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Background: Genetic heterogeneity in type I interferon (IFN)-related gene IFI44L may account for variable susceptibility to respiratory tract infections (RTIs) in children.Methods: In 2 prospective, population-based birth cohorts, the STEPS Study and the FinnBrain Birth Cohort Study, IFI44L genotypes for rs273259 and rs1333969 were determined in relation to the development of RTIs until 1 or 2 years of age, respectively. At age 3 months, whole-blood transcriptional profiles were analyzed and nasal samples were tested for respiratory viruses in a subset of children.Results: In the STEPS Study (n = 1135), IFI44L minor/minor gene variants were associated with lower rates of acute otitis media episodes (adjusted incidence rate ratio, 0.77 [95% confidence interval, .61-.96] for rs273259 and 0.74 [.55-.99] for rs1333969) and courses of antibiotics for RTIs (0.76 [.62-.95] and 0.73 [.56-.97], respectively. In the FinnBrain cohort (n = 971), IFI44L variants were associated with lower rates of RTIs and courses of antibiotics for RTIs. In respiratory virus-positive 3-month-old children, IFI44L gene variants were associated with decreased expression levels of IFI44L and several other IFN-related genes.Conclusions: Variant forms of IFI44L gene were protective against early-childhood RTIs or acute otitis media, and they attenuated IFN pathway activation by respiratory viruses. [ABSTRACT FROM AUTHOR]

Objective: We aimed to clarify the association of various HLA risk alleles with different types of autoantibodies initiating islet specific autoimmunity. Methods: Follow‐up cohorts from the Finnish Type 1 Diabetes Prediction and Prevention (DIPP) study and children diagnosed with type 1 diabetes (T1D) from the Finnish Pediatric Diabetes Register (FPDR) were analyzed for the presence of autoantibodies to insulin (IAA), glutamic acid decarboxylase (GADA), IA‐2 antigen (IA‐2A), and zinc transporter 8 (ZnT8A); and genotyped for HLA DR/DQ alleles. In the DIPP study, autoantibodies were regularly analyzed from birth up to 15 years of age. Results: In the DIPP cohort, 621 children developed one single persistent autoantibody, GADA in 284, IAA in 268, and IA‐2A in 40 cases. Highly significant differences in the specificity of the first autoantibody were observed between HLA genotypes. Homozygotes for the DR3‐DQ2 haplotype had almost exclusively GADA as the first autoantibody, whereas a more even distribution between GADA and IAA was found in DR3‐DQ2/DR4‐DQ8 as well as DR3‐DQ/x and DR4‐DQ8/x genotypes (x referring to neutral haplotypes). In DR4‐DQ8 positive genotypes with the DRB1*04:01 allele IAA was more often the first autoantibody than in DRB1*04:04 positive genotypes. Various neutral haplotypes also significantly affected the relative proportions of different initial autoantibodies. These findings were confirmed and expanded in a series of 1591 T1D children under the age of 10 years from FPDR. Conclusions: These results emphasize the importance of HLA class II polymorphisms in the recognition of autoantigen epitopes in the initiation of various pathways of the autoimmune response. [ABSTRACT FROM AUTHOR]

A declining first-phase insulin response (FPIR) is associated with positivity for multiple islet autoantibodies, irrespective of class II HLA DR-DQ genotype. We examined the associations of FPIR with genetic variants outside the HLA DR-DQ region in the Finnish Type 1 Diabetes Prediction and Prevention (DIPP) study in children with and without multiple autoantibodies. Association between FPIR and class I alleles A*24 and B*39 and eight single nucleotide polymorphisms outside the HLA region were analyzed in 438 children who had one or more FPIR results available after seroconversion. Hierarchical linear mixed models were used to analyze repeated measurements of FPIR. In children with multiple autoantibodies, the change in FPIR over time was significantly different between those with various PTPN2 (rs45450798), FUT2 (rs601338), CTSH (rs3825932), and IKZF4 (rs1701704) genotypes in at least one of the models. In general, children carrying susceptibility alleles for type 1 diabetes experienced a more rapid decline in insulin secretion compared with children without susceptibility alleles. The presence of the class I HLA A*24 allele was also associated with a steeper decline of FPIR over time in children with multiple autoantibodies. Certain genetic variants outside the class II HLA region may have a significant impact on the longitudinal pattern of FPIR. [ABSTRACT FROM AUTHOR]

Genetic predisposition could be assumed to be causing clustering of autoimmunity in individuals and families. We tested whether HLA and non-HLA loci associate with such clustering of autoimmunity. We included 1,745 children with type 1 diabetes from the Finnish Pediatric Diabetes Register. Data on personal or family history of autoimmune diseases were collected with a structured questionnaire and, for a subset, with a detailed search for celiac disease and autoimmune thyroid disease. Children with multiple autoimmune diseases or with multiple affected first- or second-degree relatives were identified. We analysed type 1 diabetes related HLA class II haplotypes and genotyped 41 single nucleotide polymorphisms (SNPs) outside the HLA region. The HLA-DR4-DQ8 haplotype was associated with having type 1 diabetes only whereas the HLA-DR3-DQ2 haplotype was more common in children with multiple autoimmune diseases. Children with multiple autoimmune diseases showed nominal association with RGS1 (rs2816316), and children coming from an autoimmune family with rs11711054 (CCR3-CCR5). In multivariate analyses, the overall effect of non-HLA SNPs on both phenotypes was evident, associations with RGS1 and CCR3-CCR5 region were confirmed and additional associations were implicated: NRP1, FUT2, and CD69 for children with multiple autoimmune diseases. In conclusion, HLA-DR3-DQ2 haplotype and some non-HLA SNPs contribute to the clustering of autoimmune diseases in children with type 1 diabetes and in their families. [ABSTRACT FROM AUTHOR]

GTPase of the immunity-associated protein (GIMAP) family members are differentially regulated during human Th cell differentiation and have been previously connected to immune-mediated disorders in animal studies. GIMAP4 is believed to contribute to the Th cell subtype-driven immunological balance via its role in T cell survival. GIMAP5 has a key role in BB-DR rat and NOD mouse lymphopenia. To elucidate GIMAP4 and GIMAP5 function and role in human immunity, we conducted a study combining genetic association in different immunological diseases and complementing functional analyses. Single nucleotide polymorphisms tagging the GIMAP haplotype variation were genotyped in Finnish type 1 diabetes (T1D) families and in a prospective Swedish asthma and allergic sensitization birth cohort. Initially, GIMAP5 rs6965571 was associated with risk for asthma and allergic sensitization (odds ratio [OR] 3.74, p = 0.00072, and OR 2.70, p = 0.0063, respectively) and protection from T1D (OR 0.64, p = 0.0058); GIMAP4 rs13222905 was associated with asthma (OR 1.28, p = 0.035) and allergic sensitization (OR 1.27, p = 0.0068). However, after false discovery rate correction for multiple testing, only the associations of GIMAP4 with allergic sensitization and GIMAP5 with asthma remained significant. In addition, transcription factor binding sites surrounding the associated loci were predicted. A gene-gene interaction in the T1D data were observed between the IL2RA rs2104286 and GIMAP4 rs9640279 (OR 1.52, p = 0.0064) and indicated between INS rs689 and GIMAP5 rs2286899. The follow-up functional analyses revealed lower IL-2RA expression upon GIMAP4 knockdown and an effect of GIMAP5 rs2286899 genotype on protein expression. Thus, the potential role of GIMAP4 and GIMAP5 as modifiers of immune-mediated diseases cannot be discarded. [ABSTRACT FROM AUTHOR]