Killeen, Anthony A.

Significance Statement Intensive treatment of hypertension is beneficial for cardiovascular disease and cognitive function, but at the short-term expense of reduced kidney function. In a randomized trial of intensive versus standard systolic BP lowering, the authors found an association between a large decline in eGFR and increased incidence of probable dementia and mild cognitive impairment, but no link between urinary albumin-to-creatinine ratio and occurrence of dementia or mild cognitive impairment. Decline in eGFR occurred more frequently in the intensive treatment group, but did not modify the beneficial effect of intensive treatment on cognitive function. Among hypertensive adults, declining eGFR may be a marker for those at higher risk for dementia or mild cognitive impairment, independent of the intensity of hypertension treatment. Background Intensively treating hypertension may benefit cardiovascular disease and cognitive function, but at the short-term expense of reduced kidney function. Methods We investigated markers of kidney function and the effect of intensive hypertension treatment on incidence of dementia and mild cognitive impairment (MCI) in 9361 participants in the randomized Systolic Blood Pressure Intervention Trial, which compared intensive versus standard systolic BP lowering (targeting <120 mm Hg versus <140 mm Hg, respectively). We categorized participants according to baseline and longitudinal changes in eGFR and urinary albumin-to-creatinine ratio. Primary outcomes were occurrence of adjudicated probable dementia and MCI. Results Among 8563 participants who completed at least one cognitive assessment during follow-up (median 5.1 years), probable dementia occurred in 325 (3.8%) and MCI in 640 (7.6%) participants. In multivariable adjusted analyses, there was no significant association between baseline eGFR <60 ml/min per 1.73 m 2 and risk for dementia or MCI. In time-varying analyses, eGFR decline ≥30% was associated with a higher risk for probable dementia. Incident eGFR <60 ml/min per 1.73 m 2 was associated with a higher risk for MCI and a composite of dementia or MCI. Although these kidney events occurred more frequently in the intensive treatment group, there was no evidence that they modified or attenuated the effect of intensive treatment on dementia and MCI incidence. Baseline and incident urinary ACR ≥30 mg/g were not associated with probable dementia or MCI, nor did the urinary ACR modify the effect of intensive treatment on cognitive outcomes. Conclusions Among hypertensive adults, declining kidney function measured by eGFR is associated with increased risk for probable dementia and MCI, independent of the intensity of hypertension treatment.

Abstract Introduction: Antiphospholipid antibody syndrome (APS) is characterized by arterial or venous thrombosis, and/or adverse obstetric outcomes in the presence of persistent antiphospholipid antibodies (APab). Between 2–10% of all patients with APS are reported to present solely with anti beta-2 glycoprotein 1 antibodies (b2GP1 abs) (ref 1). In 2006 the Sapporo criteria were revised to include b2GP1 abs to the panel of diagnostic tests. While presence of a lupus anticoagulant (LA) has been found to correlate well with occurrence of thromboses, the prognostic and predictive roles of b2GP1 abs and anticardiolipin antibodies (ACLA) need better definition. Previous studies suggest both the severity of the initial event and the risk for recurrent events is greater among patients demonstrating presence of more than one APab on laboratory testing (ref 2 and 3), but this aspect needs further confirmation. Objectives: To identify the spectrum of clinical thrombotic and obstetric manifestations associated with the different APab profiles; To determine the prevalence and clinical significance of the b2GP1 ab positive and ACLA/LA negative phenotype; and To evaluate the significance of IgM b2GP1 ab and IgM ACLA. Methods: Medical records of patients tested for all three antiphospholipid antibodies at the University of Minnesota Medical Center from Dec 2000 to Dec 2005 were reviewed. Patients that met the modified criteria for APS were included. IgG and IgM ACLA were measured using the Diamedix kit (VAX diagnostics) and IgG and IgM b2GP1 abs using the Inovalite kit (NOVA diagnostics). LA was determined using standard protocol. Results: Over the 5 year period, all three laboratory assays were obtained in 560 individuals, but only 76 (13.5%) patients who met both the clinical and laboratory criteria for APS were included in this study. Seven of the 76 patients (9.2%) had isolated, persistently positive b2GP1 abs. LA alone was present in 21 patients (27.6%). Twenty nine patients (38%) had all three APabs, and had a higher incidence of thrombosis at multiple sites at the time of diagnosis as well as increased rate of recurrent events, in comparison to those with two or less than two APab. Isolated ACLA was present in only 2 patients (2.6%). Interestingly, both IgM (47%) and IgG (50%) b2GP1 abs were associated with thrombosis, whereas only IgG ACLA was found to be associated with thrombosis. Conclusion: The presence of b2GP1 abs as the sole laboratory anomaly is uncommon, but is noted in patients with APS, thus warranting it’s testing at the time of clinical suspicion. Amongst the different antibody types LA seems to be the strongest predictor for thrombotic events and ACLA seems to have a weaker link, consistent with the results of previous studies (ref 4). The presence of all three AP antibodies does increase the risk for recurrent and multiple thromboses.

