Abstract: We examined the association between plasma 25-hydroxyvitamin D [25(OH)D] concentration and islet autoimmunity (IA) and whether vitamin D gene polymorphisms modify the effect of 25(OH)D on IA risk. We followed 8,676 children at increased genetic risk of type 1 diabetes at six sites in the U.S. and Europe. We defined IA as positivity for at least one autoantibody (GADA, IAA, or IA-2A) on two or more visits. We conducted a risk set sampled nested case-control study of 376 IA case subjects and up to 3 control subjects per case subject. 25(OH)D concentration was measured on all samples prior to, and including, the first IA positive visit. Nine polymorphisms in VDR, CYP24A, CYP27B1, GC, and RXRA were analyzed as effect modifiers of 25(OH)D. Adjusting for HLA-DR-DQ and ancestry, higher childhood 25(OH)D was associated with lower IA risk (odds ratio = 0.93 for a 5 nmol/L difference; 95% CI 0.89, 0.97). Moreover, this association was modified by VDR rs7975232 (interaction P = 0.0072), where increased childhood 25(OH)D was associated with a decreasing IA risk based upon number of minor alleles: 0 (1.00; 0.93, 1.07), 1 (0.92; 0.89, 0.96), and 2 (0.86; 0.80, 0.92). Vitamin D and VDR may have a combined role in IA development in children at increased genetic risk for type 1 diabetes.

Abstract: Type 1 diabetes (T1D) results from immune-mediated destruction of insulin-producing beta cells. Prevention efforts have focused on immune modulation and supporting beta cell health before or around diagnosis; however, heterogeneity in disease progression and therapy response has limited translation to clinical practice, highlighting the need for precision medicine approaches to T1D disease modification. Methods To understand the state of knowledge in this area, we performed a systematic review of randomized-controlled trials with $$\ge$$ ≥ 50 participants cataloged in PubMed or Embase from the past 25 years testing T1D disease-modifying therapies and/or identifying features linked to treatment response, analyzing bias using a Cochrane-risk-of-bias instrument. Results We identify and summarize 75 manuscripts, 15 describing 11 prevention trials for individuals with increased risk for T1D, and 60 describing treatments aimed at preventing beta cell loss at disease onset. Seventeen interventions, mostly immunotherapies, show benefit compared to placebo (only two prior to T1D onset). Fifty-seven studies employ precision analyses to assess features linked to treatment response. Age, beta cell function measures, and immune phenotypes are most frequently tested. However, analyses are typically not prespecified, with inconsistent methods of reporting, and tend to report positive findings. Conclusions While the quality of prevention and intervention trials is overall high, the low quality of precision analyses makes it difficult to draw meaningful conclusions that inform clinical practice. To facilitate precision medicine approaches to T1D prevention, considerations for future precision studies include the incorporation of uniform outcome measures, reproducible biomarkers, and prespecified, fully powered precision analyses into future trial design.

Abstract: The risk for autoimmunity and subsequently type 1 diabetes is 10-fold higher in children with a first-degree family history of type 1 diabetes (FDR children) than in children in the general population (GP children). We analyzed children with high-risk HLA genotypes (n = 4,573) in the longitudinal TEDDY birth cohort to determine how much of the divergent risk is attributable to genetic enrichment in affected families. Enrichment for susceptible genotypes of multiple type 1 diabetes–associated genes and a novel risk gene, BTNL2, was identified in FDR children compared with GP children. After correction for genetic enrichment, the risks in the FDR and GP children converged but were not identical for multiple islet autoantibodies (hazard ratio [HR] 2.26 [95% CI 1.6–3.02] ) and for diabetes (HR 2.92 [95% CI 2.05–4.16]). Convergence varied depending upon the degree of genetic susceptibility. Risks were similar in the highest genetic susceptibility group for multiple islet autoantibodies (14.3% vs .12.7%) and diabetes (4.8% vs. 4.1%) and were up to 5.8-fold divergent for children in the lowest genetic susceptibility group, decreasing incrementally in GP children but not in FDR children. These findings suggest that additional factors enriched within affected families preferentially increase the risk of autoimmunity and type 1 diabetes in lower genetic susceptibility strata.

Abstract: Defective alleles within the PRF1 gene, encoding the pore-forming protein perforin, in combination with environmental factors, cause familial type 2 hemophagocytic lymphohistiocytosis (FHL2), a rare, severe autosomal recessive childhood disorder characterized by massive release of cytokines—cytokine storm. Objective: The aim of this study was to determine the function of hypomorph PRF1:p.A91V g.72360387 G  〉  A on multiple sclerosis (MS) and type 1 diabetes (T1D). Methods: We cross-compare the association data for PRF1:p.A91V mutation derived from GWAS on adult MS and pediatric T1D in Sardinians. The novel association with T1D was replicated in metanalysis in 12,584 cases and 17,692 controls from Sardinia, the United Kingdom, and Scotland. To dissect this mutation function, we searched through the coincident association immunophenotypes in additional set of general population Sardinians. Results: We report that PRF1:p.A91V, is associated with increase of lymphocyte levels, especially within the cytotoxic memory T-cells, at general population level with reduced interleukin 7 receptor expression on these cells. The minor allele increased risk of MS, in 2903 cases and 2880 controls from Sardinia p = 2.06 × 10 −4 , odds ratio OR = 1.29, replicating a previous finding, whereas it protects from T1D p = 1.04 × 10 −5 , OR = 0.82. Conclusion: Our results indicate opposing contributions of the cytotoxic T-cell compartment to MS and T1D pathogenesis.

