Doxorubicin-induced cardiac dysfunction in unselected patients with a history of early-stage breast cancer.

Cardiomyopathy is a known complication of anthracycline-based adjuvant chemotherapy and is more commonly reported in population-based studies of breast cancer survivors than in clinical trials. This study prospectively evaluated the prevalence of elevated cardiac biomarkers in unselected patients who had been treated with doxorubicin for early-stage breast cancer and the prevalence of reduced LVEF in patients with an elevated biomarker. All participants underwent an examination, symptom inventory, medical record review, and biomarker analysis for BNP, troponin, and plasma and urine NT-proBNP. Patients who had one or more elevated biomarkers were referred for echocardiogram; systolic dysfunction was defined as LVEF less than 55 %. Multivariable logistic regression was used to determine the associations between age, BMI, cumulative dose of doxorubicin, diabetes, hypertension, and left-sided radiation therapy and the risk of reduced LVEF. Among the 269 patients who underwent lab testing (mean age 56 years, mean time since completion of doxorubicin-based chemotherapy 6 years), 192 (72 %) had one or more elevated biomarker. Among the 166 patients who completed an echocardiogram, 11.5 % had a LVEF < 55 %. After adjusting for covariates known to affect cardiac function, multivariable logistic regression revealed plasma NT-proBNP to be the only measured cardiac biomarker associated with systolic dysfunction. There is a relationship between NT-proBNP and the frequency of reduced LVEF in women treated with doxorubicin for curative intent; further study of NT-proBNP as a potential biomarker for subclinical cardiac dysfunction after exposure to anthracyclines is warranted.

Forced TR2/TR4 expression in sickle cell disease mice confers enhanced fetal hemoglobin synthesis and alleviated disease phenotypes.

Sickle cell disease (SCD) is a hematologic disorder caused by a missense mutation in the adult ß-globin gene. Higher fetal hemoglobin (HbF) levels in red blood cells of SCD patients have been shown to improve morbidity and mortality. We previously found that nuclear receptors TR2 and TR4 repress expression of the human embryonic ε-globin and fetal γ-globin genes in definitive erythroid cells. Because forced expression of TR2/TR4 in murine adult erythroid cells paradoxically enhanced fetal γ-globin gene expression in transgenic mice, we wished to determine if forced TR2/TR4 expression in a SCD model mouse would result in elevated HbF synthesis and thereby alleviate the disease phenotype. In a "humanized" sickle cell model mouse, forced TR2/TR4 expression increased HbF abundance from 7.6% of total hemoglobin to 18.6%, accompanied by increased hematocrit from 23% to 34% and reticulocyte reduction from 61% to 18%, indicating a significant reduction in hemolysis. Moreover, forced TR2/TR4 expression reduced hepatosplenomegaly and liver parenchymal necrosis and inflammation in SCD mice, indicating alleviation of usual pathophysiological characteristics. This article shows that genetic manipulation of nonglobin proteins, or transcription factors regulating globin gene expression, can ameliorate the disease phenotype in a SCD model animal. This proof-of-concept study demonstrates that modulating TR2/TR4 activity in SCD patients may be a promising therapeutic approach to induce persistent HbF accumulation and for treatment of the disease.

Reflexing Suspicious ß-Region Findings on Capillary Serum Protein Electrophoresis to Immunofixation or Immunosubtraction for Detecting Monoclonal Proteins.