Abstract Abstract 4048 Poster Board III-983 Introduction Iron deficiency is the most common nutritional disorder in the world with an estimated two billion affected persons. Although commonly considered environmental in origin, the existence of multiple genetic disorders of iron metabolism in man, rodents and other vertebrates suggest a genetic contribution to iron deficiency. Methods: The Hemochromatosis and Iron Overload Screening (HEIRS) Study is a multi-center, multi-ethnic study in which transferrin saturation (TS), serum ferritin (SF), and HFE mutations were determined in 101,168 adults. To identify genomic locations associated with iron deficiency, we performed a genome-wide association study (GWAS) using DNA collected from white HEIRS Study participants who had SF ≤ 12 μg/L (cases) and an equal number of white controls (SF > 100 μg/L in men, SF > 50 μg/L in women) frequency-matched to cases by sex and geographic location. Men aged ≥ 25 y and women ≥ 50 y were included in both groups. Tissue body iron, an index of iron deficiency, was estimated from serum transferrin receptor (sTfR) and SF. Genotyping was performed with the Illumina HumanCNV370K Beadchip platform. Quality control filters excluded single nucleotide polymorphisms (SNPs) or samples with > 5% missing genotypes, SNPs showing heterozygosity or Hardy-Weinberg deviations (P<10−7), and SNPs with minor allele frequency < 0.02. Population admixture/structure was assessed using principal component analysis. Regression analysis was used to examine the association between outcomes (case-control status, tissue body iron, serum ferritin, transferrin receptor, serum iron, total iron-binding capacity [TIBC], and unsaturated iron-binding capacity [UIBC]) and each SNP genotype variable; covariates included age, sex, and geographic location. Replication for 56 SNPs was conducted in a population attending primary care clinics at a Veterans Affairs (VA) medical center using the iPlex platform. Eligibility within the VA replication population was restricted to age and self-reported white ethnicity as for the HEIRS subset from a total of 2559 people (138 women). VA participants with SF ≤ 20 μg/L were classified as iron-deficient cases and frequency matched 1:2 with controls (men with SF > 100 μg/L and women with SF > 50 μg/L). Results The GWAS genomic control parameter was not significantly different from 1.0. There were 392 cases (96 men) and 390 controls (96 men) in the HEIRS subset GWAS with average age (SD) of 59 (10) y and 61 (11) y, respectively. Geometric mean SF (minimum, maximum), and mean (SD) for sTfR and tissue body iron in the HEIRS subset were 7.5 (1.2, 12) μg/L, 6.4 (3.77) mg/kg and -2.0 (2.50) for cases and 141 (51, 881) μg/L, 3.0 (0.98) mg/kg and 10.8 (2.5) for controls. After quality control tests, GWAS analysis included genotype data for 331,060 SNPs in 734 individuals (364 cases, 370 controls). For the VA replication population there were 67 male and 11 female cases, and 136 male and 27 female controls for whom DNA was successfully prepared; the average age (SD) was 68 (12) y for cases and 65 (11) y for controls. Regression analysis identified seven SNPs within four independent regions that replicated associations found in the GWAS (GWAS P<1×10-4 and VA P<0.05).The SNP rs6735681 on chromosome 2p24 was associated with serum iron (GWAS P<3.9×10-5, VA P=0.038). Three SNPs on chromosome 2p14 (rs6750096, rs2698541 and rs2698530) significantly influenced both TIBC and UIBC (GWAS P<2.9×10-5, VA P< 0.04 for all). Two SNPs in the TF gene region on chromosome 3q22 also showed significant effects on TIBC and UIBC (GWAS P<4.7×10-6, VA P<0.03 for all). The SNP rs10512064 on chromosome 9q21 was associated with serum ferritin concentration and tissue body iron (GWAS P<2.5×10-5, VA P<0.05 for both). Conclusion: From these GWAS and replication studies, we have identified three new genetic loci and one known iron gene, TF, associated with iron phenotype variability. These results point to specific loci as targets for gene identification and TF polymorphisms as determinants of iron metabolism, which in turn may play a role in regulation of body iron status. Disclosures: No relevant conflicts of interest to declare.

