Country as the primary risk factor for renal amyloidosis in familial Mediterranean fever.

OBJECTIVE: Familial Mediterranean fever (FMF), the prototype of autoinflammatory disorders, is caused by recessive mutations in the MEFV gene. Some FMF patients develop renal amyloidosis, a potentially fatal condition. This complication has mainly been associated with the M694V mutation, although the different study designs, small numbers of patients, and/or evaluation of few or no covariables calls this association into question. The aim of this study was to examine the controversial issue of amyloidosis susceptibility in FMF by determining the relative contributions of MEFV and numerous epidemiologic factors to the risk of renal amyloidosis. METHODS: Online questionnaires were completed at the MetaFMF database by patients at 35 centers in 14 countries. Using a standardized mode of data collection, we retrieved crude initial data from over half of the genetically confirmed FMF patients referred worldwide until May 2003 (2,482 cases, including 260 patients who developed renal amyloidosis). RESULTS: Amyloid nephropathy was present in 11.4% of the cases. In the total study population, country of recruitment was the leading risk factor for this manifestation (odds ratio 3.2 [95% confidence interval 1.8-5.9]), followed by M694V homozygosity, proband status, and disease duration. Differing results were found when countries were stratified. CONCLUSION: Country of recruitment, rather than MEFV genotype, is the key risk factor for renal amyloidosis in FMF. This risk, which parallels infant mortality rates, indicates a possible environmental origin of amyloidosis susceptibility. The patient's country should be considered in addition to MEFV genotype as an indication for prophylactic colchicine, a treatment suggested for asymptomatic individuals who are incidentally discovered to be M694V homozygous.

Infevers: an evolving mutation database for auto-inflammatory syndromes.

The Infevers database (http://fmf.igh.cnrs.fr/infevers/) was established in 2002 to provide investigators with access to a central source of information about all sequence variants associated with periodic fevers: Familial Mediterranean fever (FMF), TNF Receptor Associated Periodic Syndrome (TRAPS), Hyper IgD Syndrome (HIDS), Familial Cold Autoinflammatory Syndrome/Muckle-Wells Syndrome/Chronic Infantile Neurological Cutaneous and Articular Syndrome (FCAS/MWS/CINCA). The prototype of this group of disorders is FMF, a recessive disease characterized by recurrent bouts of unexplained inflammation. FMF is the pivotal member of an expanding family of autoinflammatory disorders, a new term coined to describe illnesses resulting from a defect of the innate immune response. Therefore, we decided to extend the Infevers database to genes connected with autoinflammatory diseases. We present here the biological content of the Infevers database, including the introduction of two new entries: Crohn/Blau and Pyogenic sterile arthritis, pyoderma gangrenosum and acne (PAPA syndrome). Infevers has a range of query capabilities, allowing for simple or complex interrogation of the database. Currently, the database contains 291 sequence variants in related genes (MEFV, TNFRSF1A, MVK, CARD15, PSTPIP1, and CIAS1), consisting of published data and personal communications, which has revealed or refined the preferential mutational sites for each gene. This database will continue to evolve in its content and to improve in its presentation.

INFEVERS: the Registry for FMF and hereditary inflammatory disorders mutations.

We have established the INFEVERS--INternet periodic FEVERS--website (which is freely accessible at http://fmf.igh.cnrs.fr/infevers/). Our objectives were to develop a specialist site to gather updated information on mutations responsible for hereditary inflammatory disorders: i.e. Familial Mediterranean Fever (FMF), TRAPS (TNF Receptor 1A Associated Syndrome), HIDS (HyperIgD Syndrome), MWS (Muckle-Wells Syndrome)/FCU (Familial Cold Urticaria)/CINCA (Chronic Infantile Neurological Cutaneous and Articular Syndrome). Contributors submit their novel mutations through a 3 step form. Depending on the disease concerned, a member of the editorial board is automatically solicited to overview and validate new submissions, via a special secured web interface. If accepted, the new mutation is available on the INFEVERS web site and the discoverer, who is informed by email, is credited by having his/her name and date of the discovery on the site. The INFEVERS gateway provides researchers and clinicians with a common access location for information on similar diseases, allowing a rapid overview of the corresponding genetic defects at a glance. Furthermore, it is interactive and extendable according to the latest genes discovered.

The MetaFMF website: a high quality tool for meta-analysis of FMF.

We present here the MetaFMF database (freely accessible at http://fmf.igh.cnrs.fr/metaFMF/index_us.html) that attempts to gather and unify, in a common resource, data on phenotype-genotype correlation in familial Mediterranean fever (FMF). A single accession form, including a large number of quality controls, has been implemented such that data, collected worldwide, are included in an homogeneous manner. The inclusion criterion has the objective to avoid interpretational bias: patients will be included only if they bear at least two mutations. The clinical form has been set up by an International editorial board (12 FMF expert centres), which guarantees the validity of the data. Data are anonymous and submitted by a secure interface, in which the researcher is logged in with a specific ID and password. A pilot study on 211 patients has shown the feasibility and relevance of this project. We anticipate that the use of MetaFMF will enable reliable assessment of phenotype-genotype correlations in FMF, and define a set of severe versus mild mutations/genotypes. It should also highlight reasons for previous inconsistencies in such correlations.

Transcriptome analysis of monocytic leukemia cell differentiation.

The human leukemia cell line U937 is a well-established model for studying monocytic cell differentiation. We used a modified protocol (SADE) of serial analysis of gene expression (SAGE) and developed a SADE linker-anchored PCR assay to investigate the pattern of expression of known genes and to identify new transcripts in proliferating cells and during cell growth arrest and differentiation. We implemented new informatic tools to compare expression profiles before and after exposure of cells to differentiation inducers. From the analysis of 47,388 tags, we identified 13,806 distinct transcripts, 265 of which showed significant variations (P<0.01). Among 1219 well-identified genes, major changes concerned transcription and translation components, cytoskeleton, and macrophage-specific genes. Nearly half of the tags, some of them expressed at high levels, matched partially characterized genes or ESTs, or revealed yet-unknown transcripts, providing a wealth of new candidate genes that may reveal novel aspects of terminal monocytic differentiation.