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Background Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants continue to emerge, and effective tracking requires rapid return of results. Surveillance of variants is typically performed by whole genome sequencing (WGS), which can be financially prohibitive and requires specialized equipment and bioinformatic expertise. Genotyping approaches are rapid methods for monitoring SARS-CoV-2 variants but require continuous adaptation. Fragment analysis may represent an approach for improved SARS-CoV-2 variant detection. Methods A multiplex fragment analysis approach (CoVarScan) was validated using PCR targeting variants by size and fluorescent color. Eight SARS-CoV-2 mutational hot spots in variants of concern (VOCs) were targeted. Three primer pairs (recurrently deleted region [RDR] 1, RDR2, and RDR3–4) flank RDRs in the S-gene. Three allele-specific primers target recurrent spike receptor binding domain mutants. Lastly, 2 primer pairs target recurrent deletions or insertions in ORF1A and ORF8. Fragments were resolved and analyzed by capillary electrophoresis (ABI 3730XL), and mutational signatures were compared to WGS results. Results We validated CoVarScan using 3544 clinical respiratory specimens. The assay exhibited 96% sensitivity and 99% specificity compared to WGS. The limit of detection for the core targets (RDR1, RDR2, and ORF1A) was 5 copies/reaction. Variants were identified in 95% of samples with cycle threshold (CT) Conclusions Multiplex fragment analysis is adaptable and rapid and has similar accuracy to WGS to classify SARS-CoV-2 variants.

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Additional file 1. Complete drug list.

Key Points Question What is the accuracy of low-density lipoprotein cholesterol (LDL-C) estimation when comparing the Friedewald, extended Martin/Hopkins, and Sampson equations with LDL-C measured through ultracentrifugation at triglyceride levels of 400 to 799 mg/dL? Findings In this cross-sectional study of 111 939 patients, across all individual guideline LDL-C classes from, Importance Low-density lipoprotein cholesterol (LDL-C) is typically estimated with the Friedewald or Martin/Hopkins equation; however, if triglyceride levels are 400 mg/dL or greater, laboratories reflexively perform direct LDL-C (dLDL-C) measurement. The use of direct chemical LDL-C assays and estimation of LDL-C via the National Institutes of Health Sampson equation are not well validated, and data on the accuracy of LDL-C estimation at higher triglyceride levels are limited. Objective To compare an extended Martin/Hopkins equation for triglyceride values of 400 to 799 mg/dL with the Friedewald and Sampson equations. Design, Setting, and Participants This cross-sectional study evaluated consecutive patients at clinical sites across the US with patient lipid distributions representative of the US population in the Very Large Database of Lipids from January 1, 2006, to December 31, 2015, with triglyceride levels of 400 to 799 mg/dL. Data analysis was performed from November 9, 2020, to March 23, 2021. Main Outcomes and Measures Accuracy in LDL-C classification according to guideline-based categories and absolute errors between estimated LDL-C and dLDL-C levels. Patients were randomly assigned 2:1 to derivation and validation data sets. Levels of dLDL-C were measured by vertical spin-density gradient ultracentrifugation. The LDL-C levels were estimated using the Friedewald method, with a fixed ratio of triglycerides to very low-density lipoprotein cholesterol (VLDL-C ratio of 5:1), extended Martin/Hopkins equation with a flexible ratio, and Sampson equation with VLDL-C estimation by multiple least-squares regression. Results A total of 111 939 patients (mean [SD] age, 52 [13] years; 65.0% male) with triglyceride levels of 400 to 799 mg/dL were included, representing 2.2% of 5 081 680 patients in the database. Across all individual guideline LDL-C classes (, This cross-sectional study of patients with lipid distributions representative of the US population compares the accuracy of 3 low-density lipoprotein level estimation methods with triglyceride levels of 400 to 799 mg/dL.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus causes a spectrum of clinical manifestations, ranging from asymptomatic to mild, moderate, or severe illness with multi-organ failure and death. Using a new machine learning algorithm developed by us, we have reported a significantly higher number of predicted COVID-19 cases than the documented counts across the world. The sole reliance on confirmed symptomatic cases overlooking the symptomless COVID-19 infections and the dynamics of waning immunity may not provide ‘true’ spectrum of infection proportion, a key element for an effective planning and implementation of protection and prevention strategies. We and others have previously shown that strategic orthogonal testing and leveraging systematic data-driven modeling approach to account for asymptomatics and waning cases may situationally have a compelling role in informing efficient vaccination strategies beyond prevalence reporting. However, currently Centers for Disease Control and Prevention (CDC) does not recommend serological testing either before or after vaccination to assess immune status. Given the 27% occurrence of breakthrough infections in fully vaccinated (FV) group with many being asymptomatics and still a larger fraction of the general mass remaining unvaccinated, the relaxed mask mandate and distancing by CDC can drive resurgence. Thus, we believe it is a key time to focus on asymptomatics (no symptoms) and oligosymptomatics (so mild that the symptoms remain unrecognized) as they can be silent reservoirs to propagate the infection. This perspective thus highlights the need for proactive efforts to reevaluate the current variables/strategies in accounting for symptomless and waning fractions.

