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Ramírez JC, Parrado R, Sulleiro E, de la Barra A, Rodríguez M, Villarroel S, Irazu L, Alonso-Vega C, Alves F, Curto MA, García L, Ortiz L, Torrico F, Gascón J, Flevaud L, Molina I, Ribeiro I, Schijman AG. First external quality assurance program for bloodstream Real-Time PCR monitoring of treatment response in clinical trials of Chagas disease. PLoS One 2017; 12:e0188550. [PMID: 29176887 PMCID: PMC5703561 DOI: 10.1371/journal.pone.0188550] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Accepted: 11/09/2017] [Indexed: 02/04/2023] Open
Abstract
Real-Time PCR (qPCR) testing is recommended as both a diagnostic and outcome measurement of etiological treatment in clinical practice and clinical trials of Chagas disease (CD), but no external quality assurance (EQA) program provides performance assessment of the assays in use. We implemented an EQA system to evaluate the performance of molecular biology laboratories involved in qPCR based follow-up in clinical trials of CD. An EQA program was devised for three clinical trials of CD: the E1224 (NCT01489228), a pro-drug of ravuconazole; the Sampling Study (NCT01678599), that used benznidazole, both conducted in Bolivia; and the CHAGASAZOL (NCT01162967), that tested posaconazole, conducted in Spain. Four proficiency testing panels containing negative controls and seronegative blood samples spiked with 1, 10 and 100 parasite equivalents (par. eq.)/mL of four Trypanosoma cruzi stocks, were sent from the Core Lab in Argentina to the participating laboratories located in Bolivia and Spain. Panels were analyzed simultaneously, blinded to sample allocation, at 4-month intervals. In addition, 302 random blood samples from both trials carried out in Bolivia were sent to Core Lab for retesting analysis. The analysis of proficiency testing panels gave 100% of accordance (within laboratory agreement) and concordance (between laboratory agreement) for all T. cruzi stocks at 100 par. eq./mL; whereas their values ranged from 71 to 100% and from 62 to 100% at 1 and 10 par. eq./mL, respectively, depending on the T. cruzi stock. The results obtained after twelve months of preparation confirmed the stability of blood samples in guanidine-EDTA buffer. No significant differences were found between qPCR results from Bolivian laboratory and Core Lab for retested clinical samples. This EQA program for qPCR analysis of CD patient samples may significantly contribute to ensuring the quality of laboratory data generated in clinical trials and molecular diagnostics laboratories of CD.
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Affiliation(s)
- Juan C. Ramírez
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular “Dr. Héctor N. Torres” (INGEBI-CONICET), Buenos Aires, Argentina
| | - Rudy Parrado
- Instituto de Investigaciones Biomédicas (IIBISMED), Universidad Mayor de San Simón, Cochabamba, Bolivia
| | - Elena Sulleiro
- Hospital Universitari Vall d'Hebron, Universitat Autònoma de Barcelona, PROSICS Barcelona, Barcelona, Spain
| | - Anabelle de la Barra
- Instituto de Investigaciones Biomédicas (IIBISMED), Universidad Mayor de San Simón, Cochabamba, Bolivia
| | - Marcelo Rodríguez
- Instituto Nacional de Enfermedades Infecciosas (INEI)-ANLIS "Dr. Carlos G. Malbrán", Buenos Aires, Argentina
| | - Sandro Villarroel
- Instituto de Investigaciones Biomédicas (IIBISMED), Universidad Mayor de San Simón, Cochabamba, Bolivia
| | - Lucía Irazu
- Instituto Nacional de Enfermedades Infecciosas (INEI)-ANLIS "Dr. Carlos G. Malbrán", Buenos Aires, Argentina
| | | | - Fabiana Alves
- Drugs for Neglected Diseases initiative (DNDi), Geneva, Switzerland
| | - María A. Curto
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular “Dr. Héctor N. Torres” (INGEBI-CONICET), Buenos Aires, Argentina
| | - Lineth García
- Instituto de Investigaciones Biomédicas (IIBISMED), Universidad Mayor de San Simón, Cochabamba, Bolivia
| | - Lourdes Ortiz
- Universidad Autónoma Juan Misael Saracho, Tarija, Bolivia
| | | | - Joaquim Gascón
- ISGlobal, Barcelona Centre for International Health Research (CRESIB), Hospital Clínic-Universitat de Barcelona, Barcelona, Spain
