Megan M. O’Byrne

Pessimistic explanatory style: A PSYCHOLOGICAL RISK FACTOR FOR POOR PAIN AND FUNCTIONAL OUTCOMES TWO YEARS AFTER KNEE REPLACEMENT

Seligmans theory of causal attribution predicts that patients with a pessimistic explanatory style will have less favourable health outcomes. We identified 702 patients who had undergone 894 primary total knee replacements between 1993 and 2005, who responded to follow-up surveys at two (n = 783 knee replacements) and/or five years (n = 443 knee replacements) and had also completed the Minnesota Multiphasic Personality Inventory long before the joint replacement (median = 16.6 and 14.5 years for two- and five-year cohorts, respectively). Scores from the Minnesota Multiphasic Personality Inventory Optimism-Pessimism scale were used to categorise patients as pessimistic (t-score > 60) or non-pessimistic (t-score < or = 60). Multivariate logistic regression models assessing the effect of pessimistic explanatory style on pain or improvement in knee function were adjusted for gender, age, distance from the place of treatment and depression score. Pessimists reported (a) significantly more moderate or severe pain at two years with odds ratio 2.21 (95% confidence interval (CI) 1.12 to 4.35; p = 0.02), but not at five years when the odds ratio was 1.21 (95% CI 0.51 to 2.83; p = 0.67); and (b) less improvement in knee function at two years when the odds ratio was 0.53 (95% CI 0.30 to 0.96; p = 0.04), but not at five years when the odds ratio was 1.26 (95% CI 0.57 to 2.77; p = 0.57). No significant associations with moderate or severe limitation of activity were seen at two or five years. We conclude that a pessimistic explanatory style is associated with worse pain and functional outcomes two years after total knee replacement.

A large observational study to concurrently assess persistence of measles specific B-cell and T-cell immunity in individuals following two doses of MMR vaccine.

The measurement of measles-specific neutralizing antibodies, directed against the surface measles virus hemagglutinin and fusion proteins, is considered the gold standard in measles serology. We assessed functional measles-specific neutralizing antibody levels in a racially diverse cohort of 763 young healthy adolescents after receipt of two doses of measles-mumps-rubella vaccine, by the use of an automated plaque reduction microneutralization (PRMN) assay, and evaluated their relevance to protective antibody levels, as well as their associations with demographic and clinical variables. We also concurrently assessed measles-specific IFNγ Elispot responses and their relation to the observed antibody concentrations. The geometric mean titer for our cohort was 832mIU/mL (95% CIs: 776; 891). Sixty-eight subjects (8.9%) had antibody concentrations of less than the protective threshold of 210mIU/mL (corresponding to PRMN titer of 120; suggesting protection against symptomatic disease), and 177 subjects (23.2%) demonstrated persisting antibody concentrations above 1841mIU/mL (corresponding to PRMN titer of 1052; suggesting total protection against viral infection), 7.4 years after vaccination, in the absence of wild-type virus boosting. The mean measles-specific IFNγ Elispot response for our cohort was 46 (95% CIs: 43; 49) IFNγ-positive spots per 200,000 cells with no relation of cellular immunity measures to the observed antibody concentrations. No significant associations between antibody titers and demographic and clinical variables, including gender and race, were observed in our study. In conclusion, in a large observational study of measles immunity, we used an automated high-throughput measles virus-specific neutralization assay to measure humoral immunity, and concurrently determined measles-specific cellular immunity to aid the assessment of potential susceptibility to measles in vaccinated populations.

Common SNPs/Haplotypes in IL18R1 and IL18 Genes Are Associated With Variations in Humoral Immunity to Smallpox Vaccination in Caucasians and African Americans

BACKGROUND Identifying genetic factors that influence poxvirus immunity across races may assist in the development of better vaccines and approaches for vaccine development. METHODS We performed an extensive candidate-gene genetic screen (across 32 cytokine and cytokine receptor genes) in a racially diverse cohort of 1056 healthy adults after a single dose of smallpox vaccine. Associations between single-nucleotide polymorphisms (SNPs)/haplotypes and vaccinia virus-specific neutralizing antibodies were assessed using linear regression methodologies. RESULTS The combined analysis identified 63 associations between candidate SNPs and antibody levels after smallpox vaccination with P < .05. Thirty-one of these were within the IL18R1 and IL18 genes. Five IL18R1 SNPs, including a coding synonymous polymorphism rs1035130 (Phe251Phe) and 2 promoter SNPs (rs6710885, rs2287037), all in linkage disequilibrium, were associated with significant variations in antibody levels in both Caucasians (P ≤ .016) and African Americans (P ≤ .025). Similarly, associations with 2 intronic IL18 SNPs (rs2043055 and rs5744280) were consistent in the Caucasian (P ≤ .023) and African American samples (P ≤ .014). Haplotype analysis revealed highly significant associations between IL18R1 haplotypes and vaccinia virus-specific antibody levels (P < .001, by combined analysis) that were consistent across races. CONCLUSIONS Our study provides evidence for IL18 and IL18R1 genes as plausible genes regulating the humoral immune response to smallpox vaccine in both Caucasians and African Americans.

