Etat fébrile et Hépatosplénomégalie chez une femme de 25 ans: approche diagnostique [A 25-year-old woman with fever and hepatosplenomegaly: diagnostic approach]

We proceeded to an extensive etiologic search in a young women with a hepatosplenomegaly and a chronic persistent fever. We discuss the differential diagnosis of this situation with a final diagnosis of sarcoidosis.

Association of mutations in the NALP3/CIAS1/PYPAF1 gene with a broad phenotype including recurrent fever, cold sensitivity, sensorineural deafness, and AA amyloidosis.

OBJECTIVE: Familial cold urticaria (FCU) and Muckle-Wells syndrome (MWS) are dominantly inherited autoinflammatory disorders that cause rashes, fever, arthralgia, and in some subjects, AA amyloidosis, and have been mapped to chromosome 1q44. Sensorineural deafness in MWS, and provocation of symptoms by cold in FCU, are distinctive features. This study was undertaken to characterize the genetic basis of FCU, MWS, and an overlapping disorder in French Canadian, British, and Indian families, respectively. METHODS: Mutations in the candidate gene NALP3, which has also been named CIAS1 and PYPAF1, were sought in the study families, in a British/Spanish patient with apparent sporadic MWS, and in matched population controls. Identified variants were sought in 50 European subjects with uncharacterized, apparently sporadic periodic fever syndromes, 48 subjects with rheumatoid arthritis (RA), and 19 subjects with juvenile idiopathic arthritis (JIA). RESULTS: Point mutations, encoding putative protein variants R262W and L307P, were present in all affected members of the Indian and French Canadian families, respectively, but not in controls. The R262W variant was also present in the subject with sporadic MWS. The V200M variant was present in all affected members of the British family with MWS, in 2 of the 50 subjects with uncharacterized periodic fevers, and in 1 of 130 Caucasian and 2 of 48 Indian healthy controls. No mutations were identified among the subjects with RA or JIA. CONCLUSION: These findings confirm that mutations in the NALP3/CIAS1/PYPAF1 gene are associated with FCU and MWS, and that disease severity and clinical features may differ substantially within and between families. Analysis of this gene will improve classification of patients with inherited or apparently sporadic periodic fever syndromes.

Adénopathies et fièvre chez une patiente VIH positive [Immunocompromised HIV patient with lymphadenopathy and fever].

The case of a immunocompromised HIV patient with fever and lymphadenopathy discussed in an anatomo-pathological round. This complex clinical case was used as an opportunity to discuss the broad differential diagnosis of fever in an immunocompromized individual with multiples lymphadenopathies. Clinical reasoning leading to the probable diagnosis based on clinical, biological and radiological informations is not only a difficult task for the speaker but also a rich source of learning opportunities for our medical community.

Periodic fever, aphthous stomatitis, pharyngitis, cervical adenitis syndrome is linked to dysregulated monocyte IL-1β production.

BACKGROUND: The exact pathogenesis of the pediatric disorder periodic fever, aphthous stomatitis, pharyngitis, cervical adenitis (PFAPA) syndrome is unknown. OBJECTIVES: We hypothesized that PFAPA might be due to dysregulated monocyte IL-1β production linked to genetic variants in proinflammatory genes. METHODS: Fifteen patients with PFAPA syndrome were studied during and outside a febrile episode. Hematologic profile, inflammatory markers, and cytokine levels were measured in the blood. The capacity of LPS-stimulated PBMCs and monocytes to secrete IL-1β was assessed by using ELISA, and active IL-1β secretion was visualized by means of Western blotting. Real-time quantitative PCR was performed to assess cytokine gene expression. DNA was screened for variants of the MEFV, TNFRSF1A, MVK, and NLRP3 genes in a total of 57 patients with PFAPA syndrome. RESULTS: During a febrile attack, patients with PFAPA syndrome revealed significantly increased neutrophil counts, erythrocyte sedimentation rates, and C-reactive protein, serum amyloid A, myeloid-related protein 8/14, and S100A12 levels compared with those seen outside attacks. Stimulated PBMCs secreted significantly more IL-1β during an attack (during a febrile episode, 575 ± 88 pg/mL; outside a febrile episode, 235 ± 56 pg/mL; P < .001), and this was in the mature active p17 form. IL-1β secretion was inhibited by ZYVAD, a caspase inhibitor. Similar results were found for stimulated monocytes (during a febrile episode, 743 ± 183 pg/mL; outside a febrile episode, 227 ± 92 pg/mL; P < .05). Genotyping identified variants in 15 of 57 patients, with 12 NLRP3 variants, 1 TNFRSF1A variant, 4 MEFV variants, and 1 MVK variant. CONCLUSION: Our data strongly suggest that IL-1β monocyte production is dysregulated in patients with PFAPA syndrome. Approximately 20% of them were found to have NLRP3 variants, suggesting that inflammasome-related genes might be involved in this autoinflammatory syndrome.