| | - Laurence Flevaud
- Médecins Sans Frontières Operational Center Barcelona-Athens (OCBA), Barcelona, Spain
| | - Israel Molina
- Hospital Universitari Vall d'Hebron, Universitat Autònoma de Barcelona, PROSICS Barcelona, Barcelona, Spain
| | - Isabela Ribeiro
- Drugs for Neglected Diseases initiative (DNDi), Geneva, Switzerland
| | - Alejandro G. Schijman
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular “Dr. Héctor N. Torres” (INGEBI-CONICET), Buenos Aires, Argentina
- * E-mail:
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Systemic and mucosal differences in HIV burden, immune, and therapeutic responses. J Acquir Immune Defic Syndr 2011; 56:401-11. [PMID: 21239996 DOI: 10.1097/qai.0b013e31820cdfdb] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
BACKGROUND Mucosal tissues represent major targets for HIV transmission but differ in susceptibility and reservoir function by unknown mechanisms. METHODS In a cross-sectional study, HIV RNA and infectious virus were compared between oral and genital compartments and blood in HIV-infected women, in association with clinical parameters, copathogens, and putative innate and adaptive HIV inhibitors. RESULTS HIV RNA was detectable in 24.5% of women from all 3 compartments, whereas 45% had RNA in only 1 or 2 sites. By comparison, infectious HIV, present in blood of the majority, was rare in mucosal sites. Innate mediators, secretory leukocyte protease inhibitor and thrombospondin, were highest in mucosae. Highly active antiretroviral therapy was associated with an 80% decreased probability of shedding. Multivariate logistic regression models revealed that mucosal HIV RNA was associated with higher plasma RNA, infectious virus, and total mucosal IgA, but not IgG. There was a 37-fold increased probability of detecting RNA in both genital and oral specimens (P = 0.008; P = 0.02, respectively) among women in highest versus lowest IgA tertiles. CONCLUSIONS Mucosal sites exhibit distinct characteristics of infectious HIV, viral shedding, and responses to therapy, dependent upon both systemic and local factors. Of the putative innate and adaptive mucosal defense factors examined, only IgA was associated with HIV RNA shedding. However, rather than being protective, there was a striking increase in probability of detectable HIV RNA shedding in women with highest total IgA.
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Jiang Y, Qiu M, Zhang G, Xing W, Xiao Y, Pan P, Yao J, Ou CY, Su X. Quality assurance in the HIV/AIDS laboratory network of China. Int J Epidemiol 2011; 39 Suppl 2:ii72-8. [PMID: 21113040 PMCID: PMC2992624 DOI: 10.1093/ije/dyq224] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Background In 2009, there were 8273 local screening laboratories, 254 confirmatory laboratories, 35 provincial confirmatory central laboratories and 1 National AIDS Reference Laboratory (NARL) in China. These laboratories were located in Center for Disease Control and Prevention (CDC) facilities, hospitals, blood donation clinics, maternal and child health (MCH) hospitals and border health quarantine health-care facilities. Methods The NARL and provincial laboratories provide quality assurance through technical, bio-safety and managerial training; periodic proficiency testing; on-site supervisory inspections; and commercial serologic kit evaluations. Results From 2002 to 2009, more than 220 million HIV antibody tests were performed at screening laboratories, and all reactive and indeterminate samples were confirmed at confirmatory laboratories. The use of highly technically complex tests, including CD4 cell enumeration, viral load, dried blood spot (DBS)-based early infant diagnosis (EID), drug resistance (DR) genotyping, HIV-1 subtyping and incidence assays, have increased in recent years and their performance quality is closely monitored. Conclusion China has made significant progress in establishing a well-coordinated HIV laboratory network and QA systems. However, the coverage and intensity of HIV testing and quality assurance programmes need to be strengthened so as to ensure that more infected persons are diagnosed and that they receive timely prevention and treatment services.
