Childhood-Onset Non-Infectious Uveitis in the "Biologic Era". Results From Spanish Multicenter Multidisciplinary Real-World Clinical Settings.

OBJECTIVE: To characterize and describe clinical experience with childhood-onset non-infectious uveitis. STUDY DESIGN: A multicenter retrospective multidisciplinary national web-based registry of 507 patients from 21 hospitals was analyzed. Cases were grouped as immune disease-associated (IMDu), idiopathic (IDIu) or ophthalmologically distinct. Characteristics of juvenile idiopathic arthritis-associated (non-HLA-B27-related) uveitis (JIAu), IDIu, and pars planitis (PP) were compared. RESULTS: IMDu (62.3%) and JIAu (51.9%) predominated in young females; and IDIu (22.7%) and PP (13.6%) in older children, without sex imbalance. Ocular complications occurred in 45.3% of cases (posterior synechiae [28%], cataracts [16%], band keratopathy [14%], ocular hypertension [11%] and cystoid macular edema [10%]) and were associated with synthetic (86%) and biologic (65%) disease-modifying antirheumatic drug (DMARD) use. Subgroups were significantly associated (p < 0.05) with different characteristics. JIAu was typically anterior (98%), insidious (75%), in ANA-positive (69%), young females (82%) with fewer complications (31%), better visual outcomes, and later use of uveitis-effective biologics. In contrast, IDIu was characteristically anterior (87%) or panuveitic (12.1%), with acute onset (60%) and more complications at onset (59%: synechiae [31%] and cataracts [9.6%]) and less DMARD use, while PP is intermediate, and was mostly bilateral (72.5%), persistent (86.5%) and chronic (86.8%), with more complications (70%; mainly posterior segment and cataracts at last visit), impaired visual acuity at onset, and greater systemic (81.2%), subtenon (29.1%) and intravitreal (10.1%) steroid use. CONCLUSION: Prognosis of childhood uveitis has improved in the "biologic era," particularly in JIAu. Early referral and DMARD therapy may reduce steroid use and improve outcomes, especially in PP and IDIu.

Mucosal Immune Defence Gene Polymorphisms as Relevant Players in the Pathogenesis of IgA Vasculitis?

ITGAM-ITGAX (rs11150612, rs11574637), VAV3 rs17019602, CARD9 rs4077515, DEFA (rs2738048, rs10086568), and HORMAD2 rs2412971 are mucosal immune defence polymorphisms, that have an impact on IgA production, described as risk loci for IgA nephropathy (IgAN). Since IgAN and Immunoglobulin-A vasculitis (IgAV) share molecular mechanisms, with the aberrant deposit of IgA1 being the main pathophysiologic feature of both entities, we assessed the potential influence of the seven abovementioned polymorphisms on IgAV pathogenesis. These seven variants were genotyped in 381 Caucasian IgAV patients and 997 matched healthy controls. No statistically significant differences were observed in the genotype and allele frequencies of these seven polymorphisms when the whole cohort of IgAV patients and those with nephritis were compared to controls. Similar genotype and allele frequencies of all polymorphisms were disclosed when IgAV patients were stratified according to the age at disease onset or the presence/absence of gastrointestinal or renal manifestations. Likewise, no ITGAM-ITGAX and DEFA haplotype differences were observed when the whole cohort of IgAV patients, along with those with nephritis and controls, as well as IgAV patients, stratified according to the abovementioned clinical characteristics, were compared. Our results suggest that mucosal immune defence polymorphisms do not represent novel genetic risk factors for IgAV pathogenesis.

Dual latent tuberculosis screening with tuberculin skin tests and QuantiFERON-TB assays before TNF-α inhibitor initiation in children in Spain.

