An update on evidence based diagnostic and confirmatory testing strategies for heparin induced thrombocytopenia using combined immunological and functional assays.
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An update on evidence based diagnostic and confirmatory testing strategies for heparin induced thrombocytopenia using combined immunological and functional assays.
the purpose of this text to provide a brief review of the diagnostic / strategy when Heparin Induced Thrombocytopenia confirmation (HIT) by using a combination of immunology / functional test in addition to clinical probability. laboratory diagnosis of HIT is of primordial importance as related complications can be severe and life-threatening fast and can provoke limb amputation in some cases. The first act in the presence of HIT is to draw suspicion to begin heparin and alternative anticoagulant.
While vitamin K antagonists is not appropriate, including the choice of anticoagulant Fondaparinux, Sodium Danaparoid, DOACs, Argatroban, and bivalirudin. However, if HIT is excluded, the patient can benefit more from high therapeutic efficacy and antithrombotic drug, which remains superior to all anticoagulants substitution treatment. HIT is suspected by the reduced number of platelets >> 50% on 2 consecutive count or platelets <100 G / L, and the probability of clinically significant (4 Ts score). testing the patient’s plasma is required for diagnosis.
The first laboratory investigations involving immunological measurement of heparin dependent IgG antibodies (mainly targeted for heparin-platelet factor 4 complex). When positive, a functional assay for platelet activation, carried out at a low concentration and a high heparin, enabling confirm the disease. In any case, if the immuno-assay is negative, HIT can be excluded with high probability, and heparin may be continued (if the decision favors the clinical examination).
Conversely, the higher the concentration of IgG antibodies is (and affinity), the higher the likelihood of developing HIT. Has now become a functional test to confirm antibody platelet activation capacity, and therefore confirming the presence of HIT. Until now, the gold reference method for testing the antibody-dependent platelet activation is a C14-Serotonin Release Assay, available only very few laboratories working with radio-isotope. A simple, sensitive, and accurate test flow cytometry become now available for all clinical sites, and can easily be used to test the capacity of heparin-dependent antibodies to activate platelets, at low heparin concentrations.
This technique can be performed in any laboratory equipped with a flow cytometer and can make diagnosis confirmation HIT provided quickly, which introduces substantial improvements to the management of patients with HIT. We believe that the evidence-based updates on this topic was timely and well secured.
An update on evidence based diagnostic and confirmatory testing strategies for heparin induced thrombocytopenia using combined immun An update on evidence based diagnostic and confirmatory testing strategies for heparin induced thrombocytopenia using combined immunological and functional assays.ological and functional assays.
Rate false positive rate of rapid diagnostic tests for malaria caused by Plasmodium non-immunological factors and infectious agents.
Malaria rapid diagnostic test (RDT) can produce false positive (FP) results in patients with human African trypanosomiasis and rheumatoid factor (RF), but specificity against other infectious agents and immunological factors are largely unknown. the low diagnostic specificity due to cross-reactivity can lead to over-estimate the number of cases of malaria and over-use of antimalarial drugs, at no cost to diagnose and treat the underlying condition is true.
Data from the WHO Malaria RDT Product Testing Program were analyzed to assess the FP of 221 RDT against four agents of infection (Chagas, dengue fever, Leishmaniasis and Schistosomiasis) and four immunological factors (antibody anti-nuclear antibody anti-rat humans (HAMA), RF and plasma quickly returned). Only RDT with FP level against net negative samples less than 10% were included.
Paired t-tests were used to compare the level of product-specific FP at net negative samples and samples containing non-Plasmodium infection and immunological factors agent.
