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1.
Am J Transplant ; 20(11): 3106-3112, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32476285

RESUMO

Universal screening of potential organ donors and recipients for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is now recommended prior to transplantation in the United States during the coronavirus disease 19 (COVID-19) pandemic. Challenges have included limited testing capacity, short windows of organ viability, brief lead time for notification of potential organ recipients, and the need to test lower respiratory donor specimens to optimize sensitivity. In an early U.S. epicenter of the outbreak, we designed and implemented a system to expedite this testing and the results here from the first 3 weeks. The process included a Laboratory Medicine designee for communication with organ recovery and transplant clinical staff, specialized sample labeling and handoff, and priority processing. Thirty-two organs recovered from 14 of 17 screened donors were transplanted vs 70 recovered from 23 donors during the same period in 2019. No pretransplant or organ donors tested positive for SARS-CoV-2. Median turnaround time from specimen receipt was 6.8 hours (donors), 6.5 hours (recipients): 4.5 hours faster than daily inpatient median. No organ recoveries or transplantations were disrupted by a lack of SARS-CoV-2 testing. Waitlist inactivations for COVID-19 precautions were reduced in our region. Systems that include specialized ordering pathways and adequate testing capacity can support continued organ transplantation, even in a SARS-CoV-2 hyperendemic area.


Assuntos
Teste para COVID-19/métodos , COVID-19/diagnóstico , Programas de Rastreamento/métodos , Transplante de Órgãos , Pandemias , SARS-CoV-2 , Transplantados , COVID-19/epidemiologia , Seguimentos , Humanos , Estudos Retrospectivos , Doadores de Tecidos/estatística & dados numéricos
2.
Clin Chem ; 57(7): 1050-6, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21566071

RESUMO

BACKGROUND: Chemiluminescence immunoassay (CIA) is used to detect hepatitis C virus (HCV) antibody status on the basis of signal-to-cutoff (S/Co) ratios. Positive results of antibody to HCV (anti-HCV) are followed by either recombinant immunoblot assay (RIBA) to confirm anti-HCV positivity or reverse transcription (RT)-PCR to detect viremia. We hypothesized that by analyzing S/Co ratios, we could determine a strategy to reduce unnecessary supplementary testing in our population. METHODS: CIA was performed to screen for anti-HCV, and positive results were followed up with RT-PCR testing. Negative RT-PCR results were followed up with RIBA, whereas positive RT-PCR results were assumed to be RIBA positive. ROC curves were analyzed to determine the optimal S/Co ratios to predict HCV infection. RESULTS: We determined the S/Co ratios on 34 243 veteran patient samples. We found that with the CIA method 9.0% of patients had positive test results for anti-HCV. An S/Co ratio <3.0 ruled out active HCV infection and exposure with 100% negative predictive value. When the S/Co ratio was ≥20.0, positive predictive values were 98.5% compared with RIBA results, and 81.0% compared with RT-PCR results. CONCLUSIONS: RIBA is not necessary to confirm negative or positive CIA anti-HCV if the S/Co ratio is <3.0 or ≥20.0, respectively. To confirm HCV exposure, samples with an S/Co ratio between 3.0 and 19.9 should be followed up with RIBA unless PCR testing has been performed and the result is positive. Samples with an S/Co ratio ≥20.0 or positive RIBA results should be further tested by RT-PCR to determine HCV viremia status.


Assuntos
Hepacivirus/imunologia , Anticorpos Anti-Hepatite C/sangue , Hepatite C/diagnóstico , Algoritmos , Hepacivirus/genética , Hepatite C/sangue , Hepatite C/imunologia , Humanos , Imunoensaio/métodos , Medições Luminescentes , Curva ROC , Estudos Retrospectivos , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Viremia/sangue , Viremia/diagnóstico , Viremia/imunologia
3.
Am J Clin Pathol ; 129(3): 459-63, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-18285270

RESUMO

Free testosterone (FT) measurement by equilibrium dialysis and liquid chromatography-tandem mass spectroscopy (LCMS/MS) is the "gold standard." We hypothesized that calculated FT values could substitute for measured values; compared FT results reported by Walter Reed Army Medical Center (WRAMC), Washington, DC, with results reported by the Seattle Veterans Affairs Health Care System, Seattle, WA, for 3 patient groups; and evaluated the calculated FT values by gold-standard measurements. Groups 1 and 2 included samples from 54 patients evaluated in Seattle and 94 evaluated at a primary care clinic in Alaska whose samples were analyzed in Seattle, respectively, whose care resulted in ordering an FT measurement. Group 3 included samples from 64 patients evaluated in endocrine WRAMC clinics. Calculated FT values between the 2 facilities demonstrated a strong correlation (R2 = 0.98) for all 212 patients. In a comparison of calculated FT values with measured levels, group 3 had an R2 = 0.93; however, samples with FT values less than 50 pg/mL had a poorer correlation (R2 = 0.45). Calculated FT values may accurately reflect and be substituted in the clinical setting for gold-standard values when levels are more than 50 pg/mL.