Tumor-necrosis-factor-α inhibitors (anti-TNF-α) are associated with an increased risk of tuberculosis (TB) disease, primarily due to reactivation of latent TB infection (LTBI). We assessed the performance of parallel LTBI screening with tuberculin skin test (TST) and QuantiFERON-TB Gold In-Tube assays (QFT-GIT) before anti-TNF-α treatment in children with immune-mediated inflammatory disorders in a low TB-burden setting. We conducted a multicenter cohort study involving 17 pediatric tertiary centers in Spain. LTBI was defined as the presence of a positive TST and/or QFT-GIT result without clinical or radiological signs of TB disease. A total of 270 patients (median age:11.0 years) were included, mainly with rheumatological (55.9%) or inflammatory bowel disease (34.8%). Twelve patients (4.4%) were diagnosed with TB infection at screening (LTBI, n = 11; TB disease, n = 1). Concordance between TST and QFT-GIT results was moderate (TST+/QFT-GIT+, n = 4; TST-/QFT-GIT+, n = 3; TST+/QFT-GIT-, n = 5; kappa coefficient: 0.48, 95% CI: 0.36-0.60). Indeterminate QFT-GIT results occurred in 10 patients (3.7%) and were associated with young age and elevated C-reactive protein concentrations. Eleven of 12 patients with TB infection uneventfully completed standard LTBI or TB treatment. During a median follow-up period of 6.4 years, only 2 patients developed TB disease (incidence density: 130 (95% CI: 20-440) per 100,000 person-years), both probable de novo infections. CONCLUSION: A substantial number of patients were diagnosed with LTBI during screening. The dual strategy identified more cases than either of the tests alone, and test agreement was only moderate. Our data show that in children in a low TB prevalence setting, a dual screening strategy with TST and IGRA before anti-TNF-α treatment is effective. WHAT IS KNOWN: • The optimal screening strategy for latent tuberculosis in children with immune-mediated inflammatory disorders remains uncertain. • Children receiving anti-TNF-α drugs are at increased risk of developing severe tuberculosis disease. WHAT IS NEW: • A dual screening strategy, using TST and an IGRA assay, identified more children with latent tuberculosis than either of the tests alone. • Identification and treatment of latent tuberculosis before initiation of anti-TNF-α therapy averted incident tuberculosis cases.

Recomendaciones para el diagnóstico y tratamiento de la baja masa ósea para la edad cronológica y la osteoporosis infantil en Atención Primaria / Recommendations for the diagnosis and treatment of low bone mass for chronological age and childhood osteoporosis in primary care

Introducción: la ausencia en nuestro medio de protocolos de manejo y de derivación de los pacientes de riesgo hace que exista una gran variabilidad en la actividad preventiva y en el manejo clínico respecto a la osteoporosis infantil en los pediatras de nuestro país. Método: recientemente, el Grupo de Trabajo de Osteogénesis Imperfecta y Osteoporosis Infantil, de la Sociedad Española de Reumatología Pediátrica (SERPE) ha publicado un documento de consenso con recomendaciones sobre el diagnóstico y tratamiento de la osteoporosis secundaria infantil. En este artículo, resumimos aquellas más relevantes en el ámbito de Atención Primaria. Un panel de expertos, compuesto por pediatras y reumatólogos, elaboró una serie de recomendaciones basadas en la evidencia tras realizar una revisión cualitativa de la literatura. El nivel de evidencia se determinó para cada sección utilizando el sistema del Centro de Medicina basada en la Evidencia de Oxford (CEBM). Se realizó una encuesta Delphi para aquellas recomendaciones con un nivel de evidencia de IV o V. Se incluyeron todas las recomendaciones que tuvieron un nivel de concordancia superior o igual al 70%. Esta encuesta se envió a todos los miembros de la Sociedad Española de Reumatología Pediátrica. Resultados: se obtuvieron 51 recomendaciones, categorizadas en ocho secciones. Las recomendaciones resultantes son: cuándo sospechar y cómo prevenir la osteoporosis infantil y la baja masa ósea según la edad cronológica; qué métodos de detección y diagnóstico utilizar; cuáles son los tratamientos actuales y cómo prevenir la osteoporosis inducida por los corticoesteroides. Conclusión: la detección precoz y un enfoque terapéutico adecuado de la baja masa mineral ósea desde Atención Primaria (AP) son fundamentales para mejorar la salud ósea de nuestra población infantil. Las recomendaciones expuestas pueden ayudar a tomar las medidas de prevención y tratamiento correctas en la población infantil de riesgo (AU)

