Acute chest syndrome in sickle cell disease due to the new influenza A (H1N1) virus infection

Sickle cell disease: healthcare professionals' views of patients in the emergency department

Most patients with sickle cell disease (SCD) need support from healthcare services to manage their condition, including painful vaso-occlusive crises. Vaso-occlusive crises should be treated as a medical emergency, but the quality of the care patients receive when they present to the emergency department (ED) is often suboptimal. This article reports the findings of a literature review on the views of ED nurses and doctors about patients with SCD. The review included four studies, all of which had been conducted in the US, demonstrating that research on the topic is limited. The review found mostly negative views, including the belief that patients misuse pain medicines and demonstrate drug-seeking behaviours. Racial bias, widely recognised as a negative influence on the care of patients with SCD, was not mentioned in any of the studies. Staff education regarding SCD is required to ensure patients receive the care they need when they present to the ED.

Case Fatality Rate and Severity of COVID-19 among Patients with Sickle Cell Disease: A Systematic Review and Meta-Analysis

The sickle cell disease (SCD) population has been considered particularly vulnerable to viral pandemics since the emergence of H1N1 in 2009. In this sense, the advance of the COVID-19 pandemic from 2020 has brought this group of patients to the center of concern. However, scientific knowledge about the susceptibility of patients with SCD to a severe COVID-19 pandemic is still insufficient, and efforts to establish a general profile of the disease in these patients, remain inadequate. The present study, therefore, sought to characterize the case fatality rate and severity of COVID-19 in patients with SCD throughout the world. A systematic review of Pubmed/MEDLINE, Scopus, Cochrane Library, and Virtual Health Library databases through December 2021 was then performed. Subsequently, the primary and secondary outcomes were used in the meta-analysis in RStudio® software. Seventy-two studies were included with 6,011 SCD patients confirmed to have SARS-CoV-2 infection between mid-2020 and early 2022. The mean age of patients was 27 years. During this period, 218 deaths caused by COVID-19 were reported in the studied population, corresponding to an overall case fatality rate of 3%. In addition, 10% of patients with SCD were admitted to the ICU after complications caused by COVID-19, and 4% of them required invasive ventilatory support. In conclusion, the high fatality rate, intensive care unit admission and need for mechanical ventilation due to COVID-19 in young patients with SCD indicate that this population is at high risk for severe disease progression.

Clinical predictors of poor outcomes in patients with sickle cell disease and COVID-19 infection

SCD patients with COVID-19 display a broad range of severity, with a higher case fatality than the non-SCD population (10.9% vs 3.3%).

Older patients not treated with hydroxyurea with end organ damage who present with acute kidney injury, and elevated LDH and D-dimer level are at higher risk of death.

We aimed to identify predictors of outcomes and survival in patients living in 4 major metropolitan areas who had sickle cell disease (SCD) and COVID-19 to inform best approaches to prevention and care. Data were collected at baseline and during the clinical course in SCD patients diagnosed with COVID-19 in four COVID-19 epicenters. Patients were followed up posthospital discharge for up to 3 months. Of sixty-six SCD patients with COVID-19, fifty patients (75%) required hospitalization, and seven died (10.6%). Patients with preexisting kidney disease (chronic kidney disease) were more likely to be hospitalized. The most common presenting symptom was vaso-occlusive pain. Acute chest syndrome occurred in 30 (60%) of the 50 hospitalized patients and in all who died. Older age and histories of pulmonary hypertension, congestive heart failure, chronic kidney disease, and stroke were more prevalent in patients who died, as were higher creatinine, lactate dehydrogenase, and D-dimer levels. Anticoagulation use while inpatient was twice less common in patients who died. All deaths occurred in individuals not taking hydroxyurea or any other SCD-modifying therapy. Patients with SCD and COVID-19 exhibited a broad range of disease severity. We cannot definitively state that the overall mortality is higher in patients with SCD, although our case fatality rate was ∼10% compared with ∼3% in the general population, despite a median age of 34 years. Individuals with SCD aged >50 years, with preexisting cardiopulmonary, renal disease, and/or stroke not receiving hydroxyurea, who present with high serum creatinine, lactate dehydrogenase, and D-dimer levels, are at higher risk of death, irrespective of genotype or sex.

Respiratory pathogens and acute chest syndrome in children with sickle cell disease

BACKGROUND

Acute chest syndromes (ACS) may be associated with upper respiratory tract infections, but the epidemiology of viral and intracellular respiratory pathogens in children with sickle cell disease (SCD) is not precisely known. The aim of this study was to describe the epidemiology of viral and intracellular respiratory pathogens in children with SCD presenting with fever and/or ACS.

MATERIALS AND METHODS

An observational, prospective, single-centre cohort study with nested case-control analysis was conducted on children with SCD admitted from October 2016 to October 2017 for fever and/or ACS to the paediatric department of Robert Debré university hospital, Paris, France. They were screened for 20 respiratory pathogens by a multiplex PCR in the nasopharynx (FilmArray).

RESULTS

We included 101 children. M/F sex ratio of 0.45. The median age was 3.2 years (IQR: 1.4-8.2). At least one pathogen was isolated in 67 patients (67%). The most frequent viruses were as follows: rhinovirus (n=33), adenovirus (n=14), respiratory syncytial virus (n=13) and parainfluenza viruses (n=11). Mycoplasma pneumoniae was detected in one case. Twenty-three (23%) presented with or developed ACS. A nested case-control analysis was performed, after pairing ACS with non-ACS children for age and inclusion period. There was no statistical association between any viral detection or multiple viral infection, and ACS (p=0.51) even though parainfluenza viruses were twice as common in ACS.

