Sigma1 Receptors

At week 18, only IgG antibodies were analyzed

At week 18, only IgG antibodies were analyzed. L-asparaginase, and methotrexate. All patients were tested SARS-CoV-2 PCR-positive on April 28 or 29, 2020. Clinical characteristics are shown in Supplementary Table?1. The majority of patients demonstrated a mild course of COVID-19 with minimal symptoms. Fever was the most common symptom (14/18); anosmia was reported in K252a 4 (22%) patients. Among 12 patients with a lung CT scan performed, in 6 (50%) no lung involvement was found, in 5 (42%) and 1 (8%) lung involvement of CT grade 1 and 2, respectively, was observed (Supplementary Table?1). In total, we collected 113 residual serum specimens from these patients at different time points and detected serum IgM and IgG against the receptor binding domain (RBD) of the S protein (anti-RBD) and the nucleocapsid protein (anti-N) of SARS-CoV-2 (Fig.?1A, Supplementary Table?2) using ELISA kits developed by XEMA Company (Moscow, Russia) (see Supplementary information). In four patients, specimens obtained prior to PCR testing were available, which contained no detectable anti-SARS-CoV-2 antibodies. Seroconversion was observed in 92% patients by week 3 and in 100% patients by week 6 post-exposure (Fig.?1A, Supplementary Table?2). The seropositive rate was maintained at around 80% for at least three consecutive weeks declining to 54% by week 18 post-exposure (Fig.?1A, Supplementary Table?2). Open in a separate window Fig. 1 Dynamics and magnitude of the anti-SARS-CoV-2 antibody response in pediatric oncology patients, by week after a positive PCR test for SARS-CoV-2.A The dynamics of the anti-SARS-CoV-2 IgG and IgM antibody seroprevalence rate was examined in 133 serum specimens obtained at the indicated time points from 18 pediatric oncology K252a patients after a SARS-CoV-2 PCR-positive test. At week 18, only IgG antibodies were analyzed. The level of anti-RBD (B) and anti-N (C) IgG antibodies are depicted as median (Me) positivity indexes (PI) representing the ratio between the specimen and the internal cut-off control K252a optical density in the ELISA assay. Error bars indicate interquartile ranges (IQR). Dashed lines on (B and C) show the positivity threshold. The actual GPIIIa number of specimens analyzed by time points is given in Supplementary Table?2. Anti-RBD IgG were the most prevalent antibodies detected in 92% patients by week 6 (Fig.?1A, Supplementary Table?2). The highest seroprevalence rate for anti-N IgG was around 70C75%. The rate of anti-RBD IgM was 23C44% by weeks 3 to 4 4; IgM antibodies vanished at the end of the 9-week follow-up period. Anti-N IgM were detected in two patients (in one patient simultaneously with anti-RBD IgM). To assess the anti-SARS-CoV-2 antibody profile distribution at the specimen level, we selected virus-specific Ig-positive serum specimens, where both anti-SARS-CoV-2 IgG and IgM antibodies were measured ( em n /em ?=?85). The majority of specimens (71/85; 84%) contained anti-RBD IgG antibodies alone or in combination with anti-N IgG and/or anti-RBD IgM (Supplementary Table?3). In 8/85 (9%) specimens, exclusively anti-N IgG was present. Anti-SARS-CoV-2 IgM was detected in 15/85 (18%) virus-specific Ig-positive specimens; all IgM-positive specimens concurrently contained virus-specific IgG antibodies, except one specimen, where only anti-RBD IgM was detected (Supplementary Table?3). Next, we analyzed the magnitude of the IgG antibody response using positivity index (PI) values calculated as the ratio between the specimen and the internal cut-off control optical density, which reflected the antibody level (Fig.?1B, C). The level of anti-RBD IgG increased up to a median PI value of 3.27 (IQR 3.04) over weeks 3C4, and plateaued at a median PI value around 2.0 by week 6 persisting at that level at least until week 9. At the last flow-up time point (week 18), a median PI value declined to 0.95 (IQR.

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