We use cookies to understand how you use our site and to improve your experience. This includes personalizing content and advertising. To learn more, click here. By continuing to use our site, you accept our use of cookies. Cookie Policy.

Features Partner Sites Information LinkXpress
Sign In
Advertise with Us
Technopath Clinical Diagnostics

THERMO FISHER SCIENTIFIC

  Gold Thermo Fisher Scientific provides analytical instruments, lab equipment, specialty diagnostics, reagents and integrat... read more Featured Products: More products

Download Mobile App




Events

ATTENTION: Due to the COVID-19 PANDEMIC, many events are being rescheduled for a later date, converted into virtual venues, or altogether cancelled. Please check with the event organizer or website prior to planning for any forthcoming event.
24 Jan 2022 - 27 Jan 2022

Toxoplasmic Encephalitis in HIV Patients Detected in Urine

By LabMedica International staff writers
Posted on 25 Mar 2021
Print article
Image: The EASY-nLC 1200 HPLC, high-throughput capacity in a nano-flow UHPLC (Photo courtesy of Thermo Fisher Scientific)
Image: The EASY-nLC 1200 HPLC, high-throughput capacity in a nano-flow UHPLC (Photo courtesy of Thermo Fisher Scientific)
Toxoplasma encephalitis (TE) is the most commonly reported neurological opportunistic infection in human immunodeficiency virus (HIV)-infected patients since the introduction of combination ART (cART). Diagnosis of TE is challenging under the best clinical circumstances.

The poor clinical sensitivity of quantitative polymerase chain reaction (qPCR) for Toxoplasma gondii in blood and cerebrospinal fluid (CSF) and the limited availability of molecular diagnostics and imaging technology leaves clinicians in resource-limited settings with few options other than empiric treatment.

An international team of scientists led by the University of Illinois Chicago (Chicago, IL, USA) recruited in a study 164 HIV positive patients from Peru and Bolivia and 51 ambulatory HIV/T. gondii positive patients for controls. Blood and urine specimens were taken at enrollment, which for most hospitalized patients was shortly after admission; remnant CSF was collected if the subject underwent lumbar puncture as part of their medical care. CD4 and CD8 cell counts and viral loads were abstracted from participants’ charts.

The investigators have described a proof of concept for novel urine diagnostics for TE using Poly-N-isoproplyacrylamide nanoparticles dyed with Reactive Blue-221 to concentrate antigens, substantially increasing the limit of detection. After nanoparticle-concentration, a standard western blotting technique with a monoclonal antibody was used for antigen detection. Toxoplasma gondii IgG serological status was determined with an in-house enzyme linked immunosorbent assay (ELISA). For qPCR, target sequences were amplified using a Light Cycler (Applied Biosciences, Foster City, CA, USA). Digested samples were analyzed by parallel-reaction-monitoring (PRM) on an Orbitrap Fusion mass spectrometer with a nanospray EASY-nLC 1200 HPLC (Thermo Fisher Scientific, Waltham, MA, USA).

The team reported that the limit of detection (LoD) of T. gondii antigens GRA1 and SAG1 was 7.8pg/mL and 31.3pg/mL, respectively. To characterize this diagnostic approach, 164 hospitalized HIV-infected patients with neurological symptoms compatible with TE were tested for 1) T. gondii serology (121/147, positive samples/total samples tested), 2) qPCR in cerebrospinal fluid (11/41), 3) qPCR in blood (10/112), and 4) urinary GRA1 (30/164) and SAG1 (12/164). GRA1 appears to be superior to SAG1 for detection of TE antigens in urine. Fifty-one HIV-infected, T. gondii seropositive but asymptomatic persons all tested negative by nanoparticle western blot and blood qPCR, suggesting the test has good specificity for TE for both GRA1 and SAG1. In a subgroup of 44 patients, urine samples were assayed with mass spectrometry PRM for the presence of T. gondii antigens. PRM identified antigens in eight samples, six of which were concordant with the urine diagnostic.

The authors concluded that their results demonstrate nanoparticle technology’s potential for a noninvasive diagnostic test for TE and that GRA1 is a promising target for antigen based diagnostics for TE. The study was published on March 2, 2021 in the journal PLOS Neglected Tropical Diseases.

Related Links:
University of Illinois Chicago
Applied Biosciences
Thermo Fisher Scientific


Gold Supplier
SARS-CoV-2/Flu A/B & RSV Test
RespiBio Panel 3 (RBRP3)
New
Immunodiagnostic Analyzer
LiCA 5000
New
Photometer
RIELE Photometer 505
New
Automatic Urine Sediment Analyzer
US-120

Print article
IIR Middle East

Channels

Molecular Diagnostics

view channel
Illustration

Point-of-Care Lateral Flow Test Detects Bladder Cancer Using Urine Sample within Minutes

A breakthrough diagnostics platform uses a multiplexed lateral flow assay that detects 10 bladder cancer biomarkers from a urine sample in either laboratory or point-of-care settings. SCIENION (Berlin,... Read more

Hematology

view channel
Image: Bone marrow aspirate from a patient with Acute Myeloid Leukemia: Blasts are the predominant population and have a high nuclear to cytoplasmic ratio and generally lack granules. (Photo courtesy of Professor Peter G. Maslak, MD)

Cord Blood and Matched Related Donor Transplantation Compared in Acute Myeloid Leukemia

The prognosis of primary refractory and relapsed acute myeloid leukemia is poor, with a five-year overall survival of less than 10%. Allogeneic hematopoietic stem cell transplantation (HSCT) is the only... Read more

Industry

view channel
Illustration

Global Immunofluorescence Assay (IFA) Market to Surpass USD 4 Billion by 2028 Due to Growing Burden of Infectious Diseases

The global immunofluorescence assay (IFA) market is expected to reach USD 4.01 billion by 2028, driven by the increasing global healthcare burden of chronic and infectious diseases, rising application... Read more
Copyright © 2000-2022 Globetech Media. All rights reserved.