ABSTRACT
BACKGROUND: Neutralizing antibodies (NAbs) against SARS-CoV-2 infection have a pivotal role in protective immune response; however, their measurement requires specialized facilities. We evaluated the degree of correlation between NAbs and anti-SARS-CoV-2 IgG/total Ig antibodies detected by chemiluminescent immunoassay in asymptomatic and previously symptomatic SARS-CoV-2 patients. METHODS: A total of 1241 participants (previously symptomatic patients and asymptomatic individuals), who were screened for SARS-CoV-2 infection by RT-PCR or serology, were enrolled in our study. Sera were analyzed for the presence of anti-spike-1(S1)-SARS-CoV-2 IgG/total Ig antibodies, using Ortho Clinical Diagnostics, USA. A signal/cut-off value (S/CO) ≥ 1 was considered reactive. NAbs were measured in 103 random samples from groups using microneutralization assay, with titer ≥ 1:10 being considered positive. RESULTS: Asymptomatic (n = 229) and 261 previously symptomatic individuals with positive serology and negative RT-PCR were finally included. Significant higher anti-S1-IgG titers were seen in asymptomatic individuals (P < 0.0001). Conversely, anti-S1-total Ig titers were significantly higher in previously symptomatic (P < 0.0001). NAbs were detected in both groups, however, higher titers were seen in previously symptomatic patients. There is a correlation between NAbs and both IgG/total anti-S1-SARS-CoV-2 antibodies (r = 0.47, P < 0.0001 and r = 0.49, P < 0.0001, respectively). IgG and total Ig could predict a neutralization titer of ≥ 1:160 at S/CO >4.44 and >65 with AUC 0.69 and 0.67, respectively. CONCLUSION: Asymptomatic SARS-CoV-2 infection can produce comparable antibodies response to previously symptomatic individuals, however higher neutralization activity was seen in the previously symptomatic. Anti-S1-SARS-CoV-2 IgG/total Ig antibodies showed a correlation with neutralization activity and can be used to estimate the presence of protective immunity.
Subject(s)
COVID-19 , SARS-CoV-2 , Antibodies, Neutralizing , Antibodies, Viral , COVID-19/diagnosis , Humans , Immunoassay , Immunoglobulin G , LuminescenceABSTRACT
Diagnosis of a patient with aseptic meningitis may be so-difficult because of the large vanety of potential etiologic agents as viruses, fungi, parasites and some drugs and the overlap between self-limited viral illnesses and potentially fatal bact~nial infections.
Subject(s)
Meningitis, Aseptic/etiology , Zoonoses , Animals , Diagnosis, Differential , HIV Infections/diagnosis , Helminthiasis/complications , Humans , Lyme Disease/complications , Meningitis, Aseptic/chemically induced , Meningitis, Aseptic/microbiology , Meningitis, Aseptic/parasitology , Meningitis, Bacterial/diagnosis , Meningitis, Viral/diagnosis , Mumps/complications , Mycoses/complications , Protozoan Infections/complications , Syphilis/complications , Tick-Borne Diseases/complications , Zoonoses/parasitologyABSTRACT
The Hymenoptera are the third largest order of insects, comprising the sawflies, wasps, bees and ants. Worldwide, over 150,000 species are recognized, with many more remaining to be described. The name refers to the wings of the insects, but the original derivation is ambiguous. The Ancient Greek υµÎ·ν (hymen) for membrane provides a pLusible etymology for the term because these insects have membranous wings. However, a key characteristic of this order is that the hind wings are connected to the fore wings by a series of hooks called hamuli. Thus, another plausible etymology involves, Hymen, the Ancient Greek god of marriage, as these insects have "married wings" in flight. Stinging insects and the medical risk associated with their venoms are complex topics, and presentation of information pertaining to them requires the use of technical terms. The most common reactions to these stings are transient pain and redness at the site lasting a few hours (local reaction), and exaggerated swelling lasting a few days (large local reaction). The most dangerous immediate reaction is anaphylaxis, which is potentially fatal.
