Hyperimmunoglobulinaemia D and periodic fever mimicking familial Mediterranean fever in the Mediterranean

Current State of Precision Medicine in Primary Systemic Vasculitides

Precision medicine (PM) is an emerging data-driven health care approach that integrates phenotypic, genomic, epigenetic, and environmental factors unique to an individual. The goal of PM is to facilitate diagnosis, predict effective therapy, and avoid adverse reactions specific for each patient. The forefront of PM is in oncology; nonetheless, it is developing in other fields of medicine, including rheumatology. Recent studies on elucidating the genetic architecture of polygenic and monogenic rheumatological diseases have made PM possible by enabling physicians to customize medical treatment through the incorporation of clinical features and genetic data. For complex inflammatory disorders, the prevailing paradigm is that disease susceptibility is due to additive effects of common reduced-penetrance gene variants and environmental factors. Efforts have been made to calculate cumulative genetic risk score (GRS) and to relate specific susceptibility alleles for use of target therapies. The discovery of rare patients with single-gene high-penetrance mutations informed our understanding of pathways driving systemic inflammation. Here, we review the advances in practicing PM in patients with primary systemic vasculitides (PSVs). We summarize recent genetic studies and discuss current knowledge on the contribution of epigenetic factors and extracellular vesicles (EVs) in disease progression and treatment response. Implementation of PM in PSVs is a developing field that will require analysis of a large cohort of patients to validate data from genomics, transcriptomics, metabolomics, proteomics, and epigenomics studies for accurate disease profiling. This multi-omics approach to study disease pathogeneses should ultimately provide a powerful tool for stratification of patients to receive tailored optimal therapies and for monitoring their disease activity.

Vasculitis in Systemic Autoinflammatory Diseases

Autoinflammatory diseases (AID) are diseases of the innate immune system, characterized by recurrent episodes of localized or systemic inflammation. Vasculitis may accompany AID. The causes of the association of vasculitis with monogenic AID are still debated. Among the monogenic AID, Familial Mediterranean Fever (FMF) is the most common. IgA-related vasculitis (IgAV) and Polyarteritis Nodosa (PAN) involving small and/or medium-sized vessels have an increased frequency among FMF patients. There are also case reports revealing vasculitic features in Cryopyrin-Associated Periodic Fever Syndrome (CAPS), Tumor Necrosis Factor Receptor-Associated Periodic Syndrome (TRAPS), Mevalonate Kinase Deficiency (MKD), also known as Hyper IgD syndrome (HIDS), Deficiency of IL-1 Receptor Antagonist (DIRA) and Pyogenic Arthritis, Pyoderma gangrenosum, and Acne (PAPA) patients. Central nervous system vasculitis and vasculopathy have been reported in DIRA and PAPA patients whereas small vessel involvement affecting skin has been reported in CAPS, TRAPS, and MKD patients. Alternatively, vasculitis can also be a leading feature especially in the recently defined monogenic AID (Otulipenia, Deficiency of Adenosine Deaminase 2-DADA2, Haploinsufficiency of A20) and interferonopathies (STING-associated vasculopathy with onset in infancy-SAVI). DADA2 often presents as a PAN-like disease. In otulipenia, patients have painful subcutaneous nodules caused by septal panniculitis with small and medium vessel vasculitis. Haploinsufficiency of A20 (also called Familial Behcet-like Autoinflammatory Syndrome) results in a phenotype very similar to the variable vessel vasculitis of Behcet's disease with recurrent oral-genital ulcers, in addition to, skin rash, uveitis, and polyarthritis. SAVI is an autoinflammatory vasculopathy with increased Interferon (IFN) signature, causing severe skin lesions resulting in ulceration, necrosis, and in some cases, amputation. Behcet's Disease (BD) is a multifactorial polygenic AID characterized by recurrent attacks of oral-genital ulcers, skin lesions, uveitis and a unique vasculitis affecting both arteries and veins of all sizes. Many clinical features overlap with other autoinflammatory diseases and overexpression of proinflammatory cytokines is an important feature of the disease.

Mevalonate kinase gene mutations and their clinical correlations in Behçet's disease

AIM

Genetics is suggested to play a role in the development of Behçet's disease (BD). Shared phenotipic features requires an approach to differential diagnosis from periodic febrile syndromes. We planned to study for mevalonate kinase (MVK) as a candidate for a susceptibility gene for Behçet's disease.

