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PloS One 2014Dried blood spots (DBS) have been used as alternative specimens to plasma to increase access to HIV viral load (VL) monitoring and early infant diagnosis (EID) in remote... (Review)
Review
BACKGROUND
Dried blood spots (DBS) have been used as alternative specimens to plasma to increase access to HIV viral load (VL) monitoring and early infant diagnosis (EID) in remote settings. We systematically reviewed evidence on the performance of DBS compared to plasma for VL monitoring and EID.
METHODS AND FINDINGS
Thirteen peer reviewed HIV VL publications and five HIV EID papers were included. Depending on the technology and the viral load distribution in the study population, the percentage of DBS samples that are within 0.5 log of VL in plasma ranged from 52-100%. Because the input sample volume is much smaller in a blood spot, there is a risk of false negatives with DBS. Sensitivity of DBS VL was found to be 78-100% compared to plasma at VL below 1000 copies/ml, but this increased to 100% at a threshold of 5000 copies/ml. Unlike a plasma VL test which measures only cell free HIV RNA, a DBS VL also measures proviral DNA as well as cell-associated RNA, potentially leading to false positive results when using DBS. The systematic review showed that specificity was close to 100% at DBS VL above 5000 copies/ml, and this threshold would be the most reliable for predicting true virologic failure using DBS. For early infant diagnosis, DBS has a sensitivity of 100% compared to fresh whole blood or plasma in all studies.
CONCLUSIONS
Although limited data are available for EID, DBS offer a highly sensitive and specific sampling strategy to make viral load monitoring and early infant diagnosis more accessible in remote settings. A standardized approach for sampling, storing, and processing DBS samples would be essential to allow successful implementation.
TRIAL REGISTRATION
PROSPERO Registration #: CRD42013003621.
Topics: Dried Blood Spot Testing; Early Diagnosis; HIV Infections; HIV-1; Humans; Infant; Reproducibility of Results; Sensitivity and Specificity; Viral Load
PubMed: 24603442
DOI: 10.1371/journal.pone.0086461 -
Clinical Rheumatology Feb 2013This study aims to compare different methods of monosodium urate crystal (MSU) detection in synovial fluid (SF) and the effect of sample storage and handling on crystal... (Comparative Study)
Comparative Study Meta-Analysis Review
This study aims to compare different methods of monosodium urate crystal (MSU) detection in synovial fluid (SF) and the effect of sample storage and handling on crystal detection. A systematic literature search was performed in MEDLINE, EMBASE, the Cochrane Library and the American College of Rheumatology/European League Against Rheumatism conference abstracts of 2010 and 2011. Studies that compared a method for detecting MSU crystals in SF with polarised light microscopy (PLM) or compared various SF storage and handling factors with the detection of MSU crystals as an outcome were included. Twelve studies out of 247 identified references were included in the review. Seven studies compared different methods of MSU crystal detection in SF with PLM. Due to study heterogeneity, methodological limitations and risk of bias, no firm conclusions could be drawn from the available data. Five studies examining SF storage and handling factors were identified. A reduction in MSU crystal concentration was observed over time at room temperature that was not seen in refrigerated samples. The use of anticoagulation as a storage medium provided no benefit. Dried cytospin preparations appeared to be a suitable medium for long-term storage and delayed crystal analysis for at least 12 months. The existing data do not provide a compelling argument for the replacement of PLM as the current standard. SF sample storage and handling have an effect on MSU crystals and may impact on the reliability of analysis.
Topics: Chemistry, Clinical; Crystallization; Gout; Humans; Reproducibility of Results; Specimen Handling; Synovial Fluid; Uric Acid
PubMed: 23138881
DOI: 10.1007/s10067-012-2107-0 -
The Cochrane Database of Systematic... Oct 2009Impaction grafting is a technique to restore bone loss both in the femur and the acetabulum during revision hip arthroplasty surgery. Initially impaction grafting was... (Review)
Review
BACKGROUND
Impaction grafting is a technique to restore bone loss both in the femur and the acetabulum during revision hip arthroplasty surgery. Initially impaction grafting was undertaken using fresh frozen femoral head allografts that were milled to create morselized bone pieces that could be impacted to create a neo-cancellous bone bed prior to cementation of the new implant. Results of medium and long term outcome studies have shown variable results using this technique. Currently both processed and non-processed allograft bone are used and the purpose of this review was to analyse the evidence for both.
OBJECTIVES
To determine the clinical effectiveness of processed (freeze dried or irradiated) bone in comparison to fresh frozen (unprocessed) bone.
SEARCH STRATEGY
We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (1985 to 2008), EMBASE (1985 to 2008), CINAHL(1985 to 2008) and the National Research Register. Additional sources were also searched. Handsearching of relevant journals and conference abstracts was also undertaken. Searches were complete to 31 August 2008.
SELECTION CRITERIA
Randomised controlled trials that compared different types of bone for impaction grafting.
DATA COLLECTION AND ANALYSIS
Three hundred and sixty references were identified from the searches. Following detailed eligibility screening, three hundred and fifty nine references did not meet the eligibility criteria. Further details are required about one trial in order to determine it's eligibility.
MAIN RESULTS
No trials were identified that met the criteria for inclusion in the review.
AUTHORS' CONCLUSIONS
Good quality randomised controlled trials are required in this area so that a surgeon's choice of bone graft can be informed by evidence rather than personal preference.
Topics: Arthroplasty, Replacement, Hip; Bone Transplantation; Humans; Reoperation; Specimen Handling; Transplantation, Homologous
PubMed: 19821362
DOI: 10.1002/14651858.CD006351.pub2 -
Antiviral Therapy 2009Dried spots on filter paper made of whole blood (dried blood spots; DBS), plasma (dried plasma spots; DPS) or serum (dried serum spots) hold promise as an affordable and... (Review)
Review
BACKGROUND
Dried spots on filter paper made of whole blood (dried blood spots; DBS), plasma (dried plasma spots; DPS) or serum (dried serum spots) hold promise as an affordable and practical alternative specimen source to liquid plasma for HIV type-1 (HIV-1) viral load determination and drug resistance genotyping in the context of the rapidly expanding access to antiretroviral therapy (ART) for HIV-1-infected individuals in low- and middle-income countries. This report reviews the current evidence for their utility.
METHODS
We systematically searched the English language literature published before 2009 on Medline, the websites of the World Health Organization and US Centers for Disease Control and Prevention, abstracts presented at relevant international conferences and references from relevant articles.
RESULTS
Data indicate that HIV-1 viral load determination and resistance genotyping from DBS and DPS is feasible, yielding comparable test performances, even after storage. Limitations include reduced analytical sensitivity resulting from small analyte volumes (approximately 3.5 log(10) copies/ml at 50 microl sample volume), nucleic acid degradation under extreme environmental conditions, impaired efficiency of nucleic acid extraction, potential interference of archived proviral DNA in genotypes obtained from DBS and the excision of spots from the filters in high-volume testing.
CONCLUSIONS
This technology offers the advantages of a stable specimen matrix, ease of sample collection and shipment. The current sensitivity in drug resistance testing is appropriate for public health surveillance among pretreatment populations. However, consistently improved analytical sensitivity is needed for their routine application in the therapeutic monitoring of individuals receiving ART, particularly at the onset of treatment failure.
Topics: Anti-HIV Agents; Blood Specimen Collection; Drug Resistance, Viral; HIV Infections; HIV-1; Humans; Plasma; RNA, Viral; Reverse Transcriptase Polymerase Chain Reaction; Viral Load
PubMed: 19704164
DOI: No ID Found