C-reactive protein is more suitable than Serum Amyloid A to monitor crises and attack-free periods in Systemic Auto-Inflammatory Diseases

Abstract

Background: With their broad presentations and no global biomarker to discriminate crises and attack-free periods, Systemic Auto-Inflammatory Diseases (SAID) are difficult to manage. This study assessed Serum Amyloid A (SAA), C-reactive protein (CRP) and serum calprotectin as potential biomarkers to monitor patients with SAID.

Method: SAA (already studied in Familial Mediterranean Fever (FMF)), CRP and serum calprotectin were measured on SAID adult patients from Juvenile Inflammatory Rheumatism (JIR) cohort during their follow-up visits between 2020 and 2022. Crises and attack-free periods were clinically determined.

Results: 96 measures, mainly from FMF (43 %) and Unclassified SAID (USAID) (37 %) patients were included. Using ROC curves, a threshold with sensitivity and specificity of/over 75 % was determined for SAA (9 mg/L) and CRP (9 mg/L) but not for serum calprotectin, not investigated further. With this threshold, the results were similar in FMF and USAID patients' subgroups. SAA and CRP showed a positive correlation with crises and attack-free periods in SAID patients (r = 0.4796, p < 0.001 and r = 0.5525, p < 0.001, respectively) as in FMF and USAID patients, with no significant difference between both markers in diagnosis value and ROC curves Area Under Curve (AUC) (p = 0.32). Only the CRP results were not influenced by obesity.

Conclusion: SAA and CRP can discriminate crisis and attack-free periods in our cohort of SAID patients mainly composed of FMF and USAID patients. However, only CRP can be used regardless of body mass index. It is the first report of common biomarkers for all SAID, including USAID patients, with CRP widely accessible in routine worldwide.

C-reactive protein is more suitable than Serum Amyloid A.pdf

Download PDF • 1.27MB

National Protocol for Diagnosis and Care of Familial Mediterranean Fever

S. Georgin-Laviallea,h,∗, L. Saveya,h, L. Cuissetc, G. Boursiere,h, J.-J. Boffab,h,

M. Delplanquea,h, R. Bourguibaa,h, J.-B. Monfortd,h, I. Touitoue,h, G. Grateaua,h,

I. Kone-Pautf,h, V. Hentgeng,h, Collaborators1

Summary:

Familial Mediterranean Fever is the world's most common monogenic autoinflammatory disease. It mainly affects people from the Mediterranean region. The mutated gene is MEFV, which codes for pyrin. Transmission is autosomal recessive. Patients present with recurrent attacks of fever since childhood, associated with abdominal and/or thoracic pain lasting an average of 2 to 3 days, and a biological inflammatory syndrome. Other symptoms include arthralgia or arthritis of large joints such as the knees and ankles, myalgia of the lower limbs and pseudo-eryzipelas of the ankles. Its most severe complication is inflammatory amyloidosis, or AA amyloidosis, which can lead to renal failure. Treatment is based on colchicine, which helps prevent relapses and the onset of renal amyloidosis.

This work presents national recommendations for the diagnosis, management and follow-up of Familial Mediterranean Fever in France, where we estimate there are between 5,000 and 10,000 patients with the disease at all stages of life. Diagnosis is suspected on the basis of clinical and anamnestic elements, and confirmed by genetic analysis. These recommendations also propose a “treat-to-target” approach to disease treatment, particularly in cases of suspected colchicine resistance - a very rare situation that should remain a situation of elimination, particularly after verification of colchicine compliance. Two special situations are also addressed in these recommendations: renal failure and pregnancy.

​© 2023 Publié par Elsevier Masson SAS au nom de Société Nationale Franc¸ aise de Médecine Interne (SNFMI).

French recommandation for the diagnostic and care of FMF Rev Med int.pdf

Download PDF • 1.91MB