The coronavirus disease 19 (COVID-19) pandemic continues to impose a significant burden on global health infrastructure. While identification and containment of new cases remain important, laboratories must now pivot and consider an assessment of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) immunity in the setting of the recent availability of multiple COVID-19 vaccines. Here, we have utilized the latest Abbott Alinity semiquantitative IgM and quantitative IgG spike protein (SP) serology assays (IgM(SP) and IgG(SP)) in combination with Abbott Alinity IgG nucleocapsid (NC) antibody test (IgG(NC)) to assess antibody responses in a cohort of 1,236 unique participants comprised of naive, SARS-CoV-2-infected, and vaccinated (including both naive and recovered) individuals. The IgM(SP) and IgG(SP) assays were highly specific (100%) with no cross-reactivity to archived samples collected prior to the emergence of SARS-CoV-2, including those from individuals with seasonal coronavirus infections. Clinical sensitivity was 96% after 15 days for both IgM(SP) and IgG(SP) assays individually. When considered together, the sensitivity was 100%. A combination of NC- and SP-specific serologic assays clearly differentiated naive, SARS-CoV-2-infected, and vaccine-related immune responses. Vaccination resulted in a significant increase in IgG(SP) and IgM(SP) values, with a major rise in IgG(SP) following the booster (second) dose in the naive group. In contrast, SARS-CoV-2-recovered individuals had several-fold higher IgG(SP) responses than naive following the primary dose, with a comparatively dampened response following the booster. This work illustrates the strong clinical performance of these new serological assays and their utility in evaluating and distinguishing serological responses to infection and vaccination.

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The rapid spread of SARS-CoV-2 Variants of Concern (VOC) necessitates systematic efforts for epidemiological surveillance. The current method for identifying variants is viral whole genome sequencing (WGS). Broad clinical adoption of sequencing is limited by costly equipment, bioinformatics support, technical expertise, and time for implementation. Here we describe a scalable, multiplex, non-sequencing-based capillary electrophoresis assay to affordably screen for SARS-CoV-2 VOC.

An accurate creatinine (Cr) estimate is pivotal for the assessment of renal function. Both patient- and practice-spawned factors palliate the test accuracy of serum creatinine (sCr) and can erratically represent actual kidney function. This study evaluated the caregivers’ awareness of enzymatic serum creatinine (E-sCr) assay interfering in dopamine/dobutamine (DD)-infused patient samples and the frequency of such interference in a critical care setting. We conducted an sCr awareness survey among UT Southwestern physicians, nurses, and pharmacists. We then performed a cross-sectional E-sCr comparison against the kinetic Jaffe method using the DD-infused patient samples collected from central venous catheters (CVC), peripherally inserted central catheter (PICC) lines, and the peripheral vein (PV). We retrospectively compared the longitudinal E-sCr results of the CVC/PICC draws with the corresponding blood urea nitrogen (BUN) levels. The survey results show a significant lack of awareness among caregivers about the negative interference of DD infusions on E-sCr. Cross-sectional E-sCr assessment relative to the Jaffe method displayed a negative interference in 12% of CVC/PICC line samples (7/57 DD-infused patients) compared to none in the PV draws. A longitudinal assessment of E-sCr, BUN, and potassium (K) levels from CVC/PICC line samples further confirmed a spurious decrease for E-sCr in about 12/50 (24%) patients who did not show a concurrent BUN or K decrease. The results suggest that a direct PV sampling accompanied by clinical laboratory-directed proactive discussion/activities can foster awareness among caregivers and eschew the false E-sCr estimates in DD-infused patients.

