Kinetics of dried blood spot-measured anti-SARS-CoV2 Spike IgG in mRNA-vaccinated healthcare workers.

Introduction: One of the major criticisms facing the research community during SARS-CoV2 pandemic was the lack of large-scale, longitudinal data on the efficacy of the SARS-CoV2 mRNA vaccines. Currently, even if COVID-19 antiviral treatments have been authorized by European Medicine Agency, prevention through approved specific vaccines is the best approach available in order to contain the ongoing pandemic. Objectives: Here, we studied the antibody kinetic over a one-year period from vaccination with the Pfizer-BioNTech (Pfizer) vaccines and subsequent boosting with either the BioNTech or Moderna (Spikevax) vaccines in a large cohort of 8,071 healthcare workers (HCW). We also described the impact of SARS-CoV2 infection on antibody kinetic over the same period. Methods: We assessed the anti SARS-CoV2 Spike IgG antibody kinetic by the high throughput dried blood spot (DBS) collection method and the GSP®/DELFIA® Anti-SARS-CoV2 IgG assay (PerkinElmer®). Results: Our data support existing models showing that SARS-CoV2 vaccination elicits strong initial antibodies responses that decline with time but are transitorily increased by administering a vaccine booster. We also showed that using heterologous vaccine/booster combinations a stronger antibody response was elicited than utilizing a booster from the same vaccine manufacturer. Furthermore, by considering the impact of SARS-CoV2 infection occurrence in proximity to the scheduled booster administration, we confirmed that booster dose did not contribute significantly to elicit higher antibody responses. Conclusion: DBS sampling in our large population of HCWs was fundamental to collect a large number of specimens and to clarify the effective mRNA vaccine-induced antibody kinetic and the role of both heterologous boosters and SARS-CoV2 infection in modulating antibody responses.

[Acro-ischemic injuries in children-adolescents during CoViD-19 pandemic: from lifestyle changes due to lockdown to interferone.] / Le lesioni acro-ischemiche nei bambini-adolescenti in tempi di CoViD-19: dal micro-ambiente da clausura all'interferone.

At the end of March 2020, just over a month after the first ascertained case of CoViD-19 infection in Italy, the first reports of acute lesions of acro-ischemia appeared, especially in pre-adolescents and adolescents. These manifestations have been called in the course of these months in various ways, from "acro-ischemia acuta", "erythema pernio", "chilblains", up to characterize them more recently as "CoViD Toes". Clinical manifestations do not usually associate with other typical symptoms of Covid-19 and do not find a classical and defined serological antibody response (IgG and IgM). From a clinical point of view it is a localized and self-resolving problem of an interesting and relatively new pathogenetic model of disease in relation to a viral agent. Future studies must make us understand if there is in this specific condition a low viral load is not detectable by current methods and if this explains the inability to produce an adequate immune response for CoViD-19. It is important to determine whether the interferon immune response in some subjects can be the cause of both the low viremia and the endothelial damage so localized in the acral-site, as happens in other models of diseases (chilblain-lupus like). On the contrary, some authors believe that the acral lesions are attributable to chilblains caused by a series of favourable environmental conditions due to forced enclosure. We report the descriptive experience of 14 cases of acro-ischemia in children and adolescents observed in the territorial area of Ravenna and Rimini. The cases were subjected to the nasopharyngeal swab and to the search for antibodies with ELISA method for CoViD-19 both with negative results.

Multicenter Evaluation of the C6 Lyme ELISA Kit for the Diagnosis of Lyme Disease.

Lyme disease (LD), caused by infection with Borrelia burgdorferi, is the most common tick-borne infection in many regions of Eurasia. Antibody detection is the most frequently used laboratory test, favoring a two-step serodiagnostic algorithm; immunoenzymatic detection of antibodies to C6 has been shown to perform similarly to a standard two-step workflow. The aim of this study was the performance evaluation of the C6 Lyme ELISA kit compared to a standard two-step algorithm in three laboratories located in the northeastern region of Italy which cater to areas with different LD epidemiology. A total of 804 samples were tested, of which 695 gave concordant results between C6 testing and routine workflow (564 negative, 131 positive). Wherever available, clinical presentation and additional laboratory tests were analyzed to solve discrepancies. The C6 based method showed a good concordance with the standard two-step algorithm (Cohen's κ = 0.619), however, the distribution of discrepancies seems to point towards a slightly lower specificity of C6 testing, which is supported by literature and could impact on patient management. The C6 ELISA, therefore, is not an ideal stand-alone test; however, if integrated into a two-step algorithm, it might play a part in achieving a sensitive, specific laboratory diagnosis of LD.