CONCLUSIONS

Viral detection in febrile children with SCD is frequent, but its association with ACS was not demonstrated. In this study, M. pneumoniae was rare in young children with SCD experiencing ACS.

Convergence of Inflammatory Pathways in Allergic Asthma and Sickle Cell Disease

The underlying pathologies of sickle cell disease and asthma share many characteristics in terms of respiratory inflammation. The principal mechanisms of pulmonary inflammation are largely distinct, but activation of common pathways downstream of the initial inflammatory triggers may lead to exacerbation of both disease states. The altered inflammatory landscape of these respiratory pathologies can differentially impact respiratory pathogen susceptibility in patients with sickle cell disease and asthma. How these two distinct diseases behave in a comorbid setting can further exacerbate pulmonary complications associated with both disease states and impact susceptibility to respiratory infection. This review will provide a concise overview of how asthma distinctly affects individuals with sickle cell disease and how pulmonary physiology and inflammation are impacted during comorbidity.

Challenges in the Management of Sickle Cell Disease During SARS-CoV-2 Pandemic

The management of sickle cell disease (SCD) and its complications in the COVID-19 era is very challenging. The recurrent sickling process in SCD causes tissue hypoxemia and micro-infarcts, resulting in end organ damage. Since the outbreak of SARS-CoV-2 pandemic, little data has been published about SCD concerning clinical presentation with COVID-19 and management. Hydroxyurea has been the cornerstone of management in children and adults with SCD, with evidence of its effect on controlling end organ damage. There are several anti-sickling drugs that have been approved recently that might have an additive value toward the management of SCD and its complications. The role of simple and exchange transfusions is well established and should always be considered in the management of various complications. The value of convalescent plasma has been demonstrated in small case series, but large randomized controlled studies are still awaited. Immunomodulatory agents may play a role in reducing the damaging effects of cytokines storm that contributes to the morbidity and mortality in advanced cases. Prophylactic anticoagulation should be considered in every management protocol because SCD and COVID-19 are thrombogenic conditions. Management proposals of different presentations of patients with SCD and COVID-19 are outlined.

Vascular Permeability Drives Susceptibility to Influenza Infection in a Murine Model of Sickle Cell Disease

Sickle cell disease (SCD) is a major global health concern. Patients with SCD experience disproportionately greater morbidity and mortality in response to influenza infection than do others. Viral infection is one contributing factor for the development of Acute Chest Syndrome (ACS), a major cause of morbidity and mortality in SCD patients. We determined whether the heightened sensitivity to influenza infection could be reproduced in the two different SCD murine models to ascertain the underlying mechanisms of increased disease severity. In agreement with clinical observations, we found that both genetic and bone marrow-transplanted SCD mice had greater mortality in response to influenza infection than did wild-type animals. Despite similar initial viral titers and inflammatory responses between wild-type and SCD animals during infection, SCD mice continued to deteriorate and failed to resolve the infection, resulting in increased mortality. Histopathology of the lung tissues revealed extensive pulmonary edema and vascular damage following infection, a finding confirmed by heightened vascular permeability following virus challenge. These findings implicate the development of exacerbated pulmonary permeability following influenza challenge as the primary factor underlying heightened mortality. These studies highlight the need to focus on prevention and control strategies against influenza infection in the SCD population.

Improvement in influenza vaccination rates in a pediatric sickle cell disease clinic

BACKGROUND

Children with sickle cell disease (SCD) are at increased risk of complications from influenza. However, despite widespread recommendations that these patients receive an annual influenza immunization, reported vaccination rates remain very low at under 50%.

PROCEDURE

Our aim was to increase the influenza vaccination rate among our pediatric patients with SCD aged 6 months to 21 years over two influenza seasons, 2012-2013 and 2013-2014, to 80%, consistent with the Health People 2020 goal. We used multiple quality improvement methods, based on the literature and our previous experience in other aspects of SCD care, including parent and provider education, enhancement of our EHR, use of a SCD patient registry and reminder and recall done by a patient navigator.

RESULTS

We vaccinated 80% of our pediatric patients with SCD for influenza during the 2012-2013 season and 90% of patients in 2013-2014. Our early season vaccination rates were nearly double that of those for the general population.

CONCLUSIONS

Use of quality improvement methods can increase rates of influenza vaccination for this high-risk population, suggesting that less health care utilization and lower cost might result.

Severe pandemic H1N1 and seasonal influenza in children and young adults with sickle cell disease

Influenza causes excess morbidity in sickle cell disease (SCD). H1N1 pandemic influenza has been severe in children. To compare H1N1 with seasonal influenza in SCD (patients younger than 22), we reviewed medical records (1993-2009). We identified 123 cases of laboratory-confirmed influenza (94 seasonal, 29 H1N1). Those with seasonal influenza were younger (median 4.4 vs 8.7 years old, P = .006) and had less asthma (24% vs 56%, P = .002). Those with H1N1 influenza more often had acute chest syndrome (ACS; 34% vs 13%, P = .01) and required intensive care (17% vs 3%, P = .02), including mechanical ventilation (10% vs 0%, P = .02). In multivariate analysis, older age (odds ratio [OR] 1.1 per year, P = .04) and H1N1 influenza (OR 3.0, P = .04) were associated with ACS, and older age (OR 1.1 per year, P = .02) and prior ACS (OR 3.3 per episode in last year, P < .006) with intensive care. Influenza, especially H1N1, causes critical illness in SCD and should be prevented.