The COVID-19 pandemic continues to impose a significant burden on global health infrastructure. While identification and containment of new cases remains important, laboratories must now pivot and consider assessment of SARS-CoV-2 immunity in the setting of the recent availability of multiple COVID-19 vaccines. Here we have utilized the latest Abbott Alinity semi-quantitative IgM and quantitative IgG spike protein (SP) serology assays (IgMSP and IgGSP) in combination with Abbott Alinity IgG nucleocapsid (NC) antibody test (IgGNC) to assess antibody responses in a cohort of 1236 unique participants comprised of naïve, SARS-CoV-2 infected, and vaccinated (including both naïve and recovered) individuals. The IgMSP and IgGSP assays were highly specific (100%) with no cross-reactivity to archived samples recovered prior to the emergence of SARS-CoV-2, including those from individuals with seasonal coronavirus infections. Clinical sensitivity was 96% after 15 days for both IgMSP and IgGSP assays individually. When considered together, the sensitivity was 100%. A combination of NC- and SP-specific serologic assays clearly differentiated naïve, SARS-CoV-2-infected, and vaccine-related immune responses. Vaccination resulted in a significant increase in IgGSP and IgMSP titers, with a major rise in IgGSP following the booster (second) dose in the naïve group. In contrast, SARS-CoV-2 recovered individuals had several fold higher IgGSP responses than naïve following the primary dose, with a comparatively dampened response following the booster. This work illustrates the strong clinical performance of these new serological assays and their utility in evaluating and distinguishing serological responses to infection and vaccination.

Introduction: The Friedewald equation (F-LDL-C) and the Martin-Hopkins algorithm (MH-LDL-C) estimate direct LDL-C from a standard lipid panel. Discordant LDL-C estimates by the two methods may carry significant clinical implications. We evaluated the clinical variables associated with discordant LDL-C estimates and the association of discordance with risk of incident atherosclerotic cardiovascular disease (ASCVD) in the Dallas Heart Study (DHS), a multi-ethnic, population based prospective cohort. Methods: We estimated F-LDL-C and MH-LDL-C in 2824 DHS participants (42% male; mean age 43.5 years) with TG ≤ 400 mg/dL, who were not on baseline lipid lowering therapy and were free of prior ASCVD. We divided the cohort into quintiles of LDL-C discordance (MH-LDL-C minus F-LDL-C, in mg/dL) and assessed associations with ASCVD risk factors. We evaluated associations between discordance and incident ASCVD by sequentially adjusted Cox regression models, and we generated restricted cubic spline plots of discordance and hazard for ASCVD. Results: There were 228 ASCVD events over a median of 12.3 years. Clinical characteristics across discordance quintiles are shown in the Table . After adjustment for traditional ASCVD risk factors, there was a linear association between higher LDL-C discordance and increased risk of ASCVD events ( Figure ) with the highest hazard in Quintile 5 (HR 1.5, 95% CI 1.1 - 2.0). Conclusions: Discordant LDL-C estimates were largely associated with male sex, White and Hispanic races, and characteristics of the metabolic syndrome. Individuals in the highest quintile of discordant LDL-C estimates, with MH-LDL-C > F-LDL-C, had greater risk for incident ASCVD.

Background: Patients with hematological malignancies (HM), including multiple myeloma (MM), frequently suffer from immune deficiency-associated infectious complications because of both the disease and the treatment. Alarming results from China and the UK confirm the vulnerability of HM patients to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection-driven coronavirus disease 2019 (COVID-19). Given that the immunoassay interference from the endogenous monoclonal immunoglobulin (M paraprotein) and treatment antibodies continually challenges the MM management, it is critical to evaluate the SARS-CoV-2 serology tests for suspected interference/cross-reactivity. Methods: We compared the degree of interference in three SARS-CoV-2 serology assay platforms in HM patients with and without COVID-19 and on various therapeutic monoclonal antibody (t-mAb) treatments. Further, we confirmed the cross-reactivity in pooled samples from normal and COVID-19 + samples spiked with respective antibodies in vitro. Results: None of the 93 HM patient samples with or without t-MAbs showed cross-reactivity on any of the three serology platforms tested. Conclusions: The tested three serologic assays for SARS-CoV-2 are specific and do not have cross-reactivity with M-components or t-MAbs indicating that they can be used safely in oncology practice and in research exploring the immunologic response to COVID-19 in patients with HM.