OBJECTIVES: Monoclonal immunoglobulins (M-proteins) that migrate in the ß region on serum protein electrophoresis (SPEP) are often cloaked by this region's normal constituents. The present study interrogates the utility of using both quantitative and qualitative alterations in ß-region bands for detection of ß-migrating M-proteins. METHODS: Consecutive SPEP cases analyzed by capillary electrophoresis were searched to identify the initial workup on 1,841 patients with increased total ß regions, suspicious ß-region findings resulting in reflex immunofixation (IFE), or immunosubtraction (ISUB). To augment quantitative information, separate ß1 and ß2 measurements were established and retrospectively used to evaluate their sensitivity for M-protein detection. RESULTS: We identified M-proteins in 205 (11.1%) cases, including immunoglobulin A (IgA) (54%), IgG (24%), IgM (13%), and free light chain (9%) isotypes. Of the 15 cases flagged by separate ß1 and ß2 measurements that were not identified by total ß-region measurement, 1 progressed to myeloma. Of the 56 ß-migrating M-proteins identified by qualitative features but without increase in any of the ß-region measurements, 1 progressed to myeloma. CONCLUSIONS: A combination of separate measurements for ß1 and ß2 regions together with detection of ß-region distortions increase sensitivity for identifying ß-migrating M-proteins via reflex IFE or ISUB.

Differences in Performance Characteristics Among Four High-Throughput Assays for the Detection of Antibodies Against SARS-CoV-2 Using a Common Set of Patient Samples.

OBJECTIVES: Serologic testing for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has experienced a changing landscape of available assays coupled with uncertainty surrounding performance characteristics. Studies are needed to directly compare multiple commercially available assays. METHODS: Residual serum samples were identified based on SARS-CoV-2 reverse transcription polymerase chain reaction (RT-PCR) testing, clinical test results, and collection dates. Serum samples were analyzed using assays from four different manufacturers: DiaSorin anti-SARS-CoV-2 S1/S2 IgG, EUROIMMUN anti-SARS-CoV-2 IgG ELISA, Roche Elecsys anti-SARS-CoV-2, and Siemens SARS-CoV-2 Total antibody assays. RESULTS: Samples from SARS-CoV-2 RT-PCR-positive patients became increasingly positive as time from symptom onset increased. For patients with latest sample 14 or more days after symptom onset, sensitivities reached 93.1% to 96.6%, 98.3%, and 96.6% for EUROIMMUN, Roche, and Siemens assays, respectively, which were superior to the DiaSorin assay at 87.7%. The specificity of Roche and Siemens assays was 100% and superior to DiaSorin and EUROIMMUN assays, which ranged from 96.1% to 97.0% and 86.3% to 96.4%, respectively. CONCLUSIONS: Laboratories should be aware of the advantages and limitations of serology testing options for SARS-CoV-2. The specificity and sensitivity achieved by the Roche and Siemens assays would be acceptable for testing in lower-prevalence regions and have the potential of orthogonal testing advantages if used in combination.

Diagnostic patterns and stress testing trends after implementing high-sensitivity troponin assay.

OBJECTIVES: High-sensitivity troponin T (hsTnT) testing was approved in the United States to better facilitate diagnosis of acute coronary syndrome (ACS). Although hsTnT has been widely studied internationally, the impact of hsTnT on discharge diagnoses and health care utilization within the United States is less known. We sought to evaluate the effects of implementing hsTnT on diagnosis patterns and stress testing utilization. STUDY DESIGN: We performed a retrospective cohort analysis consisting of patients with suspected ACS undergoing either conventional troponin I (n = 14,631) or hsTnT (n = 7237) testing between January 2016 and February 2019. METHODS: Log-binomial regression with interrupted time series modeled diagnosis patterns, and logistic regression with segmented time trends modeled stress testing rates. Observed trends were compared with expected trends using average marginal effect (AME). RESULTS: Rates of acute myocardial infarction-related diagnoses were similar in the post-hsTnT period (AME, -0.6%; P = .065). Post hsTnT introduction, patients were more likely to receive a diagnosis of heart failure (2.1%; P < .001) or atrial fibrillation/flutter (0.9%; P < .001) and less likely to receive a diagnosis of hypertensive heart disease (-10.2%; P < .01) or hypertensive heart disease with chronic kidney disease (-3.7%; P < .001). Likelihood of receiving stress testing increased after hsTnT implementation (2.3%; P < .001). CONCLUSIONS: Variations in discharge diagnosis patterns and increases in stress test utilization were observed following hsTnT implementation. Hospitals can expect similar changes, which may have long-term implications on health care utilization, cost, and hospital reimbursement.

