[Autoinflammatory diseases]. / Enfermedades autoinflamatorias.

The monogenic autoinflammatory diseases are rare, genetic disorders resulting in constitutive innate immune defects leading to excessive response to danger signals, spontaneous activation of inflammatory mediators or loss of inhibitory regulators. During the past 15 years, a growing number of monogenic inflammatory diseases have been described and their respective responsible genes identified. The proteins encoded by these genes are involved in the regulatory pathways of inflammation and are mostly expressed in cells of the innate immune system. Although a group of patients exhibit episodic systemic inflammation (periodic fevers), these disorders are mediated by continuous overproduction and release of pro-inflammatory mediators, notably IL-1ß, and are best considered as autoinflammatory diseases rather than periodic fevers. The most common autoinflammatory diseases are familial Mediterranean fever (FMF), TNF receptor-associated periodic syndrome (TRAPS), mevalonate kinase deficiency/hyperimmunoglobulin D syndrome (MKD/HIDS) and the cryopyrin-associated periodic syndromes (CAPS). Clinical features often include fever, cutaneous rash, serosal involvement and acute phase reactants. Autoantibodies are usually absent but may accompany certain syndromes. Diagnosis remains clinical and is based on the different phenotypic features. Genetic diagnosis is of utmost importance, but must be performed judiciously and interpreted cautiously. Treatment with biologic agents that block proinflammatory cytokines, particularly IL-1, has proved to be dramatically effective in many patients. Still, in many cases of autoinflammation no genetic abnormalities are detected and treatment remains suboptimal, raising the question of novel pathogenic mutations in unexplored genes and pathways.

Enfermedades autoinflamatorias / Autoinflammatory diseases

Las enfermedades autoinflamatorias monogénicas son desórdenes raros que resultan en defectos del sistema inmune innato, originando excesiva respuesta a señales de peligro, activación espontánea de vías inflamatorias o pérdida de reguladores inhibitorios. En los últimos 15 años un creciente número de enfermedades inflamatorias monogénicas han sido descriptas y sus respectivos genes responsables identificados. Las proteínas codificadas por estos genes están involucradas en las vías regulatorias de la inflamación y están expresadas fundamentalmente en las células del sistema inmune innato. Si bien un grupo de pacientes exhibe inflamación sistémica episódica (fiebres periódicas), estos desórdenes están mediados por una continua sobreproducción y liberación de mediadores pro-inflamatorios -especialmente la interleucina 1beta- y su conceptualización como enfermedades autoinflamatorias es preferible por sobre la de fiebres periódicas. Las enfermedades más frecuentes son fiebre mediterránea familiar (FMF), TRAPS, deficiencia de mevalonatocinasa/síndrome de hiper IgD (MKD/HIDS) y los síndromes periódicos asociados a criopirina (CAPS). Sus características clínicas frecuentemente incluyen fiebre, erupciones cutáneas, compromiso de serosas y reactantes de fase aguda. Los autoanticuerpos están usualmente ausentes pero pueden observarse en ciertos síndromes. El diagnóstico es clínico y se basa en las características fenotípicas. El diagnóstico genético es muy importante pero debe ser realizado de manera juiciosa e interpretado con cautela. El tratamiento con agentes biológicos que bloquean citocinas pro-inflamatorias, particularmente IL-1, ha demostrado ser efectivo en muchos pacientes. Sin embargo, en otros tantos casos no se descubren anormalidades genéticas y el tratamiento es subóptimo, planteando la posibilidad de mutaciones patogénicas en genes y vías aún no explorados.

