A case of mevalonate kinase deficiency, neonatal Sweet syndrome, and inflammatory bowel disease.

Mevalonate kinase deficiency is a group of rare metabolic autoinflammatory disorders that present with recurrent fevers, abdominal pain, arthralgias, adenopathy, and a variety of cutaneous manifestations. The skin findings may mimic cellulitis, erythema elevatum diutinum, IgA vasculitis, and Sweet syndrome, and there is often a morbilliform or urticarial rash and aphthous stomatitis. Mevalonate kinase deficiency is one of the identified monogenic variants that can cause very early onset inflammatory bowel disease (IBD). We present a rare case of a patient with mevalonate kinase deficiency, neonatal Sweet syndrome, and infantile-onset IBD, who has been successfully treated with canakinumab therapy.

Recurrent macrophage activation syndrome due to hyperimmunoglobulin D syndrome: a case-based review.

Hyperimmunoglobulin D syndrome (HIDS) is a hereditary autoinflammatory disease characterized by recurrent inflammatory attacks with fever, abdominal pain, lymphadenopathy, aphthous stomatitis, and skin lesions. There are few reports on HIDS patients complicated with macrophage activation syndrome (MAS); however, to our knowledge, there is no case of HIDS with recurrent MAS attacks. We report two pediatric patients initially diagnosed as Kawasaki disease and systemic juvenile idiopathic arthritis presented with recurrent MAS episodes with prolonged fever, skin rash, hepatosplenomegaly, cervical lymphadenopathy, aphthous stomatitis, headache, pancytopenia, hyperferritinemia, and hypofibrinogenemia, finally diagnosed as HIDS with a documented homozygous MVK gene mutation. This is the first report on recurrent MAS attacks due to HIDS in pediatric patients who were successful treated with corticosteroids and anti-IL-1 therapies. Thus, clinicians should be vigilantly investigated signs of autoinflammatory diseases in patients with recurrent MAS attacks during their disease course, and HIDS should be considered an underlying disease for triggering recurrent MAS attacks. We have also reviewed the current literature regarding HIDS cases complicated with a MAS attack and summarized their demographic, treatment, and outcome characteristics. Key points • Hyperimmunoglobulin D syndrome should be considered in differential diagnosis in patients who experienced recurrent macrophage activation syndrome attacks.

Ischemic stroke is a potential complication of uncontrolled inflammation in mevalonate kinase deficiency - A case report.

OBJECTIVES: Mevalonate kinase deficiency (MKD) is an autosomal recessive autoinflammatory disease characterized by recurrent systemic inflammation attacks. Despite interconnections with inflammation, thrombosis is rare or underreported in MKD. Our goal is to report evidence of uncontrolled inflammation as the cause of ischemic stroke. MATERIALS AND METHODS: Case report. RESULTS: A 39-year-old French-Canadian patient consulted for stroke. He reported a previous diagnosis of familial Mediterranean fever and hospitalizations nearly monthly since birth for recurrent inflammatory attacks despite colchicine prophylaxis. Attacks were triggered by infections or stress, lasted 3-7 days, and included fever up to 41°C, painful lymphadenopathies, abdominal pain, polyarthralgia and maculopapular rash. Stroke culminated his most recent inflammatory attack. Brain MRI confirmed an acute infarct, without chronic ischemic damage. Blood tests documented increased C-reactive protein, amyloid A and immunoglobulin-D. Prothrombotic and autoantibody tests, cervicocephalic CT-angiography, echocardiography, cardiac monitoring, and toxic screen were unremarkable. Infections were excluded. His only sister had similar attacks. In both cases, sequencing of 32 autoinflammatory-associated genes identified two pathogenic mevalonate kinase mutations. Their non-consanguineous parents, half-brother and four children were asymptomatic. Following treatment with anti-interleukin-1beta monoclonal antibodies, he no longer had inflammatory attacks or stroke in >4 years. CONCLUSION: This MKD patient experienced an ischemic stroke during an attack, attributed to uncontrolled inflammation. Investigations excluded other stroke etiologies. Recurrent febrile attacks starting before age 1 and lasting >3 days, gastrointestinal symptoms, painful lymphadenopathies, maculopapular rash, triggers, aphthous stomatitis, non-Mediterranean ancestry, and ineffectiveness of colchicine prophylaxis are consistent with MKD. Anti-interleukin-1 therapy prevents recurrent autoinflammatory attacks.