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Affiliation(s)
- Yan Jiang
- Chinese Center for Disease Control and Prevention, Beijing, People's Republic of China.
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Navazesh M, Mulligan R, Kono N, Kumar SKS, Nowicki M, Alves M, Mack WJ. Oral and systemic health correlates of HIV-1 shedding in saliva. J Dent Res 2010; 89:1074-9. [PMID: 20671205 DOI: 10.1177/0022034510375290] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
The relationship among oral and systemic health and HIV shedding in saliva is not well-understood. We hypothesized that oral and systemic health are associated with HIV shedding in saliva of HIV-infected women. Saliva from 127 participants enrolled in the Women's Interagency HIV Study (WIHS) was collected at repeated visits over a 5½-year study period (October 1998 through March 2004) and was evaluated for HIV-1 RNA. Demographic, lifestyle, and systemic and oral health characteristics were evaluated as possible correlates of salivary HIV-1 shedding. Multivariate models showed significantly increased risk of HIV-1 shedding in saliva as blood levels of CD4 cell counts decreased (p < 0.0001) and HIV RNA increased (p < 0.0001). Diabetes (p = 0.002) and a high proportion of gingival bleeding sites (p = 0.01) were associated with increased likelihood, while anti-retroviral therapy (p = 0.0003) and higher levels of stimulated saliva flow rates (p = 0.02) were associated with a lower likelihood of HIV-1 RNA shedding in saliva.
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Affiliation(s)
- M Navazesh
- Division of Periodontology, Diagnostic Sciences and Dental Hygiene, 925 West 34th Street, DEN 4320, Herman Ostrow School of Dentistry of USC, University of Southern California, Los Angeles,CA 90089-0641, USA.
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Li X, Chu H, Gallant JE, Hoover DR, Mack WJ, Chmiel JS, Muñoz A. Bimodal virological response to antiretroviral therapy for HIV infection: an application using a mixture model with left censoring. J Epidemiol Community Health 2007; 60:811-8. [PMID: 16905728 PMCID: PMC2566033 DOI: 10.1136/jech.2005.044644] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
STUDY OBJECTIVE To assess whether HIV RNA levels (log(10) scale) in highly active antiretroviral therapy (HAART) treated population have a bimodal distribution, suggesting optimal or suboptimal response to HAART. METHODS The study population from two ongoing cohort studies comprised 564 men (4785 person visits) and 1173 women (8675 person visits) with known dates of HAART initiation and with HIV RNA measurements before and after initiation. Values below detection limit of assays were treated in the analysis as left censored. Maximum likelihood methods were used to estimate parameters and to determine possible bimodality of HIV RNA distributions. RESULTS A two component mixture model fitted HIV RNA levels significantly better than did a single component distribution at different years from HAART initiation in both therapy experienced and therapy naive patients. In the fifth year after HAART initiation, 32% of men and 44% of women had HIV RNA in the higher component with medians of 5247 and 9253 copies/ml, respectively, suggesting suboptimal virological response to HAART, which was associated with poor adherence and lower frequency of CCR5 heterozygous genotype. CONCLUSION The bimodal distribution of HIV RNA persisted during the years after HAART initiation. The high occurrence of suboptimal virological response at the fifth year after HAART initiation underscore the needs for careful monitoring and patient education about the importance of treatment adherence. This data analysis overcomes limitations of measurement techniques of observations having values below detection limits and serves to characterise the dynamics of the virological response to therapies.