Assuntos
Química Clínica/métodos , Testosterona/sangue , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , District of Columbia , Feminino , Humanos , Pessoa de Meia-Idade , Radioimunoensaio , Reprodutibilidade dos Testes , Globulina de Ligação a Hormônio Sexual/análise , Washington
4.
BMC Infect Dis ; 7: 63, 2007 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-17594484

RESUMO

BACKGROUND: Low vitamin E levels are often found in HIV-1 infection, and studies have suggested that higher levels may decrease the risk of disease progression. However, vitamin E supplementation has also been reported to increase CCR5 expression, which could increase HIV-1 replication. We hypothesized that vitamin E levels at HIV-1 acquisition may influence disease progression. METHODS: Vitamin E status was measured in stored samples from the last pre-infection visit for 67 Kenyan women with reliably estimated dates of HIV-1 acquisition. Regression analyses were used to estimate associations between pre-infection vitamin E and plasma viral load, time to CD4 count <200 cells/muL, and mortality. RESULTS: After controlling for potential confounding factors, each 1 mg/L increase in pre-infection vitamin E was associated with 0.08 log10 copies/mL (95% CI -0.01 to +0.17) higher set point viral load and 1.58-fold higher risk of mortality (95% CI 1.15-2.16). The association between higher pre-infection vitamin E and mortality persisted after adjustment for set point viral load (HR 1.55, 95% CI 1.13-2.13). CONCLUSION: Higher pre-infection vitamin E levels were associated with increased mortality. Further research is needed to elucidate the role vitamin E plays in HIV-1 pathogenesis.


Assuntos
Infecções por HIV/sangue , Infecções por HIV/mortalidade , HIV-1/patogenicidade , Carga Viral , Vitamina E/sangue , Adulto , Contagem de Linfócito CD4 , Feminino , Infecções por HIV/metabolismo , Humanos , Quênia/epidemiologia , Estudos Prospectivos , Análise de Sobrevida , Deficiência de Vitamina E/virologia
5.
Int J STD AIDS ; 18(3): 202-6, 2007 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-17362556

RESUMO

Observational studies have suggested that low serum beta-carotene concentrations may influence HIV-1 disease progression. However, randomized trials have not demonstrated beneficial effects of beta-carotene supplementation. To understand this discrepancy, we conducted a cross-sectional study among 400 HIV-1-seropositive women in Mombasa, Kenya, to correlate serum beta-carotene concentrations with several measures of HIV-1 disease severity. beta-Carotene concentrations were significantly associated with biologic markers of HIV-1 disease progression (CD4 count, HIV-1 plasma viral load, serum C-reactive protein [CRP] concentration, and serum albumin level). In multivariate analysis, beta-carotene concentrations below the median were associated with elevated CRP (>10 mg/l, adjusted odds ratio [aOR] 3.32, 95% confidence interval [CI] 1.99-5.53, P<0.001) and higher HIV-1 plasma viral load (for each log(10) copies/mL increase, aOR 1.38, 95% CI 1.01-1.88, P=0.04). In the context of negative findings from randomized trials of beta-carotene supplementation in HIV-1-seropositive individuals, these results suggest that low beta-carotene concentrations primarily reflect more active HIV-1 infection rather than a deficiency amenable to intervention.


Assuntos
Infecções por HIV/sangue , HIV-1/crescimento & desenvolvimento , beta Caroteno/sangue , Adulto , Proteína C-Reativa/metabolismo , Contagem de Linfócito CD4 , Estudos Transversais , Progressão da Doença , Feminino , Infecções por HIV/tratamento farmacológico , Infecções por HIV/imunologia , Infecções por HIV/virologia , Humanos , Quênia , Carga Viral , Vitamina A/administração & dosagem , beta Caroteno/deficiência
6.
Clin Biochem ; 39(1): 91-4, 2006 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-16325792

RESUMO

BACKGROUND: Sex hormone binding globulin (SHBG) is an important regulator of testosterone and estradiol. STUDY DESIGN: We validated the Diagnostic Products Corporation (DPC) and Roche Diagnostic SHBG immunoassays on the DPC Immulite 2000 and Roche Modular E170 analyzers. RESULTS: The coefficient of variation for SHBG kits from both manufacturers was in the range of 3.9-7.7% (between-run) and 0.95-5.0% (within-run), free of interference from hemoglobin, bilirubin, lipid, and rheumatoid factor, and linear up to at least 170 nM SHBG. The results of the two methods, however, were biased by up to 29% depending on the SHBG concentration. CONCLUSION: The SHBG assays perform well but standardization is needed.