The ability to rapidly and accurately identify a patient's COVID‐19 status has had significant impact on emergency departments (ED) and health systems globally. Since the identification of SARS‐CoV‐2 illness in the United States, there has been rapid development in patient testing capacity following initial challenges including sparse availability. This was made possible by increasing availability of diagnostic molecular tests in several formats, from laboratory based traditional, RT‐PCR methods to near patient testing rapid point of care PCR tests.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has presented significant challenges for laboratories including supply chain limitations with restricted access to reagents and sample collection materials (i.e. swabs, viral transport media (VTM)) for patients testing. Therefore, saliva has been evaluated as an alternative specimen for COVID-19 diagnosis. comparable performance between dry nasal swabs (NS) and nasopharyngeal swabs (NPS) collected in VTM has been observed with the ID NOW for SARS-CoV-2; the majority of false-negative results occur with higher cycle number (CN) or cycle threshold (Ct) values suggesting low viral load in these specimens. We performed clinical validation of saliva specimens on the ID NOW molecular platform to detect SARS-CoV-2. Saliva was compared to nasopharyngeal swabs tested on the ID NOW and the Cepheid molecular assay. We also performed stability studies of saliva samples over 5 days. A total of 96 saliva samples and 64 paired NPS were analyzed. We observed 78% (18/23) positive percent agreement (PPA) and 100% (44/44) negative percent agreement (NPA) between matched saliva and nasopharyngeal specimens performed on ID NOW. We found 83% (19/23) PPA and 100% NPA (25/25) between saliva run on the ID NOW and Cepheid assay. Six saliva specimens positive for SARS-CoV-2 were continuously positive for five days when stored at room temperature. Therefore, we propose further investigation of saliva as an alternative sample type for testing symptomatic patients with ID NOW as a promising method to address COVID-19 testing.

BackgroundInitial reports indicate adequate performance of some serological-based SARS-CoV-2 assays. However, additional studies are required to facilitate interpretation of results, including how antibody levels impact immunity and disease course.MethodsIn this study, a total of 968 subjects were tested for IgG antibodies reactive to SARS-CoV-2. We confirmed analytic specificity using 656 plasma samples from healthy donors, 49 sera from patients with rheumatic disease, and 90 specimens from individuals positive for PCR-based respiratory viral panel. One-hundred seventy-three cases of confirmed or suspected SARS-CoV-2 were tested for IgG. A subgroup of 37 SARS-CoV-2 PCR-positive cases was tested for nucleocapsid-specific IgM antibody using an in-house developed microarray method. Antibody levels were compared between disease severity groups.ResultsAll specificity specimens were negative for SARS-CoV-2 IgG antibodies (0/656, 0%). Cross reactivity was not detected in specimens with antinuclear antibodies and rheumatoid factor, or cases with previous diagnosis of viral infection including human coronavirus. Positive agreement of IgG with PCR was 83% of samples confirmed to be more than 14 days from symptom onset, with less than 100% sensitivity attributable to a case with severe immunosuppression. Virus-specific IgM was positive in a higher proportion of cases less than 3 days from symptom onset. No association was observed between mild and severe disease course with respect to IgG and IgM levels.ConclusionsThe studied SARS-CoV-2 IgG assay had 100% specificity and no adverse cross-reactivity. Index values of IgG and IgM antibodies did not predict disease severity in our patient population.

Background: Therapeutic humanized IgG1 kappa monoclonal antibody (t-mAb), daratumumab (DARA) is a Food and Drug Administration approved drug for the treatment of relapsed/refractory plasma cell myeloma (PCM). DARA appears on serum protein electrophoresis (SPEP) and on serum immunofixation (sIFE) as an IgG kappa monoclonal immunoglobulin protein (M-protein), complicating the assessment of the patients&rsquo, response to therapy. A more ominous threat to patient safety can occur with the misinterpretation of the presence of a small t-mAb spike as being the residual product of the patient&rsquo, s neoplastic clone, presented either as oligoclonality or new clonality, which could result in incorrect interpretation of failure to achieve remission. Methods: In this report, we describe a novel and cost-effective technique based on biotinylated recombinant CD38 and streptavidin-coated magnetic beads to capture and remove residual DARA present in PCM patient serum samples. The treated samples are then run like regular samples on SPEP and sIFE. We validated this simple technique in DARA-spiked PCM samples and patient samples on DARA treatment. Results: Our simple capture technique completely extracted DARA in all of the tested serum specimens and allowed the assessment of residual M-protein without DARA interference. The results were reproducible and highly specific for DARA, and did not have any impact on endogenous M-protein migration and quantification by SPEP and sIFE. The cost of this technique is much lower and it can be performed in-house with a very short turnaround time compared to the currently available alternative methods. There is a great need for such reflex technologies to avoid interpretation errors. Conclusions: This method is an effective way to eliminate DARA interference in SPEP and sIFE, and can be easily implemented in any clinical laboratory without any patent restriction. This simple technique can be adopted for other t-mAbs using their respective ligands and will help to reduce additional doses of toxic treatment and further testing in patients on t-mAbs with a false positive M-protein spike.

