Different disease subtypes with distinct clinical expression in familial Mediterranean fever: results of a cluster analysis

Familial mediterranean fever: assessment of clinical manifestations, pregnancy, genetic mutational analyses, and disease severity in a national cohort

The aims of this study were to investigate the main clinical and laboratory features, including pregnancy and genetic analysis, of Turkish Familial Mediterranean Fever (FMF) patients and to analyze the relationships between genotypic features, age of disease onset, clinical findings, and disease severity. A study was planned within a national network of 22 different centers. Demographics, clinical and laboratory findings, attack characteristics, drugs, pregnancy and birth history, disease severity, and gene mutation analyses were evaluated. Disease severity, assessed using a scoring system developed by Pras et al., was evaluated in relation to gene mutations and age of disease onset. A total of 979 patients (643 females and 336 males; mean age: 35.92 ± 11.97 years) with FMF were included in the study. Of a total of 585 pregnancies, 7% of them resulted in preterm birth and 18.1% resulted in abortions. During pregnancy, there was no FMF attack in 61.4% of patients. Of the MEditerranean FeVer (MEFV) mutations, 150 (24.3%) cases were homozygous, 292 (47.3%) cases were heterozygous, and 175 (28.4%) were compound heterozygous. Patients with homozygous gene mutations had more severe disease activity, earlier age of disease onset, higher rates of joint and skin involvement, sacroiliitis, and amyloidosis. Patients with compound heterozygous genotype displayed severe disease activity in close resemblance to patients with homozygous mutation. In addition, patients with compound heterozygous mutations had higher rates of protracted febrile myalgia and elevated fibrinogen levels. In 63.9% of compound heterozygous patients, age of onset was < 20 years, with greater disease severity, and high rates of attack frequency and colchicine resistance. Our results suggest that indicators for disease severity include early onset of disease and homozygous gene mutations. Furthermore, patients with compound heterozygous mutations displayed significant presentations of severe disease activity.

Exon 2: Is it the good police in familial mediterranean fever?

Objective

Familial Mediterranean fever (FMF) is the most common autoinflammatory disease. Most of the identified disease-causing mutations are located on exon 10. As the number of studies about the effect of the exonal location of the mutation and its phenotypic expression is limited, we aimed to investigate whether the exonic location of the Mediterranean fever (MEFV) mutation has an effect on the clinical manifestation in patients with FMF.

Methods

Study population was derived from the main FMF registry that included 2246 patients from 15 different rheumatology clinics. We categorized the mutations according to their exon locations and retrieved the clinical and demographic information from the database.

Results

Patients having the MEFV mutations on exon 2 or 10 (n:1526) were divided into three subgroups according to the location of the MEFV mutations: Group 1 (exon 2 mutations), Group 2 (exon 10 mutations), and Group 3 (both exon 2 and exon 10 mutations). Group 2 patients were of a significantly younger age at onset, and erysipel-like erythema, arthritis, amyloidosis, and a family history of FMF were more common in this group.

Conclusion

Patients with FMF and exon 10 mutations show more severe clinical symptoms and outcome. Exon 2 mutations tend to have a better outcome.

Blood group 'A' may have a possible modifier effect on familial Mediterranean fever and blood group '0' may be associated with colchicine resistance

Aim/purpose: Our aim was to investigate the association between blood groups and colchicine resistance in familial Mediterranean fever (FMF) patients.

METHODS

This is a single-center, cross-sectional study. Between January and December 2016, 385 FMF patients were assessed by the Adult and Pediatric Rheumatology outpatient clinics and 297 patients had blood groups (ABO and Rh) results. The patients were grouped into two groups: colchicine-responsive patients (Group CR) and colchicine-unresponsive patients (Group CUR).

RESULTS

Patients with blood group A had 1.5-fold higher FMF compared with non-A blood group (OR: 1.50 [95% CI: 1.11-1.87]), particularly having a Rh (+) blood group (OR: 1.47 [95% CI: 1.13-1.91]). Furthermore, patients with blood group A had a better response to colchicine treatment than non-A blood group; (OR: 2.21 [95% CI: 1.15-4.27]). Patients with blood group O were prominently associated with colchicine resistance.

