frequently the R92Q TNFRSF1A variant (n = 51; 46%) followed by the Q703K NLRP3 variant (n = 15; 14%) and the E148Q substitution (n = 9; 8%) in the MEFV gene. The disease course of MS was not influenced by the genetic variants and did not differ from MS patients (n = 51) without mutations. AID patients without MS most frequently harbored MEFV mutations (n = 19, 43%) followed by NLRP3- (n = 17, 39%) and TNFRSF1A (n = 8, 18%) low-penetrance variants. Sixteen (36%) of them suffered from severe CNS involvement predominantly recurrent aseptic meningoencephalitis and optic neuritis accompanied by abnormal MRI and CSF results. Severe CNS inflammation was associated with the Q703K allele. Headache was a highly prevalent neurological symptom (up to 74%), irrespective of the underlying genetic variation. The NLRP3 cohort without MS more frequently exhibited affections of the cranial nerves (CN) (p = 0.0228) and motor symptoms (p = 0.0455). Elevated acute-phase reactants were detected in all patients, and fever episodes were present in up to 50%. Arthralgias were the most frequently identified constitutional symptom among all subgroups.

Conclusions

Our data highlight the high prevalence of neurological manifestations, including concomitant MS, among NLRP3-, MEFV-, and TNFRSF1A low-penetrance variants. In particular, patients carrying the Q703K NLRP3 variant are at risk for severe CNS inflammation and CN affection.

Increased Prevalence of NLRP3 Q703K Variant Among Patients With Autoinflammatory Diseases: An International Multicentric Study

Background: The NLRP3 inflammasome has been recognized as one of the key components of innate immunity. Gain-of-function mutations in the exon 3 of NLRP3 gene have been implicated in inflammatory diseases suggesting the presence of functionally important sites in this region. Q703K (c.2107C>A, p.Gln703Lys, also known in the literature as Q705K) is a common variant of NLRP3, that has been considered to be both clinically unremarkable or disease-causing with a reduced penetrance. Objectives: We aimed to investigate the potential genetic impact of the NLRP3 variant Q703K in patients with recurrent fever presenting with two autoinflammatory diseases: PFAPA (periodic fever, aphthous stomatitis, pharyngitis and cervical adenitis) and CAPS (cryopyrin-associated periodic syndrome), as well as with undefined autoinflammatory disease (uAID). Methods: This is an international multicentric observational retrospective study characterizing the clinical phenotype of patients presenting with recurrent fever suspected to be of auto-inflammatory origin and where the Q703K NLRP3 variant was found. Monocytes of parents of 6 Q703K+ PFAPA patients were studied and levels of pro-inflammatory cytokines produced by monocytes of Q703K+ and Q703K- parents have been compared by ELISA. Results: We report 42 patients with the Q703K NLRP3 genetic variant: 21 were PFAPA patients, 6 had a CAPS phenotype, and 15 had an uAID. The phenotypes of PFAPA, CAPS and uAID were quite similar between Q703K positive and negative patients with the exception of increased prevalence of pharyngitis in the Q703K positive CAPS population compared to the negative one. The in vitro production of IL-1β was not significantly different between Q703K+ and Q703K- monocytes from asymptomatic parents. Conclusion: The evidence we report in our study shows an increased prevalence of NLRP3 Q703K in patients with autoinflammatory diseases, suggesting an association between the Q703K variant and the risk of PFAPA, CAPS and uAID syndromes. However, we did not show a functional effect of this mutation on the inflammasome basal activity.

Consensus protocols for the diagnosis and management of the hereditary autoinflammatory syndromes CAPS, TRAPS and MKD/HIDS: a German PRO-KIND initiative

BACKGROUND

Rare autoinflammatory diseases (AIDs) including Cryopyrin-Associated Periodic Syndrome (CAPS), Tumor Necrosis Receptor-Associated Periodic Syndrome (TRAPS) and Mevalonate Kinase Deficiency Syndrome (MKD)/ Hyper-IgD Syndrome (HIDS) are genetically defined and characterized by recurrent fever episodes and inflammatory organ manifestations. Early diagnosis and early start of effective therapies control the inflammation and prevent organ damage. The PRO-KIND initiative of the German Society of Pediatric Rheumatology (GKJR) aims to harmonize the diagnosis and management of children with rheumatic diseases nationally. The task of the PRO-KIND CAPS/TRAPS/MKD/HIDS working group was to develop evidence-based, consensus diagnosis and management protocols including the first AID treat-to-target strategies.

