Prospective Evaluation of Amplification-Boosted ELISA for Heat-Denatured p24 Antigen for Diagnosis and Monitoring of Pediatric Human Immunodeficiency Virus Type 1 Infection

The performance in pediatrie human immunodeficiency virus type 1 (HIV-1) infection of a signal-amplification boosted ELISA for HIV-1 p24 antigen in plasma after heat-mediated immune complex dissociation was prospectively compared with polymerase chain reaction-based procedures. Diagnostic sensitivity and specificity of the p24 antigen test were 100% and 99.2%, respectively. Quantification revealed RNA in 85.7% and p24 antigen in 87.4% of 230 samples from 25 infected children. Concentrations of these indices in individual samples correlated (P < .0001). Introduction or modification of antiretroviral treatment showed concordant responses of RNA and p24 antigen in 39 (90.7%) of 43 instances. The treatment-induced changes in concentrations of RNA were higher than those of p24 antigen in 11 instances. In 1 instance, however, the concentration change of p24 antigen was greater than that of RNA (P = .002). Variation of RNA concentrations was more marked than that of p24 antigen (P = .002). The p24 antigen test was equivalent to PCR for diagnosing and monitoring pediatrie HIV-1 infectio

Coumermycin inhibition of murine retro virus replication in cultured cells

The effect of coumermycin A, activity on the infection and replication of murine type C retroviruses was studied in vitro. The infectivity of five prototype ecotropic retroviruses was reduced by 50 to 94%, with viral titres decreased up to seven-fold. These values were substantiated by progeny production studies. Similar results were obtained with five strains of xenotropic retroviruses. Delayed inhibition of growth kinetics in mouse SC-1 cells was observed with 7-5 and 10mg/l of coumermycin A,. This effect was markedly reduced after three cycles of freezing and thawing of the drug. Changes in the absorption spectra of coumermycin A, were observed after eight cycles of freezing and thawing

Clinical and economic importance of applying the guidelines for the diagnosis of viral encephalitis

Viral encephalitis are diseases with complex diagnostic problems, because symptoms are similar to those of flu syndrome and they will resolve in about a week. Brain involvement and prognosis depend on pathogen and patient immunity. In 2008, the American Society of Infectious Diseases has approved guidelines to guide clinician to an appropriate diagnostic evaluation: clinician should ask specific tests, without resorting to a general request (eg. neurotropic viruses), reducing time and costs of etiologic diagnosis. The guidelines set out methods and the proper timing to execute tests for each virus, indicating when to integrate molecular research with antibody research to avoid false negative results, and how to interpret results. During the period September 2007 - August 2009, microbiology laboratory of San Martino hospital in Genoa has analyzed 300 cerebrospinalis liquor from Liguria with a clinical diagnosis of suspected viral encephalitis.The search for viruses HSV1, HSV2,VZV, EBV,CMV, HHV6,Adenovirus, Enterovirus and JCV was performed by real time PCR. Only 51 liquor were positive (16 HSV1, 5 HSV2, 4 VZV, 17 EBV, 2 CMV, 2 HHV6, 1 Adenovirus, 4 Enterovirus and 4 JCV with 4 coinfection). This study confirms that the percentage of encephalitis with a recognized etiologic agent remains very low, despite the increase in positivity in the last two years.This confirms the importance of applying the guidelines to improve the diagnosis of viral encephalitis

DECAY OF HIV-1 2LTR DNA IN INFECTED INDIVIDUALS AFTER THREE TO EIGHT YEARS OF SUSTAINED CONTROL OF VIREMIA.

Covert human immunodeficiency virus (HIV) replication was ongoing during the first 3 years of aviremia in 22 patients, as determined by detection of DNA containing two long terminal repeats (2LTR DNA). Although total HIV DNA was detected in 60 2LTR DNA-negative samples, the absence of 2LTR DNA in 90% of patients following 7 to 8 years of highly active antiretroviral therapy suggests suppression of cryptic viral replication

Decay of Human Immunodeficiency Virus Type 1 Unintegrated DNA Containing Two Long Terminal Repeats in Infected Individuals after 3 to 8 Years of Sustained Control of Viremia

Covert human immunodeficiency virus (HIV) replication was ongoing during the first 3 years of aviremia in 22 patients, as determined by detection of DNA containing two long terminal repeats (2LTR DNA). Although total HIV DNA was detected in 60 2LTR DNA-negative samples, the absence of 2LTR DNA in 90% of patients following 7 to 8 years of highly active antiretroviral therapy suggests suppression of cryptic viral replication

Level of Human Immunodeficiency Virus DNA in Peripheral Blood Mononuclear Cells Correlates with Efficacy of Antiretroviral Therapy

A novel colorimetric assay was developed and validated for accurate quantitation of human immunodeficiency virus (HIV) DNA in peripheral blood mononuclear cells (PBMCs). We tested 318 sequential samples from 56 subjects, 53 of whom were undergoing dual or triple therapy. Patients were considered responders when viremia levels were below 5,000 HIV RNA copies/ml. The mean DNA copy numbers for untreated and responder subjects were similar (72 and 75, respectively), while it was 4.54-fold higher for nonresponders (339). This report provides strong evidence that HIV DNA levels in PBMCs correlate with therapeutic efficacy and suggests that DNA quantitation is a useful tool to monitor the decay of the HIV reservoir toward disease remission, especially when viremia is undetectable

Comparison of Two Human Immunodeficiency Virus (HIV) RNA Surrogate Assays to the Standard HIV RNA Assay

Human immunodeficiency virus (HIV) RNA testing is the gold standard for monitoring antiretroviral therapy in HIV-infected patients. However, equipment and reagent costs preclude widespread use of the assay in resource-limited settings. The Perkin-Elmer Ultrasensitive p24 assay and the Cavidi Exavir Load assay both offer potentially simpler, less costly technologies for monitoring viral load. These assays were compared to the Roche Amplicor HIV-1 Monitor Test, v1.5, using panels of clinical samples (subtype B) from HIV-positive subjects and HIV-spiked samples (subtypes A, C, D, CRF_01AE, CRF_02AG, and F). The Ultrasensitive p24 assay detected 100% of the spiked samples with virus loads of >250,000copies/ml and 61% of the clinical samples with virus loads of 219 to 288,850 copies/ml. Detection rates were improved substantially if an external lysis buffer was added to the procedure. The Cavidi assay detected 54 to 100% of spiked samples with virus loads >10,000 copies/ml and 68% of the clinical samples. These detection rates were also greatly improved with a newly implemented version of this kit. Coefficients of variation demonstrate good reproducibility for each of these kits. The results from the Cavidi v1.0, Cavidi v2.0, and Perkin-Elmer, and the Perkin-Elmer Plus external buffers all correlated well with the results from the Roche Monitor Test (r = 0.83 to 0.96, r = 0.84 to 0.99, r = 0.58 to 0.67, and r = 0.59 to 0.95, respectively). Thus, the use of these two assays for monitoring patients, together with less-frequent confirmation testing, offers a feasible alternative to frequent HIV RNA testing in resource-limited settings