Case Report: Comorbid Hyper-IgD Syndrome and Hidradenitis Suppurativa - A New Syndromic Form of HS? A Report of Two Cases.

Hidradenitis Suppurativa (HS) is a chronic suppurative disease of the pilosebaceous unit. The current model of HS pathophysiology describes the condition as the product of hyperkeratinisation and inflammation at the hair follicular unit. Environmental factors (such as smoking and obesity), gender, genetic predisposition, and skin dysbiosis are considered the main pathogenic drivers of the disease. Autoinflammatory syndromes associated with HS are rare but may help to highlight the potential roles of autoinflammation and dysregulated innate immune system in HS. Therefore, it is of major relevance to increase the awareness about these diseases in order to improve the understanding of the disease and to optimize the management of the patients. Herein, we report for the first time, to our knowledge, two clinical cases of Hyper-IgD syndrome-associated HS. Hyper-IgD is an autoinflammatory syndrome caused by a mevalonate kinase deficiency (MKD), a key kinase in the sterol and isoprenoid production pathway. We describe the potentially shared pathophysiological mechanisms underpinning comorbid MKD-HS and propose therapeutic options for the management of these patients.

Uveitis, glaucoma, and cataract with mevalonate kinase deficiency.

We report 7 years of follow-up data on ocular findings in a 2-month-old boy who presented with early-onset bilateral granulomatous panuveitis with subsequent development of secondary glaucoma and total cataract, along with multisystem involvement. He was diagnosed with mevalonate kinase deficiency (MKD), with a homozygous missense variant in exon-6 of the mevalonate kinase (MVK) gene on chromosome-12 that resulted in the substitution of aspartic acid for asparagine at codon 205 (p.Asn205Asp). Despite being managed with topical/systemic steroids and immunosuppression therapy with methotrexate and a short course of adalimumab, the patient continued to develop recurrent episodes of uveitis along with multisystem manifestations. The occurrence of early-onset uveitis is rare, as is the diagnosis of MKD.

Case Report: Mevalonic Aciduria Complicated by Acute Myeloid Leukemia After Hematopoietic Stem Cell Transplantation.

Mevalonic aciduria (MA) is the most severe clinical subtype of mevalonate kinase deficiency (MKD) caused by an inherited defect in the mevalonate pathway. The treatment of MKD focuses on the suppression of recurrent hyperinflammatory attacks using anti-inflammatory drugs. Recently, allogeneic hematopoietic stem cell transplantation (HCT) was shown to successfully ameliorate autoinflammatory attacks in patients with MKD. Here, we report a case of an infant who showed severe recurrent systemic inflammation and was diagnosed with MA. Although she responded to steroids, her symptoms relapsed after the dose was tapered, and organ deterioration occurred. Therefore, at the age of 11 months, HCT from a matched, unrelated donor was performed for curative treatment. However, at 50 days after transplantation, acute myeloid leukemia was diagnosed, which was chemo-refractory. A second HCT from her haploidentical father was performed to treat the acute myeloid leukemia, but the patient died of sepsis on day 4 after transplantation. This is the first report of malignancy following HCT for MA. Our findings suggest that normalizing the mevalonate pathway after HCT in patients with MKD impacts patients differently depending on the clinical spectrum and severity of disease.

Vasculitis in a patient with mevalonate kinase deficiency (MKD): a case report.