METHODS

The national CAPS/TRAPS/MKD/HIDS expert working group was established, defined its aims and conducted a comprehensive literature review synthesising the recent (2013 to 2018) published evidence including all available recommendations for diagnosis and management. General and disease-specific statements were anchored in the 2015 SHARE recommendations. An iterative expert review process discussed, adapted and refined these statements. Ultimately the GKJR membership vetted the proposed consensus statements, agreement of 80% was mandatory for inclusion. The approved statements were integrated into three disease specific consensus treatment plans (CTPs). These were developed to enable the implementation of evidence-based, standardized care into clinical practice.

RESULTS

The CAPS/TRAPS/MKD/HIDS expert working group of 12 German and Austrian paediatric rheumatologists completed the evidence synthesis and modified a total of 38 statements based on the SHARE recommendation framework. In iterative reviews 36 reached the mandatory agreement threshold of 80% in the final GKJR member survey. These included 9 overarching principles and 27 disease-specific statements (7 for CAPS, 11 TRAPS, 9 MKD/HIDS). A diagnostic algorithm was established based on the synthesized evidence. Statements were integrated into diagnosis- and disease activity specific treat-to-target CTPs for CAPS, TRAPS and MKD/HIDS.

CONCLUSIONS

The PRO-KIND CAPS/TRAPS/MKD/HIDS working group established the first evidence-based, actionable treat-to-target consensus treatment plans for three rare hereditary autoinflammatory diseases. These provide a path to a rapid evaluation, effective control of disease activity and tailored adjustment of therapies. Their implementation will decrease variation in care and optimize health outcomes for children with AID.

Neurological manifestations of autoinflammatory diseases in Chinese adult patients

OBJECTIVE

Systemic autoinflammatory diseases (SAIDs) are a group of disorders characterized by a dysregulation of innate immune system leading to multi-systemic inflammation. We aim to assess the neurological manifestations of Chinese adult patients with SAIDs.

METHODS

Eighty adult patients (≥16 years) were diagnosed as SAIDs from April 2015 to June 2019, at the center of adult autoinflammatory diseases, Department of Rheumatology, Peking Union Medical College Hospital. Clinical and genetic features of these patients were collected. All patients underwent neurologic, ophthalmologic and otolaryngologic evaluation.

RESULTS

Totally 31 out of 80 (38.8%) patients had neurological manifestations, including 14 familial Mediterranean fever (45.2%), 6 NLRP3-associated autoinflammatory disease (19.4%), 5 tumor necrosis factor receptor-associated periodic fever syndrome (16.1%), 5 NLRP12-associated autoinflammatory disease (16.1%), and 1 Yao syndrome (3.2%). Twenty patients (64.5%) were adult-onset. The median time of diagnosis delay was 11.7 years (0.5-50 years). The common neurological damage included headache (28 patients, 90.3%), sensorineural hearing loss (6, 19.4%), dizziness (4, 12.9%), cerebral infarction/hemorrhage (4, 12.9%), chronic aseptic meningitis (3, 9.7%), intracranial hypertension (3, 9.7%), papilledema (3, 9.7%), optic neuritis (2, 6.5%), and hydrocephalus (1, 3.2%). Severe neurological damage was observed in 8 patients (25.8%), including brain atrophy, hydrocephalus, complete hearing loss, chronic aseptic meningitis and optic neuritis.

CONCLUSION

Neurological damage was diverse in SAIDs patients. Neurological symptoms should be fully realized by physicians, in not only pediatric but also adult patients with SAIDs. CSF analysis and brain images should be performed promptly. Early diagnosis and appropriate treatment are essential to avoid irreversible neurological complications.

