Systemic and Mucosal Humoral Immune Response Induced by Three Doses of the BNT162b2 SARS-CoV-2 mRNA Vaccines.

BNT162b2 (BioNTech/Pfizer) was the first SARS-CoV-2 mRNA vaccine approved by the European Medicines Agency. We monitored the long-term humoral responses of healthcare workers (HCWs) who received three vaccine doses. A total of 59 healthcare workers were studied: 47 were never SARS-CoV-2-infected (naïve-HCWs), and 12 (infected-HCWs) recovered from COVID-19 before the first vaccine. Serum and saliva were collected at baseline (before the first dose), just before the second dose, 1, 3, 6, and 9 months after the second dose, and 10 days after the third vaccine. SARS-CoV-2-specific IgG and IgA were evaluated in serum and saliva, respectively, and the presence of neutralizing antibodies (NAb) was analyzed in serum. SARS-CoV-2-specific IgG peaked one month after the second vaccine in naïve-HCWs but right before this timepoint in infected-HCWs. IgG titers significantly decreased during follow-up and at month 9 were still detectable in 50% of naïve-HCWs and 90% of infected-HCWs. NAb were significantly decreased 6 months after the second vaccine in naïve-HCWs and 9 months after this dose in infected-HCWs. Salivary SARS-CoV-2-specific IgA titers were significantly higher in infected-HCWs and were undetectable 9 months after the second vaccine in 43% of the naïve-HCWs alone. The third vaccine greatly increased humoral IgG and mucosal IgA in both groups. Two BNT162b2 doses induced strong systemic and humoral immune responses; to note, these responses weakened over time, although they are more prolonged in individuals who had recovered from COVID-19. The third vaccine dose quickly boosts systemic and mucosal humoral responses.

Hypomagnesemia after heart transplantation or left ventricular assist device implant for end-stage heart failure.

BACKGROUND: Patients with advanced heart failure undergoing heart transplant (HTx) or left ventricular assist device (LVAD) implant are at high risk of magnesium deficiency, that may favor development of diabetes. We aimed to comparatively assess prevalence and correlates of hypomagnesemia during cardiac rehabilitation between 51 HTx and 46 LVAD recipients. METHODS AND RESULTS: We measured serum magnesium and correlated it to clinical and laboratory findings upon admission (T1 ) and at discharge (T2) from cardiac rehabilitation. Among LVAD, magnesium levels increased from admission to discharge. Among HTx, magnesium concentrations were below normal in 33% and 47% at T1 and T2 , respectively, and decreased from admission to discharge. HTx on tacrolimus showed greater decreases in magnesium and increases in glucose levels than those on cyclosporine. Magnesium levels were inversely associated with >15 mg/dL increased glucose concentrations between T2 and T1 (HR 0.373, 95% CI 0.154-0.903, P = .029) after adjustment for pre-existing diabetes, insulin resistance markers, calcineurin inhibitors (cyclosporine/tacrolimus), prednisone doses, and magnesium supplementation. CONCLUSION: Hypomagnesemia is rare in LVAD recipients, but common within 1 month from HTx, worsens during rehabilitation, despite immunosuppression tapering and magnesium supplements, and is independently associated to increasing glucose levels. Studies evaluating whether correcting hypomagnesemia improves outcome are warranted.

Monosodium Urate Crystals Activate the Inflammasome in Primary Progressive Multiple Sclerosis.

Inflammasome-driven inflammation is postulated to play a role in multiple sclerosis (MS), but there is no direct evidence that the nod-like receptor protein 3 (NLRP3) inflammasome is involved in MS pathogenesis. Uric acid was shown to be one of the "danger" signals involved in the activation of NLRP3 inflammasome; notably, the concentration of uric acid is increased in the serum and in the cerebrospinal fluid of MS individuals. To better investigate the role of the NLRP3 inflammasome in MS-associated inflammation, we primed with lipopolysaccharide and stimulated with monosodium urate crystals PBMCs of 41 MS patients with different disease phenotypes. Eleven individuals with primary progressive MS (PPMS), 10 individuals with stable relapsing-remitting MS (SMS), 10 individuals with acute relapsing-remitting MS (AMS), 10 individuals with benign MS were analyzed; 10 healthy controls were enrolled as well in the study. The expression of the NLRP3, apoptosis-associated speck-like protein containing CARD (ASC), caspase-1, caspase-8, IL-1ß, and IL-18 inflammasome genes was evaluated by RT-PCR. NLRP3 and ASC-speck protein expression was analyzed by FlowSight AMNIS, whereas production of the pro-inflammatory cytokines IL-1ß and IL-18 and of caspase-1 and caspase-8 was measured by ELISA in supernatants. Results showed that uric acid serum concentration was significantly increased in PPMS; in these and in AMS patients, mRNA for NLRP3, ASC, and IL-18 was upregulated as well, but caspase-8 mRNA was upregulated only in PPMS. Expression of NLRP3 and ASC-speck protein was significantly increased in PPMS, SMS, and AMS patients, but IL-18 and caspase-8 production was significantly increased only in PPMS, in whom a direct correlation between hyperuricemia and caspase-8 was detected. The NLRP3/caspase-8 inflammasome pathway is activated in PPMS, possibly as a consequence of hyperuricemia. Therapeutic strategies reducing NLRP3 activation and/or lowering hyperuricemia could be useful in the therapy of PPMS.