www.fevertravel.ch : an online study prototype to evaluate the safety and feasibility of computerized guidelines for fever in returning travellers and migrants

Résumé Suite à la publication des recommandations de pratiques cliniques sur la prise en soins de patients fébriles au retour des tropiques, nous avons développé un site internet de consultation www.fevertravel.ch qui comprend un arbre décisionnel et des caractéristiques diagnostiques spécifiques fournissant une assistance diagnostique aux médecins de premier recours. Nous avons ensuite intégré une composante de recherche afin d'évaluer l'implémentation de ces recommandations de pratiques cliniques informatisées. De plus, le site est capable d'enregistrer : (1) le chemin parcouru par le médecin au travers de l'arbre décisionnel, (2) les tests diagnostics effectués, (3) les diagnostics initial et final ainsi que les devenirs des patients et (4) les raisons de non-adhérence lorsque les médecins divergent de l'attitude proposée. Nous croyons que la technologie internat est un moyen puissant pour atteindre des médecins provenant de différents horizons dans leur propre environnement et qu'il pourrait se montrer être un outil de recherche efficace pour disséminer les recommandations de pratiques cliniques et évaluer leur justesse-adéquation. Dans cet article, nous décrivons le design, le contenu, l'architecture et l'implémentation du système de ce prototype d'étude interactive qui vise à intégrer une recherche opérationnelle en médecine de premier recours.

Effect of malaria and fever on energy metabolism in Gambian children.

The aim of the present study was to measure the changes in resting energy expenditure (REE) induced by malaria and to assess to what extent they are related to fever and nutritional status. The REE of 19 Gambian children (mean age +/- SEM, 9 +/- 1 y; weight, 24 +/- 2 kg; expected weight for height 86 +/- 1%) were measured with a hood system at repeated intervals at the onset of malaria crisis (test A), 3 to 4 d after therapy (test B), and 14 to 21 d later (test C). Axillary temperature averaged 39.2 +/- 0.1, 36.6 +/- 0.1, and 36.7 +/- 0.1 degrees C in the tests A, B, and C, respectively. REE in test A was significantly higher than REE in test B (223 +/- 10 versus 174 +/- 8 kJ/kg.d, p less than 0.0001), but in test C (169 +/- 8 kJ/kg.d), it did not differ from that observed in test B. The percentage of increase in REE was significantly correlated with the difference in axillary temperature (r = 0.46, p less than 0.05); the slope of the regression line indicated an increase of 6.9% in REE/degree C of fever. Furthermore, the individual increase in REE/degree C was correlated to the percentage of weight for height of the children (r = 0.54, p less than 0.05), indicating that the child's nutritional status influences the magnitude of the hypermetabolism due to fever. We concluded that Gambian children suffering from an acute episode of malaria have an increase in REE averaging 30%; however, REE promptly returns to baseline value a few days after the beginning of therapy.

Fièvre à répétition chez l'enfant: penser au syndrome de PFAPA [Periodic fever in children: keep in mind the PFAPA syndrome]

Les maladies autoinflammatoires font partie du diagnostic différentiel de l'état fébrile à répétition chez l’enfant. Ces maladies sont caractérisées par des poussées inflammatoires sans cause évidente. Certaines de ces maladies, comme la Fièvre méditerranéenne familiale, ont une origine génétique et nécessitent un traitement régulier pour éviter des conséquences graves à long terme. Le syndrome de PFAPA est la plus fréquente des fièvres récurrentes et son diagnostic se base sur des critères diagnostiques peu précis. Son traitement reste controversé. La prednisone en dose unique permet d'interrompre la poussée et l'amygdalectomie peut induire une rémission dans une majorité des cas. The autoinflammatory diseases should be considered in the differential diagnosis of recurrent fever in childhood. These diseases are characterized by inflammatory episodes without an evident cause. Some of these diseases, like the Familial Mediterranean Fever, have a genetic origin and need a chronic treatment to avoid severe complications on the long term. PFAPA syndrome is the most frequent cause of recurrent fever and is diagnosed based on unspecific criteria. The treatment is still controversial. One dose of Prednisone is able to interrupt the flare and tonsillectomy may induce a remission in the majority of the cases

Fièvre, adénopathie: une situation clinique de toxoplasmose aiguë chez une patiente immunocompétente [Fever and lymphadenopathy: acute toxoplasmosis in an immunocompetent patient].