Assuntos
Imunoensaio , Globulina de Ligação a Hormônio Sexual/análise , Humanos , Imunoensaio/instrumentação , Modelos Lineares , Reprodutibilidade dos Testes , Testosterona
7.
BMC Infect Dis ; 6: 85, 2006 May 19.
Artigo em Inglês | MEDLINE | ID: mdl-16712720

RESUMO

BACKGROUND: Low serum selenium has been associated with lower CD4 counts and greater mortality among HIV-1-seropositive individuals, but most studies have not controlled for serum albumin and the presence of an acute phase response. METHODS: A cross-sectional study was conducted to evaluate relationships between serum selenium concentrations and CD4 count, plasma viral load, serum albumin, and acute phase response markers among 400 HIV-1-seropositive women. RESULTS: In univariate analyses, lower CD4 count, higher plasma viral load, lower albumin, and the presence of an acute phase response were each significantly associated with lower serum selenium concentrations. In multivariate analyses including all four of these covariates, only albumin remained significantly associated with serum selenium. For each 0.1 g/dl increase in serum albumin, serum selenium increased by 0.8 microg/l (p < 0.001). Women with an acute phase response also had lower serum selenium (by 5.6 microg/l, p = 0.06). CONCLUSION: Serum selenium was independently associated with serum albumin, but not with CD4 count or plasma viral load, in HIV-1-seropositive women. Our findings suggest that associations between lower serum selenium, lower CD4 count, and higher plasma viral load may be related to the frequent occurrence of low serum albumin and the acute phase response among individuals with more advanced HIV-1 infection.


Assuntos
Reação de Fase Aguda/sangue , Infecções por HIV/sangue , Infecções por HIV/patologia , Selênio/sangue , Albumina Sérica/metabolismo , Adulto , Peso Corporal , Contagem de Linfócito CD4 , Estudos Transversais , Feminino , Humanos , RNA Viral/sangue
8.
Ann Clin Lab Sci ; 36(2): 157-62, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-16682511

RESUMO

This study evaluated serum kappa and lambda free light chain (FLC) concentrations in a Veterans Affairs (VA) population. We hypothesized that our older, mostly male, population should not differ in serum FLC ranges from levels previously established for younger male and female populations and that the assay would improve our screening protocol for plasma cell dyscrasias (PCD). Serum kappa and lambdaFLC were assayed in 312 consecutive serum samples collected during a 16-week period from veterans whose clinical presentation indicated a need for serum protein electrophoresis (SPEP) analysis. We reviewed our laboratory information system (LIS) files to evaluate the patients' diagnoses and treatment status in conjunction with serum FLC levels. All assays and validation studies were conducted using an immunoturbidimetric method with a Roche/Hitachi 911 modular analytical system. The intra-assay variability (CV) was <5%, based on 13 replicate assays of 4 control samples and 1 blank sample. Of the 312 patients, the SPEP results were normal in 235 and abnormal in 77. Of the 235 patients with normal SPEP results, 37 had abnormal FLC values and 20 of these were diagnosed as PCD. Of the 77 patients with abnormal SPEP results, only 9 had diagnoses unrelated to PCD. Using the FLC assay in conjunction with retrospective reviews of medical records, we obtained an 86% detection rate of PCD. This detection rate increased to 100% when both SPEP and FLC results were considered. In conclusion, this study documents an important role for serum FLC assays in diagnosing and monitoring PCD in a VA population. Our results support previously established serum FLC reference ranges that were obtained in younger, male and female populations. Using the serum FLC results in conjunction with SPEP results improves the sensitivity and specificity for managing VA patients whose clinical presentation indicates the need to evaluate PCD.