Mild SARS-CoV-2 Illness Is Not Associated with Reinfections and Provides Persistent Spike, Nucleocapsid, and Virus-Neutralizing Antibodies.

Uncertainty exists whether mild COVID-19 confers immunity to reinfection. Questions also remain regarding the persistence of antibodies against SARS-CoV-2 after mild infection. We prospectively followed at-risk individuals with and without SARS-CoV-2 for reinfection and monitored the spike and nucleocapsid antibodies. This prospective cohort study was conducted over two visits, 3 to 6 months apart, between May 2020 and February 2021. Adults with and without COVID-19, verified by FDA EUA-approved SARS-CoV-2 RT-PCR assays, were screened for spike and nucleocapsid antibody responses using FDA EUA-approved immunoassays and for pseudoviral neutralization activity. The subjects were monitored for symptoms, exposure to COVID-19, COVID-19 testing, seroconversion, reinfection, and vaccination. A total of 653 subjects enrolled; 129 (20%) had a history of COVID-19 verified by RT-PCR at enrollment. Most had mild disease, with only three requiring hospitalization. No initially seropositive subjects experienced a subsequent COVID-19 infection during the follow-up versus 15 infections among initially seronegative subjects (infection rates of 0.00 versus 2.05 per 10,000 days at risk [P = 0.0485]). In all, 90% of SARS-CoV-2-positive subjects produced spike and nucleocapsid responses, and all but one of these had persistent antibody levels at follow-up. Pseudoviral neutralization activity was widespread among participants, did not decrease over time, and correlated with clinical antibody assays. Reinfection with SARS-CoV-2 was not observed among individuals with mild clinical COVID-19, while infections continued in a group without known prior infection. Spike and nucleocapsid COVID-19 antibodies were associated with almost all infections and persisted at stable levels for the study duration. IMPORTANCE This article demonstrates that people who have mild COVID-19 illnesses and produce antibodies are protected from reinfection for up to 6 months afterward. The antibodies that people produce in this situation are stable for up to 6 months as well. Clinical antibody assays correlate well with evidence of antibody-related viral neutralization activity.

Comprehensive Analysis of Steroid Biomarkers for Guiding Primary Aldosteronism Subtyping.

Adrenal vein sampling (AVS) is required to distinguish unilateral from bilateral aldosterone sources in primary aldosteronism (PA), and cortisol is used for AVS data interpretation, but cortisol has several pitfalls. In this study, we present the utility of several other steroids in PA subtyping, both during AVS, as well as in peripheral serum. We included patients with PA who underwent AVS at University of Michigan between 2012 and 2018. We used mass spectrometry to simultaneously quantify 17 steroids in adrenal veins (AV) and periphery, both at baseline and after cosyntropin administration. PA was classified as unilateral or bilateral based on a lateralization index ≥ or <4, respectively, separately for baseline and post-cosyntropin administration. Of 131 participants, AV catheterizations was deemed failed in 28 (21 %) patients (36 AVs) at baseline. Eight steroids demonstrated higher AV/periphery ratios than cortisol (P<0.01 for all); 11ß-hydroxyandrostenedione, 11-deoxycortisol, and corticosterone rescued most failed baseline catheterizations. Lateralization was generally consistent when using these alternative steroids. Based on pre- and post-cosyntropin data, the remaining 103 patients were classified as: U/U, 37; B/B, 32; U/B, 20; B/U, 14. Discriminant analysis of multi-steroid panels from peripheral serum showed distinct profiles across the 4 groups, with highest aldosterone, 18-oxocortisol and 11-deoxycorticosterone in U/U patients. In conclusion, 11ß-hydroxyandrostenedione and 11-deoxycortisol are superior to cortisol for AVS data interpretation. Single assay multi-steroid panels measured in peripheral serum are helpful in stratified PA subtyping and have the potential to circumvent AVS in a subset of patients with PA.