Abstract: Asparaginase therapy is an important component of treatment for childhood acute lymphoblastic leukemia (ALL). However, immune responses to asparaginase during treatment can lead to suboptimal asparaginase exposure and possibly to worse outcome. Potential factors that can affect the incidence of asparaginase allergies include the pharmaceutical formulation of asparaginase, the number of asparaginase doses, treatment schedule, concurrent medications, ALL lineage, and racial ancestry. While genetic variations in the Human Leukocyte Antigen (HLA) genes have been implicated in allergic reactions to several drugs, no investigation has determined the influence of HLA on asparaginase allergies. Asparaginase allergy data from children with ALL who were enrolled on either SJCRH protocols [Total XIIIA (n =91), Total XV (n =320) and Total XVI (n =130)] or Children’s Oncology Group (COG) protocols [POG-9906 (n= 125) and AALL0232 (n= 1,204)] were used to investigate the influence of HLA class II genes on asparaginase allergies. Germline DNA was interrogated using the Affymetrix 500K, Affymetrix 6.0, or Illumina Exome Beadchip arrays. The T1DGC reference panel that contains both SNP data (Illumina Immunochip) and typed HLA class II alleles of unrelated European individuals (n= 4,938) was used to impute the HLA alleles of ALL patients with confirmed European ancestry. BEAGLE was used to impute HLA-DRB1 and HLA-DQB1 alleles at four-digit resolution. In a subset of 61 patients whose HLA type had been determined clinically, there was 94% concordance between imputed and typed HLA status. Using data on the occurrence of allergic reactions in patients enrolled in SJCRH protocols and adjusting for treatment arm, gender, age, and ALL lineage, HLA-DRB1*07:01 was identified as an asparaginase allergy risk allele (n = 541, p = 1.4 x 10-3, OR = 1.92), and the association was validated in the cohort of COG patients (n = 1,329, p = 0.01, OR = 1.49). Overall, patients with the HLA-DRB1*07:01 allele had a higher incidence of allergies compared to those without the allele (26% versus 18%, n = 1,870, p = 7.5 x 10-5, OR = 1.64). To determine the amino acid features of HLA-DRB1*07:01 that confer a greater risk of allergy, polymorphic amino acid positions associated with the imputed HLA-DRB1 alleles were inferred. Association analysis identified a glycine residue in HLA-DRB1 amino acid position 73 as the most significant residue associated with asparaginase allergies (n = 1,870, p = 4.5 x 10-5, OR = 1.50). This variant and other significantly associated variants (p 〈 5.5 x 10-4) were determined to be localized within the antigen binding pocket of the HLA-DRB1 protein, suggesting that binding of asparaginase peptide fragments to the HLA protein is an important determinant of the immune response to asparaginase. To investigate if HLA-DRB1 alleles with higher affinity for asparaginase peptide fragments were associated with a higher incidence of asparaginase allergy, the Immune Epitope Database (IEDB) was used to computationally predict the affinity of various HLA alleles for asparaginase. Using the IEDB binding scores, alleles were assigned to either a high or low binding category. Using the imputed HLA-DRB1 alleles of ALL patients, we found that patients whose alleles predicted high affinity binding to asparaginase had a higher incidence of allergies compared to those predicted to carry low-binding alleles (n = 1,870, p = 3.3 x 10-4, OR = 1.38). HLA-DRB1*07:01 was predicted to be a high-binding allele, consistent with its association with allergy. We conclude that HLA-DRB1*07:01 is associated with asparaginase allergy due to amino acid variants within the binding pocket of HLA-DRB1 that confer high binding affinity of HLA-DRB1 to asparaginase. Disclosures: Relling: Sigma-Tau Pharmaceuticals: I receive funding for investigator-initiated research on the pharmacology of asparaginase from Sigma-Tau Pharmaceuticals., I receive funding for investigator-initiated research on the pharmacology of asparaginase from Sigma-Tau Pharmaceuticals. Other; St. Jude Children’s Research Hospital : I have in the past received a portion of the income St. Jude receives from licensing patent rights related to TPMT polymorphisms as clinical diagnostics., I have in the past received a portion of the income St. Jude receives from licensing patent rights related to TPMT polymorphisms as clinical diagnostics. Patents & Royalties. Hunger:Jazz Pharmaceuticals: I receive funding for investigator-initiated research of asparaginase from Jazz Pharmaceuticals., I receive funding for investigator-initiated research of asparaginase from Jazz Pharmaceuticals. Other; Sigma-Tau Pharmaceuticals: I receive funding for investigator-initiated research of asparaginase from Sigma-Tau Pharmaceuticals. Other. Evans:St. Jude: In accordance with institutional policy, St. Jude allocates a portion of the income it receives from licensing inventions and tangible research materials to those researchers responsible for creating this intellectual property. Patents & Royalties, Under this policy, I and/or my spouse have in the past received a portion of the income St. Jude receives from licensing patent rights related to TPMT polymorphisms as clinical diagnostics., Under this policy, I and/or my spouse have in the past received a portion of the income St. Jude receives from licensing patent rights related to TPMT polymorphisms as clinical diagnostics. Other.

