ABSTRACT
Vaccines having aided in escaping the majority of the population from immunological naïvety, our strategies are now shifting towards an increased focus on identifying and protecting the extremely vulnerable. We here describe the results of testing 12 patients, those with lymphoid malignancies having been targeted their B-cells for therapy with rituximab-containing regimens or a Bruton tyrosine kinase inhibitor, for anti-SARS-CoV-2 spike antibodies after receiving the BNT162b2 mRNA vaccine doses. The interval from last dosing of B-cell depletion therapy to SARS-CoV-2 vaccination was at median 5.3 (range 3.1–6.6) months. Using the ‘seroprotection' threshold of 775 [BAU/mL] for the anti-spike antibody titer, our finding points out the crucial unresponsiveness of the targeted population with 0/12 (0%) achieving ‘seroprotection'. Although IgG seroconversion was observed in 4/12 (33%), supporting the overall benefit of vaccination, the figures still point out a potential need for optimization of practice. IgA was further less responsive (unsuccessful ‘seroconversion' in 11/12 (92%)), implicating an underlying class switch defect. Those with depletion on B-cells are caught at a dilemma between, being too early and too late on receiving SARS-CoV-2 vaccines. They wish to get over their immunological naïvety at the earliest, while, in order to assure quality immune memory, are also required to hold the patience for their B-cells to repopulate. Although it remains an issue whether intensified vaccine schedules and/or regimens will lead to stronger immunogenicity or more effective boosters for non-responders, we shall take advantage of every increasing evidence in order to optimize current options. © 2022 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases
ABSTRACT
Background: Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has recently become an emerging pandemic threat worldwide The prevalence of SARS-CoV-2 infection is relatively low in Japan;3,269 confirmed cases and 984 deaths were reported as of July 16, 2020 However, prevalence of subclinical SARS-CoV-2 infection remains to be determined In addition, whether it affects the clinical course of chronic liver diseases is still unknown Materials and Methods: A total of 1,462 serum samples were collected from patients without respiratory symptoms who visited outpatient clinic of Department of Hepatology in our hospital: 600 were taken before the SARS-CoV-2 endemic (Jun-Aug 2018 and Dec 2018-Feb 2019) as controls, and 862 were taken after SARSCoV- 2 was identified (Jan-Jun 2020). Of the 862 patients (63 ± 15 years old, 388 women and 474 men), 137 (15 9%) had HBsAg and 447 (51 9%) had anti-HCV;138 (16 0%) had HCC IgM and IgG antibodies against SARS-CoV-2 were detected in serum by using the SARS-CoV-2 IgM & IgG Quantum Dot Immunoassay (Mokobio Biotechnology R & D Center Inc ) Results: The positive rates of IgM and IgG anti-SARS-CoV-2 throughout the study period are shown in Table Even before the SARS-CoV-2 endemic, IgG anti-SARS-CoV-2 values were positive in 11/600 (1 8%) patients (median 0 16, range 0 10- 1 51), but IgM anti-SARS-CoV-2 were negative in all patients After SARS-CoV-2 identified, IgG anti-SARS-CoV-2 values were positive in 6/300 (2 0%) patients (median 0 26, range 0 14-1 08), and among them, 1/6 (17%) patient was also positive for IgM anti-SARS-CoV-2 (value, 4 38) between Janand Mar 2020 Moreover, between Apr and Jun 2020, IgG anti- SARS-CoV-2 values were positive in 10/562 (1 8%) patients (median 0 27, range 0 12-4 16), and among them, 6/10 (60%) patients was also positive for IgM anti-SARS-CoV-2 (median 0 66, range 0 32-1 36) Of the 7 IgM anti-SARS-CoV-2 positive patients (70 ± 8 years old, 4 women and 3 men), 2 (29%) had HBsAg, 4 (57%) had anti-HCV, and 1 (14%) had autoimmune hepatitis (receiving prednisolone);none had HCC or other types of cancer Comorbidities included hypertension in 2 patients, diabetes in 1 and rheumatoid arthritis in 2 (including 1 receiving prednisolone). No significant worsening of liver diseases was observed in any patients Conclusion: The false positive rates of IgG anti-SARS-CoV-2 were 1 to 2%, a little higher in patients with chronic liver diseases than the reported rates The results of IgM anti-SARS-CoV-2 testing suggested that subclinical SARS-CoV-2 infection is rare in Osaka, Japan, but the prevalence is increasing over time We found no evidence that subclinical SARS-CoV-2 infection was associated with progression of chronic liver diseases.