BACKGROUND: Mevalonate kinase deficiency (MKD) is a rare autoinflammatory condition caused by biallelic loss-of-function (LOF) mutations in mevalonate kinase (MVK) gene encoding the enzyme mevalonate kinase. Patients with MKD display a variety of non-specific clinical manifestations, which can lead to diagnostic delay. We report the case of a child presenting with vasculitis that was found by genetic testing to be caused by MKD, and now add this autoinflammatory disease to the ever-expanding list of causes of monogenic vasculitides. CASE PRESENTATION: A 2-year-old male presented with an acute 7-day history of high-grade fever, abdominal pain, diarrhoea, rectal bleeding and extensive purpuric and necrotic lesions, predominantly affecting the lower limbs. He had been suffering from recurrent episodes of fever from early in infancy, associated with maculopapular/petechial rashes triggered by intercurrent infection, and after vaccines. Extensive infection screen was negative. Skin biopsy revealed small vessel vasculitis. Visceral digital subtraction arteriography was normal. With a diagnosis of severe idiopathic cutaneous vasculitis, he was treated with corticosteroids and mycophenolate mofetil. Despite that his acute phase reactants remained elevated, fever persisted and the vasculitic lesions progressed. Next-generation sequencing revealed compound heterozygous mutation in MVK c.928G > A (p.V310M) and c.1129G > A (p.V377I) while reduced mevalonate enzyme activity was confirmed suggesting a diagnosis of MKD as a cause of the severe vasculitis. Prompt targeted treatment with IL-1 blockade was initiated preventing escalation to more toxic vasculitis therapies and reducing unnecessary exposure to cytotoxic treatment. CONCLUSIONS: Our report highlights the broad clinical phenotype of MKD that includes severe cutaneous vasculitis and emphasizes the need to consider early genetic screening for young children presenting with vasculitis to exclude a monogenic vasculitis which may be amenable to targeted treatment.

AA amyloidosis revealing mevalonate kinase deficiency: A report of 20 cases including two new French cases and a comprehensive review of literature.

INTRODUCTION: Mevalonate kinase deficiency (MKD) is a rare autosomal recessive autoinflammatory disease that can lead to an inflammatory A amyloidosis (AA). METHODS: To study the occurrence of AA in MKD patients we performed a systemic review of the literature and described two novel patients. RESULTS: Amyloidosis occurred in 20 MKD patients, renal impairment being always the revealing symptom of AA. Although an accurate prevalence estimation is not possible since exact MKD prevalence is unknown, AA seems rare in MKD (about 6% if we estimate MKD prevalence at 300 patients worldwide). MVK gene study, available in 18 out of the 20 patients, confirmed two pathogenic mutations in all tested individuals. The most frequent genotype was V377I/I268T (n = 9/18). Retrospective search of clinical signs of MKD established, in all patients carrying MVK pathogenic mutations, a disease onset within the first four years of life. Nephrotic syndrome (n = 15), end-stage renal failure (n = 5) or both (n = 8) pointed out kidney amyloidosis. The youngest patient with renal amyloidosis was a European four-year-old girl previously misdiagnosed with PFAPA syndrome. Five patients died of AA amyloidosis despite the use of a biotherapy for two of them; kidney transplant was performed in nine individuals. Colchicine was not effective in any patient. Anti-interleukin-1 anakinra (n = 8), anti TNF etanercept (n = 7) and anti-interleukin 6 tocilizumab (n = 5) treatments were partially effective. CONCLUSION: Inflammatory A amyloidosis, a rare complication of MKD, can cause death or necessitate kidney transplantation. Early diagnosis and cytokine blocking biotherapy using anti-IL1, anti-TNF or anti-IL6 agents are required to prevent terminal renal failure.

A case report of mevalonate kinase deficiency in a 14-month-old female with fevers and lower extremity weakness.