Toxoplasmosis is an infectious disease caused by the intracellular parasite Toxoplasma gondii. In Switzerland about a third of the population has antibodies against this pathogen and has thus already been in contact with the parasite or has contracted the disease. Immunocompetent patients are usually asymptomatic (80-90%) during primary infection. The most common symptom is neck or occipital lymphadenopathy. Serology is the diagnostic gold standard in immunocompetent individuals. The presence of IgM antibodies is however not sufficient to make a definite diagnosis of acute toxoplasmosis. Distinction between acute and chronic toxoplasmosis requires additional serological tests (IgG avidity test). If required, the most used and probably most effective treatment is the combination of pyrimethamine and sulfadiazine, with folinic acid.

Fièvre jaune: nouvelles recommandations [Yellow fever: new recommendations].

Indication for yellow fever vaccination is not always easy to assess. The decision to immunize is not only based on the actual risk of the disease in a specific location, but also on public health considerations in the visited country (in order to respectively avoid epidemics in endemic countries or the introduction of the virus in zones where the vectors mosquitoes are present) and on travelers' risk factors for severe or even fatal vaccine adverse events. WHO has recently published new recommendations regarding vaccination against yellow fever after concluding that one dose of vaccine generates a life-long protection. This article tends to clarify the strategy to adopt in 2013 using cases frequently encountered in the practice of travel medicine.

Regulation of the cardiac voltage-gated sodium channel Nav1.5 : regulation of Nav1.5 by ubiquitin-protein ligases of the Nedd4/Nedd4-like family and characterisation of two novel mutations in the gene encoding Nav1.5 (SCN5A) implicated in the Brugada syndrome triggered by fever

