Delayed Hemolytic Transfusion Reaction in Sickle Cell Disease: A Case Series.

BACKGROUND Transfusion therapy has a well-established role in the management of several sickle cell disease (SCD)-related complications. Nevertheless, the benefits of transfusion must outweigh the possible risks, including iron overload, infections, and transfusion reactions. Alloimmunization is the underlying etiology of most delayed hemolytic transfusion reactions (DHTR). DHTR is often underestimated and underdiagnosed in sickle cell disease patients as it mimics a vaso-occlusive crisis in presentation. Alloimmunization to RBC antigens can be a serious complication of transfusion, which is of particular interest in individuals with SCD, as the occurrence rate is higher in this population. This complication represents a secondary immunological phenomenon that typically arises after the emergence of an alloantibody to which the patient had been previously sensitized to. CASE REPORT Here, we report 2 cases of delayed hemolytic transfusion reaction (DHTR) in which the patients showed evidence of alloimmunization from previous blood transfusions. The patients were managed with a variety of medications, including supportive treatments, utilization of immunosuppressive agents, and enhancement of erythropoiesis. Both patients had evidence of clinical and laboratory improvement following the management. CONCLUSIONS DHTR is considered one of the most deleterious complications of transfusion in SCD patients. The diagnosis and management of DHTR is very challenging, especially because it can present differently in this population. A high index of clinical suspicion is needed in addition to the laboratory criteria.

The Impact of Vaccination Against SARS-CoV-2 Virus on the Outcome of COVID-19 Disease.

Background: Coronavirus disease 2019 (COVID-19) is a rapidly spreading infection that is on the rise. New variants are continuously appearing with variable degrees of lethality and infectivity. The extensive work since the start of the pandemic has led to the evolution of COVID-19 vaccines with varying mechanisms. We aim to determine real-world data by looking at the different clinical outcomes associated with COVID-19 vaccination, focusing on the rate of hospitalization, severity, and mortality. Methodology: A retrospective observational study included 624 patients with COVID-19 infection who were hospitalized at King Fahad Hospital of the University and King Fahad Military Medical City between April and July 2021. The cohort was divided into 3 groups: unvaccinated, partially vaccinated (PV), and fully vaccinated (FV). The severity and outcome of COVID-19 disease were compared among the three groups. Among the vaccinated group, we studied the effect of vaccine type on the severity and outcome of COVID-19 disease. Results: We found that 70.4% of patients with COVID-19 disease who required hospitalization were unvaccinated. Un-vaccination was a significant predictor of critical COVID-19 disease (OR 2.31; P <0.001), whereas full vaccination was associated with significantly milder disease severity (OR 0.36; P 0.01). Moreover, un-vaccination status was an independent predictor of longer hospitalization (OR 3.0; P <0.001), a higher requirement for ICU admission (OR 4.7; P <0.001), mechanical ventilation (OR 3.6; P <0.001), and death (OR 4.8; P <0.001), whereas the FV group had a lower risk of ICU admission (OR 0.49; P 0.045). Unvaccinated patients with comorbidities had worse severity and outcome of COVID-19 infection (P<0.05). Both vaccine types (Pfizer and AstraZeneca) had similar protective effects against the worst outcomes of COVID-19 disease. Conclusion: COVID-19 vaccination has been shown to be effective in reducing hospitalization, the severity of COVID-19 infection, and improving outcomes, especially in high-risk group patients. COVID-19 vaccination programs should continue to improve the outcome of such a disease.