Lower frequency of anti-citrullinated protein antibodies among early arthritis patients with high body mass index.

OBJECTIVES: To investigate the role of body mass index (BMI) in the phenotypic and genotypic characteristics of early arthritis patients. METHODS: We analysed the clinical and laboratory parameters from the baseline visit of patients (670 patients [78.51% women]) included in the PEARL study. The WHO definition for low weight, normal weight, overweight and obesity (BMI <18.5, 18.5-25, 25-30 or ≥30 kg/m2, respectively) was applied. Anticitrullinated protein antibodies (ACPA) were studied by ELISA and HLA-DRB1* were genotyped by sequence speci c oligonucleotide probes. The relationship between BMI classification and other variables was analysed using Kruskall-Wallis, Anova and Chi-Square tests. Then multivariate logistic regression was performed to establish the role of BMI in ACPA positivity and ordered logistic regression to establish its relationship with ACPA level. RESULTS: Among the patients studied, 255 (38.06%) were considered overweight and 136 (20.3%) obese. High BMI patients had significantly more pain perception and disability than normal weight patients, whereas no clear differences in disease activity were observed between high BMI and normal weight patients. ACPA positivity was significantly less frequent in overweight and obese patients compared to normal BMI patients. This information was confirmed by adjusting for smoking habit and the presence of shared epitope. CONCLUSIONS: Our data support the theory that high BMI patients suffer more frequently from ACPA-negative RA. Nevertheless, although no disease activity differences were observed, these patients showed higher pain and disability scores since the beginning of disease.

Eosinophilia Associated With Immune Deficiency.

The differential diagnosis of eosinophilia is broad and includes infections, malignancies, and atopy as well as inborn errors of immunity (IEI). Certain types of IEIs are known to be associated with elevated numbers of eosinophils and frequently elevated serum IgE, whereas for others the degree and frequency of eosinophilia are less established. The molecular defects underlying IEI are heterogeneous and affect different pathways, which highlights the complex regulations of this cell population within the immune system. In this review, we list and discuss clinical manifestations and therapies of immune deficiency or immune dysregulation disorders associated with peripheral blood or tissue eosinophilia with or without raised IgE levels. We present illustrative case vignettes for the most common entities and propose a diagnostic algorithm aiming to help physicians systematically to evaluate patients with eosinophilia and suspicion of an underlying IEI.

Protein and functional isoform levels and genetic variants of the BAFF and APRIL pathway components in systemic lupus erythematosus.

Systemic lupus erythematosus (SLE) is the prototype of an autoimmune disease. Belimumab, a monoclonal antibody targets BAFF, is the only biologic approved for SLE and active lupus nephritis. BAFF is a cytokine with a key-regulatory role in the B cell homeostasis, which acts by binding to three receptors: BAFF-R, TACI and BCMA. TACI and BCMA also bind APRIL. Many studies reported elevated soluble BAFF and APRIL levels in the sera of SLE patients, but other questions about the role of this system in the disease remain open. The study aimed to investigate the utility of the cytokine levels in serum and urine as biomarkers, the role of non-functional isoforms, and the association of gene variants with the disease. This case-control study includes a cohort (women, 18-60 years old) of 100 patients (48% with nephritis) and 100 healthy controls. We used ELISA assays to measure the cytokine concentrations in serum (sBAFF and sAPRIL) and urine (uBAFF and uAPRIL); TaqMan Gene Expression Assays to quantify the relative mRNA expression of ΔBAFF, ßAPRIL, and εAPRIL, and next-generation sequencing to genotype the cytokine (TNFSF13 and TNFSF13B) and receptor (TNFRSF13B, TNFRSF17 and TNFRSF13C) genes. The statistical tests used were: Kruskal-Wallis (qualitative variables), the Spearman Rho coefficient (correlations), the Chi-square and SKAT (association of common and rare genetic variants, respectively). As expected, sBAFF and sAPRIL levels were higher in patients than in controls (p ≤ 0.001) but found differences between patient subgroups. sBAFF and sAPRIL significantly correlated only in patients with nephritis (rs = 0.67, p ≤ 0.001) and ßAPRIL levels were lower in patients with nephritis (p = 0.04), and ΔBAFF levels were lower in patients with dsDNA antibodies (p = 0.04). Rare variants of TNFSF13 and TNFRSF13B and TNFSF13 p.Gly67Arg and TNFRSF13B p.Val220Ala were associated with SLE. Our study supports differences among SLE patient subgroups with diverse clinical features in the BAFF/APRIL pathway. In addition, it suggests the involvement of genetic variants in the susceptibility to the disease.

Characterization of a novel HLA-DRB1*03 allele, DRB1*03:171.

DRB1*03:171 was described in a Caucasian Spanish family.