METHOD

Consecutive Behçet patients and apperently healthy subjects were included. Severity score of Behçet disease was calculated. Genotyping of mevalonate kinase gene was performed by polymerase chain reaction/sequence-based typing technique.

RESULTS

Fifty BD patients (median age: 38.30 ± 11.06 years) and 51 controls (median age: 33.88 ± 12.47 years) were recruited. Three types of mutations have been found: first, a single nucleotide polymorphism (SNP) c.769-38C>T (rs35191208) in 21 of 50 BD patients and in 15 of 51 controls. Both groups were comparable for the frequency of c.769-38C>T (P > 0.05). In all of the cases with c.769-38C>T, a second SNP, c885+24G>A (rs2270374) was also present (previously reported to be in linkage disequilibrium with the first SNP). A third SNP, c.769-7T>G (rs104895331) was found in three of 50 BD patients and in one of the control group. We found this SNP together with c769-38C>T and c.885+24G>A. The neurological involvement was found to be more frequent in the BD patients with c.769-3C>T when compared to the BD patients without this polymorphism (P = 0.012).

CONCLUSION

Our results suggested that the effects of MVK mutations in Behçet's disease could be an additional genetic susceptibility factor for the patients with neurological involvement. However, these results need confirmation in larger study populations and in different ethnic groups.

Different clinical presentation of the hyperimmunoglobulin D syndrome (HIDS) (four cases from Turkey)

Hyperimmunoglobulin D syndrome (HIDS) is one of the autoinflammatory syndromes which are characterized by febrile attacks. Duration and frequency of the febrile attacks, as well as typical organ involvements vary greatly. Recently, it is possible to reach more reliable data by the possibilities that are opened up by molecular genetics in order to highlight the aetiopathogenesis of this group of diseases. Typical patients with HIDS have an onset of disease in the first year of life. Here, we report four Turkish HIDS cases; three of whom, the symptoms started at a later age. The diagnoses were made by relevant clinical symptoms along with MVK mutations detected by DNA sequencing method. As summarised in this article, HIDS could be presented with a broad spectrum of symptoms. Although most of the HIDS patients are reported from Europe and especially Dutch ancestry, case reports are presented from all over the world. For this reason, HIDS should be kept in mind for the differential diagnosis of periodic fever syndromes or before accepting an FMF patient as colchichine resistant. We suppose that the phenomenon of "later-onset HIDS" should shed light into unresolved clinical problems of patients with periodic fever. Especially in countries that FMF is more frequent such as Turkey, even though the symptoms start later than classic cases, HIDS should be kept in mind for differential diagnosis of periodic fever syndromes.

Hyperimmunoglobulinemia D and periodic fever syndrome; treatment with etanercept and follow-up

The hyperimmunoglobulinemia D and periodic fever syndrome (HIDS) is an autoinflammatory syndrome. It is caused by the mutations of the mevalonate kinase gene. There is no consensus for specific therapy of HIDS, but there are some case reports and studies in regards to its treatment with drugs like colchicine, steroids, nonsteroid anti-inflammatory drugs, simvastatin, anakinra, thalidomide, and etanercept. We are reporting a case evaluated for the complaints of abdominal pain and febrile episodes with massive hepatomegaly, not common finding on physical examination, its treatment with etanercept, and long-term follow-up.

Atypical hypergammaglobulinaemia D syndrome with amyloidosis: an overlap with familial Mediterranean fever?

A case of hypergammaglobulinaemia D and periodic fever syndrome, developing an amyloidosis-related nephrotic syndrome, is reported. Since such a complication represents a typical feature of another disease characterized by recurrent febrile attacks, i.e., familial Mediterranean fever, an overlap syndrome between these two rare clinical disorders can be suggested.

Association of hyperimmunoglobulinaemia D syndrome with erythema elevatum diutinum

Hyperimmunoglobulinaemia D and periodic fever syndrome was observed in a female patient with erythema elevatum diutinum. The association of this skin disease with hyperimmunoglobulinaemia D may indicate a pathogenetic relationship. The skin lesions responded to dapsone therapy.