Hints for Genetic and Clinical Differentiation of Adult-Onset Monogenic Autoinflammatory Diseases

Monogenic autoinflammatory diseases (mAIDs) are inherited errors of innate immunity characterized by systemic inflammation recurring with variable frequency and involving the skin, serosal membranes, synovial membranes, joints, the gastrointestinal tube, and/or the central nervous system, with reactive amyloidosis as a potential severe long-term consequence. Although individually uncommon, all mAIDs set up an emerging chapter of internal medicine: recent findings have modified our knowledge regarding mAID pathophysiology and clarified that protean inflammatory symptoms can be variably associated with periodic fevers, depicting multiple specific conditions which usually start in childhood, such as familial Mediterranean fever, tumor necrosis factor receptor-associated periodic syndrome, cryopyrin-associated periodic syndrome, and mevalonate kinase deficiency. There are no evidence-based studies to establish which potential genotype analysis is the most appropriate in adult patients with clinical phenotypes suggestive of mAIDs. This review discusses genetic and clinical hints for an ideal diagnostic approach to mAIDs in adult patients, as their early identification is essential to prompt effective treatment and improve quality of life, and also highlights the most recent developments in the diagnostic work-up for the most frequent hereditary periodic febrile syndromes worldwide.

Cryopyrin-associated periodic fever syndrome in children: A case-based review

Cryopyrin-associated periodic fever syndrome (CAPS) represents an increasingly recognized disease group entity, with varied presentations. CAPS includes 3 clinical entities, namely, familial cold-induced autoinflammatory syndrome (FCAS; MIM #120100), Muckle-Wells syndrome (MWS; MIM #191900) and chronic inflammatory neurologic cutaneous and articular syndrome (CINCA; MIM #607115); which share several overlapping clinical features. These patients often present with early-onset episodes of fever and rash, and variable systemic signs and symptoms, making it a great mimicker of other systemic autoimmune diseases. The episodes are transient and related to exposure to cold temperature and worsen in the winter season. We hereby present a case presenting with recurrent seasonal fever and rash, diagnosed as FCAS/ MWS overlap based on clinical signs and symptoms and positive testing for NLRP3 gene mutation. We also discuss the clinical presentation and complications of CAPS, chiefly FCAS and MWS, along with the previously described pediatric cases of CAPS. We tried to review the complexities of management of such patients, including the genetic diagnosis and the role of biological therapy. Based on the review of the literature, given the evident broad spectrum of symptoms and signs, use of next-generation sequencing can help in prompt diagnosis and early initiation of biological agents, which may play a great role in reducing the complications that these patients may experience in the long run.

Periodic fever syndromes and the autoinflammatory diseases (AIDs)

Innate immune system represents the ancestral defense against infectious agents preserved along the evolution and species; it is phylogenetically older than the adaptive immune system, which exists only in the vertebrates. Cells with phagocytic activity such as neutrophils, macrophages, and natural killer (NK) cells play a key role in innate immunity. In 1999 Kastner et al. first introduced the term “autoinflammation” describing two diseases characterized by recurrent episodes of systemic inflammation without any identifiable infectious trigger: Familial Mediterranean Fever (FMF) and TNF Receptor Associated Periodic Syndrome (TRAPS). Autoinflammatory diseases (AIDs) are caused by self-directed inflammation due to an alteration of innate immunity leading to systemic inflammatory attacks typically in an on/off mode. In addition to inflammasomopathies, nuclear factor (NF)-κB-mediated disorders (also known as Rhelopathies) and type 1 interferonopathies are subjects of more recent studies.

This review aims to provide an overview of the field with the most recent updates (see “Most recent developments in..” paragraphs) and a description of the newly identified AIDs.

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Autoinflammatory diseases are caused by self-directed inflammation.

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Alteration of innate immunity leads to systemic inflammation attacks.

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The autoinflammatory field is exponentially expanding.

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The advances in AIDs have led to new insights into immune system understanding.

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Autoimmunity and autoinflammation features may be simultaneously present.

What's new in autoinflammation?