Assuntos
Cadeias kappa de Imunoglobulina/sangue , Cadeias lambda de Imunoglobulina/sangue , Programas de Rastreamento/métodos , Paraproteinemias/diagnóstico , Idoso , Eletroforese das Proteínas Sanguíneas , Feminino , Humanos , Masculino , Mieloma Múltiplo/diagnóstico , Nefelometria e Turbidimetria/métodos , Valores de Referência , Sensibilidade e Especificidade , Veteranos
9.
Ann Clin Lab Sci ; 35(1): 66-72, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-15830711

RESUMO

The purpose of this study was to validate the Albumin Cobalt Binding (ACB) assay at the Seattle Veterans Affairs (VA) Hospital to determine if it would provide an earlier rule-out of acute coronary syndrome (ACS) in patients, compared to current use of cardiac injury markers. This study compares the distribution of ischemia modified albumin (IMA) values of our patient population to those provided by the kit manufacturer. IMA values were determined photometrically on a Roche Modular Analytical System on 200 subjects: 69 subjects not experiencing chest pain (normals), 78 subjects presenting to the emergency room (ER) with chest pain whose initial and subsequent troponin results were negative (non-converters), and 53 subjects presenting to the ER with chest pain whose initial troponin result was negative but subsequent troponin results were positive (converters). Based on the relationships between IMA values in the initial samples from the non-converters and converters, we constructed a ROC curve to identify an optimum IMA rule-out value. The IMA values (mean+/-SD) for the normals, non-converters, and converters were 89+/-7.1, 100+/-13.9, and 126+/-14.1 U/ml, respectively, and each mean was statistically different from the means of the other groups. The ROC curve comparing converters and non-converters showed an area of 0.89 (p <0.001) compared to the line of identity. An IMA cut-off of 97 U/ml gives a 98% sensitivity and 45% specificity and may be the best decision point to differentiate between these groups in our population. Nine of 78 non-converters were classified as having unstable angina. In conclusion, the ACB assay has a strong negative predictive value and sensitivity in our population for predicting the troponin results at 6 to 24 hr post-presentation. Because ACB results may be facility- and instrument-dependent, each facility should conduct an independent ROC analysis to determine the optimal IMA rule-out level. The ACB assay, when used in conjunction with cardiac injury markers and assessment of unstable angina, holds promise in reducing inappropriate low-risk hospital admissions and improving the clinical management of patients with chest pain.


Assuntos
Dor no Peito/diagnóstico , Cobalto/metabolismo , Doença das Coronárias/diagnóstico , Albumina Sérica/metabolismo , Doença Aguda , Idoso , Angina Instável/sangue , Angina Instável/diagnóstico , Biomarcadores , Dor no Peito/sangue , Cobalto/sangue , Doença das Coronárias/sangue , Emergências , Reações Falso-Positivas , Humanos , Pessoa de Meia-Idade , Valores de Referência , Reprodutibilidade dos Testes
10.
J Anal Toxicol ; 29(8): 825-9, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-16374942

RESUMO

Opiate toxicology testing is routinely performed in the hospital setting to identify abusers and/or to determine those patients who are not taking prescribed opiate analgesics such as oxycodone. Commercially available assays for opiate detection in urine have decreased sensitivity for oxycodone, which contributes to a high false-negative rate. Functioning as a beta site, our Veterans Affairs hospital evaluated a new enzyme immunoassay, DRI Oxycodone Assay, for its use in the qualitative and semiquantitative detection of oxycodone in urine. We hypothesize that an immunoassay for oxycodone with superior sensitivity and specificity, when compared to the traditional opiate assays, would reduce the need for more expensive and time-consuming confirmatory testing. We used the new liquid homogenous enzyme immunoassay to determine oxycodone results in a total of 148 urine samples from 4 different sample groups. Gas chromatography-mass spectroscopy was subsequently used to confirm the presence or absence of oxycodone (or its primary metabolite, noroxycodone). We also evaluated within-run, between-run, and linearity studies and conducted a crossover study to establish a cutoff value for oxycodone. In our patient population, we used the new DRI immunoassay to evaluate 17,069 urine samples to estimate oxycodone misuse profiles (patients not taking prescribed oxycodone or taking oxycodone without a prescription) during a 4-month period. The sensitivity and specificity of the new oxycodone immunoassay were 97.7% and 100%, respectively, at the cutoff concentration of 300 ng/mL. The assay linearity was 1,250 ng/mL, and the sensitivity was 10 ng/mL. Within-run precision and between-run coefficient of variation were 2.3% and 1.8%, respectively. None of the 15 compounds that we evaluated for interference had crossover significant enough to produce a positive oxycodone result when using 300 ng/mL as the cutoff value. None of the 17,069 oxycodone immunoassays was followed with a request for confirmation. Among patients with positive results (n = 224), 93 (41.5%) were not prescribed oxycodone. The new DRI Oxycodone Assay is a sensitive and specific screening test for the determination of oxycodone. The improved opiate screening results may lead to better patient and prescription management, to decreased laboratory spending, and to the identification of oxycodone abusers, which could result in decreased oxycodone-related mortality.