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Affiliation(s)
- Xiuhong Li
- Room E7648, Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA
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Al-Harthi L, Voris J, Du W, Wright D, Nowicki M, Frederick T, Landay A, Kovacs A. Evaluating the impact of hepatitis C virus (HCV) on highly active antiretroviral therapy-mediated immune responses in HCV/HIV-coinfected women: role of HCV on expression of primed/memory T cells. J Infect Dis 2006; 193:1202-10. [PMID: 16586355 PMCID: PMC3126663 DOI: 10.1086/500843] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2005] [Accepted: 10/27/2005] [Indexed: 01/29/2023] Open
Abstract
OBJECTIVE To evaluate the impact of hepatitis C virus (HCV) on the immune system before receipt of highly active antiretroviral therapy (HAART) and on immune recovery after receipt of HAART among human immunodeficiency virus (HIV)/HCV-coinfected women enrolled in the Women's Interagency HIV Study. METHODS The study included 294 HIV-infected women who initiated HAART and attended 2 follow-up visits. The women were grouped on the basis of positive HCV antibody and HCV RNA tests. There were 148 women who were HCV antibody negative, 34 who were HCV antibody positive but RNA negative, and 112 who were HCV antibody and RNA positive. Immune recovery was measured by flow-cytometric assessment for markers of activation and maturation on CD4+ and CD8+ T cells. Data analysis used repeated measures of variance.Results. HIV/HCV coinfection is associated with an increased number of CD4+ and CD8+ primed/memory T cells. HIV/HCV coinfection, however, did not affect any further decreases in CD4+ or CD4+ and CD8+ naive/memory T cell counts or enhanced T cell activation. HIV/HCV coinfection also did not affect HAART responses in the CD4+ and CD8+ T cell compartment. CONCLUSIONS HCV does not affect immune responses to HAART in HIV/HCV-coinfected individuals but is associated with an expansion of CD4+ and CD8+ memory T cell subsets. Functional impairment in the CD4+ and CD8+ T cell compartments still needs to be assessed in coinfected patients.
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Affiliation(s)
- Lena Al-Harthi
- Rush University Medical Center, Chicago, Illinois 60612, USA.
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Nowicki MJ, Laskus T, Nikolopoulou G, Radkowski M, Wilkinson J, Du WB, Rakela J, Kovacs A. Presence of hepatitis C virus (HCV) RNA in the genital tracts of HCV/HIV-1-coinfected women. J Infect Dis 2005; 192:1557-65. [PMID: 16206070 PMCID: PMC3164119 DOI: 10.1086/491742] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2005] [Accepted: 05/27/2005] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Hepatitis C virus (HCV)-infected women--in particular, those coinfected with human immunodeficiency virus type 1 (HIV-1)--can transmit infection to their children and sex partners. METHODS The present study was conducted to analyze the presence of HCV RNA in cervicovaginal lavage (CVL) fluid from 71 women (58 HCV/HIV-1-coinfected women and 13 HCV-infected, HIV-1-uninfected women) enrolled in the Women's Interagency HIV Study. RESULTS HCV RNA was detected (by a commercial polymerase chain reaction assay) in CVL fluid from 18 (29%) of the HIV-1-infected women and from none of the HIV-1-uninfected women (P<.05). Multivariate analysis revealed that risk factors for the presence of HCV RNA in CVL fluid were HCV viremia (odds ratio [OR], 16.81; P=.02) and HIV-1 RNA in CVL fluid (OR, 19.87; P=.02). This observation suggests local interactions between HIV-1 and HCV in the genital tract compartment. There was no correlation between HCV RNA in CVL fluid and CD4, CD8, or CD3 cell counts, HIV-1 RNA viremia, the number of leukocytes in CVL fluid, or HIV-1 therapy. Furthermore, in 3 of 5 analyzed patients who had a detectable CVL HCV RNA load, we found viral variants differing in the 5' untranslated region that were present neither in plasma nor in peripheral-blood mononuclear cells. CONCLUSIONS Our observations point to the importance of the genital tract compartment, in which local HCV replication could be facilitated by local HIV-1 replication.
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Affiliation(s)
- Marek J Nowicki
- Maternal-Child and Adolescent Center for Infectious Diseases and Virology, University of Southern California, Los Angeles 90033, and Mayo Clinic, Scottsdale, USA.