The monogenic autoinflammatory diseases are rare, genetic disorders resulting in constitutive innate immune defects leading to excessive response to danger signals, spontaneous activation of inflammatory mediators or loss of inhibitory regulators. During the past 15 years, a growing number of monogenic inflammatory diseases have been described and their respective responsible genes identified. The proteins encoded by these genes are involved in the regulatory pathways of inflammation and are mostly expressed in cells of the innate immune system. Although a group of patients exhibit episodic systemic inflammation (periodic fevers), these disorders are mediated by continuous overproduction and release of pro-inflammatory mediators, notably IL-1β, and are best considered as autoinflammatory diseases rather than periodic fevers. The most common autoinflammatory diseases are familial Mediterranean fever (FMF), TNF receptor-associated periodic syndrome (TRAPS), mevalonate kinase deficiency/hyperimmunoglobulin D syndrome (MKD/HIDS) and the cryopyrin-associated periodic syndromes (CAPS). Clinical features often include fever, cutaneous rash, serosal involvement and acute phase reactants. Autoantibodies are usually absent but may accompany certain syndromes. Diagnosis remains clinical and is based on the different phenotypic features. Genetic diagnosis is of utmost importance, but must be performed judiciously and interpreted cautiously. Treatment with biologic agents that block proinflammatory cytokines, particularly IL-1, has proved to be dramatically effective in many patients. Still, in many cases of autoinflammation no genetic abnormalities are detected and treatment remains suboptimal, raising the question of novel pathogenic mutations in unexplored genes and pathways.

Glucose-6-phosphate dehydrogenase deficiency A- variant in febrile patients in Haiti.

Haiti is one of two remaining malaria-endemic countries in the Caribbean. To decrease malaria transmission in Haiti, primaquine was recently added to the malaria treatment public health policy. One limitation of primaquine is that, at certain doses, primaquine can cause hemolytic anemia in individuals with glucose-6-phosphate dehydrogenase (G6PD) deficiency (G6PDd). In this study, we genotyped two mutations (A376G and G202A), which confer the most common G6PDd variant in West African populations, G6PDd A-. We estimated the frequency of G6PDd A- in a sample of febrile patients enrolled in an on-going malaria study who represent a potential target population for a primaquine mass drug administration. We found that 33 of 168 individuals carried the G6PDd A- allele (includes A- hemizygous males, A- homozygous or heterozygous females) and could experience toxicity if treated with primaquine. These data inform discussions on safe and effective primaquine dosing and future malaria elimination strategies for Haiti.

Interleukin-1 receptor antagonist gene polymorphism increases susceptibility to septic shock in children with acute lymphoblastic leukemia.

BACKGROUND: Interleukin-1 receptor antagonist polymorphism (ILRN) 2 (ILRN*2) has been associated with a poor outcome in septic patients because of an elevated production of anti-inflammatory cytokines. In >70% of patients, morbidity and mortality in childhood acute lymphoblastic leukemia is caused by infections. The aim of this study was to determine the association between this polymorphism and the frequency of septic shock from the time of diagnosis until completion of treatment. METHODS: This cohort study was conducted in 57 consecutive children with acute lymphoblastic leukemia. At the end of follow-up, children were stratified according to their IL1RN polymorphism (ILRN*1/ILRN*2), evaluating the impact of genotype on the severity of febrile neutropenic events during their treatment. RESULTS: Overall survival was 80% at 55 months after treatment. The average number of febrile neutropenic events in this cohort was 2.82 per patient. Genotype distribution was 50.9% for homozygote IL-1RN*1, 38.6% for heterozygote ILRN*1/ILRN*2 and 10.5% for homozygote IL-1RN*2. The risk of presenting septic shock for homozygote IL1RN*2/IL1RN*2 and heterozygote ILRN*1/ILRN*2 patients was significantly greater (odds ratio, 45; P = 0.001) adjusted for age, gender, risk of leukemia and presence of pathogenic bacteria. Genotype IL-1RN*2 is associated with the risk of development of septic shock in children with acute lymphoblastic leukemia. Further research in larger population-based studies is needed to replicate these findings. CONCLUSIONS: This information would allow us to identify more predictive factors in this group of acute lymphoblastic leukemia patients in whom this information is lacking to establish an earlier and more aggressive approach.