Influence of host genetic variation on rubella-specific T cell cytokine responses following rubella vaccination

The variability of immune response modulated by immune response gene polymorphisms is a significant factor in the protective effect of vaccines. We studied the association between cellular (cytokine) immunity and HLA genes among 738 schoolchildren (396 males and 342 females) between the ages of 11 and 19 years, who received two doses of rubella vaccine (Merck). Cytokine secretion levels in response to rubella virus stimulation were determined in PBMC cultures by ELISA. Cell supernatants were assayed for Th1 (IFN-gamma, IL-2, and IL-12p40), Th2 (IL-4, IL-5, and IL-10), and innate/proinflammatory (TNF-alpha, GM-CSF, and IL-6) cytokines. We found a strong association between multiple alleles of the HLA-DQA1 (global p-value 0.022) and HLA-DQB1 (global p-value 0.007) loci and variations in rubella-specific IL-2 cytokine secretion. Additionally, the relationships between alleles of the HLA-A (global p-value 0.058), HLA-B (global p-value 0.035), and HLA-C (global p-value 0.023) loci and TNF-alpha secretion suggest the importance of HLA class I molecules in innate/inflammatory immune response. Better characterization of these genetic profiles could help to predict immune responses at the individual and population level, provide data on mechanisms of immune response development, and further inform vaccine development and vaccination policies.

Effects of Vitamin A and D Receptor Gene Polymorphisms/Haplotypes on Immune Responses to Measles Vaccine

Objective Vitamins A and D, and their receptors, are important regulators of the immune system, including vaccine immune response. We assessed the association between polymorphisms in the vitamin A receptors [retinoic acid receptor &agr;, retinoic acid receptor &bgr; (RARB), and retinoic acid receptor &ggr;] and vitamin D receptor (VDR)/retinoid X receptor &agr; (RXRA) genes and interindividual variations in immune responses after two doses of measles vaccine in 745 children. Methods Using a tag single nucleotide polymorphism (SNP) approach, we genotyped 745 healthy children for the 391 polymorphisms in vitamin A receptor and VDR genes. Results The RARB haplotype (rs6800566/rs6550976/rs9834818) was significantly associated with variations in both measles antibody (global, P=0.013) and cytokine secretion levels, such as interleukin (IL)-10 (global, P=0.006), interferon (IFN)-&agr; (global, P=0.008), and tumor necrosis factor-&agr; (global, P=0.039) in the Caucasian subgroup. Specifically, the RARB haplotype, AAC, was associated with higher (t-statistic: 3.27, P=0.001) measles antibody levels. At the other end of the spectrum, haplotype GG for rs6550978/rs6777544 was associated with lower antibody levels (t-statistic: −2.32, P=0.020) in the Caucasian subgroup. In a sensitivity analysis, the RARB haplotype, CTGGGCAA, remained marginally significant (P<0.02) when the single SNP rs12630816 was included in the model for IL-10 secretion levels. A significant association was found between lower measles-specific IFN-&ggr; Enzyme-linked immunosorbent spot responses and haplotypes rs11102986/rs11103473/rs11103482/rs10776909/rs12004589/rs35780541/rs2266677/rs875444 (global, P=0.004) and rs6537944/rs3118571 (global, P<0.001) in the RXRA gene for Caucasians. We also found associations between multiple RARB, VDR, and RXRA SNPs/haplotypes and measles-specific IL-2, IL-6, IL-10, IFN-&agr;, IFN-&ggr;, IFN&lgr;-1, and TNF-&agr; cytokine secretions. Conclusion Our results suggest that specific allelic variations and haplotypes in the vitamin A receptor and VDR genes may influence adaptive immune responses to measles vaccine.

Multigenic control of measles vaccine immunity mediated by polymorphisms in measles receptor, innate pathway, and cytokine genes.

Measles infection and vaccine response are complex biological processes that involve both viral and host genetic factors. We have previously investigated the influence of genetic polymorphisms on vaccine immune response, including measles vaccines, and have shown that polymorphisms in HLA, cytokine, cytokine receptor, and innate immune response genes are associated with variation in vaccine response but do not account for all of the inter-individual variance seen in vaccinated populations. In the current study we report the findings of a multigenic analysis of measles vaccine immunity, indicating a role for the measles virus receptor CD46, innate pattern-recognition receptors (DDX58, TLR2, 4, 5, 7 and 8) and intracellular signaling intermediates (MAP3K7, NFKBIA), and key antiviral molecules (VISA, OAS2, MX1, PKR) as well as cytokines (IFNA1, IL4, IL6, IL8, IL12B) and cytokine receptor genes (IL2RB, IL6R, IL8RA) in the genetic control of both humoral and cellular immune responses. This multivariate approach provided additional insights into the genetic control of measles vaccine responses over and above the information gained by our previous univariate SNP association analyses.

Compound heterozygous NOTCH1 mutations underlie impaired cardiogenesis in a patient with hypoplastic left heart syndrome.