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Strickler HD, Burk RD, Fazzari M, Anastos K, Minkoff H, Massad LS, Hall C, Bacon M, Levine AM, Watts DH, Silverberg MJ, Xue X, Schlecht NF, Melnick S, Palefsky JM. Natural History and Possible Reactivation of Human Papillomavirus in Human Immunodeficiency Virus–Positive Women. ACTA ACUST UNITED AC 2005; 97:577-86. [PMID: 15840880 DOI: 10.1093/jnci/dji073] [Citation(s) in RCA: 395] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
BACKGROUND Little is known in human immunodeficiency virus (HIV)-positive women about how the combination of plasma HIV RNA level and CD4+ T-cell count is associated with the natural history of human papillomavirus (HPV) infection or about HPV reactivation--whether it occurs and with what frequency in HIV-positive women. METHODS HIV-positive (n = 1848) and -negative (n = 514) women were assessed at semiannual visits (total person-years = 5661) for cervicovaginal HPV with polymerase chain reaction assays and for squamous intraepithelial lesions (SILs) by Pap smear. We studied the prevalent detection of HPV and SILs with generalized estimating equations and the incident detection and persistence of HPV and SILs with multivariable Cox models. All statistical tests were two-sided. RESULTS We observed a strong interaction between the associations of CD4+ and plasma HIV RNA strata with both prevalent (P(interaction) = .002) and incident (P(interaction) = .001) detection of HPV. Indeed, the hazard ratio for incident HPV detection peaked between 4.0 and 5.0, with either a CD4+ count of less than 200 cells per mm3 or an HIV RNA level of more than 100,000 copies per mL. Although incident HPV detection in all women was associated with the number of recent sex partners (P(trend)<.001), 22% of sexually inactive HIV-positive women with a CD4+ count of less than 200 cells/mm3 also had at least one incidentally detected HPV type. The association between CD4+/HIV RNA strata and HPV persistence was statistically significantly smaller (P<.001) than for incident HPV detection. SIL prevalence, incident detection, and persistence had similar associations with CD4+/HIV RNA strata as HPV (above). CONCLUSION In HIV-positive women, plasma HIV RNA level and CD4+ count in combination appear to have a strong and statistically interactive association with incident detection of HPV, some of which may reflect HPV reactivation (e.g., in sexually inactive women). The more moderate association between HIV coinfection and HPV persistence could partly explain why cervical cancer rates have not reached more epidemic proportions in HIV-positive women.
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Affiliation(s)
- Howard D Strickler
- Department of Epidemiology and Population Health, Albert Einstein College of Medicine, 1300 Morris Park Ave., Belfer #1308, Bronx, NY 10461, USA.
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Stevens W, Wiggill T, Horsfield P, Coetzee L, Scott LE. Evaluation of the NucliSens EasyQ assay in HIV-1-infected individuals in South Africa. J Virol Methods 2004; 124:105-10. [PMID: 15664057 DOI: 10.1016/j.jviromet.2004.11.009] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2004] [Revised: 11/09/2004] [Accepted: 11/10/2004] [Indexed: 10/26/2022]
Abstract
We compared the performance of the NucliSens EasyQ assay (bioMerieux) combined with the manual NucliSens miniMag extraction methodology to the Roche Cobas Ampliprep/Standard Amplicor Monitor methodology (Roche Diagnostics) for HIV-1 RNA quantitation in HIV-1-infected individuals in South Africa. Plasma samples (284) from HIV sero-positive patients at different stages of infection were analyzed. The distribution of results was typical of the clinical samples received at the laboratory where 20% have viral load results <400 copies/ml (2.6 log) and 18% have viral load results >750000 copies/ml (5.8 log) using the Roche Amplicor Monitor standard assay. All statistical analyses were performed using log10-transformed values for all the variables in the analyses, i.e. log10EasyQIU/ml, and log10RNA (log10 copies/ml, Amplicor). Roche values were converted from RNA copies per ml to IU/ml by multiplying the Roche value by 0.51. HIV RNA levels quantitated by the NucliSens EasyQ assay correlated significantly with those of the Roche Cobas Amplicor Monitor assay (r=0.874, p<0.0001). Reproducibility of the NucliSens EasyQ assay in the log6IU range yielded CV variance of 1.3-2.84% for two well-trained technologists. In addition, a retrospective evaluation of the performance of the NucliSens EasyQ assay in 102 runs (2448) samples was conducted in the laboratory over a 4-month interval. Factors considered during this evaluation included time taken to perform the assay, volume requirements, number of required repeats, potential for contamination.
