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Infections in Solid Organ Transplant Recipients Admitted to the Critical Care Unit
Published in Cheston B. Cunha, Burke A. Cunha, Infectious Diseases and Antimicrobial Stewardship in Critical Care Medicine, 2020
Almudena Burillo, Patricia Muñoz, Emilio Bouza
Fungal infections should be aggressively pursued in colonized patients and in those with risk factors. Isolation of Candida spp. or Aspergillus spp. from superficial sites may indicate infection. Early stages of fungal infection may be challenging to detect [194,195]. Fungal elements may be rapidly detected in wet mounts with potassium hydroxide or immunofluorescent calcofluor white stain. In approximately 50% of patients, an Indian ink preparation allows the identification of encapsulated C. neoformans, particularly in CSF. The latex agglutination test or enzyme immunoassay cryptococcal antigen shows a higher sensitivity. The fluorescent antibody stains, toluidine blue O and NAAT, permit the detection of P. jirovecii. The detection of H. capsulatum antigen is quite sensitive and the detection of Aspergillus spp. antigen is useful, although its efficiency is lower than in hematological patients [196–198]. When a fungal infection is suspected, a fundus examination, blood and respiratory cultures, Aspergillus spp. and Cryptococcus spp. antigen detection tests, and NAAT are mandatory.
Rheumatoid arthritis
Published in Gabriel Virella, Medical Immunology, 2019
George C. Tsokos, Gabriel Virella
Methods used for the detection of rheumatoid factor. RF and anti-Ig antibodies can be detected in the serum of affected patients by a variety of techniques: The Rose-Waaler test is a passive hemagglutination test that uses sheep or human erythrocytes coated with anti-erythrocyte antibodies as indicators. The agglutination of the IgG-coated red cells to titers greater than 16 or 20 is considered as indicative of the presence of RF. These tests detect mostly the classic IgM rheumatoid factor specific for IgG.The latex agglutination test, in which IgG-coated polystyrene particles are mixed with serum suspected of containing RF or anti-Ig antibodies (see Chapter 15). The agglutination of latex particles by serum dilutions greater than 1:20 is considered as a positive result. This test detects anti-Ig antibodies of all isotypes.
Disseminated Histoplasmosis, Coccidioidomycosis, And Cryptococcosis
Published in Lourdes R. Laraya-Cuasay, Walter T. Hughes, Interstitial Lung Diseases in Children, 2019
The diagnosis is established by the demonstration of Cryptococcus neoformans in sputum or biopsy specimens from the infected lung by direct histological examination and isolation in culture. In the disseminated form the organism may be found in spinal fluid, urine, skin lesions, bone marrow, and blood. The organism cannot be definitely identified unless it is cultured, but the unique, thick capsule provides a characteristic useful in direct histologic examinations. The capsule of the yeast may be revealed with an India ink preparation or by a mucicarmine stain. Specimens for culture should be inoculated onto several Sabourand dextrose agar plates, without cycloheximide. The cryptococcal antigen test is a useful diagnostic aid, especially if central nervous system infection exists, but it is less sensitive with cryptococcosis limited to the lung. This latex agglutination test can be applied to spinal fluid, pleural fluid, serum, or urine. Approximately 90% of patients with meningitis will have detectable cryptococcal polysaccharide antigen in the spinal fluid.
Incidence and clinical outcome of Cryptococcosis in a nation with advanced HIV surveillance program
Published in The Aging Male, 2020
Fatma Ben Abid, Hussam Abdel Rahman S. Al Soub, Muna Al Maslamani, Wanis Hamad Ibrahim, Hafedh Ghazouani, Abdullatif Al-Khal, Saad Taj-Aldeen
Routine laboratory investigations are usually unhelpful to establish the diagnosis. Lumbar puncture preceded by neuro-imaging is the key for diagnosis for cryptococcal meningitis. Cerebrospinal (CSF) pressure is usually elevated. CSF analysis typically shows lymphocytic pleocytosis with high protein and low glucose in half of the cases. CSF should be tested for India ink, cryptococcal latex agglutination test and fungal culture. The yield of India ink testing is much less in HIV-negative cases compared to HIV-infected cases (60% and 90% respectively) [19]. This is usually explained by the higher concentration of the yeast in the CSF of AIDS patients as compared to those who are immuno-competent. Latex agglutination test or enzyme-linked immunosorbent assay (ELISA) rarely misses positive cases with the exception of cases with very early disease or in those with very high titers due to the prozone effect [21]. Fungal culture is the gold-standard and is positive in nearly all cases. Nevertheless, cryptococcal culture can take a long time.
Accuracy of two plasma antibody tests and faecal antigen test for non-invasive detection of H. pylori in middle-aged Caucasian general population sample
Published in Scandinavian Journal of Gastroenterology, 2018
Sabine Skrebinska, Ilva Daugule, Daiga Santare, Sergejs Isajevs, Inta Liepniece-Karele, Dace Rudzite, Ilze Kikuste, Aigars Vanags, Ivars Tolmanis, Juris Atstupens, Jin Young Park, Rolando Herrero, Marcis Leja
The latex-agglutination test is based on passive agglutination reaction between antigens and antibodies. The ELISA test, on the other hand, is based on the detection of antibodies by adding a marked enzyme. However, latex-agglutination method could be even easily applicable than ELISA method since no special equipment is required other than a spectrometer, which is generally available in clinical laboratories [7]. In addition, sample preparation is easier and allows the processing of hundreds of samples in a short time [7]. On the other hand, ELISA method requires special equipment and the reaction should be measured in an automated ELISA instrument.
Evaluation of a commercial enzyme-linked immunosorbent assay (ELISA) for detecting antibodies against Toxoplasma gondii from naturally and experimentally infected pigs
Published in Infectious Diseases, 2019
Giusi Macaluso, Santina Di Bella, Giuseppa Purpari, Elisabetta Giudice, Francesco Mira, Francesca Gucciardi, Anna Maria Fausta Marino, Carmelo Russo, Maria Angeles Gómez-Morales, Annalisa Guercio
The prevalence of T. gondii in slaughter animals is being assessed on the basis of serological examination. Serological tests (e.g. indirect fluorescent antibody test (IFAT), enzyme-linked immune sorbent assay (ELISA), Sabin-Feldman Dye Test, modified agglutination test, Western blot, latex agglutination test and indirect hemagglutination test are generally highly sensitive and have been largely used worldwide [14–16].