Delayed B cell repopulation after rituximab treatment in multiple sclerosis patients with expanded adaptive natural killer cells.

BACKGROUND AND PURPOSE: The aim was to evaluate whether adaptive NKG2C+ natural killer (NK) cells, characterized by enhanced antibody-dependent cell cytotoxicity (ADCC), may influence time to B cell repopulation after rituximab treatment in multiple sclerosis (MS) patients. METHODS: This was a prospective observational study of MS patients treated with rituximab monitoring peripheral B cells for repeated doses. B cell repopulation was defined as CD19+ cells above 2% of total lymphocytes, classifying cases according to the median time of B cell repopulation as early or late (≤9 months, >9 months, respectively). Basal NK cell immunophenotype and in vitro ADCC responses induced by rituximab were assessed by flow cytometry. RESULTS: B cell repopulation in 38 patients (24 relapsing-remitting MS [RRMS]; 14 progressive MS) was classified as early (≤9 months, n = 19) or late (>9 months, n = 19). RRMS patients with late B cell repopulation had higher proportions of NKG2C+ NK cells compared to those with early repopulation (24.7% ± 16.2% vs. 11.3% ± 10.4%, p < 0.05), and a direct correlation between time to B cell repopulation and percentage of NKG2C+ NK cells (R 0.45, p < 0.05) was observed. RRMS cases with late repopulation compared with early repopulation had a higher secretion of tumor necrosis factor α and interferon γ by NK cells after rituximab-dependent NK cell activation. The NK cell immunophenotype appeared unrelated to B cell repopulation in progressive MS patients. CONCLUSIONS: Adaptive NKG2C+ NK cells in RRMS may be associated with delayed B cell repopulation after rituximab, a finding probably related to enhanced depletion of B cells exerted by NK-cell-mediated ADCC, pointing to the use of personalized regimens with anti-CD20 monoclonal antibody therapy in some patients.

Misdiagnosis Worsens Prognosis in Subarachnoid Hemorrhage With Good Hunt and Hess Score.

Background and Purpose- Our aim was to describe variables associated with initial misdiagnosis of subarachnoid hemorrhage (SAH). We also analyzed the relationship of misdiagnosis with poor outcome and complications in good Hunt and Hess (HH) cases. Methods- In a prospective cohort of 401 patients with SAH, misdiagnosis was defined as failure to correctly identify, at first physician contact, a subsequently documented SAH; this meant no urgent radiological study and lumbar puncture was performed. Poor outcome was defined as modified Rankin Scale score 3 to 6 at 3-month follow-up. We recorded age, sex, hypertension, diabetes mellitus, current smoking, previous antithrombotic treatment, initial HH and radiological severity, presence of aneurysm, first therapeutic procedure, hydrocephalus, delayed cerebral ischemia (DCI), rebleeding, and procedure-related complications. Results- Misdiagnosis was confirmed in 104/401 (25.9%) patients, who also had a longer time-to-admission to hospital. Misdiagnosis was associated with less clinical and radiological severity, compared with a correct diagnosis; the 2 groups did not differ in age or cardiovascular risk factor profile. Poor outcome was registered in 167/401 patients (41.6%). Age, misdiagnosis, and greater clinical and radiological initial severity were independent predictors of poor outcome. In the 236 patients (58.8% of cohort) with HH 1-2, misdiagnosis was associated with poor outcome in univariate and multivariate analysis, respectively (odds ratio=3.89; 95% CI, 1.89-8.01). Delayed cerebral ischemia (odds ratio=2.47; 95% CI, 1.2-5.09) and procedure-related complications (odds ratio=2.27; 95% CI, 1.07-4.82) were independently associated with misdiagnosis. Conclusions- Misdiagnosis is an unresolved problem in SAH, and it is a missed opportunity for good outcome in patients with HH 1-2. The poor outcome is partially explained by a higher risk of delayed cerebral ischemia and procedure-related complications in misdiagnosed patients. There is a need to improve the diagnostic strategy in patients reporting only a headache (HH 1-2) after SAH.

Is There Less Alteration of Smell Sensation in Patients With Omicron SARS-CoV-2 Variant Infection?

The ongoing pandemic Coronavirus Disease 2019 (COVID-19) caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a matter of global concern in terms of public health Within the symptoms secondary to SARS-CoV-2 infection, hyposmia and anosmia have emerged as characteristic symptoms during the onset of the pandemic. Although many researchers have investigated the etiopathogenesis of this phenomenon, the main cause is not clear. The appearance of the new variant of concern Omicron has meant a breakthrough in the chronology of this pandemic, presenting greater transmissibility and less severity, according to the first reports. We have been impressed by the decrease in anosmia reported with this new variant and in patients reinfected or who had received vaccination before becoming infected. Based on the literature published to date, this review proposes different hypotheses to explain this possible lesser affectation of smell. On the one hand, modifications in the SARS-CoV-2 spike protein could produce changes in cell tropism and interaction with proteins that promote virus uptake (ACE-2, TMPRSS2, and TMEM16F). These proteins can be found in the sustentacular cells and glandular cells of the olfactory epithelium. Second, due to the characteristics of the virus or previous immunity (infection or vaccination), there could be less systemic or local inflammation that would generate less cell damage in the olfactory epithelium and/or in the central nervous system.

Neuromuscular Diseases Care in the Era of COVID-19.

The COVID-19 pandemic has pushed health systems to their limit and forced readjustment of standards of care for different pathologies. Management of neuromuscular diseases becomes a challenge since most of them are chronic, disabling, progressive, and/or require immunosuppressive drugs. There are three main aspects of COVID-19 that affect neuromuscular diseases care. The first one relates to how SARS-CoV2 directly affects different neuromuscular pathologies. Respiratory weakness, as seen in myasthenia gravis, amyotrophic lateral sclerosis, and myopathies, and the use of immunomodulatory drugs (Myasthenia Gravis and Chronic Inflammatory Demyelinating Polyneuropathy) make this group of patients potentially more vulnerable. Secondly, safety measures also affect proper care, limiting care continuity, and physical rehabilitation (one of the essential aspects of myopathies treatment). Telemedicine can partially solve the problem allowing for a continuum of close care, avoiding unnecessary visits, and even guaranteeing the attention of professionals from tertiary care centers. However, one of the crucial steps in neuromuscular diseases is diagnosis, and in most scenarios, more than one face-to-face visit is needed. Lastly, the global COVID-19 situation will also have an economic impact on patients and their families. This situation is of particular concern given that neuromuscular diseases already present difficulties due to the scarcity of resources in terms of public healthcare and research.