Autoantibody profiles reveal ubiquilin 1 as a humoral immune response target in lung adenocarcinoma.

There is considerable evidence that the presence of cancer can elicit a humoral immune response to specific proteins in the host, and these resulting autoantibodies may have potential as noninvasive biomarkers. To characterize the autoantibody repertoire present in the sera of patients with lung adenocarcinoma, we developed a high-density peptide microarray derived from biopanning a lung cancer phage display library. Using a 2,304-element microarray, we interrogated a total of 250 sera from Michigan lung cancer patients and noncancer controls to develop an "autoantibody profile" of lung adenocarcinoma. A set of 22 discriminating peptides derived from a training set of 125 serum samples from lung adenocarcinoma patients and control subjects was found to predict cancer status with 85% sensitivity and 86% specificity in an independent test set of 125 sera. Sequencing of the immunoreactive phage-peptide clones identified candidate humoral immune response targets in lung adenocarcinoma, including ubiquilin 1, a protein that regulates the degradation of several ubiquitin-dependent proteasome substrates. An independent validation set of 122 serum samples from Pittsburgh was examined using two overlapping clones of ubiquilin 1 that showed 0.79 and 0.74 of the area under the receiver operating characteristics curve, respectively. Significantly increased levels of both ubiquilin 1 mRNA and protein, as well as reduced levels of the phosphorylated form of this protein, were detected in lung tumors. Immunofluorescence using anti-ubiquilin 1 antibodies confirmed intracellular expression within tumors cells. These studies indicate that autoantibody profiles, as well as individual candidates, may be useful for the noninvasive detection of lung adenocarcinoma.

Interpretation of common endocrine laboratory tests: technical pitfalls, their mechanisms and practical considerations.

Pitfalls in hormonal assays are commonly seen in clinical practice and may lead to erroneous clinical impressions and treatments. In this article, we address common laboratory pitfalls encountered during evaluation of patients with real or presumed endocrine disorders including high dose hook effect and falsely normal prolactin in cases of macroprolactinomas, macroprolactinemia and falsely elevated prolactin, macrothyrotropinemia and falsely elevated TSH, heterophile antibodies leading to false elevation of hormonal concentration, biotin interference with different hormonal assays, cross-reactivity of steroid hormones immunoassays, and others. We describe the mechanisms of such laboratory pitfalls, review clinical scenarios in which they might occur, and discuss the ways to resolve such conundrums. The aim of this article is to present a learning material for the endocrine trainees and practitioners.

Autoantibody signatures in prostate cancer.

BACKGROUND: New biomarkers, such as autoantibody signatures, may improve the early detection of prostate cancer. METHODS: With a phage-display library derived from prostate-cancer tissue, we developed and used phage protein microarrays to analyze serum samples from 119 patients with prostate cancer and 138 controls, with the samples equally divided into training and validation sets. A phage-peptide detector that was constructed from the training set was evaluated on an independent validation set of 128 serum samples (60 from patients with prostate cancer and 68 from controls). RESULTS: A 22-phage-peptide detector had 88.2 percent specificity (95 percent confidence interval, 0.78 to 0.95) and 81.6 percent sensitivity (95 percent confidence interval, 0.70 to 0.90) in discriminating between the group with prostate cancer and the control group. This panel of peptides performed better than did prostate-specific antigen (PSA) in distinguishing between the group with prostate cancer and the control group (area under the curve for the autoantibody signature, 0.93; 95 percent confidence interval, 0.88 to 0.97; area under the curve for PSA, 0.80; 95 percent confidence interval, 0.71 to 0.88). Logistic-regression analysis revealed that the phage-peptide panel provided additional discriminative power over PSA (P<0.001). Among the 22 phage peptides used as a detector, 4 were derived from in-frame, named coding sequences. The remaining phage peptides were generated from untranslated sequences. CONCLUSIONS: Autoantibodies against peptides derived from prostate-cancer tissue could be used as the basis for a screening test for prostate cancer.