BACKGROUND: This case follows a 14-month-old female, who despite multiple presentations to several physicians, continued to have recurrent febrile episodes with gross motor delay. Her case revealed an often missed diagnosis of Mevalonate Kinase Deficiency, that now has an FDA approved treatment that both reduces recurrence and produces remission. CASE PRESENTATION: A 14-month-old female with a history of gross motor delay, frequent Upper Respiratory Tract infections, and otitis media presented to an urgent care for inconsolability and refusal to bear weight on her right leg. She had recently been treated with amoxicillin for acute otitis media and had developed a diffuse maculopapular rash, without any associated respiratory or gastrointestinal distress that persisted beyond cessation of the antibiotics. The patient presented multiple times to an urgent care over the subsequent week for fussiness, fever, anorexia, lymphadenopathy, with labs concerning for worsening anemia and elevated inflammatory markers. Subsequently, the patient was admitted to the hospital for suspected osteomyelitis versus oncologic process. X-Ray imaging of the patient's lower extremities showed osseous abnormalities inconsistent with infection. A metabolic work-up showed elevated urine mevalonic acid, and follow-up genetic testing was positive for mutations in both copies of her mevalonate kinase gene. This led to the diagnosis of MKD. CONCLUSIONS: Often, episodic presentations require multiple perspectives to reveal the underlying cause. This case illustrates how apparent simple febrile episodes has the potential for more complexity upon further evaluation.

When neonatal inflammation does not mean infection: an early-onset mevalonate kinase deficiency with interstitial lung disease.

Systemic inflammation in neonates is attributable to an infection in almost all cases. When inflammation persists, an autoinflammatory disease should be promptly suspected. We report here a case of mevalonate kinase deficiency (MKD) that presented at birth with mild symptoms and signs suggestive for a perinatal infection, together with the uncommon finding of interstitial lung disease. An extensive diagnostic work-up, performed after ineffective antibiotic treatment, demonstrated high levels of mevalonic acid in urine (7024 mM/M of creatinine, normal value <0.1). Next-generation sequencing showed a rare c.709A > T (p.T237S) homozygous mutation in the MVK gene, consistent with MKD. Treatment with anakinra led to a prompt resolution of symptoms and a sharp drop in serum inflammatory markers. The patient is now six months-old, currently undergoing evaluation for hematopoietic stem-cell transplantation. To our knowledge, this is the first case of MKD presenting within the first week of life with interstitial lung disease.

In silico validation of the Autoinflammatory Disease Damage Index.

INTRODUCTION: Autoinflammatory diseases can cause irreversible tissue damage due to systemic inflammation. Recently, the Autoinflammatory Disease Damage Index (ADDI) was developed. The ADDI is the first instrument to quantify damage in familial Mediterranean fever, cryopyrin-associated periodic syndromes, mevalonate kinase deficiency and tumour necrosis factor receptor-associated periodic syndrome. The aim of this study was to validate this tool for its intended use in a clinical/research setting. METHODS: The ADDI was scored on paper clinical cases by at least three physicians per case, independently of each other. Face and content validity were assessed by requesting comments on the ADDI. Reliability was tested by calculating the intraclass correlation coefficient (ICC) using an 'observer-nested-within-subject' design. Construct validity was determined by correlating the ADDI score to the Physician Global Assessment (PGA) of damage and disease activity. Redundancy of individual items was determined with Cronbach's alpha. RESULTS: The ADDI was validated on a total of 110 paper clinical cases by 37 experts in autoinflammatory diseases. This yielded an ICC of 0.84 (95% CI 0.78 to 0.89). The ADDI score correlated strongly with PGA-damage (r=0.92, 95% CI 0.88 to 0.95) and was not strongly influenced by disease activity (r=0.395, 95% CI 0.21 to 0.55). After comments from disease experts, some item definitions were refined. The interitem correlation in all different categories was lower than 0.7, indicating that there was no redundancy between individual damage items. CONCLUSION: The ADDI is a reliable and valid instrument to quantify damage in individual patients and can be used to compare disease outcomes in clinical studies.

Autoinflammatory associated vasculitis.