Assuntos
Técnicas Imunoenzimáticas/métodos , Oxicodona/urina , Custos e Análise de Custo , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Oxicodona/metabolismo , Estudos Retrospectivos
11.
Am J Clin Nutr ; 79(2): 218-25, 2004 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-14749226

RESUMO

BACKGROUND: Serum retinol is the most commonly used indicator of vitamin A status. Retinol is transported in a 1-to-1 complex with retinol-binding protein (RBP). RBP is easy and inexpensive to measure, and studies have shown a high correlation between concentrations of RBP and concentrations of retinol. The performance of RBP in the context of infection or protein malnutrition, however, has not been evaluated. OBJECTIVE: Our aim was to determine whether RBP is a good surrogate measure for retinol in the context of HIV-1 infection, protein malnutrition, and the acute phase response. DESIGN: The relation between RBP and retinol was examined in a cross-sectional study of 600 Kenyan women. RESULTS: There was a high correlation between concentrations of RBP and those of retinol (r = 0.88). When equimolar cutoffs were used, RBP predicted marginal vitamin A status (retinol < 1.05 micro mol/L) with 93% sensitivity and 75% specificity and vitamin A deficiency (retinol < 0.70 micro mol/L) with 91% sensitivity and 94% specificity. Similarly high sensitivities and specificities were found among subgroups with HIV-1 infection, a positive acute phase response, and protein malnutrition. Protein malnutrition and a positive acute phase response were common, especially among HIV-1-infected women, and were independently and synergistically associated with lower RBP concentrations. CONCLUSIONS: Equimolar RBP cutoffs predict vitamin A deficiency with high sensitivity and specificity, even in the context of infection and protein malnutrition. Like retinol, RBP may not accurately identify true vitamin A status under all conditions, because the acute phase response and protein malnutrition depress RBP concentrations. However, RBP may be a simple, inexpensive tool for assessment of vitamin A deficiency in population studies.


Assuntos
Reação de Fase Aguda/etiologia , Infecções por HIV/sangue , Desnutrição Proteico-Calórica/sangue , Proteínas de Ligação ao Retinol/metabolismo , Deficiência de Vitamina A/sangue , Vitamina A/sangue , Adulto , Estudos Transversais , Feminino , Infecções por HIV/complicações , Humanos , Quênia/epidemiologia , Estado Nutricional , Desnutrição Proteico-Calórica/complicações , Deficiência de Vitamina A/epidemiologia , Deficiência de Vitamina A/etiologia
12.
Am J Kidney Dis ; 39(1): 134-45, 2002 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11774112

RESUMO

Homocysteine (tHcy) is a risk factor for atherosclerosis in patients with end-stage renal disease and chronic renal insufficiency (CRI). Vitamin B6 deficiency may result in high tHcy levels, especially after a methionine load (PML). Therefore, we evaluated vitamin B6 metabolism and tHcy (fasting and PML) levels in patients with CRI and those on hemodialysis (HD) therapy before and during high-dose sequential vitamin B6 and folic acid supplementation in male patients (27 patients, HD, 17 patients, CRI) and 19 age-matched healthy controls. Vitamin B6 doses were 100 mg/d in patients with CRI and 200 mg/d in HD patients, plus folic acid (5 mg/d), for more than 3 months in each period. We analyzed vitamin B6 metabolites by high-performance liquid chromatography in plasma and red blood cells (RBCs) and fasting tHcy in all cases and PML in subgroups of 11 HD patients and 14 patients with CRI. We found vitamin B6 deficiency and high tHcy (fasting and PML) levels in all patients. Plasma and RBC levels of pyridoxal and pyridoxal phosphate were abnormally low, whereas levels of pyridoxic acid (PA), an end product of vitamin B6 metabolism, were extremely high in both groups. Fasting and PML tHcy levels were partially resistant to vitamin B6 supplements, with different response patterns in HD patients and those with CRI. Thus, the PML defect was more responsive to folic acid in HD patients, whereas vitamin B6 partially reduced PML tHcy levels in patients with CRI. Resistance of tHcy to vitamin B6 treatment in patients with CRI and HD patients is not caused by poor absorption or low tissue stores. Rather, nonvitamin factors or potentially toxic PA levels may be implicated in abnormal vitamin B6 and/or tHcy metabolism during renal insufficiency.