Effect of Diabetes Mellitus on Sickle Hemoglobin Quantitation in Sickle Cell Trait.

OBJECTIVES: We evaluated the effect of diabetes on sickle hemoglobin (HbS) measurement on two common clinical hemoglobin separation platforms. METHODS: We performed a method comparison between the Bio-Rad Variant II high-performance liquid chromatography (HPLC) and Sebia Capillarys 2 Flex Piercing capillary electrophoresis (CE) using clinical specimens from 38 patients without hemoglobin variants and 57 patients with sickle cell trait (AS) (HbA1c%, 4.1%-15.4%). We investigated the effect of intermethod Hb% differences on result interpretation by a panel of expert clinical observers. RESULTS: In diabetic specimens, HPLC undermeasured HbS% up to 7.4% vs CE, due to S1c eluting closely with A0 in HPLC. This increased concern for underlying α-thalassemia in diabetic patients with AS based on HPLC results. HPLC P2% was linearly related to HbA1c% and can be a screen for diabetic AS samples. CONCLUSIONS: Glycosylation can interfere with HbS% measurement by HPLC. Susceptible specimens should be identified and preferentially analyzed via CE.

Quality Control Practices for Chemistry and Immunochemistry in a Cohort of 21 Large Academic Medical Centers.

OBJECTIVES: In the United States, minimum standards for quality control (QC) are specified in federal law under the Clinical Laboratory Improvement Amendment and its revisions. Beyond meeting this required standard, laboratories have flexibility to determine their overall QC program. METHODS: We surveyed chemistry and immunochemistry QC procedures at 21 clinical laboratories within leading academic medical centers to assess if standardized QC practices exist for chemistry and immunochemistry testing. RESULTS: We observed significant variation and unexpected similarities in practice across laboratories, including QC frequency, cutoffs, number of levels analyzed, and other features. CONCLUSIONS: This variation in practice indicates an opportunity exists to establish an evidence-based approach to QC that can be generalized across institutions.

Cardiovascular risk factors in ethnic minority women aged < or =30 years.

Men and women of African and South Asian ancestry in the United States are increasingly recognized as being at greater risk for coronary heart disease (CHD) than Caucasians of European ancestry. Relatively little data on the genetic and lifestyle risk factors that predispose women to CHD in these ethnic minorities are available. We compared coronary risk factors in a volunteer sample of African-American, Asian Indian American, and Caucasian American women of college age. Life style, dietary, hemodynamic and anthropometric parameters, and laboratory data were sought from 70 subjects in each ethnic group. African-American women were found to have lower triglyceride levels and higher apolipoproten A-1, high-density lipoprotein (HDL), lipoprotein (a) (Lp(a)), fibrinogen, and fasting insulin levels. They also consumed more fat and cholesterol than their peers, had a higher percentage of body fat, body weight, and body mass indexes, and reported less physical activity than Caucasians. Asian Indian American women had higher Lp(a), HDL, and fibrinogen levels than Caucasian American women, and also reported less physical activity. Thus, young African- American and Asian Indian American women have several modifiable risk factors as well as some nontraditional lipid risk factors that warrant consideration for explaining the increased prevalence of CHD in these ethnic groups. The tendency toward peripheral insulin insensitivity and increased body fat in this age group of African-American women suggests diet and exercise may reduce the risk of subsequent CHD.

Analytical and clinical validation of a radioimmunoassay for the measurement of 1,25 dihydroxy vitamin D.

