Ahlem Ben Hmid

Background/Objectives: Schizophrenia (SZ) is a complex psychiatric disorder with increasing evidence pointing to an autoimmune component, including the presence of antiphospholipid antibodies (aPLs). This study aims to assess the prevalence of anticardiolipin (aCL) and anti-beta-2 glycoprotein I (aβ2GPI) antibodies, particularly the IgG, IgA, and IgM isotypes, in drug-free SZ patients compared to healthy controls, and explore their possible involvement in the disease’s pathophysiology. Methods: Eighty SZ patients meeting DSM-IV criteria were recruited, along with 80 matched healthy controls. Serum samples were analyzed using enzyme-linked immunosorbent assays (ELISA) to quantify IgG, IgA, and IgM isotypes of aCL and aβ2GPI. Results: SZ patients exhibited significantly higher levels of aCL-IgM and aCL-IgA (p < 0.05), as well as elevated aβ2GPI-IgA (22.5%, p < 0.001), compared to controls. No significant differences were observed in the aCL-IgG isotype. Interestingly, 72% of aPL-positive SZ patients were positive for aβ2GPI-IgA, with some also co-expressing multiple isotypes, suggesting a potential link between SZ and antiphospholipid syndrome (APS). Conclusions: This study is the first to report a high prevalence of aCL-IgA and aβ2GPI-IgA in SZ patients, highlighting a possible autoimmune involvement in the disease. The presence of multiple aPL isotypes, particularly IgA, suggests a need for further investigation into their role in SZ pathogenesis and their potential association with APS.

Background: Allogeneic hematopoietic stem cell transplantation (ASCT) induces acquired immunodeficiency, potentially altering vaccine response. Herein, we aimed to explore the clinical tolerance and the humoral and cellular immune responses following anti-SARS-CoV-2 vaccination in ASCT recipients. Methods: A prospective, non-randomized, controlled study that involved 43 ASCT subjects and 31 healthy controls. Humoral response was investigated using the Elecsys^® test anti-SARS-CoV-2. Cellular response was assessed using the QFN^® SARS-CoV-2 test. The lymphocyte cytokine profile was tested using the LEGENDplex™ HU Th Cytokine Panel Kit (12-plex). Results: Adverse effects (AE) were observed in 69% of patients, encompassing pain at the injection site, fever, asthenia, or headaches. Controls presented more side effects like pain in the injection site and asthenia with no difference in the overall AE frequency. Both groups exhibited robust humoral and cellular responses. Only the vaccine transplant delay impacted the humoral response alongside a previous SARS-CoV-2 infection. Noteworthily, controls displayed a Th1 cytokine profile, while patients showed a mixed Th1/Th2 profile. Conclusions: Pfizer-BioNTech^® anti-SARS-CoV-2 vaccination is well tolerated in ASCT patients, inducing robust humoral and cellular responses. Further exploration is warranted to understand the impact of a mixed cytokine profile in ASCT patients.

(1) Background: This study aimed to compare the immunogenicity of the mix-and-match CoronaVac/BNT162b2 vaccination to the homologous CoronaVac/CoronaVac regimen. (2) Methods: We conducted a simple-blinded randomized superiority trial to measure SARS-CoV-2 neutralization antibodies and anti-spike receptor binding domain (RBD) IgG concentrations in blood samples of participants who had received the first dose of CoronaVac vaccine followed by a dose of BNT162b2 or CoronaVac vaccine. The primary endpoint for immunogenicity was the serum-neutralizing antibody level with a percentage of inhibition at 90% at 21–35 days after the boost. A difference of 25% between groups was considered clinically relevant. (3) Results: Among the 240 eligible participants, the primary endpoint data were available for 100 participants randomly allocated to the mix-and-match group versus 99 participants randomly allocated to the homologous dose group. The mix-and-match regimen elicited significantly higher levels of neutralizing antibodies (median level of 96%, interquartile range (IQR) (95–97) versus median level of 94%, IQR (81–96) and anti-spike IgG antibodies (median level of 13,460, IQR (2557–29,930) versus median level of 1190, IQR (347–4964) compared to the homologous group. Accordingly, the percentage of subjects with a percentage of neutralizing antibodies > 90% was significantly higher in the mix-and-match group (90.0%) versus the homologous (60.6%). Interestingly, no severe events were reported within 30 days after the second dose of vaccination in both groups. (4) Conclusions: Our data showed the superiority of the mix-and-match CoronaVac/BNT162b2 vaccination compared to the CoronaVac/CoronaVac regimen in terms of immunogenicity, thus constituting a proof-of-concept study supporting the use of inactivated vaccines in a mix-and-match strategy while ensuring good immunogenicity and safety.