A new micro swim-up procedure for sperm preparation in ICSI treatments: preliminary microbiological testing.

OBJECTIVE: This study aimed to assess the levels of microbial contamination in semen samples before and after the micro swim-up (MSU) procedure in intra-cytoplasmic sperm injection (ICSI). The new method is an upgrade to the classic wash swim-up procedure. METHODS: Semen analysis and microbiological tests were carried out before and after the MSU procedure. A total of twenty semen samples were analyzed. RESULTS: Pathogens were observed in semen samples only before MSU and never after ICSI. Microbiological tests revealed a large prevalence of gram-positive cocci [Staphylococcus spp. (n=16, 80%) and viridans streptococci (n=10, 50%)]. The results of this study indicate that direct MSU in ICSI improved the ICSI workflow. CONCLUSION: The new workflow is faster and more affordable, and is likely to prevent infection problems that could arise from the normal microbial flora of the semen.

Comparative evaluation of two enzyme linked immunosorbent assay methods and three Western Blot methods for the diagnosis of culture-confirmed early Lyme borreliosis in Italy.

This study investigated the onset and development of the immune response to Borrelia burgdorferi infection in 30 Italian patients with culture-confirmed Lyme Borreliosis in the stage of erythema migrans (EM). All patients received antimicrobial treatment when entering the study and were prospectively evaluated monthly for up to 30 days after enrolment. A total of 60 serially collected serum samples were tested by using two different commercial enzyme-linked immunosorbent assays (ELISAs): Anti-Borrelia plus VlsE ELISA, Euroimmun, and the synthetic peptide-based ELISA, Quick ELISA C6, Immunetics. Sixty-five potentially cross-reacting sera were also tested. Anti-Borrelia plus VlsE ELISA IgG was far more sensitive than Quick ELISA C6 (56.6% and 33.3%, respectively). Moreover, considering that 17 additional sera from the first bleeding group of Lyme disease patients were IgM positive when tested by Anti-Borrelia plus VlsE IgM, the sensitivity of Anti-Borrelia plus VlsE as a whole system rose to 85.0%. Nevertheless, due to the specificity values of Anti-Borrelia plus VlsE ELISA identified in this study (98.5% for IgG and 78.5% for IgM), the need of a confirmatory test for the diagnosis of Lyme disease remains. All the sera were also tested by two different commercial Western Blot (WB) assays: Euroline-WB against Borrelia, Euroimmun, and Qualicode B. burgdorferi WB, Immunetics, in comparison with a multispecies "home made" WB. Performances of the three WB methods for the detection of IgM were very similar. On the contrary, these WBs performed with different values of sensitivity and specificity when IgGs were evaluated. The most sensitive method was the "home-made" WB IgG (71.7%), followed by the Euroline-WB IgG against Borrelia (68.3%). Qualicode B. burgdorferi WB IgG demonstrated to be only 26.6% sensitive. Both "home-made" WB IgG and Qualicode B. burgdorferi WB IgG were 100% specific, whereas Euroline-WB IgG against Borrelia scored 12 cross-reacting samples as borderline, showing a specificity value of 80.0%.

Comparative evaluation of three different ELISA methods for the diagnosis of early culture-confirmed Lyme disease in Italy.

In this study the raising and development of the immune response to Borrelia burgdorferi infection in 45 Italian patients suffering from culture-confirmed Lyme borreliosis erythema migrans was investigated. A total of 95 serially collected serum samples were tested by using three different commercial ELISAs: recomWell Borrelia (Mikrogen), Enzygnost Borreliosis (DADE Behring) and Quick ELISA C6 Borrelia (Immunetics). The sensitivities of the ELISAs were as follows: Enzygnost Borreliosis IgM, 70.5 %; Quick ELISA C6 Borrelia, 62.1 %; recomWell Borrelia IgM, 55.7 %; recomWell Borrelia IgG, 57.9 %; and Enzygnost Borreliosis IgG, 36.8 %. In order to compare the specificity values of the three ELISAs, a panel of sera obtained from blood donors (210 samples coming from a non-endemic area and 24 samples from an endemic area) was tested, as well as sera from patients suffering from some of the most common biological conditions that could result in false-positive reactivity in Lyme disease serology (n = 40). RecomWell Borrelia IgG and recomWell Borrelia IgM were the most specific (97.1 % and 98.9 %, respectively), followed by Quick ELISA C6 Borrelia (96.7 %). Enzygnost Borreliosis IgG and IgM achieved 90.1 % and 92.3 % specificity, respectively. Sera that gave discrepant results when tested by the three ELISAs were further analysed by Western blotting.