The pathogenesis of autoinflammatory diseases has shed light on the concept of inflammation in general and on our understanding of the role of the innate immune system. The autoinflammatory diseases have a large spectrum with varying features of inflammation. The most common autoinflammatory diseases are those associated with periodic fevers. The delay in diagnosis of these four common diseases (familial Mediterranean fever, cryopyrin-associated periodic fever syndrome, mevalonate kinase deficiency, and TNF receptor-associated periodic fever syndrome) results in secondary amyloidosis of the kidney. The new work towards classification criteria for these diseases is presented. Recently a group of autoinflammatory diseases that are associated with vasculitis have also been identified. These are stimulators of interferon genes (STING)-associated vasculopathy of infancy (SAVI), which is a monogenic defect associated with excessive activity in interferon alpha and deficiency of adenosine deaminase 2, which is characterized by a polyarteritis nodosa-like picture. These monogenic diseases are now in our differential diagnosis of vasculitides. Secondary amyloidosis is a complication of autoinflammatory diseases. Understanding the inflammatory mechanisms in these diseases has led to the use of targeted biologics for this complication. It is hoped that enlightening the mechanisms underlying these monogenic autoinflammatory diseases will also teach us about the pathways in common diseases.

Dermatologic and Dermatopathologic Features of Monogenic Autoinflammatory Diseases

Autoinflammatory diseases include disorders with a monogenic cause and also complex conditions associated to polygenic or multifactorial factors. An increased number of both monogenic and polygenic autoinflammatory conditions have been identified during the last years. Although skin manifestations are often predominant in monogenic autoinflammatory diseases, clinical and histopathological information regarding their dermatological involvement is still scarce. Monogenic autoinflammatory diseases with cutaneous expression can be classified based on the predominant lesion: (1) maculopapular rashes or inflammatory plaques; (2) urticarial rashes; (3) pustular, pyogenic or neutrophilic dermatosis-like rashes; (4) panniculitis or subcutaneous nodules; (5) vasculitis or vasculopathy; (6) hyperkeratotic lesions; (7) hyperpigmented lesions; (8) bullous lesions; and (9) aphthous lesions. By using this classification, this review intends to provide clinical and histopathological knowledge about cutaneous involvement in monogenic autoinflammatory diseases.

Clinical characteristics and genetic analyses of 187 patients with undefined autoinflammatory diseases

OBJECTIVES

To describe the clinical characteristics, treatment response and genetic findings in a large cohort of patients with undefined systemic autoinflammatory diseases (SAIDs).

METHODS

Clinical and genetic data from patients with undefined SAIDs were extracted from the Eurofever registry, an international web-based registry that retrospectively collects clinical information on patients with autoinflammatory diseases.

RESULTS

This study included 187 patients. Seven patients had a chronic disease course, 180 patients had a recurrent disease course. The median age at disease onset was 4.3 years. Patients had a median of 12 episodes per year, with a median duration of 4 days. Most commonly reported symptoms were arthralgia (n=113), myalgia (n=86), abdominal pain (n=89), fatigue (n=111), malaise (n=104) and mucocutaneous manifestations (n=128). In 24 patients, relatives were affected as well. In 15 patients, genetic variants were found in autoinflammatory genes. Patients with genetic variants more often had affected relatives compared with patients without genetic variants (p=0.005). Most patients responded well to non-steroidal anti-inflammatory drugs (NSAIDs), corticosteroids, colchicine and anakinra. Complete remission was rarely achieved with NSAIDs alone. Notable patterns were found in patients with distinctive symptoms. Patients with pericarditis (n=11) were older at disease onset (33.8 years) and had fewer episodes per year (3.0/year) compared with other patients. Patients with an intellectual impairment (n=8) were younger at disease onset (2.2 years) and often had relatives affected (28.6%).

CONCLUSION

This study describes the clinical characteristics of a large cohort of patients with undefined SAIDs. Among these, patients with pericarditis and intellectual impairment appear to comprise distinct subsets.