Hypoplastic left heart syndrome (HLHS) is a severe congenital heart defect (CHD) that necessitates staged, single ventricle surgical palliation. An increased frequency of bicuspid aortic valve (BAV) has been observed among relatives. We postulated number of mutant alleles as a molecular basis for variable CHD expression in an extended family comprised of an HLHS proband and four family members who underwent echocardiography and whole-genome sequencing (WGS). Dermal fibroblast-derived induced pluripotent stem cells (iPSC) were procured from the proband–parent trio and bioengineered into cardiomyocytes. Cardiac phenotyping revealed aortic valve atresia and a slit-like left ventricular cavity in the HLHS proband, isolated bicuspid pulmonary valve in his mother, BAV in a maternal 4° relative, and no CHD in his father or sister. Filtering of WGS for rare, functional variants that segregated with CHD and were compound heterozygous in the HLHS proband identified NOTCH1 as the sole candidate gene. An unreported missense mutation (P1964L) in the cytoplasmic domain, segregating with semilunar valve malformation, was maternally inherited and a rare missense mutation (P1256L) in the extracellular domain, clinically silent in the heterozygous state, was paternally inherited. Patient-specific iPSCs exhibited diminished transcript levels of NOTCH1 signaling pathway components, impaired myocardiogenesis, and a higher prevalence of heterogeneous myofilament organization. Extended, phenotypically characterized families enable WGS-derived variant filtering for plausible Mendelian modes of inheritance, a powerful strategy to discover molecular underpinnings of CHD. Identification of compound heterozygous NOTCH1 mutations and iPSC-based functional modeling implicate mutant allele burden and impaired myogenic potential as mechanisms for HLHS.

HLA haplotype and supertype associations with cellular immune responses and cytokine production in healthy children after rubella vaccine.

Secreted rubella virus-specific cytokines reflect the immunologic mechanisms underlying adoptive immune responses and are significant markers of immunity to rubella. We studied the association between measures of cellular (cytokine and frequency of cytokine-secreted cells) immune responses and HLA haplotypes (with frequencies of > or =1%) and supertypes among 738 healthy children following two doses of rubella vaccine. Haplotype effects were estimated while accounting for linkage phase ambiguity via an expectation maximization algorithm. Importantly, the majority of HLA class I and class II haplotype associations with different cytokines were consistent between Th1, Th2 and/or innate/proinflammatory cytokine groups. We found few class I supertypes (A1, A2, A3, and B7) with potential associations with IL-10 ELISPOT counts and rubella-specific IL-2, IL-10, TNF-alpha, and IL-6 cytokine secretion levels. Our data indicate that the presence or absence of certain HLA haplotypes and/or supertypes may influence the cytokine immune response to rubella vaccine, and represents a more advanced analysis compared to individual candidate gene association studies.

Associations between polymorphisms in the antiviral TRIM genes and measles vaccine immunity.

The role of polymorphisms within the antiviral tripartite motif (TRIM) genes in measles vaccine adaptive immune responses was examined. A limited association was found between TRIM5 (rs7122620) and TRIM25 (rs205499) gene polymorphisms and measles-specific antibody levels. However, many associations were found between TRIM gene SNPs and variations in cellular responses (IFN-γ Elispot and secreted cytokines IL-2, IL-6, IL-10, IFN-γ, and TNF-α). TRIM22 rs2291841 was significantly associated with an increased IFN-γ Elispot response (35 vs. 102 SFC per 2×10(5)PBMC, p=0.009, q=0.71) in Caucasians. A non-synonymous TRIM25 rs205498 (in LD with other SNPs, r(2)≥0.56), as well as the TRIM25 AAAGGAAAGGAGT haplotype, was associated with a decreased IFN-γ Elispot response (t-statistic -2.32, p=0.02) in African-Americans. We also identified polymorphisms in the TRIM5, TRIM22, and TRIM25 genes that were associated with significant differences in cytokine responses. Additional studies are necessary to replicate our findings and to examine the functional consequences of these associations.

A Clinical Deterioration Prediction Tool for Internal Medicine Patients

Many early warning models for hospitalized patients use variables measured on admission to the hospital ward; few have been rigorously derived and validated. The objective was to create and validate a clinical deterioration prediction tool using routinely collected clinical and nursing measurements. Multivariate regression analysis was used to determine clinical variables statistically associated with clinical deterioration; subsequently, the model tool was retrospectively validated using a different cohort of medical inpatients. The Braden Scale (P = .01; odds ratio [OR] = 0.91; confidence interval [CI] = 0.84-0.98), respiratory rate (P < .01; OR = 1.08; CI = 1.04-1.13), oxygen saturation (P < .01; OR = 0.97; CI = 0.96-0.99), and shock index (P < .01; OR = 2.37; CI = 1.14-3.98) were predictive of clinical deterioration 2-12 hours in the future. When applied to the validation cohort, the tool demonstrated fair concordance with actual outcomes. This tool created using routinely collected clinical measurements can serve as a very early warning system for hospitalized medical patients.