Assuntos
Homocisteína/sangue , Falência Renal Crônica/sangue , Vitamina B 6/metabolismo , Idoso , Ácido Fólico/administração & dosagem , Humanos , Masculino , Pessoa de Meia-Idade , Fosfato de Piridoxal/sangue , Vitamina B 6/administração & dosagem , Vitamina B 6/sangue
13.
Lab Med ; 45(3): e128-38, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25217517

RESUMO

To optimize transportation processes, we present herein a contingency plan that coordinates interim measures used to ensure continued and timely services when climate based events might cause an interruption of the usual specimen transportation processes. As an example, we outline the implementation and effectiveness of a contingency plan for network laboratory courier automobile transportation during times of mountain pass highway closure. Data available from an approximately 3-year period from October 10, 2010 through August 29, 2013 revealed a total of 690 complete closures in the eastbound or westbound lanes of the Interstate-90 highway in the Snoqualmie Pass area in the state of Washington. Despite the frequency of closures, the Washington State Department of Transportation was effective in limiting the duration of closures. Road closures of less than 1 hour accounted for 58.7% of the total closures. No recorded closures prevented dispatched couriers from completing a prescheduled Snoqualmie Pass route. We identified no delays as being clinically significant, despite that there were 5 instances of delays greater than 4 hours. We implemented a contingency plan of aiding courier logistics during all times of pass closure. The plan includes an easy to interpret Condition Dashboard as a status indicator and a Decision Tree that references and summarizes information. Overall, the contingency plan allows for an objective, robust, proactive decision support system that has enabled operational flexibility and has contributed to continued safe, on-time specimen transportation; clients and courier and reference laboratory staff have appreciated these features and associated outcomes.


Assuntos
Emergências , Laboratórios/organização & administração , Técnicas de Planejamento , Tempo (Meteorologia)
14.
Diabetes Care ; 30(10): 2673-8, 2007 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-17666458

RESUMO

OBJECTIVE: The purpose of this study was to determine the relationship between plasma liver enzyme concentrations, insulin sensitivity, and intra-abdominal fat (IAF) distribution. RESEARCH DESIGN AND METHODS: Plasma gamma-glutamyl transferase (GGT), aspartate transaminase (AST), alanine transaminase (ALT) levels, insulin sensitivity (insulin sensitivity index [S(I)]), IAF area, and subcutaneous fat (SCF) area were measured in 177 nondiabetic subjects (75 men and 102 women, aged 31-75 years) with no history of liver disease. On the basis of BMI (< or > or = 27.5 kg/m2) and S(I) (< or > or = 7.0 x 10(-5) min/pmol) subjects were divided into lean insulin sensitive (LIS, n = 53), lean insulin resistant (LIR, n = 60), and obese insulin resistant (OIR, n = 56) groups. RESULTS: Levels of all three liver enzymes were higher in men than in women (P < 0.0001 for each). In men, GGT levels were higher in insulin-resistant than in insulin-sensitive subjects (P < 0.01). In women, GGT levels were higher in the OIR than in the LIS group (P < 0.01) but no different in the LIR group. There was no difference in ALT and AST levels among the LIS, LIR, and OIR groups. GGT was associated with S(I) (r = -0.26, P < 0.0001), IAF area (r = 0.22, P < 0.01), waist-to-hip ratio (WHR) (r = 0.25, P = 0.001), BMI (r = 0.17, P < 0.05), and SCF area (r = 0.16, P < 0.05) after adjustments for age and sex. In men, only S(I) (r = -0.29, P < 0.05) remained independently correlated with GGT in multiple regression analysis. In women, IAF area (r = 0.29, P < 0.01) and WHR (r = 0.29, P < 0.01) were independently associated with GGT, but S(I) was not. CONCLUSIONS: In nondiabetic men GGT but not AST or ALT levels, are inversely related to insulin sensitivity independent of IAF area. However in women, GGT is related to measures of central body fat rather than to insulin sensitivity.


Assuntos
Tecido Adiposo/fisiologia , Alanina Transaminase/sangue , Aspartato Aminotransferases/sangue , Insulina/farmacologia , Obesidade/enzimologia , gama-Glutamiltransferase/sangue , Adulto , Idoso , Feminino , Humanos , Resistência à Insulina , Masculino , Pessoa de Meia-Idade , Obesidade/sangue , Valores de Referência
15.
J Nutr ; 136(6): 1624-9, 2006 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-16702331