Abstract It is well-recognized that Helicobacter pylori infection causes gastrointestinal blood loss and iron deficiency. H. pylori gastritis has also been implicated in iron deficiency refractory to oral iron replacement therapy. Although H. pylori infection is common in multiple populations, less is known about the extent to which H. pylori contributes to iron deficiency in different racial/ethnic groups. To address this question, we tested the serum collected from men aged ≥ 25 y and women ≥ 50 y in the Hemochromatosis and Iron Overload Screening (HEIRS) Study to identify those with iron deficiency (defined as serum ferritin ≤ 12 mg/L [cases]) and iron-replete controls (serum ferritin > 100 mg/L in men, serum ferritin > 50 mg/L in women). All samples were tested for H. pylori IgG antibodies and for antibodies to CagA (cytotoxin-associated gene-bearing strain). We tested 571 cases and 1142 controls. Participants were considered to have evidence of H. pylori infection if they had positive results for both antibodies or for either antibody alone. Participants who did not have a result for either test were excluded. We examined the association between the presence of H. pylori in cases and controls among Caucasians, Asian/Pacific Islanders, African Americans, and Hispanics. Among Caucasians, evidence of H. pylori infection was comparable in cases and controls; 170 of 735 controls (23.1%) and 97 of 363 cases (26.7%), respectively, were positive. Similar results were found in African Americans (56.3% of 144 controls; 55.8% of 77 cases) and Hispanics (66.7% of 159 controls; 59.5% of 79 cases). However, in Asian/Pacific Islanders, the prevalence of H. pylori was higher among cases (62.8% of 51) than controls (44.1% of 102), p=0.029 by the likelihood ratio Chi-Square test. The relative risk (RR) of iron deficiency among those with H. pylori-positivity was significantly greater than in those without (RR, 1.66; 95% CI [1.04, 2.66]). A comparison of subgroups by positivity for IgG or CagA showed that the relative risk of iron deficiency was increased among those with IgG positivity, with or without Cag A positivity (RR, 1.80 and 1.90, respectively), but not among those with CagA positivity alone (RR, 1.00). H. pylori infection is a frequent contributor to iron deficiency but is also common in the general population. Our results indicate that among HEIRS Study Asian/Pacific Islander participants, H. pylori infection is more prevalent in cases with iron deficiency than in controls. In contrast, there was no difference in the prevalence of H. pylori infection between cases and controls among Caucasians, African Americans, and Hispanics. These results have implications for the investigation of iron deficiency in Asians and Pacific Islanders. Disclosures No relevant conflicts of interest to declare.

Abstract Abstract 2095 Celiac disease (CD) is an increasingly recognized disorder in Caucasian populations of European origin. Little is known about its prevalence in non-Caucasians. While CD is thought to be a cause of iron deficiency anemia, the extent to which CD contributes to iron deficiency in Caucasians and especially non-Caucasians is unknown. Iron deficiency is one of the most common nutritional deficiencies in both the developed world and in developing countries. Thus, it is important to know the prevalence of CD in different populations and in iron-deficient and iron-replete persons. To answer these questions, we tested serum collected from Caucasian and non-Caucasian men aged ≥ 25 y and women ≥ 50 y in the Hemochromatosis and Iron Overload Screening (HEIRS) Study. In the HEIRS Study, 101,168 participants were screened with serum biochemical tests of iron status, which not only detected participants with iron overload but also identified a unique multiethnic population of participants with iron deficiency. We hypothesized that CD is more common in those with iron deficiency than in iron-replete individuals. We also examined the difference in frequency of CD between Caucasians and non-Caucasians with iron deficiency. Cases with iron deficiency (defined as serum ferritin ≤ 12 μg/L [cases]) and iron-replete controls (serum ferritin > 100 μg/L in men, serum ferritin > 50 μg/L in women) were further evaluated by using a sequential serological testing scheme whereby all samples were tested with an ELISA for human recombinant tissue transglutaminase IgA antibodies, and positive values were confirmed by endomysial antibodies. Those positive for both tests were considered double positives and were presumed to have untreated CD. Those positive for tissue transglutaminase IgA antibodies but not for endomysial antibodies were termed single positives and were considered indeterminate and excluded from analysis. We further hypothesized that low serum ferritin and an appropriate human leukocyte antigen (HLA) variant, may be predictive of CD. We used SNP-based analysis to determine HLA genotype and DQ8, DQ2.2 or DQ4, and DQ2.5 risk variants. Fisher's exact test was used to examine the association between iron−deficient case and control status and the presence of celiac disease. Log-binomial regression was applied to estimate the odds of celiac disease in iron-deficient cases relative to that of controls. A total of 1713 subjects were tested for tissue transglutaminase IgA antibodies. Participants included 1100 Caucasians, 221 African Americans, 153 Asians, and 239 Hispanics. Fourteen of 571 iron-deficient cases were positive for the double serology compared to just one of 1142 controls. All of the seropositive tests were seen in Caucasians and none in the non-Caucasians. Excluding data from participants with indeterminate serological screen results (6 Caucasians, 4 non-Caucasians), we found that CD occurred in 14 of 567 cases (2.5%) and in only 1 of 1136 (0.1%) controls (Fisher's exact test, p=1.92 10−6). CD was more common in Caucasian cases (14 of 363, 4%) than in non-Caucasian cases (0 of 204, p=0.003). Only one Caucasian control and none of the non-Caucasian controls had CD. The odds of CD in individuals with iron deficiency was 28 (3.7, 212.8) times that in controls. Thirteen of 14 iron-deficient cases with CD carried the DQ2.5 variant of the HLA genotype. Presence of DQ2.5 was highly significantly associated with celiac disease status in iron-deficient cases compared to controls (Fisher's exact test, p = 7.183 × 10−8). The results indicate that CD is a small but significant contributor to iron deficiency in Caucasians. CD is very rare in other races, even among individuals with features frequently seen in CD, such as iron deficiency. CD is also rare in Caucasians who are iron replete. CD testing should be considered for adult Caucasian males or post-menopausal females having iron deficiency without evidence of other etiologies such as gastrointestinal blood loss. Patients identified with CD may benefit from appropriate treatment. Disclosures: No relevant conflicts of interest to declare.