Introduction: due to the lack of standardised protocols for the management and referral of at-risk patients, there is substantial variability in the prevention and clinical management of childhood osteoporosis among paediatricians in Spain.Methods: the Working Group on Osteogenesis Imperfecta and Childhood Osteoporosis of the Sociedad Española de Reumatología Pediátrica (SERPE) recently published a consensus document with recommendations on the diagnosis and management of secondary childhood osteoporosis. An expert panel comprised of paediatricians and rheumatologists carried out a qualitative literature review and developed evidence-based recommendations.For each section, the level of evidence was determined using the Oxford Centre for Evidence-based Medicine (CEBM) system. A Delphi survey was conducted for those recommendations with a level of evidence of IV or V. All recommendations for which the level of agreement was 70% or greater were included. This survey was sent to all members of the SERPE.Results: the process yielded 51 recommendations categorized into 8 sections. The resulting recommendations concern when to suspect and how to prevent childhood osteoporosis and low bone mass according to chronological age; which screening and diagnosis methods to use; the current treatments and how to prevent corticosteroid-induced osteoporosis.Conclusions: early detection and an adequate approach to the treatment of low bone mass at the primary care (PC) level are essential to improve bone health in our paediatric population. These recommendations could contribute to improving prevention and treatment measures in at-risk children. (AU)

Role of the IL33 and IL1RL1 pathway in the pathogenesis of Immunoglobulin A vasculitis.

Cytokines signalling pathway genes are crucial factors of the genetic network underlying the pathogenesis of Immunoglobulin-A vasculitis (IgAV), an inflammatory vascular condition. An influence of the interleukin (IL)33- IL1 receptor like (IL1RL)1 signalling pathway on the increased risk of several immune-mediated diseases has been described. Accordingly, we assessed whether the IL33-IL1RL1 pathway represents a novel genetic risk factor for IgAV. Three tag polymorphisms within IL33 (rs3939286, rs7025417 and rs7044343) and three within IL1RL1 (rs2310173, rs13015714 and rs2058660), that also were previously associated with several inflammatory diseases, were genotyped in 380 Caucasian IgAV patients and 845 matched healthy controls. No genotypes or alleles differences were observed between IgAV patients and controls when IL33 and IL1RL1 variants were analysed independently. Likewise, no statistically significant differences were found in IL33 or IL1RL1 genotype and allele frequencies when IgAV patients were stratified according to the age at disease onset or to the presence/absence of gastrointestinal (GI) or renal manifestations. Similar results were disclosed when IL33 and IL1RL1 haplotypes were compared between IgAV patients and controls and between IgAV patients stratified according to the clinical characteristics mentioned above. Our results suggest that the IL33-IL1RL1 signalling pathway does not contribute to the genetic network underlying IgAV.

BAFF, APRIL and BAFFR on the pathogenesis of Immunoglobulin-A vasculitis.

