Impact of disease-modifying treatments on humoral response after COVID-19 vaccination: A mirror of the response after SARS-CoV-2 infection

Objective

To analyze the humoral response after COVID-19 vaccination in patients with multiple sclerosis (MS) according to disease-modifying treatments (DMTs) and in comparison with the humoral response after SARS-CoV-2 infection.

Methods

We included 28 MS patients with serological results after COVID-19 vaccination (Pfizer-BioNTech or Moderna ARNm) and 61 MS patients with serological results after COVID-19 (COVID-19 group) among patients followed up at the MS Center of Strasbourg, France, between January and April 2021. The primary endpoint was the IgG index according to DMTs (anti-CD20 mAb, sphingosine 1-phosphate receptor [S1PR] modulator and other treatments) and COVID-19 vaccine or COVID-19 groups.

Results

In the vaccinated MS patients, the median IgG index was lower in patients treated with anti-CD20 mAb and in patients treated with S1PR modulator compared to patients receiving other or no DMTs (4.80 [1.58–28.6], 16.5 [16.3–48.5], 1116 [434–1747] and 1272 [658–1886], respectively, P < 0.001). Similar results were found for MS patients after COVID-19.

Conclusions

Patients with MS and treated with S1PR modulators or anti-CD20 mAb had a reduced humoral response after COVID-19 vaccine.

Magnetic behavior of Ni nanoparticle films produced by two laser irradiations in vacuum

Ni Nanoparticle assembled thin films were prepared using an unconventional approach based on the use of a secondary nanosecond (ns) ultraviolet (UV) laser irradiation interacting with the plume of ablated nanoparticles (NPs) during the femtosecond pulsed laser deposition (fs-PLD). The secondary laser beam determines the reduction of the NPs size and their dispersion by partial vaporization of the NPs during their flight from the target to the substrate. The proper selection of the time delay between fs and ns laser pulses allows the latter to interact selectively with different parts of the NPs plume, controlling, to a certain degree, the reduction of the NPs size and dispersion. Another original effect of the UV laser irradiation is the change in the deposited films topology, due to a reduction of the NP-aggregates density and size, fostering non-uniform dense assemblies of NPs with concentration well above the percolation threshold, with the consequent reduction of the influence of the exchange interactions on the macroscopic magnetic properties. The magnetic behavior of the films prepared using two laser beams with respect to that obtained in the case of fs-PLD only is characterized by higher H(c) values (up to approximately 70%) and a good compromise between the hysteresis loops squareness and moderate exchange interactions, strongly correlated with the NPs topology.

Stepwise behaviour of magnetization temperature dependence in iron nanoparticle assembled films

An unusual stepwise behaviour is reported in the temperature dependence of the zero field cooled magnetization in iron nanoparticle dense films produced by ultra-short pulsed laser deposition assisted by irradiation of nanoparticles with a nanosecond UV laser pulse, appropriately delayed, during their flight from the target to the substrate. This behaviour, induced by the particle system's morphology, characterized by clusters of tightly coupled nanoparticles as well as by some voids between them, is ascribed to the competition between Zeeman energy density, intracluster anisotropy energy density and intercluster exchange energy density. A phenomenological model and Monte Carlo simulations are reported, which support the proposed interpretation.

[Ethical approach to informed consent for participation in clinical studies in acute cerebral infarct]

OBJECTIVE

We sought to evaluate the application of the French law for the protection of persons participating in research studies in biology and medicine. Specifically, we examined comprehension and consequences of informed consent procedures in the field of stroke, characterized by an emergency setting, cognitive impairment and poor prognosis.

PATIENTS AND METHODS

Patients (or proxies) included in recent years in clinical studies conducted in our Neurology Department for evaluating treatment of acute phase cerebral ischemia were interviewed to determine their knowledge of the disease, its treatment, the study protocol and the legal regulations, and the affective and psychological consequences of the informed consent procedure.

RESULTS

Among 72 patients included in 7 studies ([fibrinolytic agent: 3 (n = 43), anticoagulant agent: 1 (n = 4), neuroprotective drugs (n = 25)], [7 randomized studies, 6 double-blind versus placebo, 5 with a 6-hour inclusion time interval]), 15 died during the acute phase, 5 were lost to follow-up, 4 refused to participate and 7 gave very partial answers. Consent was signed by the patient in 15% of cases, the spouse in 50%, a descendant in 23%. These persons were aware of the spontaneous risk of death (85%) or definitive functional impairment (95%). Half of them thought a specific treatment existed, 11% had some idea of the mechanism of action of the proposed treatment while 67% learned about this mechanism from the information provided. Although they had received information, only 25% of the patients had knowledge of placebo and 7% of therapeutic risk. 37% expected complete recovery from the treatment, 44% partial recovery, and 13% were very disappointed by the outcome. 81% felt they were free to make their own decision. Although 86% did not know there was a law protecting them, 82% were in agreement with the requirement for their consent while 17% would have preferred to delay consent. Most wished to be given the opportunity to discuss the study again, after the acute phase, and to receive the results of the study.

CONCLUSION

This study shows that most French stroke victims and their closest relatives are unaware of the law protecting persons in biomedical research and have poor knowledge of medical data after being given appropriate information. Even so, the quality of information increases the quality of the patient-physician relationship. Patients want to be free to make their own decision to consent to biomedical research, but their desire was more for good information than for the power to make their decision alone. Being asked to give informed consent in order to participate in a clinical study accentuates the affective and psychological consequences of stroke, a factor which should be taken into consideration during follow-up.