Introduction: Despite more accurate low-density lipoprotein cholesterol (LDL-C) estimates by the Martin (mLDL-C) method, most laboratories still use the Friedewald (fLDL-C) equation. Low non-high density lipoprotein (non-HDL-C) and high triglycerides (TG) drive inaccuracy in LDL-C estimation. We compared a strategy of identifying errors in fLDL-C using non-HDL-C/TG ratios with subsequent reflex direct LDL-C testing to a strategy of using mLDL-C. Methods: We included 4,939,542 individuals (2/3 derivation, 1/3 validation dataset) with TG Results: Nearly 8% of fLDL-C results deviated >12% from direct LDL-C compared with only 2.5% of mLDL-C results in the entire population. Non-HDL-C/TG ratios of 0.6-0.9 performed best in the derivation dataset. In the validation dataset, a non-HDL-C/TG ratio of 0.7 had the highest area under the curve for identifying >12% error in fLDL-C estimates (Table). At this ratio, 14.5% of fLDL-C samples would need direct LDL-C measurement at an increase in costs of lipid testing by 10%. Conclusions: Use of non-HDL-C/TG ratio

Dietary biotin intake does not typically result in blood biotin concentrations that exceed interference thresholds for in vitro diagnostic tests. However, recent trends of high-dose biotin supplements and clinical trials of very high biotin doses for patients with multiple sclerosis have increased concerns about biotin interference with immunoassays. Estimates of the prevalence of high biotin intake vary, and patients may be unaware that they are taking biotin. Since 2016, 92 cases of suspected biotin interference have been reported to the US Food and Drug Administration. Immunoassays at greatest risk from biotin interference include thyroid and reproductive hormones, cardiac, and immunosuppressive drug tests. Several case studies have highlighted the challenge of biotin interference with thyroid hormone assays and the potential misdiagnosis of Graves' disease. Biotin interference should be suspected when immunoassay test results are inconsistent with clinical information; a clinically relevant biotin interference happens when the blood biotin concentration is high and the assay is sensitive to biotin. We propose a best practice workflow for laboratory scientists to evaluate discrepant immunoassay results, comprising: (1) serial dilution; (2) retesting after biotin clearance and/or repeat testing on an alternate platform; and (3) confirmation of the presence of biotin using depletion protocols or direct measurement of biotin concentrations. Efforts to increase awareness and avoid patient misdiagnosis should focus on improving guidance from manufacturers and educating patients, healthcare professionals, and laboratory staff. Best practice guidance for laboratory staff and healthcare professionals would also provide much-needed information on the prevention, detection, and management of biotin interference.

Objectives To investigate biotin interference on three cardiac troponin (cTn) assays and demonstrate a method to overcome biotin interference. Methods cTn levels were measured in (1) plasma from healthy volunteers on 10-mg daily biotin supplementation mixed with a plasma with known elevated troponin, (2) plasmas with known elevated cTn after mixing in reagent biotin to simulate supplementation, and (3) biotin-spiked plasma specimens pretreated with streptavidin-agarose beads. Results Daily biotin ingestion (10 mg) and studies simulating daily biotin use resulted in significant interference in the Gen5 cardiac troponin T (cTnT) assay; the contemporary Gen 4 cTnT and high-sensitivity cardiac troponin I (hs-cTnI) assays were unaffected. The biotin interference threshold was 31, 315, and more than 2,000 ng/mL for Gen5 cTnT, cTnT, and hs-cTnI assays, respectively. Streptavidin pretreatment blocked biotin interference in cTn assays. Conclusions Biotin interference is possible at plasma concentrations achievable by ingestion of over-the-counter supplements that may lead to delayed or missed diagnosis of myocardial injury with the Gen5 cTnT assay.