Abstract: Genome-wide association studies (GWASs) for osteoporotic traits have identified over 1000 associations; however, their impact has been limited by the difficulties of causal gene identification and a strict focus on bone mineral density (BMD). Here, we use Diversity Outbred (DO) mice to directly address these limitations by performing a systems genetics analysis of 55 complex skeletal phenotypes. We apply a network approach to cortical bone RNA-seq data to discover 66 genes likely to be causal for human BMD GWAS associations, including the genes SERTAD4 and GLT8D2 . We also perform GWAS in the DO for a wide-range of bone traits and identify Qsox1 as a gene influencing cortical bone accrual and bone strength. In this work, we advance our understanding of the genetics of osteoporosis and highlight the ability of the mouse to inform human genetics.

Abstract: Osteoporosis affects millions worldwide and is often caused by osteoclast induced bone loss. Here, we identify the cytoplasmic protein ELMO1 as an important ‘signaling node’ in osteoclasts. We note that ELMO1 SNPs associate with bone abnormalities in humans, and that ELMO1 deletion in mice reduces bone loss in four in vivo models: osteoprotegerin deficiency, ovariectomy, and two types of inflammatory arthritis. Our transcriptomic analyses coupled with CRISPR/Cas9 genetic deletion identify Elmo1 associated regulators of osteoclast function, including cathepsin G and myeloperoxidase. Further, we define the ‘ELMO1 interactome’ in osteoclasts via proteomics and reveal proteins required for bone degradation. ELMO1 also contributes to osteoclast sealing zone on bone-like surfaces and distribution of osteoclast-specific proteases. Finally, a 3D structure-based ELMO1 inhibitory peptide reduces bone resorption in wild type osteoclasts. Collectively, we identify ELMO1 as a signaling hub that regulates osteoclast function and bone loss, with relevance to osteoporosis and arthritis.

Abstract: The first-appearing β-cell autoantibody has been shown to influence risk of type 1 diabetes (T1D). Here, we assessed the risk of autoantibody spreading to the second-appearing autoantibody and further progression to clinical disease in The Environmental Determinants of Diabetes in the Young (TEDDY) study. RESEARCH DESIGN AND METHODS Eligible children with increased HLA-DR-DQ genetic risk for T1D were followed quarterly from age 3 months up to 15 years for development of a single first-appearing autoantibody (GAD antibody [GADA], insulin autoantibody [IAA] , or insulinoma antigen-2 autoantibody [IA-2A]) and subsequent development of a single second-appearing autoantibody and progression to T1D. Autoantibody positivity was defined as positivity for a specific autoantibody at two consecutive visits confirmed in two laboratories. Zinc transporter 8 autoantibody (ZnT8A) was measured in children who developed another autoantibody. RESULTS There were 608 children who developed a single first-appearing autoantibody (IAA, n = 282, or GADA, n = 326) with a median follow-up of 12.5 years from birth. The risk of a second-appearing autoantibody was independent of GADA versus IAA as a first-appearing autoantibody (adjusted hazard ratio [HR] 1.12; 95% CI 0.88–1.42; P = 0.36). Second-appearing GADA, IAA, IA-2A, or ZnT8A conferred an increased risk of T1D compared with children who remained positive for a single autoantibody, e.g., IAA or GADA second (adjusted HR 6.44; 95% CI 3.78–10.98), IA-2A second (adjusted HR 16.33; 95% CI 9.10–29.29; P & lt; 0.0001), or ZnT8A second (adjusted HR 5.35; 95% CI 2.61–10.95; P & lt; 0.0001). In children who developed a distinct second autoantibody, IA-2A (adjusted HR 3.08; 95% CI 2.04–4.65; P & lt; 0.0001) conferred a greater risk of progression to T1D as compared with GADA or IAA. Additionally, both a younger initial age at seroconversion and shorter time to the development of the second-appearing autoantibody increased the risk for T1D. CONCLUSIONS The hierarchical order of distinct autoantibody spreading was independent of the first-appearing autoantibody type and was age-dependent and augmented the risk of progression to T1D.