Performance of serum interleukin-18 (IL-18) levels for the follow-up of patients with Familial Mediterranean Fever

French title: Performance du taux d'interleukine 18 (IL-18) sérique pour la surveillance des patients atteints de fièvre méditerranéenne familiale.

First author: Inès Elhani

Journal: The Journal of Allergy and Clinical Immunology: In Practice (JACIP)

Author of the abstract: https://pubmed.ncbi.nlm.nih.gov/39667435/

Article traduit par le Dr Catherine Grandpeix-Guyodo

Introduction:

Inflammasome activation in Familial Mediterranean Fever (FMF) leads to increased secretion of interleukin (IL)-1β and IL-18. Monitoring FMF activity is essential due to the risk of AA amyloidosis in cases of prolonged inflammation and is classically done using CRP and SAA (serum amyloid A protein), whose values may be dissociated. This study investigated the possibility of monitoring FMF activity through total blood IL-18 assay.

Patients and methods:

This monocentric, retrospective study involved adult FMF patients who had at least one total blood IL-18 assay during their follow-up between 2022 and 2024. The data collected included the mutational status of the MEFV gene, CRP and SAA values, disease activity (considered controlled if fewer than 2 flares per year / uncontrolled if 2 or more flares per year), and finally the total IL-18 assay(s) performed during follow-up consultations (routine care).

Results:

Among 208 sampled patients, half had controlled FMF, and a total of 308 IL-18 assays were analyzable with a median measurement of 922.25 pg/mL (N < 350 pg/mL). Among patients with controlled FMF, IL-18 levels were significantly higher in homozygous patients compared to compound heterozygotes and heterozygotes.

Some patients had IL-18 assays when FMF was inactive and active, and levels showed no significant difference.

IL-18 levels were not significantly different in patients treated with anti-IL-1.

Assays > 7,000 pg/mL concerned 16 patients who had adherence issues with their colchicine treatment and rather low dosages (< 2 mg).

Discussion:

Total blood IL-18 levels appear to be correlated with genotype but not with disease activity. The persistence of high IL-18 levels in asymptomatic patients could suggest low-grade activity of the pyrin inflammasome. Very high levels may show that patients are undertreated, but the significance of IL-18 levels in terms of amyloidosis risk remains to be determined if the SAA level is normal.

The limitations of this study are the few samples per patient (generally 1), the retrospective nature, and the absence of evaluation by a disease activity score at the time of sampling.

Conclusion:

The monitoring of total blood IL-18 levels has a role that remains to be defined since it does not seem to reflect either the patient's immediate inflammatory state or FMF activity. Its interest could lie in detecting subclinical inflammatory activity and evaluating treatment adherence. Prospective studies on large cohorts will be necessary to deepen its utility in FMF.

Familial Mediterranean Fever and infertility: a possible role of inflammation

Article title: Novel use of interleukin-1 antagonists in male familial Mediterranean

fever patients with infertility: Case series

First author: Bugra Egeli

Journal: Archives of rheumatology

Link to the article: https://pubmed.ncbi.nlm.nih.gov/39507831/

Author of the abstract: Dr. Catherine Grandpeix-Guyodo

Introduction:

The main treatment for familial Mediterranean fever (FMF) is colchicine. Interleukin-1 (IL-1) inhibitors are used in cases of colchicine resistance in FMF.

Fertility disorders with azoospermia or oligospermia have been described in FMF; colchicine is often held responsible but this could be related to chronic inflammation induced by FMF.

Patients and methods: This article reports the cases of 2 men followed for FMF and suffering from infertility who successfully conceived embryos in vitro after stopping colchicine and starting treatment with IL-1 inhibitors.

Results:

Case N°1: A 38-year-old man with FMF, with homozygous M69V mutation of MEFV, treated with 2 mg colchicine/day had failed to conceive for 15 years despite 5 IVF attempts and stopping colchicine after the first 2 IVF. Semen analysis was macroscopically normal, with normal sperm count but decreased motility. Treatment with anakinra (IL-1 RA) was started, resulting in satisfactory semen analysis after 4 months and the obtaining of 2 genetically normal embryos compatible with transfer.