BAFF, APRIL and BAFF-R are key proteins involved in the development of B-lymphocytes and autoimmunity. Additionally, BAFF, APRIL and BAFFR polymorphisms were associated with immune-mediated conditions, being BAFF GCTGT>A a shared insertion-deletion genetic variant for several autoimmune diseases. Accordingly, we assessed whether BAFF, APRIL and BAFFR represent novel genetic risk factors for Immunoglobulin-A vasculitis (IgAV), a predominantly B-lymphocyte inflammatory condition. BAFF rs374039502, which colocalizes with BAFF GCTGT>A, and two tag variants within APRIL (rs11552708 and rs6608) and BAFFR (rs7290134 and rs77874543) were genotyped in 386 Caucasian IgAV patients and 806 matched healthy controls. No genotypes or alleles differences were observed between IgAV patients and controls when BAFF, APRIL and BAFFR variants were analysed independently. Likewise, no statistically significant differences were found in the genotype and allele frequencies of BAFF, APRIL or BAFFR when IgAV patients were stratified according to the age at disease onset or to the presence/absence of gastrointestinal (GI) or renal manifestations. Similar results were disclosed when APRIL and BAFFR haplotypes were compared between IgAV patients and controls and between IgAV patients stratified according to the clinical characteristics mentioned above. Our results suggest that BAFF, APRIL and BAFFR do not contribute to the genetic network underlying IgAV.

¿Es posible ofrecer un algoritmo de decisión clínica en la enfermedad COVID-19 en Atención Primaria? / Is it possible to offer a clinical decision algorithm in COVID-19 disease in Primary Care?

Hasta ahora, los datos recogidos en los casos de procesos clínicos provocados por el coronavirus SARS-CoV-2 (COVID-19) en niños sugieren que son cuadros leves en comparación con las infecciones en pacientes adultos; no obstante, se ha informado de casos graves, como el síndrome inflamatorio multisistémico (SIM), que precisa de valoración y actuación de emergencia. En el contexto de la consulta del pediatra de Atención Primaria y coincidiendo con el inicio del curso escolar, en una época en la que habitualmente aumenta la incidencia de procesos como la gripe, infección por el virus respiratorio sincitial (VRS) y otros cuadros respiratorios, es habitual la demanda por síntomas que pueden hacer sospechar cualquiera de estas infecciones. En este sentido, es importante llegar a un diagnóstico que permita el manejo más adecuado del paciente. Epidemiológicamente, de manera que se pueda disminuir la transmisión comunitaria tomando las medidas adecuadas y clínicamente para así poder ponderar el nivel de gravedad y poner en marcha las actuaciones más adecuadas. Dado que no existen escalas válidas que ofrezcan un puntaje para valorar cuál es la actuación más adecuada ante la sospecha de una infección COVID-19, planteamos los beneficios de un algoritmo de decisión clínica que tiene en cuenta las connotaciones epidemiológicas, basado en la gravedad clínica, para ofrecer la atención clínica más adecuada a los pacientes

So far, the data collected in the cases of clinical processes caused by the SARS-CoV-2 (COVID-19) coronavirus in children suggest that they are mild compared to infections in adult patients; However, serious cases such as multisystemic inflammatory syndrome (SIM) have been reported, which requires assessment and emergency action. In the context of the of the Primary Care pediatrician consultation and coinciding with the beginning of the school year, at a time when the incidence of influenza, RSV infection and other respiratory conditions usually increases, consultations for symptoms that can lead to suspect these infections. Therefore, it is important to reach a diagnosis that allows the most appropriate management of the patient and decreasing the community transmission by taking pertinent measures. Given that there are no valid scales that offer a score to assess which is the most appropriate action in the event of a suspected COVID-19 infection, we propose the benefits of a clinical decision algorithm that takes into account epidemiological connotations, based on clinical severity to offer the most appropriate clinical care to patients

Role of IRF5 in the pathogenesis of immunoglobulin-A vasculitis.