Abstract: The genesis of the cardiac action potential, which accounts for the cardiac contraction, is due to the sodium current INa mediated by the voltage-gated sodium channel Nav1.5. Several cardiac arrhythmias such as the Brugada syndrome are known te be caused by mutations in SCN5A, the gene encoding Nav1.5. Studies of these mutations allowed a better understanding of biophysical and functional properties of Nav1.5. However, only few investigations have been performed in order to understand the regulation of Nav1.5. During my thesis, I investigated different mechanisms of regulation of Nav1.5 using a heterologous expression system, HEK293 cells, coupled with a technique of sodium current recording: the patch clamp in whole cell configuration. In previous studies it has been shown that an enzyme of the Nedd4 family (Nedd4-2) regulates an epithelial sodium channel via the interaction with PY-motifs present in the latter. Interestingly, Nav1.5 contains a similar PY-motif, which motivated us to study the role of Nedd4-2 expressed in heart for the regulation of Nav1.5. In a second study, we investigated the implication of two Nav1.5 mutants, which were either less functional or net functional (Nav1.5 R535X and Nav1.5 L325R respectively) implied in the genesis of the Brugada syndrome by fever. Our results established two mechanisms implied in Nav1.5 regulation. The first one implies that following the interaction between the PY-motif of Nav1.5 and Nedd4- 2 Nav1.5 is ubiquitinated by Nedd4-2. This ubiquitination leads to the internalization of Nav1 .5. The second mechanism is a phenomenon called the "dominant negative" effect of Nav1.5 L325R on Nay1.5 where the decrease of 'Na is potentially due to the retention of Nav1.5 by Nav1.5 L325R in an undefined intracellular compartment. These studies defined two mechanisms of Nav1.5 regulation, which could play an important role for the genesis of cardiac arrhythmias where molecular processes are still poorly understood. Résumé La genèse du potentiel d'action cardiaque, permettant la contraction cardiaque, est due au courant sodique INa issu des canaux sodiques cardiaques dépendants du voltage Nav1.5. Nombreuses arythmies cardiaques telles que le syndrome de Brugada sont connues pour être liées à des mutations du gène SCN5A, codant pour Nav1.5. L'étude de ces mutations a permis une meilleure compréhension des propriétés structurelles et fonctionnelles de Nav1.5 et leurs implications dans la genèse de ces pathologies. Néanmoins peu d'études ont été menées afin de comprendre les mécanismes de régulation de Nav1.5. Mon travail de thèse a consisté à étudier des mécanismes de régulation de Nav1.5 en utilisant un système d'expression hétérologue, les cellules HEK293, couplé à une technique d'enregistrement des courants sodiques, le "patch clamp" en configuration cellule entière. La présence sur Nav1.5 d'un motif-PY similaire à ceux nécessaires pour la régulation d'un canal épithélial sodique par une enzyme de la famille de Nedd4, nous a amenée à étudier le rôle de ces ubiquitine-ligases, en particulier Nedd4-2, dans la régulation de Nav1.5. La seconde étude s'est intéressée aux conséquences de deux mutations de SCN5A codant pour deux mutants peu ou pas fonctionnels (Nav1.5 L325R et Nav1.5 R535X respectivement) retrouvées chez des patients présentant un syndrome de Brugada exacerbé par un état fébrile. Nos résultats ont permis d'établir deux mécanismes de régulation de Nav1.5 L'un par Nedd4-2 qui implique rubiquitination de Nav1.5 par cette ligase suite à l'interaction entre le motif-PY de Nav1.5 et Nedd4-2. Cette modification déclenche l'internalisation du canal impliquée dans la diminution d'INa. Le second mécanisme quant à lui est un effet "dominant négatif" de Nav1.5 L325R sur Nav1.5 aboutissant à une diminution d'INa suite à la séquestration intracellulaire potentielle de Nav1.5 par Nav1.5 L325R. Ces études ont mis en évidence deux mécanismes de régulation de Nav1.5 pouvant jouer un rôle majeur dans la genèse et/ou l'accentuation des arythmies cardiaques dont les processus moléculaires au sein des cardiomyocytes, impliquant des modifications du courant sodiques, sont encore mal compris. Résumé destiné à un large public La dépolarisation électrique de la membrane des cellules cardiaques permet la contraction du coeur. La génèse de cette activité électrique est due au courant sodique issu d'un type de canal à sodium situé dans la membrane des cellules cardiaques. De nombreuses pathologies provoquant des troubles du rythme cardiaque sont issues de mutations du gène qui code pour ce canal à sodium. Ces canaux mutants, entrainant diverses pathologies cardiaques telles que le syndrome de Brugada, ont été largement étudiées. Néanmoins, peu de travaux ont été réalisés sur les mécanismes de régulation de ce canal à sodium non muté. Mon travail de thèse a consisté à étudier certains des mécanismes de régulation de ce canal à sodium en utilisant une technique permettant l'enregistrement des courants sodiques issus de l'expression de ces canaux à sodium à la membrane de cellules mammifères. La présence sur ce canal à sodium d'une structure spécifique, similaire à celle nécessaire pour la régulation d'un canal épithélial à sodium par une enzyme appelée Nedd4-2, nous a amenée à étudier le rôle de cette enzyme dans la régulation de ce canal à sodium. La seconde étude s'est intéressée aux rôles de deux mutations du gène codant pour ce canal à sodium retrouvées chez des patients présentant un syndrome de Brugada exacerbé par la fièvre. Nos résultats nous ont permis d'établir deux mécanismes de régulation de ce canal à sodium diminuant le courant sodique l'un par l'action de l'enzyme Nedd4-2, suite à son interaction avec ce canal, qui modifie ce canal à sodium (ubiquitination) diminuant de ce fait la densité membranaire du canal. L'autre par un mécanisme suggérant un effet négatif de l'un des canaux mutants sur l'expression à la membrane du canal à sodium non muté. Ces études ont mis en évidence deux mécanismes de régulation de ce canal à sodium pouvant jouer un rôle majeur dans la genèse et/ou l'accentuation des troubles du rythme cardiaques dont les mécanismes cellulaires sont encore incompris.

Results from a multicentre international registry of familial Mediterranean fever: impact of environment on the expression of a monogenic disease in children.

BACKGROUND AND AIM: Familial Mediterranean fever (FMF) is an autoinflammatory disease caused by mutations of the MEFV gene. We analyse the impact of ethnic, environmental and genetic factors on the severity of disease presentation in a large international registry. METHODS: Demographic, genetic and clinical data from validated paediatric FMF patients enrolled in the Eurofever registry were analysed. Three subgroups were considered: (i) patients living in the eastern Mediterranean countries; (ii) patients with an eastern Mediterranean ancestry living in western Europe; (iii) Caucasian patients living in western European countries. A score for disease severity at presentation was elaborated. RESULTS: Since November 2009, 346 FMF paediatric patients were enrolled in the Eurofever registry. The genetic and demographic features (ethnicity, age of onset, age at diagnosis) were similar among eastern Mediterranean patients whether they lived in their countries or western European countries. European patients had a lower frequency of the high penetrance M694V mutation and a significant delay of diagnosis (p<0.002). Patients living in eastern Mediterranean countries had a higher frequency of fever episodes/year and more frequent arthritis, pericarditis, chest pain, abdominal pain and vomiting compared to the other two groups. Multivariate analysis showed that the variables independently associated with severity of disease presentation were country of residence, presence of M694V mutation and positive family history. CONCLUSIONS: Eastern Mediterranean FMF patients have a milder disease phenotype once they migrate to Europe, reflecting the effect of environment on the expression of a monogenic disease.