Lovastatin decreases the synthesis of inflammatory mediators in the hippocampus and blocks the hyperthermia of rats submitted to long-lasting status epilepticus.

Statins may act on inflammatory responses, decreasing oxidative stress and also reducing temperature after a brain ischemic insult. Previous data have indicated that statins protect neurons from death during long-lasting status epilepticus (SE) and attenuate seizure behaviors in animals treated with kainic acid. In this context, the study described here aimed to investigate the effect of lovastatin on body temperature and on mRNA expression levels of hippocampal cytokines such as interleukin-1ß, interleukin-6, tumor necrosis factor α, and kinin B1 and B2 receptors of rats submitted to pilocarpine-induced SE. Quantitative real-time polymerase chain reaction showed a significant decrease in mRNA expression of interleukin-1ß, interleukin-6, tumor necrosis factor α, and kinin B1 receptor in animals with SE treated with lovastatin, compared with untreated animals with SE (P<0.001). Lovastatin also reduced SE-induced hyperthermia, indicating that mechanisms related to brain protection are triggered by this drug under conditions associated with acute excitotoxicity or long-lasting SE.

IL-17 receptor signaling is required to control polymicrobial sepsis.

Sepsis is a systemic inflammatory response resulting from the inability of the host to contain the infection locally. Previously, we demonstrated that during severe sepsis there is a marked failure of neutrophil migration to the infection site, which contributes to dissemination of infection, resulting in high mortality. IL-17 plays an important role in neutrophil recruitment. Herein, we investigated the role of IL-17R signaling in polymicrobial sepsis induced by cecal ligation and puncture (CLP). It was observed that IL-17R-deficient mice, subjected to CLP-induced non-severe sepsis, show reduced neutrophil recruitment into the peritoneal cavity, spread of infection, and increased systemic inflammatory response as compared with C57BL/6 littermates. As a consequence, the mice showed an increased mortality rate. The ability of IL-17 to induce neutrophil migration was demonstrated in vivo and in vitro. Beside its role in neutrophil recruitment to the infection focus, IL-17 enhanced the microbicidal activity of the migrating neutrophils by a mechanism dependent on NO. Therefore, IL-17 plays a critical role in host protection during polymicrobial sepsis.

Displasia ectodérmica hipohidrótica: caso clínico y revisión de la literatura / Hypohydrotic ectodermal dysplasia: a clinical case and review of the literature

La displasia ectodérmica hipohidrótica (DEH) es un trastorno genético que se caracteriza por hipohidrosis, hipotricosis e hipodoncia. Comúnmente afecta a varones con una herencia recesiva ligada al X, aunque existen otras formas con herencia autosómica dominante y recesiva. Los pacientes afectados pueden presentar intolerancia al calor, fiebre, hipertermia grave e incluso muerte súbita. Objetivo: Presentan el caso clínico de un paciente portador de DEH, y actualizar el conocimiento de la etiología y medidas terapéuticas de esta patología. Caso clínico: Se reporta el caso de una niña de 7 años de edad, que presenta escaso vello, alteraciones dentarias, amastia y escasa sudoración, compatible con una DEH y una probable herencia autosómica recesiva. Se comenta su evolución y manejo clínico, junto a aspectos embriológicos, genéticos, diagnósticos y el consejo genético de esta enfermedad.

Evolutionary approach to medicine.

A new discipline in the medical field, called Darwinian (or evolutionary) Medicine, has arisen to study how natural selection could shape a machine as complex as the human body without eliminating its vulnerability to diseases. It asserts that systems and organs that form our bodies result from millions of years of evolutionary advances and are designed to survive in order to reproduce. According to this principle, Nature does not strive for complexity or perfection-it is blind and random. Using the scientific knowledge that has revolutionized biology, Darwinian Medicine seeks to provide an explanation for diseases based on the evolutionary process. This new discipline, in short, can undoubtedly help physicians in their medical practice, though further research is necessary to improve understanding of the range of its clinical application.