OBJECTIVES: Interferon regulatory factor 5 (IRF5) is a major regulator of type I interferon induction and is also critical to produce pro-inflammatory cytokines. An influence of IRF5 genetic variants on the increased risk of immune-mediated diseases has been described. Accordingly, we aimed to evaluate the implication of IRF5 in the pathogenesis of Immunoglobulin-A vasculitis (IgAV), an inflammatory vascular pathology. METHODS: Three tag genetic variants (rs2004640, rs2070197 and rs10954213), representative of 3 different haplotype blocks within IRF5, were genotyped in 372 Caucasian patients with IgAV and 876 sex and ethnically matched healthy controls by TaqMan assays. RESULTS: No significant differences in the genotype and allele frequencies between patients with IgAV and healthy controls were observed when each IRF5 polymorphism was evaluated independently. Likewise, no significant differences between patients with IgAV and healthy controls were found when we assessed the three IRF5 polymorphisms combined, conforming haplotypes. In addition, there were no significant differences in genotype, allele and haplotype frequencies of IRF5 when patients with IgAV were stratified according to the age at disease onset or to the presence/absence of gastrointestinal or renal manifestations. CONCLUSIONS: Our results do not support an influence of IRF5 on the pathogenesis of IgAV.

Influence of IL17A gene on the pathogenesis of immunoglobulin-A vasculitis.

OBJECTIVES: Cytokines signaling pathway genes represent a key component of the genetic network implicated in the pathogenesis of immunoglobulin-A vasculitis (IgAV), an inflammatory vascular pathology. Interleukin (IL)17A is described as a genetic risk locus for some autoimmune diseases, such as giant cell arteritis and spondyloarthritis. Accordingly, we aimed to determine the potential influence of IL17A on the pathogenesis of IgAV. METHODS: Five IL17A tag polymorphisms (rs4711998, rs8193036, rs3819024, rs2275913 and rs7747909), which cover the major variability of this gene, were genotyped in 360 Caucasian patients with IgAV and 1,003 sex and ethnically matched healthy controls using TaqMan probes. RESULTS: No statistically significant differences between patients with IgAV and healthy controls were observed when each IL17A genetic variant was analysed independently. Similarly, no statistically significant differences between patients with IgAV and healthy controls were found when the five IL17A polymorphisms were evaluated combined conforming haplotypes. In addition, there were no statistically significant differences in genotype, allele and haplotype frequencies of IL17A when patients with IgAV were stratified according to the age at disease onset or to the presence/absence of gastrointestinal or renal manifestations. CONCLUSIONS: Our results do not support an influence of IL17A on the pathogenesis of IgAV.

Expert panel consensus recommendations for diagnosis and treatment of secondary osteoporosis in children.

BACKGROUND: Osteoporosis incidence in children is increasing due to the increased survival rate of patients suffering from chronic diseases and the increased use of drugs that can damage bones. Recent changes made to the definition of childhood osteoporosis, along with the lack of guidelines or national consensuses regarding its diagnosis and treatment, have resulted in a wide variability in the approaches used to treat this disease. For these reasons, the Osteogenesis Imperfecta and Childhood Osteoporosis Working Group of the Spanish Society of Pediatric Rheumatology has sounded the need for developing guidelines to standardize clinical practice with regard to this pathology. METHODS: An expert panel comprised of 6 pediatricians and 5 rheumatologists carried out a qualitative literature review and provided recommendations based on evidence, when that was available, or on their own experience. The level of evidence was determined for each section using the Oxford Centre for Evidence-based Medicine (CEBM) system. A Delphi survey was conducted for those recommendations with an evidence level of IV or V. This survey was sent to all members of the SERPE. All recommendations that had a level of agreement higher or equal to 70% were included. RESULTS: Fifty-one recommendations, categorized into eight sections, were obtained. Twenty-four of them presented an evidence level 4 or 5, and therefore a Delphi survey was conducted. This was submitted electronically and received a response rate of 40%. All recommendations submitted to the Delphi round obtained a level of agreement of 70% or higher and were therefore accepted. CONCLUSION: In summary, we present herein guidelines for the prevention, diagnosis and treatment of secondary childhood osteoporosis based on the available evidence and expert clinical experience. We believe it can serve as a useful tool that will contribute to the standardization of clinical practice for this pathology. Prophylactic measures, early diagnosis and a proper therapeutic approach are essential to improving bone health, not only in children and adolescents, but also in the adults they will become in the future.