Objective: To assess the false-positive and false-negative rates of a 4th-generation human immunodeficiency virus (HIV) assay, the Abbott ARCHITECT, vs 2 HIV 3rd-generation assays, the Siemens Centaur and the Ortho-Clinical Diagnostics Vitros. Methods: We examined 123 patient specimens. In the first phase of the study, we compared 99 specimens that had a positive screening result via the 3rd-generation Vitros assay (10 positive, 82 negative, and 7 indeterminate via confirmatory immunofluorescent assay [IFA]/Western blot [WB] testing). In the second phase, we assessed 24 HIV-1 RNA–positive (positive result via the nuclear acid amplification test [NAAT] and negative/indeterminate results via the WB test) specimens harboring acute HIV infection. Results: The 4th-generation ARCHITECT assay yielded fewer false-positive results (n = 2) than the 3rd-generation Centaur (n = 9; P = .02) and Vitros (n = 82; P

Detection of PTLD uses PCR to detect circulating EBV DNA in the blood or in situ hybridization to identify EBV DNA in tissue biopsies. EBV DNA was detected in the tissue section using both real-time PCR and in situ hybridization. We report an unusual presentation of PTLD with no detectable EBV DNA in the blood using EBER-1 and EBNA-1 PCR assays. This report suggests that the use of EBV-PCR for the early detection of PTLD in blood samples may not be 100% effective in detecting disease.

Bone marrow (BM) is the key hematopoietic organ in mammals and is involved in the homeostatic proliferation of memory CD8+ T cells. Here we expanded on our previous observation that BM is a preferential site for T-cell proliferation in simian immunodeficiency virus (SIV)–infected sooty mangabeys (SMs) that do not progress to AIDS despite high viremia. We found high levels of mature T-cell proliferation, involving both naive and memory cells, in healthy SMs and rhesus macaques (RMs). In addition, we observed in both species that lineage-specific, BM-based T-cell proliferation follows antibody-mediated in vivo CD4+ or CD8+ T-cell depletion, thus indicating a role for the BM in maintaining T-cell homeostasis under depleting circumstances. We also observed that, in SIV-infected SMs, but not RMs, the level of proliferation of BM-based CD4+ T cells is higher than that of circulating CD4+ T cells. Interestingly, limited BM-based CD4+ T-cell proliferation was found in SIV-infected SMs with low CD4+ T-cell counts, suggesting a regenerative failure in these animals. Collectively, these results indicate that BM is involved in maintaining T-cell homeostasis in primates and suggest a role for BM-based CD4+ T-cell proliferation in determining the benign nature of natural SIV infection of SMs.

Bacterial infections, especially drug-resistant infections, continue to cause public health problems. While culture methods currently serve as the reference method for detecting and characterizing most bacterial infections, new molecular techniques provide the means for rapid, specific, and sensitive detection of pathogenic bacteria. Previously, molecular detection of bacteria focused on difficult-to-culture or slow-growing bacteria; however, with the advent of more robust instrumentation, molecular assays are used to identify, detect, and track the epidemiology of drug-resistant bacteria and hospital-acquired bacteria. This review discusses select nucleic acid tests (NATs), nucleic acid amplification tests (NAATs), and their applications for detecting and characterizing bacterial pathogens.

Sooty mangabeys, the natural host of simian immunodeficiency virus (SIVsm), generally avoid progressive depletion of CD4+ T cells and opportunistic infections associated with infection of humans (HIV) and macaques (SIVmac). The means by which the SIVsm-infected mangabeys maintain CD4+ T-cell levels despite high rates of viral replication is unknown. One cytokine that has a key role in the regulation of T-cell levels is interleukin-7 (IL-7). Here, the longitudinal assessment of 6 SIVsm-infected mangabeys identified an early increase in plasma IL-7 levels at weeks 1 to 5 after infection. This IL-7 increase correlated with an early decline in CD4+ T-cell levels (decline of 492-1171 cells/μL) accompanying acute viremia. Elevated IL-7 levels were followed by increased T-cell proliferation (Ki67) and maintenance of lower but stable (more than 500 cells/μL) CD4+ T-cell levels in each mangabey through 37 weeks of infection. These data contrast with our earlier studies in SIVmac-infected macaques, in which the IL-7 increase was delayed until 20 to 40 weeks after infection, just before the onset of simian AIDS. Taken together, these data suggest that timely triggering of IL-7 is important for stabilizing healthy T-cell levels in mangabeys and that timely administration of exogenous IL-7 may show benefit during pathogenic SIVmac and HIV infection.

