were 17 sera from patients with confirmed Lyme disease among the 42 CDC reference samples (Table 1). Of these, the CDC had identified 10 patients with early Lyme disease, four with Lyme arthritis, and three with Lyme neuroborreliosis (Table 3). The WB and IB results suggest that the IgG and IgM IBs tend to be as good or better than the corresponding IgG and IgM WBs at detecting all three stages of Lyme disease using CDC or internal positivity criteria. ...
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... Antigen strips were prepared essentially as described for our previously developed IB assays for borreliosis [9, 10]. ...
... IgG and IgM antibodies were detected in COVID-19 BIs essentially as described for borreliosis BIs [9,10]. Before use, each 3 mm strip was soaked in 1 ml of diluent (100 mM Tris, 0.9% NaCl, 0.1% Tween-20 and 1% skimmed milk powder) for 5 min in a bucket. ...
Formation of IgG and IgM Antibodies Against Nucleocapsid and Peak Proteins in COVID-19 Characterized by Multiple Immunoblot Assays
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April 2021 BMC INFECT DIS
Jyotsna ShahSong Liu
Hari-Hara PotulaPrerna Bhargava
Background Simple and rapid serological assays to characterize antibody responses are important in the current COVID-19 pandemic caused by SARS-CoV-2. Multiple immunoblot (IB) assays called COVID-19 IB assays were developed to detect IgG and IgM antibodies against SARS-CoV-2 virus proteins in COVID-19 patients. Methods Recombinant nucleocapsid protein and the S1, S2, and (RBD) receptor binding domain of the SARS-CoV-2 spike protein were used as target antigens in COVID-19 IBs. The specificity of the IB assay was established with 231 sera from persons with allergies, unrelated viral infections, autoimmune conditions, and suspected tick-borne diseases, and 32 goat antisera for human influenza proteins. IgG and IgM COVID-19 IB assays were performed on 84 sera obtained at different times after a positive RT-qPCR test from 37 COVID-19 patients with mild symptoms. Results The criteria for determining the overall positivity of IgG and IgM antibodies using the four SARS-CoV-2 proteins were developed by optimizing specificity and sensitivity in the COVID-19 IgG and IgM IB assays. The estimated sensitivities and specificities of COVID-19 IgG and IgM IBs for IgG and IgM antibodies individually or for IgG or IgM antibodies meet US recommendations for laboratory serological diagnostic tests. The proportion of positive IgM sera from COVID-19 patients after a positive RT-qPCR test peaked at 83% before 10 days and decreased to 0% after 100 days, while the proportions of positive IgG sera tended to stabilize between days. 11 and 65 to 78-100% and drop to 44% after 100 days. Detection of IgG or IgM antibodies was better than IgG or IgM alone in assessing seroconversion in COVID-19. Both IgG and IgM antibodies detected RBD less frequently than the S1, S2 and N proteins. Conclusions Multiplex COVID-19 IB assays offer many advantages for simultaneously assessing antibody responses to different SARS-CoV-2 proteins in COVID-19 patients.
... These consisted of 20 antibody-positive sera with titers ≥1: 40 on a Lyme IFA test and positive by a Lyme immunoblot assay for Borrelia burgdorferi s.s. infection. ; eight positive sera in an IFA test for Ehrlichia chaffeensis causing human monocytic ehrlichiosis; 12 sera positive in an IFA test for Anaplasma phagocytophilum causing human granulocytic anaplasmosis, all with IgG titers of 1: 80-1: 640, including two with IgM titers of 1: 160 and 1: 640; and 20 positive sera in an IFA test for Bartonella hensalae infections consisting of 15 sera with IgG titers of 1: 160 or 1: 320 and five sera with IgM titers of 1: 20-1: 80. Details of the tests IGeneX IFA for anaplasmosis, ehrlichiosis and bartonellosis are available at www.igenex.com ...
Combined Immunofluorescence (IFA) and Fluorescence In Situ Hybridization (FISH) Assays for the Diagnosis of Babesiosis in Patients from the USA, Europe, and Australia
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Jyotsna S Shah, Eddie Caoili, Marie Fe Patton, Nehal Tamhankar
Apicomplexan parasites of the genus Babesia cause babesiosis in humans and animals throughout the world. Human babesiosis is a predominantly zoonotic disease carried by hard ticks that is of increasing health concern in the US.