CONCLUSION

ABO blood phenogroups may be used in combination with other risk factors to identify FMF patients and patients at high risk for colchicine resistance.

Nationwide Experience With Off-Label Use of Interleukin-1 Targeting Treatment in Familial Mediterranean Fever Patients

OBJECTIVE

Approximately 30-45% of patients with familial Mediterranean fever (FMF) have been reported to have attacks despite colchicine treatment. Currently, data on the treatment of colchicine-unresponsive or colchicine-intolerant FMF patients are limited; the most promising alternatives seem to be anti-interleukin-1 (anti-IL-1) agents. Here we report our experience with the off-label use of anti-IL-1 agents in a large group of FMF patients.

METHODS

In all, 21 centers from different geographical regions of Turkey were included in the current study. The medical records of all FMF patients who had used anti-IL-1 treatment for at least 6 months were reviewed.

RESULTS

In total, 172 FMF patients (83 [48%] female, mean age 36.2 years [range 18-68]) were included in the analysis; mean age at symptom onset was 12.6 years (range 1-48), and the mean colchicine dose was 1.7 mg/day (range 0.5-4.0). Of these patients, 151 were treated with anakinra and 21 with canakinumab. Anti-IL-1 treatment was used because of colchicine-resistant disease in 84% and amyloidosis in 12% of subjects. During the mean 19.6 months of treatment (range 6-98), the yearly attack frequency was significantly reduced (from 16.8 to 2.4; P < 0.001), and 42.1% of colchicine-resistant FMF patients were attack free. Serum levels of C-reactive protein, erythrocyte sedimentation rate, and 24-hour urinary protein excretion (5,458.7 mg/24 hours before and 3,557.3 mg/24 hours after) were significantly reduced.

CONCLUSION

Anti-IL-1 treatment is an effective alternative for controlling attacks and decreasing proteinuria in colchicine-resistant FMF patients.

Second Metatarsal Transfer Lesions Due to First Metatarsal Shortening After Distal Chevron Metatarsal Osteotomy for Hallux Valgus

BACKGROUND

The first metatarsal bone can shorten after a distal chevron metatarsal osteotomy (DCMO). This shortening can result in a postoperative second metatarsal transfer lesion. The aim of the present study was to investigate the occurrence of second metatarsal transfer lesions after DCMO.

METHODS

This study involved 185 feet (138 patients), with hallux valgus (HV) deformity, treated with DCMO with Akin osteotomy. The mean patient age was 51.7 years (range, 21 to 74). Patients were followed for an average of 28 months, between June 2004 and June 2010. We measured the length of first metatarsal relative to second metatarsal preoperatively and postoperatively, using Morton's and Hardy-Clapham's methods. A second metatarsal transfer lesion was defined as a newly developed lesion, including metatarsalgia, a painful callosity, or a painless callosity, which was not present prior to the DCMO. The relation of the shortened first metatarsal after DCMO with the occurrence of second metatarsal transfer lesion was evaluated.

RESULTS

Second metatarsal transfer lesions (painless callosity) developed in 5 feet (2.7%) of 185 feet. Twenty-four preoperative second metatarsal lesions were improved postoperatively. The median shortening of the first metatarsal bone after DCMO was 0.6 mm according to Morton's method (range, -6.4 to 6.4), and 1.9 according to Hardy-Clapham's method (range, -5.8 to 5.8). According to the extent of first metatarsal shortening after DCMO by Hardy-Clapham's method and Morton's method, there was no significant difference of the occurrence of second transfer metatarsal lesions (P = .259 and P = .176, respectively).

CONCLUSIONS

In our study, second metatarsal transfer lesions developed in 2.7% of feet after DCMO. The occurrence of second metatarsal transfer lesions did not appear to be correlated with the degree of first metatarsal shortening in cases with less than 5.8 mm shortening.

LEVEL OF EVIDENCE

Level IV, retrospective case series.