OBJECTIVES: The analytical and clinical validation of the DiaSorin 1,25 dihydroxyvitamin D RIA is described. DESIGN AND METHODS: The analytical parameters assessed included analytical sensitivity, dilution linearity, intra- and inter-assay precision, recovery, specificity, and interference studies. Where appropriate, assessments were performed according to NCCLS guidelines. The clinical validation assessed normal individuals and end-stage renal disease patients. RESULTS: The analytical sensitivity of the assay is < 2.0 pg/mL or < 4.8 pM. The assay is specific for both 1,25 dihydroxyvitamin D2 and D3. Recovery ranged from 97% to 108% for spiked samples. Intra-assay precision, as %CV, ranged from 7% to 11%, while inter-assay precision was 12% to 15%. No interference was observed from bilirubin, cholesterol, hemoglobin, or triglycerides. Clinical validation demonstrated complete discrimination between normal and ESRD populations. CONCLUSIONS: These data demonstrate that the DiaSorin 1,25 (OH)(2) vitamin D RIA is a robust, accurate, and precise tool for the assessment of 1,25 (OH)(2) vitamin D.

Lipoprotein (a): perspectives from a lipid-referral program.

BACKGROUND: Lipoprotein (a) [Lp(a)] has a strong association with coronary disease (CHD). We evaluated the implications of implementing a niacin strategy in persons above low risk by the Framingham risk score (FRS). METHODS: Patients referred to a university lipid management program from January 2004 to June 2010 had an Lp(a) level measured at initial evaluation. Factors associated with an increase in Lp(a) and predictors of a high risk Lp(a) (≥50 mg/dL) were assessed. FRS and Lp(a) levels were used to assess eligibility for niacin with an Lp(a) ≥50 mg/dL. RESULTS: A total of 692 patients (57% male, mean age 52 ± 14 years) had a mean Lp(a) of 32 ± 40 mg/dL. In a multiple logistic regression model, African-American race, female gender, presence of CHD, and lower triglyceride levels were significant predictors of high risk Lp(a). Ten percent were determined to be intermediate and 44% high risk by FRS. A total of 9% of intermediate- and 26% of high-risk patients had an Lp(a) ≥50 mg/dL, and 84% were not taking niacin. A total of 19% of moderate- and high-risk patients were eligible for initiation of niacin based upon values ≥50 mg/dL. If niacin were also used for an high-density lipoprotein cholesterol levels ≤40 mg/dL, only 5.1% additional patients would require niacin. CONCLUSION: High-risk levels of Lp(a) are associated with female gender, African- American race, and CHD. 19% of moderate and high risk patients would be candidates for treatment with niacin if the indication is a cutpoint Lp(a) ≥50 mg/dL.

Use of B-natriuretic peptide as a diagnostic marker in the differential diagnosis of transfusion-associated circulatory overload.

BACKGROUND: Transfusion-associated circulatory overload (TACO) occurs when the transfusion rate or volume exceeds the capacity of a compromised cardiovascular system. Characteristic symptoms and signs associated with TACO are neither sensitive nor specific. B-natriuretic peptide (BNP) is a 32-amino-acid polypeptide secreted from the cardiac ventricles in response to ventricular volume expansion and pressure overload. This study was performed to explore the usage of BNP in the differential diagnosis of TACO. STUDY DESIGN AND METHODS: Pre- and posttransfusion BNP levels were determined in 21 patients with suspected TACO and 19 control patients. The BNP was considered significant if the posttransfusion-to-pretransfusion ratio was at least 1.5 and the posttransfusion BNP level was at least 100 pg per mL. RESULTS: The BNP test has a sensitivity and specificity of 81 and 89 percent, respectively, in diagnosis of TACO. It has a positive predictive value of 89 percent, a negative predictive value of 81 percent, and an accuracy of 87 percent. In logistic regression analysis, BNP was found to have significant predictive power independent of other clinical variables in models predicting which patients had TACO. CONCLUSIONS: Our study suggests that in patients who present symptoms suggestive of TACO, BNP can be a useful adjunct marker in confirming volume overload as the cause of acute dyspnea and symptoms related to cardiovascular compromise.