The appropriate target for BP in patients with CKD and hypertension remains uncertain. We report prespecified subgroup analyses of outcomes in participants with baseline CKD in the Systolic Blood Pressure Intervention Trial. We randomly assigned participants to a systolic BP target of <120 mm Hg (intensive group; n =1330) or <140 mm Hg (standard group; n =1316). After a median follow-up of 3.3 years, the primary composite cardiovascular outcome occurred in 112 intensive group and 131 standard group CKD participants (hazard ratio [HR], 0.81; 95% confidence interval [95% CI], 0.63 to 1.05). The intensive group also had a lower rate of all-cause death (HR, 0.72; 95% CI, 0.53 to 0.99). Treatment effects did not differ between participants with and without CKD ( P values for interactions ≥0.30). The prespecified main kidney outcome, defined as the composite of ≥50% decrease in eGFR from baseline or ESRD, occurred in 15 intensive group and 16 standard group participants (HR, 0.90; 95% CI, 0.44 to 1.83). After the initial 6 months, the intensive group had a slightly higher rate of change in eGFR (−0.47 versus −0.32 ml/min per 1.73 m 2 per year; P <0.03). The overall rate of serious adverse events did not differ between treatment groups, although some specific adverse events occurred more often in the intensive group. Thus, among patients with CKD and hypertension without diabetes, targeting an SBP<120 mm Hg compared with <140 mm Hg reduced rates of major cardiovascular events and all-cause death without evidence of effect modifications by CKD or deleterious effect on the main kidney outcome.

Context.— Both the regulations in the Clinical Laboratory Improvement Amendments of 1988 (CLIA) and the checklists of the College of American Pathologists (CAP) Laboratory Accreditation Program require clinical laboratories to verify performance characteristics of quantitative test systems. Laboratories must verify performance claims when introducing an unmodified, US Food and Drug Administration–cleared or approved test system, and they must comply with requirements for periodic calibration and calibration verification for existing test systems. They must also periodically verify the analytical measurement range of many quantitative test systems. Objective.— To provide definitions for many of the terms used in these regulations, to describe a set of basic analyses that laboratories may adapt to demonstrate compliance with both CLIA and the CAP Laboratory Accreditation Program checklists for performing calibration verification and for verifying the analytical measurement range of test systems, to review some of the recommended procedures for establishing performance goals, and to provide data illustrating the performance goals used in some of the CAP's calibration verification and linearity surveys. Data Sources.— The CAP's calibration verification and linearity survey programs, the CLIA regulations, the Laboratory Accreditation Program requirements, and published literature were used to meet these objectives. Conclusions.— Calibration verification and linearity and analytical measurement range verification should be performed using suitable materials with assessment of results using well-defined evaluation protocols. We describe the CAP's calibration verification and linearity programs that may be used for these purposes.