Omnipresence of inflammasome activities in inflammatory bone diseases

The inflammasomes are intracellular protein complexes that are assembled in response to a variety of perturbations including infections and injuries. Failure of the inflammasomes to rapidly clear the insults or restore tissue homeostasis can result in chronic inflammation. Recurring inflammation is also provoked by mutations that cause the constitutive assembly of the components of these protein platforms. Evidence suggests that chronic inflammation is a shared mechanism in bone loss associated with aging, dysregulated metabolism, autoinflammatory, and autoimmune diseases. Mechanistically, inflammatory mediators promote bone resorption while suppressing bone formation, an imbalance which over time leads to bone loss and increased fracture risk. Thus, while acute inflammation is important for the maintenance of bone integrity, its chronic state damages this tissue. In this review, we discuss the role of the inflammasomes in inflammation-induced osteolysis.

A novel knock-in mouse model of cryopyrin-associated periodic syndromes with development of amyloidosis: Therapeutic efficacy of proton pump inhibitors

BACKGROUND

Cryopyrin-associated periodic syndromes (CAPS) are a group of autoinflammatory diseases linked to gain-of-function mutations in the NOD-like receptor family, pyrin domain containing 3 (NLRP3) gene, which cause uncontrolled IL-1β secretion. Proton pump inhibitors (PPIs), which are commonly used as inhibitors of gastric acid production, also have anti-inflammatory properties, protect mice from sepsis, and prevent IL-1β secretion by monocytes from patients with CAPS.

OBJECTIVE

We sought to develop a novel Nlrp3 knock-in (KI) mouse model of CAPS to study amyloidosis, a severe CAPS complication, and test novel therapeutic approaches.

METHODS

We generated KI mice by engineering the N475K mutation, which is associated with the CAPS phenotype, into the mouse Nlrp3 gene. KI and wild-type mice received PPIs or PBS intraperitoneally and were analyzed for survival, inflammation, cytokine secretion, and amyloidosis development.

RESULTS

Mutant Nlrp3 KI mice displayed features that recapitulate the immunologic and clinical phenotype of CAPS. They showed systemic inflammation with high levels of serum proinflammatory cytokines, inflammatory infiltrates in various organs, and amyloid deposits in the spleen, liver, and kidneys. Toll-like receptor stimulated macrophages from KI mice secreted high levels of IL-1β, IL-18, and IL-1α but low amounts of IL-1 receptor antagonist. Treatment of KI mice with PPIs had a clear clinical effect, showing a reduction in inflammatory manifestations, regression of amyloid deposits, and normalization of proinflammatory and anti-inflammatory cytokine production by macrophages.

CONCLUSION

Nlrp3 KI mice displayed a CAPS phenotype with many characteristics of autoinflammation, including amyloidosis. The therapeutic effectiveness of PPIs associated with a lack of toxicity indicates that these drugs could represent relevant adjuvants to the anti-IL-1 drugs in patients with CAPS and other IL-1-driven diseases.

CINCA Syndrome With New NLRP3 Mutation and Unreported Complication of Thyroid Carcinoma

Background

Chronic infantile neurologic cutaneous and articular syndrome (CINCA) is the most severe phenotype of cryopyrin-associated periodic syndromes (CAPS) and is caused by a missense mutation in NLRP3 gene.

Case presentation

We are reporting a 15-year-old male patient with complaints of chronic arthritis and mental involvement. Further investigations showed a heterozygous c.785G>A missense mutation in Exon 3 of NLRP3 gene and coexisting medullary thyroid carcinoma 2 years later.

Conclusions

This case showed a recently identified gene variant of NLRP3 in a CINCA patient, as a heterozygous c.785G>A missense mutation in Exon 3 of NLRP3 gene and coexisted medullary thyroid carcinoma as an unreported complication of CINCA.