• Case N°2: A 33-year-old man suffering from FMF, with a heterozygous M694V mutation of MEFV, treated with colchicine for 14 years, presented with infertility with azoospermia. The failure of a first IVF under colchicine motivated its discontinuation and the prescription of Canakinumab. Successive sperm analyses showed progressive improvement in sperm motility which allowed, during the 5th IVF, the conception of a child.

Discussion:

These two cases show reversibility of Infertility under IL-1 inhibitors in FMF in 2 men: The introduction of anti-IL1 instead of colchicine allowed improvement in sperm quality in both cases.

Colchicine resistance is suggested as a predictive factor for infertility in FMF patients, suggesting that better control of inflammation may improve it.

Conclusion:

Infertility in men with FMF could be reversible and anti-IL1 could become the treatment of choice in FMF men with fertility disorders.

2025: A Year Rich in Autoinflammation, FMF, and VEXAS

In 2025, together with the team of the CEREMAIA Reference Center (Tenon Hospital, AP-HP / Sorbonne University), within the FAI2R network and the European Reference Network ERN RITA, we carried out extensive work focused on:

Familial Mediterranean Fever (FMF) and pyrin-associated diseases,

VEXAS syndrome, a prototype of hemato-inflammatory diseases,

AA amyloidosis and other rarer autoinflammatory diseases.

🔬 FMF and pyrin

We contributed to the update of the international EULAR/PReS recommendations for FMF, which incorporate recent advances regarding colchicine resistance and the use of biologic therapies (published in Annals of the Rheumatic Diseases, 2025).

Several studies based on the adult cohort of our reference center explored the following aspects: iron deficiency, liver involvement, FMF onset after the age of 65, the optimal daily dose of colchicine, and patients’ and prescribers’ perceptions of colchicine treatment.

We also conducted biological and genetic research on variants of the MEFV gene and pyrin-associated diseases, as well as on the role of IL-18 as a monitoring biomarker and as a specific signature of diseases involving the pyrin inflammasome.

🧬 VEXAS syndrome

In collaboration with the French VEXAS group and the MINHEMON club:

international reviews and recommendations were developed to structure the diagnosis and management of VEXAS syndrome, including a consensual definition of “flares,” infectious risks, and therapeutic strategies;

studies focused on specific organ involvement (kidney, nervous system, erythroblastopenia), as well as a multicenter study on VEXAS in women and across different ethnic backgrounds.

🧩 AA amyloidosis and other rare autoinflammatory diseases

We participated in a systematic review on AA amyloidosis in inflammatory rheumatic diseases, highlighting the importance of long-term strict control of inflammation.

We authored literature reviews on autoinflammatory actinopathies, A20 haploinsufficiency, and undifferentiated autoinflammatory diseases.

We also published work on diagnostic delay and the clinical presentation of cryopyrin-associated periodic syndromes (CAPS) in adulthood.

🧠 Therapeutic patient education programs

We continued the deployment of our three therapeutic education programs dedicated to AA amyloidosis, cryopyrinopathies (CAPS), and FMF. These programs aim to help patients and their relatives better understand the disease, treatments, monitoring, and warning signs.

In 2025, we notably led a session dedicated to CAPS during the weekend organized in July by the Muckle-Wells / CINCA association, in close collaboration with patient associations.

🎥 Patient webinars and online information

We launched a series of informational webinars for patients and their relatives on FMF, as well as educational videos on rare autoinflammatory diseases (AA amyloidosis, VEXAS syndrome, etc.), freely available on the CEREMAIA Tenon YouTube channel: CEREMAIA Tenon – Patient Webinars. These formats allow us to translate research findings and recommendations into practical messages for patients’ daily lives.

• All of this work shares a common goal:

• to better characterize these rare diseases,

• to refine diagnostic and monitoring strategies,

and ultimately, to provide more personalized and safer care for patients.

We warmly thank the patients, healthcare teams, colleagues from rare disease networks, and international partners for their commitment.

For those who would like to access specific articles in more detail, please feel free to contact us via private message or by email at:

ceremaia-medecine-int.tenon@aphp.fr