The systemic autoinflammatory disorders for dermatologists. Part 1: overview

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 this article, we take an overview of SAIDs and look at the common features; in Part 2, we take a more in‐depth look at the better recognized or more dermatologically relevant conditions

Paraprotein-related renal disease

Paraprotein-related renal disease represents a diverse group of rare diseases characterized by distinct renal injury caused by the direct or indirect effects of a nephrotoxic paraprotein secreted by a clone of B cells. Early diagnosis and use of rapidly effective chemotherapy agents have improved patient and renal outcomes for these disorders. Patients can present with proteinuric renal impairment or tubular dysfunction. Diagnosis is often challenging because of the wide range of disease manifestations, difficulties with detection of the pathogenic clone and the common finding of an incidental paraprotein in elderly individuals. A renal biopsy along with haematological work-up is required to link a paraprotein with kidney disease. Chemotherapy directed at the plasma cell clone can halt the production of the paraprotein, which can in turn benefit renal function

Periodic fever syndromes

Periodic fever syndromes are autoinflammatory diseases. The majority present in infancy or childhood and are characterised by recurrent episodes of fever and systemic inflammation that occur in the absence of autoantibody production or identifiable infection. The best recognised disorders include CAPS, FMF, TRAPS and MKD. Understanding the molecular pathogenesis of these disorders provides unique insights into the regulation of innate immunity. Diagnosis relies on clinical acumen and is supported by genetic testing. With the exception of FMF, which is prevalent in populations originating from the Mediterranean, these syndromes are rare and easily overlooked in the investigation of recurrent fevers. Disease severity varies from mild to life threatening, and one of the most feared complications is AA amyloidosis. Effective therapies are available for many of the syndromes, including colchicine, IL-1 blockade and anti-TNF therapies, and there is an increasing interest in blocking interferon pathways

Senile Systemic Amyloidosis: Clinical Features at Presentation and Outcome

Background Cardiac amyloidosis is a fatal disease whose prognosis and treatment rely on identification of the amyloid type. In our aging population transthyretin amyloidosis (ATTRwt) is common and must be differentiated from other amyloid types. We report the clinical presentation, natural history, and prognostic features of ATTRwt compared with cardiac‐isolated AL amyloidosis and calculate the probability of disease diagnosis of ATTRwt from baseline factors. Methods and Results All patients with biopsy‐proven ATTRwt (102 cases) and isolated cardiac AL (36 cases) seen from 2002 to 2011 at the UK National Amyloidosis Center were included. Median survival from the onset of symptoms was 6.07 years in the ATTRwt group and 1.7 years in the AL group. Positive troponin, a pacemaker, and increasing New York Heart Association (NYHA) class were associated with worse survival in ATTRwt patients on univariate analysis. All patients with isolated cardiac AL and 24.1% of patients with ATTRwt had evidence of a plasma cell dyscrasia. Older age and lower N‐terminal pro‐B‐type natriuretic peptide (NT pro‐BNP) were factors significantly associated with ATTRwt. Patients aged 70 years and younger with an NT pro‐BNP <183 pmol/L were more likely to have ATTRwt, as were patients older than 70 years with an NT pro‐BNP <1420 pmol/L. Conclusions Factors at baseline associated with a worse outcome in ATTRwt are positive troponin T, a pacemaker, and NYHA class IV symptoms. The age of the patient at diagnosis and NT pro‐BNP level can aid in distinguishing ATTRwt from AL amyloidosis

Cardiovascular disease risk assessment in patients with familial Mediterranean fever related renal amyloidosis

Chronic inflammation and proteinuria is a risk factor for cardiovascular disease (CVD) in patients with chronic kidney diseases and rheumatologic disorders. Our aim was to investigate the CVD events (CVDEs) and survival between the patients with FMF-related AA amyloidosis and glomerulonephropathies (GN) to define possible predictors for CVDEs. A prospective follow-up study with FMF-amyloidosis and glomerulonephropathy (GN) was performed and patients were followed for CVDEs. Flow-mediated dilatation (FMD), FGF-23, serum lipid, hsCRP levels, BMI and HOMA were assessed. A Cox regression analysis was performed to evaluate the risk factors for CVDEs. There were 107 patients in the FMF-amyloidosis group and 126 patients with GN group. Forty-seven CVDEs were observed during the 4.2-years follow up; all 28 patients in the FMF-amyloidosis group and 14/19 patients with GN developed CVDEs before the age of 40 (p = 0.002). CVD mortality was 2.8 times higher (95% CI 1.02–7.76) in patients with FMF-amyloidosis. Across both groups, FMD and FGF23 (p < 0.001) levels were independently associated with the risk of CVDEs. Patients with FMF-amyloidosis are at increased risk of early CVDEs with premature mortality age. FGF 23, FMD and hsCRP can stratify the risk of early CVD in patients with FMF-related AA amyloidosis