Novedades para el diagnóstico de la toxoplasmosis ocular: uso de la tomografía de coherencia óptica / Advances in the diagnosis of ocular toxoplasmosis: Use of optical coherence tomography

No disponible

Rapid and Sustained Long-Term Efficacy and Safety of Canakinumab in Patients With Cryopyrin-Associated Periodic Syndrome Ages Five Years and Younger.

OBJECTIVE: To assess long-term efficacy and safety of canakinumab and the response to vaccination in children ages ≤5 years with cryopyrin-associated periodic syndrome (CAPS). METHODS: CAPS patients (ages ≤5 years) received 2 mg/kg canakinumab subcutaneously every 8 weeks; patients with neonatal-onset multisystem inflammatory disease (NOMID) received a starting dose of 4 mg/kg in this open-label trial. Efficacy was evaluated using physician global assessment of disease activity and serum levels of C-reactive protein (CRP) and amyloid A (SAA). Adverse events (AEs) were recorded. Vaccination response was evaluated using postvaccination antibody titers at 4 and 8 weeks after immunization. RESULTS: Of the 17 patients enrolled, 12 (71%) had Muckle-Wells syndrome, 4 (24%) had NOMID, and 1 (6%) had familial cold autoinflammatory syndrome. All 17 patients had a complete response to canakinumab. Disease activity improved according to the physician global assessment, and for 65% of the patients autoinflammatory disease was characterized as "absent" at the end of the study. Median CRP levels decreased over time. No such change was evident in SAA levels. During the extension study, postvaccination antibody titers increased above protective levels in 16 (94%) of 17 assessable vaccinations. Ten of the patients (59%) had AEs suspected to be related to canakinumab; 8 (47%) experienced at least 1 serious AE (SAE). None of the AEs or SAEs required interruption of canakinumab therapy. CONCLUSION: Our findings indicate that canakinumab effectively maintains efficacy through 152 weeks and appears to have no effect on the ability to produce antibodies against standard childhood non-live vaccines. The safety profile of canakinumab was consistent with previous studies, supporting long-term use of canakinumab for CAPS in children ≤5 years of age.

Síndrome SAPHO en la infancia. Presentación de un caso clínico / SAPHO syndrome in childhood. A case report

El acrónimo síndrome SAPHO (sinovitis, acné, pustulosis, hiperostosis y osteítis) engloba tanto manifestaciones cutáneas como muculoesqueléticas, entre ellas hiperostosis de los huesos y de las articulaciones de la pared torácica anterior, asociado a manifestaciones cutáneas; acné fulminans e hidradenitis supurativa. Los criterios diagnósticos no han sido validados en niños. El tratamiento inicial con antiinflamatorios no esteroideos en ocasiones es insuficiente y puede ser preciso asociar corticoides, fármacos modificadores de la enfermedad, antagonistas del factor de necrosis tumoral o bifosfonatos. Presentamos el caso clínico de un escolar con afectación poliarticular, osteoartritis de articulación esternoclavicular con importante componente inflamatorio y acné conglobata, con buena respuesta al tratamiento con pamidronato por vía intravenosa (AU)

The acronym of SAPHO syndrome (synovitis, acne, pustulosis, hyperostosis and osteitis) combines a cluster of cutaneous and musculoskeletal manifestations, such as hyperostosis of bones of the anterior chest wall associated with acne fulminans and hidradenitis suppurativa. There are no validated diagnostic criteria in children. Nonsteroidal anti-inflammatory drugs are not always sufficient, and the use of corticosteroids, disease-modifying agents, tumor necrosis factor-α inhibitors or bisphosphonates may be necessary. We present the case of a child with polyarticular involvement, osteoarthritis of the sternoclavicular joint with severe inflammatory disorders and acne conglobata, with an excellent response to intravenous pamidronate (AU)

SAPHO syndrome in childhood. A case report. / Síndrome SAPHO en la infancia. Presentación de un caso clínico.