RESUMO

The ratio of retinol-binding protein (RBP) to transthyretin (TTR) has been proposed as an indirect method with which to assess vitamin A status in the context of inflammation. Few studies have been conducted among adults, and none examined the effect of HIV-1 infection. Our goal was to assess the RBP:TTR ratio among adults, including the effects of HIV-1 and the acute phase response. We used data from a cross-sectional study of 600 Kenyan women, of whom 400 had HIV-1. The effect of vitamin A supplementation among the HIV-1-infected participants was subsequently assessed in a randomized trial. Among HIV-1-uninfected women without an acute phase response, a RBP:TTR cut-off value of 0.25 had approximately 80% sensitivity and specificity to detect vitamin A deficiency (retinol <0.70 micromol/L). No RBP:TTR cut-off value demonstrated both high sensitivity and specificity among HIV-1 infected women without evidence of inflammation. HIV-1 infection and advanced HIV-1 disease were associated with higher RBP:TTR ratios. The effect of HIV-1 was independent of the acute phase response, which also increased the RBP:TTR ratio. Serum retinol increased with vitamin A supplementation among those with a low RBP:TTR ratio, although the effect was small and was not present among those with concurrent inflammation. Thus, the RBP:TTR ratio has modest ability to predict vitamin A deficiency among healthy adults, but HIV-1 infection alters the ratio, even in the absence of the acute phase response. Our results raise questions about the utility of this measurement given the high prevalence of HIV-1 infection in areas where vitamin A deficiency is common.


Assuntos
Reação de Fase Aguda/metabolismo , Infecções por HIV/metabolismo , HIV-1 , Pré-Albumina/metabolismo , Proteínas de Ligação ao Retinol/metabolismo , Adulto , Feminino , Humanos , Deficiência de Vitamina A/metabolismo
16.
Am J Gastroenterol ; 100(3): 607-15, 2005 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-15743359

RESUMO

OBJECTIVE: This paper compares nine strategies for determining hepatitis C antibody and viral status. They combine two tests for antibodies (enzyme immunoassays (EIA), recombinant immunoblot assays (RIBA)) and one for viremia (reverse transcription polymerase chain reaction (PCR)). Using optical density to divide EIA results into three categories (high positive, low positive, negative) was also considered. METHODS: Decision analysis compared strategies on cost as well as sensitivity and specificity with regard to antibody and viral status. Parameters in the decision tree included antibody prevalence, proportion viremic, sensitivity, specificity, and cost of individual tests. RESULTS: The two best strategies are EIA followed by PCR (EIA-->PCR); and EIA with three levels of optical density (EIA-OD), followed by RIBA for EIA-OD low positives, and then PCR for all positives (EIA-OD-->RIBA-->PCR). EIA-->PCR has equal viral sensitivity, slightly lower cost, slightly higher antibody sensitivity, but lower antibody specificity compared to EIA-OD-->RIBA-->PCR. The cost per false antibody positive avoided using EIA-OD-->RIBA-->PCR rather than EIA-->PCR is $36 when prevalence is 5%, and $193 when prevalence is 50%. Using EIA-OD-->RIBA-->PCR rather than EIA-->PCR results in 112 false antibody positives avoided for every true antibody positive missed when prevalence is 5%; this ratio is 18:1 when prevalence is 25%; and 6:1 when prevalence is 50%. CONCLUSIONS: EIA-OD-->RIBA-->PCR is the best choice when prevalence in the tested group is below 20%. As prevalence increases, the choice of EIA-OD-->RIBA-->PCR versus EIA-->PCR will depend on the relative importance of avoiding false antibody positives versus missing true antibody positives. Our analysis makes explicit the magnitude of this trade-off.


Assuntos
Hepatite C Crônica/diagnóstico , Análise Custo-Benefício , Técnicas de Apoio para a Decisão , Reações Falso-Positivas , Hepatite C Crônica/imunologia , Hepatite C Crônica/virologia , Humanos , Técnicas Imunoenzimáticas , Reação em Cadeia da Polimerase , Sensibilidade e Especificidade , Viremia/diagnóstico
17.
J Acquir Immune Defic Syndr ; 37(5): 1657-63, 2004 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-15577425

RESUMO

To test the hypothesis that micronutrient supplementation decreases genital HIV-1 shedding, a double-blind, randomized, placebo-controlled trial of 6 weeks of multivitamin plus selenium supplementation vs. placebo was conducted among 400 HIV-1-seropositive, nonpregnant, antiretroviral-naive women in Mombasa, Kenya. Primary outcome measures included cervical and vaginal shedding of HIV-1-infected cells and RNA. Secondary outcomes included plasma viral load and CD4 count. Surprisingly, the odds of detection of vaginal HIV-1-infected cells were 2.5-fold higher (P = 0.001) and the quantity of HIV-1 RNA in vaginal secretions was 0.37 log10 copies/swab higher (P = 0.004) among women who received micronutrients in comparison to placebo, even after adjustment for potential confounders including baseline HIV-1 shedding and CD4 count. The increase in vaginal HIV-1 shedding was greatest among women who had normal baseline selenium levels. Micronutrient supplementation resulted in higher CD4 (+23 cells/microL, P = 0.03) and CD8 (+74 cells/microL, P = 0.005) counts compared with placebo but did not alter the plasma viral load. In this randomized trial, micronutrients resulted in higher levels of genital HIV-1 shedding compared with placebo. The potential benefit of micronutrient supplementation in HIV-1-seropositive women should be considered in relation to the potential for increased infectivity.


