Objectives Several IgG4-related disease (IgG4-RD) phenotypes have been proposed and the first set of classification criteria have been recently created. Our objectives were to assess the phenotype distribution and the performance of the classification criteria in Spanish patients as genetic and geographical differences may exist. Methods We performed a cross-sectional multicentre study (Registro Español de Enfermedad Relacionada con la IgG4, REERIGG4) with nine participating centres from Spain. Patients were recruited from November 2013 to December 2018. The 2019 American College of Rheumatology/European League Against Rheumatism classification criteria (AECC) were used. Results We included 105 patients; 88% had Caucasian ethnicity. On diagnosis, 86% met the international pathology consensus while 92% met the Japanese comprehensive criteria. The phenotype distribution was head and neck 25%, Mikulicz and systemic (MS) 20%, pancreato-hepato-biliary (PHB) 13%, retroperitoneal and aorta (RA) 26%. Sixteen per cent had an undefined phenotype. Seventy-seven per cent of the cases met the AECC. From the 24 patients not meeting the AECC, 33% met exclusion criteria, and 67% did not get a score ≥20 points. Incomplete pathology reports were associated to failure to meet the AECC. Conclusions The PHB phenotype was rare among Spanish IgG4-RD patients. The MS phenotype was less frequent and the RA phenotype was more prevalent than in other, Asian patient series. An undefined phenotype should be considered as some patients do not fall into any of the categories. Three quarters of the cases met the 2019 AECC. Incomplete pathology reports were the leading causes of failure to meet the criteria.

Background and AimSerum IgG4 concentrations are commonly measured in clinical practice. The aim of this study was to investigate serum IgG4 concentrations in adults and their potential relationship with demographic, lifestyle, metabolic, and allergy-related factors.MethodsSerum IgG4 concentrations were measured with a commercial assay in 413 individuals (median age 55 years, 45% males) who were randomly selected from a general adult population.ResultsMedian IgG4 concentration was 26.8 mg/dL. Five out of the 413 individuals (1.2%) exhibited IgG4 concentrations >135 mg/dL, and 17 out of 411 (4.1%) exhibited an IgG4/total IgG ratio >8%. Serum IgG4 concentrations were significantly higher in males than in females and decreased with age. After adjusting for age and sex, serum IgG4 concentrations were not significantly influenced by alcohol consumption, smoking or common metabolic abnormalities (obesity and the related metabolic syndrome). Serum IgG4 concentrations were not significantly correlated with serum concentrations of proinflammatory cytokines and inflammation markers. Serum IgG4 concentrations were significantly correlated with IgE concentrations. Serum IgG4 concentrations tended to be higher in atopics (individuals with IgE-mediated sensitization to aeroallergens) than in non-atopics, particularly among atopics without respiratory symptoms. Serum IgG4 concentrations were not significantly correlated with total eosinophil blood count. Cases of IgG4-related disease were neither present at baseline nor detected after a median of 11 years of follow-up.ConclusionsStudies aimed at defining reference IgG4 values should consider partitioning by age and sex. Further studies are needed to confirm the potential influence of atopy status on serum IgG4 concentrations.

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<b><i>Background and Aim:</i></b> Few reports have investigated the association between metabolic abnormalities (obesity and related metabolic syndrome) and total serum IgE concentrations. <b><i>Methods:</i></b> This cross-sectional study included a random sample of 1,516 adult individuals (44.7% men, aged 18–91 years, median 52 years) from a single municipality in Spain. Serum IgE was measured in the ADVIA Centaur system. Atopy was defined by the presence of positive skin prick tests to a panel of common aeroallergens in the area. Body mass index and data related to the definition of metabolic syndrome were obtained from all participants. Alcohol consumption, smoking, and regular physical exercise were assessed by a questionnaire. <b><i>Results:</i></b> Atopy (present in 21.9% of 1,514 evaluable individuals) was the strongest factor determining serum IgE concentrations. Male sex and heavy alcohol drinking were independently associated with higher IgE concentrations, particularly in the non-atopic individuals. Body mass index was positively associated with IgE concentrations, independent of potential confounders, although the effect was only evident among non-atopic individuals. In that group, median IgE concentrations in normal-weight and obese individuals were 15 and 24 kU/L, respectively (<i>p</i> &#x3c; 0.001); likewise, obesity was associated with high (&#x3e;100 kU/L) IgE concentrations after adjusting for potential confounders (odds ratio: 1.79, 95% confidence interval: 1.26–2.56, <i>p</i> = 0.001). The presence of metabolic syndrome and its components, particularly abdominal obesity and hyperglycaemia, was also positively and independently associated with higher IgE concentrations in non-atopic individuals. <b><i>Conclusions:</i></b> Obesity and metabolic syndrome components are associated with high total serum IgE concentrations, particularly in non-atopic individuals.

Palabras clave: Inmunoterapia frente a veneno. Veneno de avispa. Trastornos autoinmunológicos.Venom immunotherapy (VIT) is the only highly effective way of treating patients with hymenoptera venom allergy (HVA). The most serious anaphylactic symptoms of HVA (HVA-SYS IVo) are life-threatening, thus making their occurrence an unconditional recommendation for VIT. Yet, VIT is contraindicated in immune-mediated inflammatory diseases.We present the case of a 55-year-old woman with autoinflammatory neurological disease (initially diagnosed with relapsing remitting multiple sclerosis) who received VIT following an anaphylactic reaction (SYS-IVo) to wasp sting (Vespula germanica). Allergy tests showed the presence of specific IgE antibodies to wasp venom (intradermal test at 0.001 µg/mL, 12×12 mm; sIgE class 2). The basal serum tryptase concentration was normal. Her past medical history included gastrointestinal reflux, mild gastritis, allergy to ketoprofen and metamizole sodium, and seronegative spondyloarthropathy. At the age of 50, she was diagnosed with remitting-relapsing multiple sclerosis. Her first symptoms of neurological damage were mild facial weakness, mild instability with the eyes closed in the Romberg test, and clumsy movements of the left hand. Magnetic resonance imaging (MRI) was performed twice and revealed multiple hyperintense areas that were considered demyelinating lesions. The cerebrospinal fluid study showed intrathecal production of immunoglobulins 1.75 [normal range,). Visual evoked potentials were normal. Lyme disease was excluded. The patient was treated with intravenous methylprednisolone (Solu-Medrol, 1000 mg/d over 5 days) during 3 exacerbations of the disease. Progression in her disability was measured using the Kurtzke Expanded Disability Status Scale (EDSS). Her initial EDSS was 1.5, which rose to 4.0 after the last exacerbation of the disease.The patient met the clinical and immunological criteria for VIT. Another reason in support of the decision to administer VIT was the patient's physical disability, which might have hindered attempts to avoid a sting, especially given that she lives in an area with high exposure to stinging insects. The decision to start VIT was made despite the hitherto accepted belief that autoimmunological diseases constitute a contraindication to immunotherapy. At the time the patient qualified for VIT, her condition was stable, with no new active neurological symptoms.No complications were recorded during the induction phase (ultrarush; Pharmalgen, ALK-Abelló) and a complete 5-year course of VIT. There were no local or systemic allergic reactions. Neurological symptoms did not intensify, and no new symptoms appeared. The patient did not experience exacerbation of her neurological disease; the EDSS score remained unchanged. The findings in subsequent MRI examinations of the brain were stable, with no new lesions. The MRI revealed no lesions in the temporal lobes or posterior fossa structures and no juxtacortical lesions (Figure, A). However, numerous, small,...