Autoinflammatory diseases are characterized by recurrent episodes of fever and localized or systemic inflammation and are caused by monogenic defects of innate immunity. The skin is commonly involved with various manifestations including erysipelas like rash and urticaria. Although vasculitis has been described in many autoinflammatory diseases, it has not been recognized as a characteristic feature of these diseases and autoinflammatory diseases are not listed as an etiology for vasculitis associated with a systemic disease in the 2012 Revised International Chapel Hill Consensus Conference Nomenclature of Vasculitides. We describe herein 3 patients with different autoinflammatory diseases in whom leukocytoclastic vasculitis was one of the major and presenting symptoms. A review of the vast evidence in the literature for vasculitis in the spectrum of autoinflammatory diseases and a suggested pathophysiology is presented. We suggest the term autoinflammatory associated vasculitis to describe vasculitis associated with autoinflammatory diseases. Autoinflammatory diseases should be considered within the differential diagnosis of vasculitis.

The Phenotype and Genotype of Mevalonate Kinase Deficiency: A Series of 114 Cases From the Eurofever Registry.

OBJECTIVE: Mevalonate kinase deficiency (MKD) is a rare metabolic disease characterized by recurrent inflammatory episodes. This study was undertaken to describe the genotype, phenotype, and response to treatment in an international cohort of MKD patients. METHODS: All MKD cases were extracted from the Eurofever registry (Executive Agency for Health and Consumers project no. 2007332), an international, multicenter registry that retrospectively collects data on children and adults with autoinflammatory diseases. RESULTS: The study included 114 MKD patients. The median age at onset was 0.5 years. Patients had on average 12 episodes per year. Most patients had gastrointestinal symptoms (n = 112), mucocutaneous involvement (n = 99), lymphadenopathy (n = 102), or musculoskeletal symptoms (n = 89). Neurologic symptoms included headache (n = 43), cerebellar syndrome (n = 2), and mental retardation (n = 4). AA amyloidosis was noted in 5 patients, almost twice as many as expected from findings in previous cohorts. Macrophage activation syndrome occurred in 1 patient. Patients were generally well between attacks, but 10-20% of the patients had constitutional symptoms, such as fatigue, between fever episodes. Patients with p.V377I/p.I268T compound heterozygosity had AA amyloidosis significantly more often. Patients without a p.V377I mutation more often had severe musculoskeletal involvement. Treatment with nonsteroidal antiinflammatory drugs relieved symptoms. Steroids given during attacks, anakinra, and etanercept appeared to improve symptoms and could induce complete remission in patients with MKD. CONCLUSION: We describe the clinical and genetic characteristics of 114 MKD patients, which is the largest cohort studied so far. The clinical manifestations confirm earlier reports. However, the prevalence of AA amyloidosis is far higher than expected.

Observational Study of a French and Belgian Multicenter Cohort of 23 Patients Diagnosed in Adulthood With Mevalonate Kinase Deficiency.

The aim of this study was to describe the clinical and biological features of Mevalonate kinase deficiency (MKD) in patients diagnosed in adulthood. This is a French and Belgian observational retrospective study from 2000 to 2014. To constitute the cohort, we cross-check the genetic and biochemical databases. The clinical, enzymatic, and genetic data were gathered from medical records. Twenty-three patients were analyzed. The mean age at diagnosis was 40 years, with a mean age at onset of symptoms of 3 years. All symptomatic patients had fever. Febrile attacks were mostly associated with arthralgia (90.9%); lymphadenopathy, abdominal pain, and skin lesions (86.4%); pharyngitis (63.6%); cough (59.1%); diarrhea, and hepatosplenomegaly (50.0%). Seven patients had psychiatric symptoms (31.8%). One patient developed recurrent seizures. Three patients experienced renal involvement (13.6%). Two patients had angiomyolipoma (9.1%). All but one tested patients had elevated serum immunoglobulin (Ig) D level. Twenty-one patients had genetic diagnosis; most of them were compound heterozygote (76.2%). p.Val377Ile was the most prevalent mutation. Structural articular damages and systemic AA amyloidosis were the 2 most serious complications. More than 65% of patients displayed decrease in severity and frequency of attacks with increasing age, but only 35% achieved remission. MKD diagnosed in adulthood shared clinical and genetic features with classical pediatric disease. An elevated IgD concentration is a good marker for MKD in adults. Despite a decrease of severity and frequency of attacks with age, only one-third of patients achieved spontaneous remission.

