ABSTRACT
Background: Vaccination is considered the most effective preventive strategy to fight COVID-19. The aim of this study was to evaluate two critical concerns about: 1) the kinetic response of IgG and IgM, and: 2) the hematological abnormalities in a longitudinal cohort of health-care workers (HCW) who had received 2 doses of BNT162b2 mRNA-based vaccine. Method(s): Blood and nasopharyngeal swabs were collected from 46 volunteers' participants, previous written consensus, with presumable no symptoms of COVID-19. Anti-SARS-CoV-2 serum immunoglobulin G (IgG) and M (IgM) and hematological parameters were examined. Multivariable mixed-effects models for repeated measure analysis were adopted to evaluate time changes in IgG, IgM and hematological parameters, and to investigate associations with vaccination response. Result(s): Forty-six subjects (N.=46;31.8% men;68.2% women;mean age near 36 years-old) were enrolled among healthcare workers of IRCCS MultiMedica (Milan, Italy). Overall, increase in serological IgG concentration appeared mainly between 21-28 days after the 1st dose, whereas IgM did not reach positivity in all cases. Mean blood cells counts were in normal range but we observed a significant reduction of total white blood cells and absolute lymphocyte counts after the 1st dose, persisting until the day 28. The increase of monocytes and neutrophils the day after the 1st dose subsequently decayed significantly. Eosinophils concentration showed a tendency to increase over time. Peripheral blood smear showed a growing frequency of atypical lymphocytes (lympho-variants), and of plasmacytoid forms, whereas no difference was found in large granular lymphocytes (LGL), although a decay after the boost was evident. The stratification of subjects, relative to the timing of IgG increase, showed the occurrence of 3 different patterns after vaccination, namely early-responders (R+), late-responders (R-) and pauci-responders (PR) with a peculiar kinetics of hematological parameters. Lymphocytes were significantly associated with total IgG: lower in R+ and PR compared to R- (P=0.0193 and P=00054, respectively). Conclusion(s): In healthy subjects, anti SARS-CoV-2 vaccination induced a variety of non-pathologic abnormalities. The response to vaccination was not equal in the groups examined. In PR group a major difference occurred with respect to R- and R+. This work adds novel insight into the puzzle of changes induced by SARS-CoV-2 virus.Copyright © 2022 EDIZIONI MINERVA MEDICA.
ABSTRACT
The World population is facing a health challenge never seen since the Spanish influenza of one hundred years ago. During the last months, the scientific community has been debating on the potential harmful effect of Angiotensin-converting-enzyme inhibitors (ACEi) or Angiotensin II receptor Type 1 receptor blockers (AT1-Receptor blockers, ARBs) during the COVID-19 pandemic. That is because the S spike protein of SARS8 CoV viruses utilizes the angiotensin-converting enzyme 2 (ACE2) as a receptor to enter alveolar epithelial cells. Obesity, often associated to type 2 Diabetes, was shown to worsen the prognosis of SARS-CoV2 infection. Herein we discuss the complex interaction between the Renin-Angiotensin-Aldosterone System (RAAS), its receptors, and the interaction with the Kallikrein-Kinin-System (KKS) and the potential activation of the coagulation cascade. Alteration of the equilibrium between the RAAS system and the KKS cascade may explain the frequent thromboembolic complications of COVID-19 mainly seen in obese and diabetic-obese patients. In contrast, angiotensin (1-7) contributes to maintaining a correct balance between RAAS and KKS system. Our conclusion is that the higher mortality rate in patients with obesity is linked to the alteration of RAS and RAS-KKS interaction consequent to SARS-CoV2-cell entrance. At present, no data support the necessity of modifying ACEi or ARBs treatment in hypertensive patients.