Molecular genetic evaluation of NLRP3, MVK and TNFRSF1A associated periodic fever syndromes

Periodic fever syndromes (PFSs) are a family of clinical disorders, which are characterized by recurrent episodes of fever in the absence of microbial, autoimmune or malign conditions. Most common types of PFSs are associated with four genes: MEFV, MVK, TNFRSF1A and NLRP3. This paper aims to add new data to the genotype-phenotype association of MVK-, TNFRSF-1A- and NLRP3-associated PFSs. A total number of 211 patients were evaluated. Two different approaches were used for the molecular genetic evaluation of MVK-, TNFRSF-1A- and NLRP3-associated PFSs. For the first 147 patients, Sanger sequence analysis of selected exons of MVK, TNFRSF1A and NLRP3 genes was done. For subsequent 64 patients, targeted NGS panel analysis, covering all exons of MVK, TNFRSF1A and NLRP3 genes, was used. A total number of 48 variants were detected. The "variant detection rate in index patients" was higher in the NGS group than Sanger sequencing group (19% vs. 15,1%). For the variant positive patients, a detailed genotype-phenotype table was built. In PFSs, lack of correlation exists between genotype and phenotype in the general population and even within the families. In some cases, mutations behave differently and yield unexpected phenotypes. In this study, we discussed the clinical effects of eight different variants we have detected in the MVK, TNFRSF1A and NLRP3 genes. Four of them were previously identified in patients with PFS. The remaining four were not reported in patients with PFS. Thus, we had to interpret their clinical effects by analysing their frequencies and in silico analysis predictions. We suggest that new studies are needed to evaluate the effects of these variants more clearly. To be able to demonstrate a clearer genotype-phenotype relationship, all PFS-related genes should be analysed together and the possibility of polygenic inheritance should be considered.

Spectrum of the neurologic manifestations in childhood-onset cryopyrin-associated periodic syndrome

OBJECTIVE

Neurologic complications of chronic infantile neurologic, cutaneous and articular syndrome (CINCA) are well-known, whereas there are scarce data regarding neurologic features of milder cryopyrin-associated periodic syndrome (CAPS) phenotypes. We aimed to review the neurologic features in detail and summarize the other CAPS-related manifestations in 12 children.

METHODS

All children with CAPS that have been followed-up from pediatric rheumatology outpatient clinic, were enrolled to the study. In addition to the neurologic examination, magnetic resonance imaging (MRI) of brain, electroencephalography, eye examination, hearing test and intellectual assessment were done. Demographic, clinical features, genetic analysis and laboratory tests were noted from patient records and hospital database.

RESULTS

The median age of the subjects was 7 years (range 2-19 years), with a female-to-male ratio 2/1. The phenotype was consistent with familial cold autoinflammatory syndrome in 7 patients, Muckle-Wells syndrome in 3 patients and chronic infantile neurologic, cutaneous and articular syndrome in 2 patients. Most frequently noted neurologic clinical manifestation during the entire disease course was headache (n = 4/12) followed by seizures (n = 3/12), papilledema (n = 3/12), intellectual disability (n = 2/12), aseptic meningitis (n = 2/12), hearing loss (n = 2/12) and optic atrophy (n = 1/12). MRI of the brain revealed abnormal lesions in two patients. Uveitis or conjunctivitis were seen in two children. Overall, neurological involvement was detected in 6/12 of our cohort, of which half (n = 3) was in severe form.

CONCLUSION

Half of the children with CAPS exhibited neurologic manifestations with varying degrees of severity. Increased understanding and awareness of this rare but treatable syndrome among neurologists is essential. If remains untreated and unrecognized, this autoinflammatory syndrome could lead to significant morbidity and mortality. Besides complete resolution of systemic symptoms, anti-interleukin-1 treatment may also prevent progression of neurologic findings when initiated in the early stage of the disease.

Severe cryopyrin-associated periodic syndrome first characterized by early childhood-onset sensorineural hearing loss - Case report and literature review

Infant-onset bilateral sensorineural hearing loss is a key presenting symptom of the autoinflammatory cryopyrin-associated periodic syndrome. Other symptoms include periodic fever, cold-induced urticaria-like rash, chronic aseptic meningitis, polyarticular arthralgias, and renal AA amyloidosis. Early recognition and treatment with interleukin-1 blockade are critical for preventing disabling or fatal complications. We describe a patient with severe cryopyrin-associated periodic syndrome who presented at age 18 months with macrocephaly and moderate sensorineural hearing loss, later developing systemic sequelae. The pathogenic nature of the de novo NLRP3 gene variant identified was supported by a markedly elevated serum amyloid A level and sustained clinical response to anti-IL-1 therapy.