Genome-wide association (GWA) studies revealed a number of single nucleotide polymorphisms (SNPs) significantly associated with type 1 diabetes (T1D). In an attempt to confirm some of these candidate associations, we genotyped 2046 Caucasian patients and 2417 normal controls from the United States for SNPs in five genomic regions. While no evidence was obtained for four genomic regions (rs2929366/ NM_144715 on chromosome 3, rs9127/ Q7Z4C4 on chromosome 5, rs1445898/ CAPSL on chromosome 5 and rs2302188/ NM_033543 on chromosome 19), we provide strong evidence for association between T1D and multiple SNPs in the IFIH1 linkage disequilibrium (LD) block on chromosome 2q. Among the 10 SNPs genotyped for the 2q region, four SNPs located within the IFIH1 gene or at the 5′ region of IFIH1 showed significant association with T1D in the Georgia population [odds ratio (OR) = 1.7–1.9] with the best P -value found at SNP rs1990760 ( P = 8 × 10 ⁻⁸ and OR = 1.9). Several SNPs outside of the IFIH1 gene also showed significant but weaker associations. Furthermore, IFIH1 gene expression levels in peripheral blood mononuclear cells are significantly correlated with IFIH1 genotypes, and higher IFIH1 levels are found in individuals with the susceptible genotypes ( P = 0.005). Thus, both genetic association and gene expression data suggest that IFIH1 is the most plausible candidate gene implicated in T1D in this LD block.

We have investigated the contributing role of monosodium urate (MSU) to the pathological processes associated with the induction of diabetic retinopathy (DR). In human postmortem retinas and vitreous from donors with DR, we have found a significant increase in MSU levels which correlated with the presence of inflammatory markers and enhanced expression of xanthine oxidase. Same elevation in MSU levels was also detected in serum and vitreous of streptozotocin-induced diabetic rats (STZ-rats) analyzed at 8 weeks of hyperglycemia. Furthermore, treatments of STZ-rats with the hypouricemic drugs allopurinol (50 mg/kg) and benzbromarone (10 mg/kg) given every other day resulted in a significant decrease of retinal and plasma levels of inflammatory cytokines and adhesion factors, a marked reduction of hyperglycemia-induced retinal leukostasis, and restoration of retinal blood barrier function. These results were associated with effects of the hypouricemic drugs on down-regulating diabetes-induced levels of oxidative stress markers as well as expression of components of the NLRP3 inflammasome such as NLRP3, TLR4 and IL-1β. The outcomes of these studies support a contributing role of MSU in diabetes-induced retinal inflammation and suggest that asymptomatic hyperuricemia should be considered as a risk factor for DR induction and progression.

Achromobacter spp. can establish occasional or chronic lung infections in patients with cystic fibrosis (CF). Chronic colonization has been associated with worse prognosis highlighting the need to identify markers of bacterial persistence. To this purpose, we analyzed phenotypic features of 95 Achromobacter spp. isolates from 38 patients presenting chronic or occasional infection. Virulence was tested in Galleria mellonella larvae, cytotoxicity was tested in human bronchial epithelial cells, biofilm production in static conditions was measured by crystal violet staining and susceptibility to selected antibiotics was tested by the disk diffusion method. The presence of genetic loci associated to the analyzed phenotypic features was evaluated by a genome-wide association study. Isolates from occasional infection induced significantly higher mortality of G. mellonella larvae and showed a trend for lower cytotoxicity than chronic infection isolates. No significant difference was observed in biofilm production among the two groups. Additionally, antibiotic susceptibility testing showed that isolates from chronically-infected patients were significantly more resistant to sulfonamides and meropenem than occasional isolates. Candidate genetic biomarkers associated with antibiotic resistance or sensitivity were identified. Achromobacter spp. strains isolated from people with chronic and occasional lung infection exhibit different virulence and antibiotic susceptibility features, which could be linked to persistence in CF lungs. This underlines the possibility of identifying predictive biomarkers of persistence that could be useful for clinical purposes.

Serum thromboxane-B2 (TxB2), together with arachidonic acid (AA)-induced platelet aggregation, are, at the moment, the most used tests to identify patients displaying high on-aspirin treatment platelet reactivity (HAPR). Both tests are specific for aspirin action on cyclooxygenase-1. While the correlation between serum TxB2 assay and clinical outcome is established, data are conflicting with regard to aspirin treatment and a possible association with AA-stimulated platelet markers and clinical outcome. To understand such discrepancy, we performed a retrospective study to compare both assays. We collected data from 132 patients receiving a daily dose of aspirin (100 mg/day) and data from 48 patients receiving aspirin on alternate days. All Patients who received a daily dose of aspirin were studied for AA-induced platelet aggregation together with serum TxB2 levels and AA-induced TxB2 formation was also studied in 71 patients out of entire population. Consistent with recommendations in the literature, we defined HAPR by setting a cut-off point at 3.1 ng/ml for serum levels of thromboxane B2 and 20% for AA-induced platelet aggregation. According to this cut-off point, we divided our overall population into two groups: (1) TxB2 < 3.1 ng/ml and (2) TxB2 > 3.1 ng/ml. We found low agreement between such tests to identify patients displaying HAPR. Our results show that AA-induced platelet aggregation >20% identify a smaller number of HAPR patients in comparison with TxB2. A good correlation between serum TxB2 and arachidonic acid-induced TxB2 production was found (r = 0.76619).