African tick-bite fever: a new entity in the differential diagnosis of multiple eschars in travelers. Description of five cases imported from South Africa to Switzerland.

African tick-bite fever (ATBF) is a newly described spotted fever rickettsiosis that frequently presents with multiple eschars in travelers returning from sub-Saharan Africa and, to a lesser extent, from the West Indies. It is caused by the bite of an infected Amblyomma tick, whose hunting habits explain the typical presence of multiple inoculation skin lesions and the occurrence of clustered cases. The etiological agent of ATBF is Rickettsia africae, an emerging tick-borne pathogenic bacterium. We describe herein a cluster of five cases of ATBF occurring in Swiss travelers returning from South Africa. The co-incidental infections in these five patients and the presence of multiple inoculation eschars, two features pathognomonic of this rickettsial disease, suggested the diagnosis of ATBF. Indeed, the presence of at least one inoculation eschar is observed in 53-100% of cases and multiple eschars in 21-54%. Two patients presented regional lymphadenitis and one a mild local lymphangitis. Though a cutaneous rash is described in 15-46% of cases, no rash was observed in our series. ATBF was confirmed by serology. Thus, ATBF has recently emerged as one of the most important causes of flu-like illness in travelers returning from Southern Africa. The presence of one or multiple eschars of inoculation is an important clinical clue to the diagnosis. It can be confirmed by serology or by PCR of a biopsy of the eschar. Culture can also be done in reference laboratories. Dermatologists and primary care physicians should know this clinical entity, since an inexpensive and efficient treatment is available.

Is it worth treating fever in intensive care unit patients? Preliminary results from a randomized trial of the effect of external cooling.

BACKGROUND: Antipyresis is a common clinical practice in intensive care, although it is unknown if fever is harmful, beneficial, or a negligible adverse effect of infection and inflammation. METHODS: In a randomized study, rectal temperature and discomfort were assessed in 38 surgical intensive care unit patients without neurotrauma or severe hypoxemia and with fever (temperature >/=38.5 degrees C) and systemic inflammatory response syndrome. Eighteen patients received external cooling while 20 received no antipyretic treatment. RESULTS: Temperature and discomfort decreased similarly in both groups after 24 hours. No significant differences in recurrence of fever, incidence of infection, antibiotic therapy, intensive care unit and hospital length of stay, or mortality were noted between the groups. CONCLUSIONS: These results suggest that the systematic suppression of fever may not be useful in patients without severe cranial trauma or significant hypoxemia. Letting fever take its natural course does not seem to harm patients with systemic inflammatory response syndrome or influence the discomfort level and may save costs.

Feasibility and clinical outcomes when using practice guidelines for evaluation of fever in returning travelers and migrants : a validation study.

BACKGROUND: Practice guidelines for examining febrile patients presenting upon returning from the tropics were developed to assist primary care physicians in decision making. Because of the low level of evidence available in this field, there was a need to validate them and assess their feasibility in the context they have been designed for. OBJECTIVES: The objectives of the study were to (1) evaluate physicians' adherence to recommendations; (2) investigate reasons for non-adherence; and (3) ensure good clinical outcome of patients, the ultimate goal being to improve the quality of the guidelines, in particular to tailor them for the needs of the target audience and population. METHODS: Physicians consulting the guidelines on the Internet (www.fevertravel.ch) were invited to participate in the study. Navigation through the decision chart was automatically recorded, including diagnostic tests performed, initial and final diagnoses, and clinical outcomes. The reasons for non-adherence were investigated and qualitative feedback was collected. RESULTS: A total of 539 physician/patient pairs were included in this study. Full adherence to guidelines was observed in 29% of the cases. Figure-specific adherence rate was 54.8%. The main reasons for non-adherence were as follows: no repetition of malaria tests (111/352) and no presumptive antibiotic treatment for febrile diarrhea (64/153) or abdominal pain without leukocytosis (46/101). Overall, 20% of diversions from guidelines were considered reasonable because there was an alternative presumptive diagnosis or the symptoms were mild, which means that the corrected adherence rate per case was 40.6% and corrected adherence per figure was 61.7%. No death was recorded and all complications could be attributed to the underlying illness rather than to adherence to guidelines. CONCLUSIONS: These guidelines proved to be feasible, useful, and leading to good clinical outcomes. Almost one third of physicians strictly adhered to the guidelines. Other physicians used the guidelines not to forget specific diagnoses but finally diverged from the proposed attitudes. These diversions should be scrutinized for further refinement of the guidelines to better fit to physician and patient needs.