Prevalence, demographics, and clinical characteristics of Latin American patients with spondyloarthritis

Abstract Large epidemiologic and clinical estimates of spondyloarthritis (SpA) in Latin America are not available. In this narrative review, our goal was to descriptively summarize the prevalence and features of SpA in Latin America, based on available small studies. A review of peer-reviewed literature identified 41 relevant publications. Of these, 11 (mostly based on Mexican data) estimated the prevalence of SpA and its subtypes, which varied from 0.28 to 0.9% (SpA), 0.02 to 0.8% (ankylosing spondylitis), 0.2 to 0.9% (axial SpA), and 0.004 to 0.08% (psoriatic arthritis). Demographic and/or clinical characteristics were reported in 31 of the 41 publications, deriving data from 3 multinational studies, as well as individual studies from Argentina, Brazil, Chile, Colombia, Costa Rica, Mexico, Peru, Uruguay, and Venezuela. Data relating to treatment, disease manifestations (articular and extra-articular), and comorbidities were summarized across the countries. Available data suggest that there is a variability in prevalence, manifestations, and comorbidities of SpA across Latin America. Basic epidemiologic and clinical data are required from several countries not currently represented. Data relating to current treatment approaches, patient outcomes, and socioeconomic impact within this large geographic region are also needed.(AU)

Remodelación ósea en espondiloartritis / Bone remodeling in spondyloarthritis

Spondyloarthritis is a group of several related but phenotypically distinct chronic inflammatory diseases, characterized by progressive new bone formation which leads to ankylosis and functional disability. Radiographic images evidence not only erosive changes but also overgrowth of bony structures called syndesmophytes. These inflammation, bone destruction and new bone formation are located in the entheses, which constitutes the primary organ of the disease. As a consequence, the inflammatory process results in excess of bone formation and the impact depends on the location, cell type, cytokines and local microenvironment factors. Several molecules playing a role as immune modulators or regulators of bone homeostasis, mediate the imbalance between bone resorption and formation. In the same way, animal models suggest that joint ankylosis may be independent from the effects of tumor necrosis factor alpha. Therefore, the process of new tissue (bone) formation can be considered as an additional therapeutic target. The Wnt signaling pathway, which is considered the primary regulator of osteoblastogenesis, constitutes a new research field of great interest in the last decade.

Espondiloartritis y su asociación con el Complejo Mayor de Histocompatibilidad / "Spondylarthritis and the association with Major Histocompatibility Complex"

Las espondiloartritis corresponden a un grupo heterogéneo de enfermedades crónicas caracterizadas por entesitis tanto axial como periférica, artritis y menos comúnmente manifestaciones extra articulares. Se encuentran fuertemente ligadas a factores genéticos y en algunos pacientes a infecciones por bacterias artritogénicas. Su presentación y curso clínico se encuentran influenciados por la etnia, el género y la edad de inicio de la enfermedad. La Espondilitis Anquilosante (EA) como prototipo de espondiloartritis es una enfermedad hereditaria con un 90% de susceptibilidad atribuible a factores genéticos. Desde el descubrimiento de la asociación del alelo HLA-B*27 en los años setenta, las bases moleculares de esta asociación, una de las más fuertes entre una molécula del Complejo Mayor de Histocompatibilidad y una enfermedad, permanecen sin esclarecer. La fuerte asociación del HLA-B*27 confiere a este alelo un papel significativo de susceptibilidad para el desarrollo de la enfermedad. Varios estudios han informado la asociación de otros genes dentro del Complejo Mayor de Histocompatibilidad con la susceptibilidad para el desarrollo de la enfermedad en varios grupos poblacionales.

Spondylarthritis refers to a heterogeneous group of chronic diseases characterized by both axial and peripheral enthesitis, arthritis and extra articular manifestations. There is strongly linked to genetic factors and in some patients is related to clinical infections by arthritogenic bacteria. The clinical presentation and evolution are influenced by ethnicity, gender and age of onset. Ankylosing Spondylitis as a prototype of Spondylarthritis is an inherited disease with 90% of susceptibility related to genetic factors. Since the publication of the association of HLA-B*27 in the 70's, the molecular component of this association, one of the strongest between a molecule of Major Histocompatibility Complex and disease, remains unclear. The strong association of HLA-B*27 gives to this allele a significant role in susceptibility related to disease development. Several studies have reported the association of other genes within the Major Histocompatibility Complex to susceptibility for development of the disease in others population groups.