Head-to-Head Comparison of Tissue Factor-Dependent Procoagulant Potential of Small and Large Extracellular Vesicles in Healthy Subjects and in Patients with SARS-CoV-2 Infection.

The relative contribution of small (sEVs) and large extracellular vesicles (lEVs) to the total plasma procoagulant potential is not yet well defined. Thus, we compared total and TFpos-sEVs and -lEVs isolated from healthy subjects and COVID-19 patients during the acute phase of the infection and after symptom remission in terms of (1) vesicle enumeration using nanoparticle tracking assay, imaging flow cytometry, and TF immunofluorescence localization in a single-vesicle analysis using microarrays; (2) cellular origin; and (3) TF-dependent Xa generation capacity, as well as assessing the contribution of the TF inhibitor, TFPI. In healthy subjects, the plasma concentration of CD9/CD63/CD81pos sEVs was 30 times greater than that of calceinpos lEVs, and both were mainly released by platelets. Compared to lEVs, the levels of TFpos-sEVs were 2-fold higher. The TF-dependent Xa generation capacity of lEVs was three times greater than that of sEVs, with the latter being hindered by TFPI. Compared to HSs, the amounts of total and TFpos-sEVs and -lEVs were significantly greater in acute COVID-19 patients, which reverted to the physiological values at the 6-month follow-up. Interestingly, the FXa generation of lEVs only significantly increased during acute infection, with that of sEV being similar to that of HSs. Thus, in both healthy subjects and COVID-19 patients, the TF-dependent procoagulant potential is mostly sustained by large vesicles.

Time of Onset and Risk Factors of Renal Involvement in Children with Henoch-Schönlein Purpura: Retrospective Study.

BACKGROUND: Henoch-Schönlein purpura (HSP) is a common systemic vasculitis in children, involving the skin, musculoskeletal system, gastrointestinal tract and kidneys. Some studies in children have shown possible risk factors linked with the development and severity of HSP Nephritis (HSPN). The aim of this study was to research predicting factors for the development of HSPN. METHODS: We retrospectively evaluated 132 pediatric patients with HSP, according to EULAR/PRINTO/PRESS criteria. All patients were screened for HSPN by urinalysis. Finally, we compared demographic, clinical and laboratory data in HSP patients with and without nephritis. RESULTS: The median age at HSP diagnosis [6.2 (2.6-17.5) vs. 5.5 (0.8-15.4) years, p = 0.03] and the incidence of abdominal pain (48 vs. 27%, p = 0.01) were significantly higher in HSPN patients. No differences were evidenced regarding gender, allergic diseases, skin recurrences, gastrointestinal involvement, musculoskeletal involvement, scrotal involvement, and laboratory data (white blood cell count, neutrophil count, lymphocyte count, platelet count, C-reactive protein, erythrocyte sedimentation rate, and blood concentration of IgA). CONCLUSIONS: The age at diagnosis and abdominal pain were independent risk factors for renal involvement in HSP patients. However, due to the retrospective nature of this study, further long-term and prospective studies will be necessary.

Negative effect of lockdown on juvenile idiopathic arthritis patients.

INTRODUCTION: The aim of this study is to evaluate a possible negative action of lockdown, during the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic, in the follow-up of juvenile idiopathic arthritis (JIA) patients. METHODS: We compared the number of JIA reactivations in the period March-July 2020 to the same months of 2018 and 2019. RESULTS: A total of 10 JIA reactivations have been documented on 58 patients (17%) visited in the period March-July 2018; 10 reactivations on 61 patients (16%) in the period March-July 2019; and 19 reactivations on 39 patients (49%) in the period March-July 2020, with a statistically significant increase (p <0.001). The other 19 patients who should have been visited during the same period, contacted by phone, indicated remission. Therefore, we hypothesize that the effective number of reactivations in the period March-July 2020 would be 19/58 patients (33%) which remains significantly greater than in the previous 2 years (p < 0.05). Among the 19 JIA patients reactivated in 2020, 3 spontaneously stopped the basic treatment due to parents' choice for fear of serious complications in case of SARS-CoV-2 infection and 4 had poor compliance with underlying treatment. In addition, 14/19 reactivated JIA patients did not perform the scheduled check according to the follow-up. In fact, the mean time interval between two follow-up visits was significantly greater in 2020 (157 ± 53 days, p < 0.0001) vs 2018 (108 ± 68 days) and 2019 (107 ± 40 days). CONCLUSIONS: We have found a significant increase in JIA reactivations in the period March-July 2020 compared to the same interval of 2018 and 2019. This increase may have been caused by poor compliance with background treatment, as documented in 7/19 JIA patients reactivated, and by a greater interval in follow-up checks. Therefore, it is necessary, in occasion of a new pandemic and lockdown, to implement greater controls using more appropriate telemedicine tools. Key Points • COVID-19 pandemic lockdown had a negative effect on the follow-up of JIA patients. • A significant increase in JIA reactivations was found during the lockdown. • Poor therapeutic compliance and follow-up checks have been proven during the lockdown. • It is necessary to improve telemedicine tools and scientific information during a pandemic and lockdown.

Bifid T waves in leads V2 and V3 in children: a normal variant.

INTRODUCTION: The T wave is rarely bifid, apart from patients with long QT syndrome or subjects treated with antiarrhythmic drugs. At times, a U wave partially superimposed upon the T wave is responsible for an apparently bifid T wave. Bifid T waves, in contrast, have been described in normal children in the past, but the phenomenon has not received any attention in recent years, to the extent that it is not mentioned in current textbooks of paediatric cardiology. Aim of the present study was to determine the incidence and clinical counterpart of bifid T waves in a paediatric population. METHODS: We selected 604 consecutive children free from clinically detectable heart disease; subjects whose electrocardiogram showed a bifid T wave underwent a complete clinical and echocardiographic examination. In addition, the electrocardiograms of 110 consecutive adults have also been analyzed. A T wave was considered as bifid whenever it was notched, being the 2 peaks separated from each other by a notch with duration >/= 0.02 sec and voltage >/= 0.05 mV. Moreover, in 7 children with bifid T wave in lead V2 further precordial recordings were obtained: a small electrode was gradually moved from V1 to V3, and 4 additional leads were recorded: 2 between V1 an V2, and 2 between V2 and V3. RESULTS: A bifid T wave was observed in 110 children (18,3%), with a relatively age-related incidence; the highest rate of bifid T waves (53%) occurred in the group of 5-year-old children. The bifid T wave was detected only in lead V2 in 51 cases (46,4%), only in lead V3 in 5 cases (4,6%), in both leads V2 and V3 in 50 cases (45,4%), and in leads other than V2 and V3 in 4 cases (3,6%). In the adult group, none of the examined electrocardiograms showed bifid T waves in any lead.In the bifid T wave paediatric population, the echocardiogram did not reveal any abnormality, apart from 3 subjects which had an asymptomatic mitral valve prolapse; a trivial mitral and/or tricuspid regurgitation detected by color Doppler, as well as a patent foramen ovale in infants, were not considered as abnormal findings. The QTc interval was normal in all of the subjects; the average QTc interval was not different in the bifid T wave population (402 +/- 46 msec) with respect to the control group (407 +/- 39 msec). CONCLUSION: The incidence of bifid T waves in leads V2 and V3 in normal children is high, and awareness of this phenomenon avoids possible misinterpretations leading to a diagnosis of ECG abnormalities.