ABSTRACT
Introduction A subgroup of anti-platelet factor 4 (PF4) antibodies can activate platelets via Fcgamma RIIA and cause thrombotic and thrombocytopenic diseases such as heparin-induced thrombocytopenia and vaccine-induced immune thrombotic thrombocytopenia (VITT). Nonpathological anti-PF4 antibodies are detected in 1-7 % of healthy blood donors and in 2-8 % of SARS-CoV-2 vaccinated individuals. In this study, we investigated the long-term course of anti- PF4 antibodies detected after the first SARS-CoV-2 vaccination in healthy subjects and in patients with VITT. Method Five healthy subjects (all female, median age (range): 40 years (29-62) ) who had anti-PF4 antibodies after the first vaccination with ChadOx1 nCov19 (Vaxzevria, AstraZeneca-Oxford) were included. None of the subjects developed VITT. Blood samples were collected as part of a longitudinal study (TuSeRe:exact) evaluating the immune response to SARS-CoV-2 vaccines among employees of an University Hospital. In addition, data from 4 patients with VITT (3 female, median age (range): 44 years (22 -62 years)) were included for long-term follow-up of anti-PF4 antibodies. Anti-PF4/heparin antibodies were measured using a commercially available ELISA assay (Zymutest HIA IgG, Hyphen BioMed, France). Platelet activation was tested with a modified heparin- induced platelet aggregation assay (HIPA). Results In the non-VITT group, the median (range) OD for IgG anti-PF4/heparin antibodies was 0.69 (0.60-1.83) after the first vaccination. Blood samples were available up to 16 months after the first vaccination (range: 5-16 months). Anti-PF4 antibody levels decreased in all subjects despite further vaccination. However, antibody levels returned to pre-vaccination levels in only one subject. In one subject who had received two doses of ChadOx1 nCov19, anti-PF4 antibodies remained above OD 1.0 at the last follow-up. All samples were negative in the modified HIPA assay. Patients with VITT received mRNA-based vaccine as second vaccination against SARS CoV2. No significant drop in platelet count or new thromboembolic complication was observed. Conclusion Nonpathological anti-PF4 antibodies can be detected even several months after the first vaccination. The clinical significance of these antibodies in case of subsequent exposure to a vector vaccine or heparin is not yet clear. Furthermore, subsequent vaccination seems safe in VITT patietns.
ABSTRACT
Background: Vaccine induced thrombotic thrombocytopenia (VITT) is a rare but severe complication following vaccination with ChAdOx1 nCoV-19. Antibodies directed against platelet factor 4 (PF4) are thought to be responsible for platelet activation and subsequent thromboembolic events in these patients. Because of the similarities between heparin-induced thrombocytopenia (HIT) and VITT heparin was avoided but the risk of thrombosis in VITT upon heparin administration remains unclear. Aim(s): To assess the impact of heparin used as initial anticoagulants to treat VITT. Method(s): We prospectively analyzed follow up data from 4 patients with confirmed VITT patients (3 women and 1 men;median age, 44 years [range, 22-62 years]). ELISA and functional VITT testing was performed at each time point. Result(s): The patients' clinical symptoms started between days 4 and 17 after first vaccination with ChAdOx1 nCoV-19. All patients presented with thrombocytopenia and thromboembolic events (amaurosis fugax and peripheral thrombosis and venous sinus thrombosis). The follow-up duration ranged between 8 weeks and 9 months. No additional thromboembolic event or disease progression occured in any patient. A recovery in platelet count was monitored in all four patients within 10 days after starting treatment (heparin or alternative anticoagulation combined with IVIG). In both patients who were treated with heparin, anti-PF4 antibodies were not detectable after 3 and 19 weeks respectively. All 4 patients received mRNA-based vaccine as second vaccination against SARS CoV2. No significant drop in platelet count or new thromboembolic complication was observed. Conclusion(s): In the treatment of VITT, early beginning of anticoagulation with close follow-up of the platelet count and thrombosis signs seem to be more important than the choice of anticoagulant. Subsequent vaccination with an mRNA vaccine appears to be safe in VITT patients.
ABSTRACT
COVID-19 pandemic affected the mental health of the global population. Among the most vulnerable are the healthcare workers (HCWs) who got infected but returned to the frontline after recovery. Currently, there is a dearth of information and understanding on the psychological status and actual lived experience of the recovered HCWs in the Philippines. The present study investigated the psychological status and experiences of 93 COVID-19-recovered HCWs from a tertiary hospital in the Philippines using a mixed-method approach, particularly the explanatory-sequential design. Participants completed the Impact of Event Scale-Revised, and the Depression, Anxiety, and Stress Scale-21 in the quantitative phase. Selected participants took part in focus group discussions in the qualitative phase. Integrated results showed that our participants experienced significant COVID-19-related distress (mean IES-R score = 25.5; partial impact), anxiety (mean subscale score = 7.4; mild), and depression (mean subscale score = 8.1; mild). Certain sociodemographic and professional characteristics and the length of quarantine days appear to affect the psychometric scores. The quantitative results are supported by the participant's description of recovery experiences as living in uncertainty, distress, fatigue, dissociation, and valuation of life. In summary, adequate psychological support and intervention program should be prioritized and provided by hospital management for recovered HCWs to prevent the development of more serious mental health concerns that may significantly affect their tasks in caring for patients and in-hospital management.