Costimulatory and adhesion molecules are known to play a major role in the pathogenesis of systemic lupus erythematosus. Since fish oil and calorie restriction have been reported to attenuate the development of disease in lupus prone (NZBxNZW)F1 mice, the objective of this study was to assess the expression of these key inflammatory molecules in these mice fed diets differing in n-6 and n-3 fatty acid content and fed either food restricted or ad libitum. Age-associated increases in the expression of CD28, ICAM-1, and PGP-1 molecules that are involved in the recruitment of inflamed lymphocytes into the kidney were attenuated in mice restricted in food intake. The increase in costimulatory (CD80 and CD86) and adhesion (ICAM-1, PGP-1, LFA-1, and Mac-1) in peripheral blood mononuclear cells was also attenuated by food restriction and to a lesser extent by fish oil alone. Interestingly, amelioration of lupus (laminin expression and proteinuria) correlated with the above beneficial effects and could be seen even in 24-month-old mice. In summary, food restriction and fish oil delay the onset of lupus disease and increase life span in B/W mice by prolonging the maintenance of a youthful immune phenotype.

Elevated levels of interleukin 7 (IL-7) have been correlated with various T-cell depletion conditions, including HIV infection, and suggested as an indicator of HIV disease progression (AIDS and death). Here, the assessment of pathogenic simian immunodeficiency virus (SIVmac239) infection in rhesus macaques demonstrated a clear association between a significant elevation in IL-7 levels and disease progression. In 5 macaques that progressed to simian AIDS and death, elevated IL-7 levels were unable to restore T-cell homeostasis. In contrast, increased IL-7 levels were followed by relatively high and stable T-cell numbers in the SIV-infected macaques with a slow-progressing phenotype. Further, studies in sooty mangabeys that do not progress to simian AIDS and that maintain stable T-cell numbers despite high levels of viral replication support the importance of IL-7 and T-cell homeostasis in disease progression. These data suggest that during pathogenic SIV infection with high viral replication, elevated IL-7 levels are unable to recover T-cell homeostasis, thereby leading to disease progression. The utility of IL-7 as a potential immunotherapeutic agent to improve HIV/SIV-related T-cell depletion may therefore depend on controlling the pathogenic effects of viral replication prior to the administration of IL-7. (Blood. 2004;103:973-979)

Atherosclerosis-mediated coronary artery disease is a significant cause of mortality in lupus patients. Both an activated immune system and hyperlipidemia are implicated in the pathogenesis of the atherosclerotic lesions of lupus. In this study, the increases in anticardiolipin antibodies, total cholesterol, and LDL cholesterol with age were significantly lowered by fish oil and food restriction, either alone or in combination. Food restriction also significantly decreased the elevation in anti-dsDNA antibody production seen with age in ad libitum groups. Interestingly, effects of food restriction and fish oil on both lipid profile and autoantibody production were seen from a young age. Accumulation of leukocytes in the blood vessels and deposition of IgG in the glomerular mesangium also were suppressed by food restriction. Thus, beneficial effects of fish oil and food restriction on lupus nephritis and survival could be, at least in part, due to their selective effect on atherogenic risk factors.

Moderate food and/or energy (calorie) restriction delays age-related immune dysfunction and pro- longs life span in multiple animal models. The amount and type of dietary fatty acids can also profoundly affect life span. Marine-derived fish oils contain (n-3) fatty acids, which have potent anti-inflammatory properties. We therefore examined the influence of food restriction (40% overall reduction in intake of all dietary components) combined with substitution of fish oil for corn oil in a factorial design. Autoimmune-prone (NZB 3 NZW)F(1) (B/W) mice, which develop fatal autoimmune renal disease, were used. The food-restricted/fish oil diet maximally extended median life span to 645 d (vs. 494 d for the food-restricted corn oil diet). Similarly, fish oil prolonged life span in the ad libitum-fed mice to 345 d (vs. 242 for the ad libitum/corn oil diet). Increased life span was partially associated with decreased body weight, blunting renal proinflammatory cytokine (interferon-g, interleukins-10 and -12 and tumor necrosis factor-a) levels and lower nuclear factor-kB (NF-kB). Reductions in NF-kB were preceded by enhanced superoxide dismutase, catalase and glutathione peroxidase activities. These findings demonstrate the profound additive effects of food restriction and (n-3) fatty acids in prolonging life span in B/W mice. These observations may have additional implications in the management of obesity, diabetes, cancer and/or the aging process. J. Nutr. 131: 2753-2760, 2001.