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Affiliation(s)
- W Stevens
- Department of Molecular Medicine and Haematology, School of Pathology, Faculty of Health Sciences, University of Witwatersrand and the National Health Laboratory Service, South Africa.
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Landay A, Benning L, Bremer J, Weiser B, Burger H, Nowicki M, Kovacs A. Correlates of immune activation marker changes in human immunodeficiency virus (HIV)-seropositive and high-risk HIV-seronegative women who use illicit drugs. J Infect Dis 2003; 188:209-18. [PMID: 12854075 PMCID: PMC3164115 DOI: 10.1086/376509] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2002] [Accepted: 02/24/2003] [Indexed: 01/11/2023] Open
Abstract
The majority of natural history studies of human immunodeficiency virus (HIV) infection have immune and viral parameters in men. Data demonstrating that women have lower HIV-1 RNA levels than men at the same CD4 cell counts have raised the question of immunologic differences in HIV-seropositive women. This study describes levels and changes in phenotypic markers of immune maturity, function, and activation in the CD4 and CD8 cell subsets in HIV-seropositive and high-risk HIV-seronegative women. Our primary hypothesis was that activation levels would be significantly higher among illicit drug users. However, results showed that HIV-1 RNA level was the strongest predictor of marker level and that both HIV-1 RNA level and CD4 cell count were independently associated with CD4 activation, but illicit drug use was not. In summary, this study demonstrated that immune activation was a significant pathogenic feature in women and that activation was driven by HIV infection and not illicit drug use.
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Affiliation(s)
- Alan Landay
- Department of Immunology/Microbiology, Rush Medical College, 1735 W. Harrison Street, Rm. 616 Cohn, Chicago, IL 60612, USA.
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Raggi CC, Pinzani P, Paradiso A, Pazzagli M, Orlando C. External quality assurance program for PCR amplification of genomic DNA: an Italian experience. Clin Chem 2003; 49:782-91. [PMID: 12709370 DOI: 10.1373/49.5.782] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND External quality assurance (EQA) programs for diagnostic tests based on nucleic acid amplification have not been widely implemented in clinical laboratories and remain limited to few tests. Development of specific EQA programs based on application-based proficiency testing for any diagnostic molecular target is challenging. Development of EQA trials based on methodologic proficiency testing and directed to the evaluation of analytical aspects common to the majority of PCR-based tests may be valuable. METHODS We developed an EQA program for evaluation of DNA extraction and amplification and analysis of products after PCR. Participants received a package containing primers and reference materials to evaluate three specific controls for, respectively, DNA extraction (quality and quantity), PCR performance (specificity and efficiency), and interpretation of results after electrophoresis. Each participant was asked to return to the organizers a form with their numerical results and an aliquot of all amplified samples for joint evaluation. RESULTS Results varied in all phases of the experimental procedure: preamplification, amplification, and post-PCR interpretation. To give a general estimation on the quality of performances for each laboratory, we designed a score scheme in which the results of any specific action were evaluated on the basis of the distribution around the median consensus values. The maximum possible score was 84. On the basis of total score obtained by each laboratory, we created a qualitative ranking list that provided the final interpretation of results as excellent (>63 points; n = 4 laboratories), good (53-63 points; n = 13), sufficient (42-52 points; n = 15), poor (31-41 points; n = 3), and not acceptable (<31 points; n = 4). CONCLUSIONS This survey demonstrates the importance of EQA trials based on methodologic proficiency testing directed to evaluation of analytical aspects common to the majority of PCR-based tests.
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Affiliation(s)
- Claudia Casini Raggi
- Department of Clinical Physiopathology, University of Florence, viale Pieraccini 6, 50139 Florence, Italy
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