The acronym of SAPHO syndrome (synovitis, acne, pustulosis, hyperostosis and osteitis) combines a cluster of cutaneous and musculoskeletal manifestations, such as hyperostosis of bones of the anterior chest wall associated with acne fulminans and hidradenitis suppurativa. There are no validated diagnostic criteria in children. Nonsteroidal anti-inflammatory drugs are not always sufficient, and the use of corticosteroids, disease-modifying agents, tumor necrosis factor-α inhibitors or bisphosphonates may be necessary. We present the case of a child with polyarticular involvement, osteoarthritis of the sternoclavicular joint with severe inflammatory disorders and acne conglobata, with an excellent response to intravenous pamidronate.

A genome-wide association study suggests the HLA Class II region as the major susceptibility locus for IgA vasculitis.

The genetic component of Immunoglobulin-A (IgA) vasculitis is still far to be elucidated. To increase the current knowledge on the genetic component of this vasculitis we performed the first genome-wide association study (GWAS) on this condition. 308 IgA vasculitis patients and 1,018 healthy controls from Spain were genotyped by Illumina HumanCore BeadChips. Imputation of GWAS data was performed using the 1000 Genomes Project Phase III dataset as reference panel. After quality control filters and GWAS imputation, 285 patients and 1,006 controls remained in the datasets and were included in further analysis. Additionally, the human leukocyte antigen (HLA) region was comprehensively studied by imputing classical alleles and polymorphic amino acid positions. A linkage disequilibrium block of polymorphisms located in the HLA class II region surpassed the genome-wide level of significance (OR = 0.56, 95% CI = 0.46-0.68). Although no polymorphic amino acid positions were associated at the genome-wide level of significance, P-values of potential relevance were observed for the positions 13 and 11 of HLA-DRB1 (P = 6.67E-05, P = 1.88E-05, respectively). Outside the HLA, potential associations were detected, but none of them were close to the statistical significance. In conclusion, our study suggests that IgA vasculitis is an archetypal HLA class II disease.

Interleukin 1 beta (IL1ß) rs16944 genetic variant as a genetic marker of severe renal manifestations and renal sequelae in Henoch-Schönlein purpura.

OBJECTIVES: Data from a small series suggested that the Interleukin 1 beta (IL1ß) rs16944 polymorphism may be associated with severe renal involvement and persistent renal damage (renal sequelae) in Henoch-Schönlein purpura (HSP). To confirm this association, we assessed the largest cohort of Caucasian HSP patients ever considered for genetic studies. METHODS: 338 Spanish HSP patients and 635 sex and ethnically matched controls were recruited in this study. All patients were required to have had at least 6 months' follow-up. Patients and controls were genotyped for IL1ß rs16944 by TaqMan genotyping assay. RESULTS: No differences between IL1ß rs16944 genotype or allele frequencies were found either in the case/control study or when HSP patients were stratified according to the age at disease onset, presence of nephritis or gastrointestinal manifestations. Nevertheless, 4 (25%) of the 16 HSP patients who developed severe renal manifestations carried the TT genotype versus 29 (9%) of 322 who did not develop this complication (p=0.01, OR=5.48, 95% CI: 1.01-28.10). Accordingly, patients carrying the mutant T allele had an increased risk of developing severe nephropathy (p=0.016, OR=2.35, 95% CI: 1.09-5.07). Additionally, a significant increase of the TT genotype was observed in patients with persistent renal damage when compared with those patients without this complication (25% versus 8.6%, respectively; p=0.0035, OR=4.90, 95% CI: 1.26- 18.51). Moreover, renal sequelae were more common in patients carrying the mutant T allele (p=0.0076, OR=2.20, 95% CI: 1.17-4.14). CONCLUSIONS: Our results support that the IL1ß rs16944 polymorphism may be a potential marker of severe renal manifestations and renal sequelae in HSP.