RESUMO
Although sickle cell disease (SCD) patients carry both significant left atrial (LA) remodeling and increased risk of stroke, the prevalence of atrial arrhythmia (AA) has never been prospectively evaluated. This study aims to investigate the prevalence and predictors of atrial arrhythmia in homozygous SCD (SCA). From 2019 to 2022, 130 patients with SCA were referred to the physiology department to specifically analyze cardiac function and prospectively included in the DREPACOEUR registry. They underwent a 24-hour electrocardiogram monitoring (24h-Holter), transthoracic echocardiography, and laboratory tests on the same day. The primary endpoint was the occurrence of AA, defined by the presence of excessive supraventricular ectopic activity (ESVEA) on ECG-Holter (i.e., >720 premature atrial contractions [PACs] or any run ≥ 20 PACs), recent history of paroxysmal atrial fibrillation (AF), or persistent AF. The mean patient age was 45±12 years and 48% of male. Overall, AA was found in 34 (26%) patients. Age (52±9 vs. 42±12 years, P=0.002), LA dilation (LAVi, 71±24 vs. 52±14 ml/m², P<0.001) and history of stroke without underlying cerebral vasculopathy or other defined cause (26% vs. 5%, P=0.009, OR=6.6 [1.4; 30.3]) were independently associated with AA. Age and LAVi correlated with PAC load per 24 hours on ECG-Holter (R=0.56 and 0.33, P<0.001 respectively) and an age over 47 years or a LAVi >55mL/m² could predict AA with a PPV of 33% and a NPV of 92%. AAs are frequent in SCA patients and increase with age and LA remodeling, leading to a major additional risk factor for ischemic stroke. This study provides arguments and means to early screen for AA potentially preventing cerebral complications.
RESUMO
Immunotherapy, particularly CAR-T therapy has recently emerged as an innovator for cancer treatment. Gamma-irradiated K562 cells is a common and effective method to stimulated CAR-T cells prior to treatment. However, high cost and limited equipment of gamma-irradiation is drawback of this method. This requires the establishment of CAR-T-expanding alternatives, such as X-ray-irradiated K562 cells. X-ray irradiation was used to deactivate K562 cells. The post-irradiative cell survival was investigated by counting of the number of cells, staining with Trypan Blue and PI. FACS analysis was applied to detect the expression of cell surface markers. The production of CD19-CAR-T cells were executed from fresh blood donor by CD19-CAR-plasmid transfection, followed by the stimulation with X-ray-irradiated K562 feeder cells. The function of produced CAR-T cells was checked by their ability to kill Daudi cells. X-ray-irradiation inhibited the propagation and viability of K562 cells in a dose- and time-dependent manner. Interestingly, CAR-T-stimulating effectors were remained on the surface of X-ray-irradiated K562 cells. CD-19-CAR-T cells were produced successfully, suggested by number of CAR-positive cells in transfected and stimulated population, compared to un-transfected group. Lastly, our data showed that engineered CAR-T cells effectively killed Daudi cells. Our data demonstrated the efficacy of X-ray on deactivation K562 feeder cells which subsequently stimulated and expanded functional CAR-T cells. Thus, X-ray can be used as an alternative to inactivate K562 cells prior to using as a feeder of CAR-T cells.