Calorie restriction (CR) is known to prolong the life span and maintain an active immune function in aged mice, but it is still not known if rodents under CR can respond optimally to bacterial infection. We report here on the influence of CR on the response of peritoneal macrophages to lipopolysaccharide, splenic NF-κB and NF–interleukin-6 (IL-6) activities, and mortality in polymicrobial sepsis induced by cecal ligation and puncture (CLP). Macrophages from 6-month-old C57BL/6 mice on a calorie-restricted diet were less responsive to lipopolysaccharide, as evidenced by lower levels of IL-12 and IL-6 protein and mRNA expression. Furthermore, in vitro lipopolysaccharide-stimulated macrophages from mice under CR also expressed decreased lipopolysaccharide receptor CD14 levels as well as Toll-like receptor 2 (TLR2) and TLR4 mRNA levels. In addition, the phagocytic capacity and class II (I-Ab) expression of macrophages were also found to be significantly lower in mice under CR. Mice under CR died earlier (P< 0.005) after sepsis induced by CLP, which appeared to be a result of increased levels in serum of the proinflammatory cytokines tumor necrosis factor alpha and IL-6 and splenic NF-κB and NF–IL-6 activation 4 h after CLP. However, mice under CR survived significantly (P< 0.005) longer than mice fed ad libitum when injected with paraquat, a free radical-inducing agent. These data suggest that young mice under CR may be protected against oxidative stress but may have delayed maturation of macrophage function and increased susceptibility to bacterial infection.

Immunoglobulin production by the salivary gland plays an important role in oral and upper respiratory tract immunity. Age and/or disease may compromise salivary gland function. In order to gain insight into the role of calorie restriction (CR) on immunoglobulin (Ig) production, we determined the effect of ad libitum (AL) feeding and CR in young (3 months) and old (18-24 months) C57BL/6 mouse submandibular glands (SM). The SM tissues were fragmented and cultured in the absence (control) or presence of either Th-1 cytokines, such as interleukin-2 (IL-2) and interferon-gamma (IFN-gamma), or Th-2 cytokines, e.g. IL-4 and IL-5, for seven days. Culture supernatants were then analyzed for immunoglobulin A (IgA), IgM, and IgG2a levels by ELISA. Aging increased basal (control) IgA and IgM production by 3.1-and 3.7-fold, respectively, in AL mice. CR prevented the age-dependent rise of both IgA and IgM, maintaining levels equal to those of young AL mice. Interestingly, age resulted in a decrease of Th-1 cytokine-induced IgA and IgM, and increased IgG2a secretion in AL mice, while Th-2 cytokines did not appear to have an age effect. In general, CR suppressed Ig production induced by both Th-1 and Th-2 cytokines in young mice. In contrast, CR in old mice resulted in enhanced IgA and IgM production to levels similar to those in their young counterparts, while IgG2a was predominantly suppressed by Th-1 and not Th-2 cytokines. The data presented herein show, for the first time, the ability of CR to offset age-induced changes in submandibular gland Ig production, which may play a role in maintaining mucosal immune function, including proper oral health.

Role of glutathione on kidney mitochondrial integrity and function during stone forming process in hyperoxaluric state was investigated in male albino rats of Wistar strain. Hyperoxaluria was induced by feeding ethylene glycol (EG) in drinking water. Glutathione was depleted by administering buthionine sulfoximine (BSO), a specific inhibitor of glutathione biosynthesis. Glutathione monoester (GME) was administered for supplementing glutathione. BSO treatment alone or along with EG, depleted mitochondrial GSH by 40% and 51% respectively. Concomitantly, there was remarkable elevation in lipid peroxidation and oxidation of protein thiols. Mitochondrial oxalate binding was enhanced by 74% and 129% in BSO and BSO + EG treatment. Comparatively, EG treatment produced only a 33% increase in mitochondrial oxalate binding. Significant alteration in calcium homeostasis was seen following BSO and BSO + EG treatment. This may be due to altered mitochondrial integrity and function as evidenced from decreased activities of mitochondrial inner membrane marker enzymes, succinate dehydrogenase and cytochrome-c-oxidase and respiratory control ratio and enhanced NADH oxidation by mitochondria in these two groups. NADH oxidation (r = -0.74) and oxalate deposition in the kidney (r = -0.70) correlated negatively with mitochondrial glutathione depletion. GME supplementation restored normal level of GSH and maintained mitochondrial integrity and function, as a result of which oxalate deposition was prevented despite hyperoxaluria. These results suggest that mitochondrial dysfunction resulting from GSH depletion could be a contributing factor in the development of calcium oxalate stones.