Familial Mediterranean Fever: Clinical State Of The Art

The clinical role of anakinra in the armamentarium against familial Mediterranean fever

INTRODUCTION

Familial Mediterranean Fever (FMF) is the most common autoinflammatory disease that has mainly been treated with colchicine since 1972. A significant portion of patients do not respond to colchicine and require further treatment, mainly IL-1β antagonists such as anakinra, canakinumab and rilonacept as IL-1β has a crucial role in pathogenesis of FMF. This review summarizes the current approach to treating FMF and discovers the pharmacological and clinical utility of IL-1 blocking agents based on accumulated evidence with a focus on anakinra.

AREAS COVERED

This review focuses on anakinra treatment in FMF. The data obtained from case reports, case series, retrospective studies and a Phase III trial are analyzed. Safety and efficacy profiles of anakinra are discussed.

EXPERT OPINION

Anakinra is the cheapest anti-IL-1 agent used in the treatment of colchicine-resistant FMF. It is shown to be effective and safe when used in adjunct to colchicine however its short half-life and potential to cause injection site reactions limit its use.

Efficacy and safety of anti-interleukin-1 treatment in familial Mediterranean fever patients: a systematic review and meta-analysis

OBJECTIVES

FMF is the most common hereditary monogenic fever syndrome marked by recurrent attacks of fever and polyserositis. Colchicine is the current recommended first-line treatment for FMF. However, a small portion of FMF patients are unresponsive or intolerant to colchicine. Anti-IL-1 agents are alternative treatment options for colchicine-resistant or -intolerant FMF patients. This systematic review and meta-analysis aimed to provide qualitative and quantitative evidence for the efficacy and safety of anti-IL-1 agents in adult and paediatric FMF patients.

METHODS

MEDLINE, EMBASE, CENTRAL and Web of Science were screened from inception to May 2023. We included adult and paediatric FMF patients who received continuous treatment with at least one of the anti-IL-1 drugs: anakinra, canakinumab and rilonacept. The primary efficacy outcome was the proportion of patients who achieved complete remission of attacks and the primary safety outcome was the proportion of patients who experienced at least one adverse event during treatment. A random-effects meta-analysis was performed for the quantitative synthesis.

RESULTS

Fourty-four reports consisting of 1399 FMF patients were included. Sixty percent (95% CI 49%, 72%) of the adult patients and 81% (95% CI 72%, 89%) of the paediatric patients achieved complete remission. Anti-IL-1 agents significantly decreased levels of inflammatory markers. At least one adverse event was observed in 25% (95% CI 13%, 37%) of the adult patients and 12% (95% CI 3%, 21%) of the paediatric patients.

CONCLUSION

Anti-IL-1 agents were effective and demonstrated a low adverse event profile in paediatric and adult FMF patients.

Intima media thickness of carotid arteries in familial Mediterranean fever: a systematic review and meta-analysis

AIM

To perform a systematic review and meta-analysis of studies reporting data on atherosclerosis and inflammatory markers in familial Mediterranean fever (FMF).

METHODS

EMBASE and PubMed databases were screened according to PRISMA guidelines from inception to January 2022 for articles reporting measurements of the intima media thickness (IMT) of carotid arteries and eventually carotid plaques; random effect meta-analyses for continuous outcomes and Peto's odds ratio for rare events were employed.

RESULTS

The screening and selection search strategy yielded 18 case controls studies (16 full papers and 2 abstracts); the IMT was greater in FMF (n = 1112) than in controls (n = 901) (p < 0.0001) with wide heterogeneity (I2 = 86.4%); a sensitivity analysis according to mean age of participants, male to female ratio, disease duration, C-reactive protein (CRP), serum amyloid A (SAA), fibrinogen (FNG), atherogenic index of plasma (AIP), colchicine use and NOQAS revealed that the heterogeneity variance was partly explained by CRP (p = 0.01) and to a much lesser extent by the AIP (p = 0.10). The pooled prevalence of carotid plaques was greater in FMF (n = 137) than in controls (n = 156) (19% vs 8.3%, p = 0.02) with low heterogeneity.

CONCLUSION

FMF is characterised by premature atherosclerosis expressed as a thicker intima media and a greater prevalence of carotid plaques, partially related to the C-reactive protein, as expected by the autoinflammatory nature of FMF. Key Points • Familial Mediterranean fever is characterised by premature atherosclerosis. • C-reactive protein relates to intima media thickness in keeping with the autoinflammatory nature Familial Mediterranean fever. • Targeting the inter-critical low-grade inflammation may be relevant to minimise the additional cardiovascular risk posed by premature atherosclerosis.

Late-onset familial mediterranean fever: single-center experience and literature review

Familial Mediterranean fever (FMF) is a hereditary, autoinflammatory disease characterized by recurrent fever and serositis attacks. The disease onset occurs before 20 years of age in 90% of patients and rarely after the 4th decade. The aim of this study is to screen our FMF patient pool for patients with disease onset after age of 40 and to compare them to patients with early onset with regard to clinical and genetic features. The charts of 2020 patients registered in our FMF center in the years 2008-2017 were screened with regard to age of disease onset. Patients with disease onset after the age of 40 were considered as late-onset group (Group 1). The control group (Group 2) consisted of patients with a disease onset before the age of 20 who were randomly selected from the patient pool with twice the number of probands. Demographic, clinical and genetic data were recorded. Out of 2020 patients, the attacks of FMF had started after the fourth decade in 41 patients (2.02%), (Group 1). The male to female ratio was 1:1.7 in both groups. The delay of diagnosis was 5.6 ± 5.75 years in group 1, 10.7 ± 12.3 years in group 2. The only significant difference with regard to clinical features between two groups was the frequency of fever, which was present in 26 (63.4%) patients in group 1 and 67 (81.7%) in group 2 (p = 0.026). M694V mutation was more prevalent among early-onset group whereas exon 2 variants were more frequent in patients with late onset. The mean colchicine dose in the last 6 months was 1.38 ± 0.64 mg in group 1, and 1.61 ± 0.47 mg in group 2. FMF may start after 40 years of age in approximately 2% of the patients. Lower frequency of fever, lower daily colchicine dose and lower prevalence of exon 10 mutations point out that FMF patients with a disease onset after 40 years of age experience a milder disease compared to those with an onset before the second decade of life.