Amyloid A amyloidosis secondary to hyper IgD syndrome and response to IL-1 blockage therapy.

A 62-year-old woman with a history of genetically confirmed hyperimmunoglobulinaemia D and periodic fever syndrome (HIDS) was admitted because of chronic diarrhoea. During admission she developed a rapidly progressive nephrotic syndrome. Reactive amyloid A (AA) amyloidosis was confirmed after colonic and renal biopsy which showed deposition of amyloid. After initial treatment with high-dosed corticosteroids, therapy was switched to anakinra, an IL-1 receptor antagonist, but her symptoms persisted. After cessation of anakinra, a marked exacerbation of the intestinal symptoms was noted. Nine months after the initial diagnosis of reactive amyloidosis without any amelioration of the symptoms and a decreasing quality of life, our patient declined further treatment and died soon after. This case demonstrates that AA amyloidosis does occur in patients with HIDS and can present with intestinal symptoms and proteinuria. Once amyloidosis is diagnosed the goal of treatment is to prevent further complications. In this case report we give an overview of previous cases with amyloidosis complicating HIDS with the treatments received and propose a step-up treatment plan for future cases.

Amyloidosis in a child with hyperimmunoglobulinemia D syndrome.

Hereditary periodic fever syndromes are a group of genetic diseases clinically characterized by recurrent febrile attacks. Patients are at variable risks for the development of systemic reactive (AA) amyloidosis, leading to the nephrotic syndrome and kidney failure. We present the first report of the occurrence of renal AA amyloidosis causing severe nephrotic syndrome in a Turkish child affected with hyperimmunoglobulinemia D syndrome.

AA amyloidosis complicating the hereditary periodic fever syndromes.

OBJECTIVE: AA amyloidosis is a life-threatening complication of the hereditary periodic fever syndromes (HPFS), which are otherwise often compatible with normal life expectancy. This study was undertaken to determine the characteristics, presentation, natural history, and response to treatment in 46 patients who had been referred for evaluation at the UK National Amyloidosis Centre. METHODS: Disease activity was monitored by serial measurement of serum amyloid A. Renal function was assessed by measurement of serum creatinine and albumin levels, the estimated glomerular filtration rate, and proteinuria from 24-hour urine collections. The amyloid load was measured by serum amyloid P scintigraphy. RESULTS: Twenty-four patients had familial Mediterranean fever, 12 patients had tumor necrosis factor receptor-associated periodic syndrome, 6 patients had cryopyrin-associated periodic syndromes, and 4 patients had mevalonate kinase deficiency. The median age at onset of HPFS was 5 years; median age at presentation with AA amyloidosis was 38 years. Diagnosis of an HPFS had not been considered prior to presentation with AA amyloidosis in 23 patients (50%). Eleven patients (24%) had end-stage renal failure (ESRF) at presentation; of these, 3 had received transplants prior to referral. A further 13 patients developed ESRF over the followup period, with 10 undergoing renal transplantation. The median time to progression to ESRF from onset of AA amyloidosis was 3.3 years (interquartile range [IQR] 2-8), with a median time to transplant of 4 years (IQR 3-6). Eleven patients (24%) died. The median survival in the entire cohort was 19 years from diagnosis of AA amyloidosis. Of the 37 patients who were treated successfully, or in whom at least partial suppression of the underlying HPFS was achieved, 17 (46%) showed amyloid regression, 14 (38%) showed a stable amyloid load, and 2 (5%) showed increased amyloid deposition over the followup period. CONCLUSION: AA amyloidosis remains a challenging and serious late complication of HPFS; however, outcomes are excellent when HPFS is diagnosed early enough to allow effective treatment, thus preventing or retarding further amyloid deposition and organ damage.