Assuntos
Colo do Útero/virologia , HIV-1/efeitos dos fármacos , Micronutrientes/administração & dosagem , Selênio/administração & dosagem , Vagina/virologia , Eliminação de Partículas Virais/efeitos dos fármacos , Vitaminas/administração & dosagem , Adolescente , Adulto , Suplementos Nutricionais , Método Duplo-Cego , Feminino , Infecções por HIV/virologia , Humanos , Pessoa de Meia-Idade , RNA Viral/análise
18.
J Infect Dis ; 185(8): 1187-91, 2002 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-11930332

RESUMO

Observational studies have associated vitamin A deficiency with vaginal shedding of human immunodeficiency virus (HIV) type 1-infected cells and mother-to-child HIV-1 transmission. To assess the effect of vitamin A supplementation on vaginal shedding of HIV-1, a randomized, double-blind, placebo-controlled trial of 6 weeks of daily oral vitamin A (10,000 IU of retinyl palmitate) was conducted among 400 HIV-1-infected women in Mombasa, Kenya. At follow-up, there was no statistically significant difference in the prevalence of HIV-1 DNA (18% vs. 21%, P=.4) or the quantity of HIV-1 RNA (3.12 vs. 3.00 log(10) copies/swab, P=1.0) in vaginal secretions of women receiving vitamin A, compared with women receiving placebo. No significant effect of supplementation on plasma HIV-1 load or CD4 or CD8 cell counts was observed, and no effect was seen among women who were vitamin A deficient at baseline. Vitamin A supplementation is unlikely to decrease the infectivity of women infected with HIV-1.


Assuntos
Síndrome da Imunodeficiência Adquirida/imunologia , HIV-1/efeitos dos fármacos , Eliminação de Partículas Virais/efeitos dos fármacos , Vitamina A/administração & dosagem , Síndrome da Imunodeficiência Adquirida/virologia , Adolescente , Adulto , Suplementos Nutricionais , Método Duplo-Cego , Feminino , Seguimentos , HIV-1/fisiologia , Humanos , Pessoa de Meia-Idade , Vagina/virologia , Deficiência de Vitamina A/imunologia
19.
J Acquir Immune Defic Syndr ; 31(2): 243-9, 2002 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-12394804

RESUMO

Among HIV-1-infected individuals, vitamin A deficiency has been associated with faster disease progression and greater infectivity in observational studies, but randomized clinical trials have shown no effect of vitamin A supplementation. We conducted a cross-sectional study of 400 HIV-1-infected and 200 HIV-1-uninfected women in Mombasa, Kenya to examine the relations between vitamin A deficiency (serum retinol <30 microg/dL) and HIV-1 status, HIV-1 disease stage, and the acute phase response (serum C-reactive protein >or=10 mg/L and/or alpha1-acid glycoprotein >or=1.2 g/L). Among the HIV-1-infected women, the effect of vitamin A supplementation was examined in a randomized trial. Vitamin A deficiency was independently associated with HIV-1 infection (OR = 2.7, 95% CI: 1.9-4.0) and the acute phase response (OR = 2.8, 95% CI: 1.9-4.1). Among HIV-1-infected women, vitamin A deficiency and the acute phase response were associated with each other and were both independently associated with higher HIV-1 plasma viral load and lower CD4 count. HIV-1-infected women having an acute phase response had no increase in serum vitamin A levels after supplementation. Serum levels increased significantly among women without an acute phase response, although not to normal levels among women who were deficient at baseline. Among HIV-1-infected individuals, it is likely that low serum vitamin A concentrations reflect more active infection and the acute phase response. These results provide possible explanations for the disparity between observational studies and randomized trials of vitamin A for HIV-1 infection.


Assuntos
Infecções por HIV/complicações , Infecções por HIV/tratamento farmacológico , HIV-1 , Deficiência de Vitamina A/complicações , Deficiência de Vitamina A/tratamento farmacológico , Vitamina A/uso terapêutico , Adolescente , Adulto , Biomarcadores/sangue , Proteína C-Reativa/análise , Contagem de Linfócito CD4 , Estudos Transversais , Feminino , Infecções por HIV/sangue , Humanos , Quênia , Pessoa de Meia-Idade , Razão de Chances , Orosomucoide/análise , Carga Viral , Vitamina A/sangue
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