Discussion:
Coronavirus is the novel virus responsible for the latest pandemic that declared by World Health Organization WHO on March 11,2019. Taking a good history to define the risk of infection is critical as patient might be asymptomatic. However, symptomatic patients may present with fever, dyspnea, fever, fatigue, and generalized muscle ache. Other non-typical symptoms like gastrointestinal were also reported[6]. Severity of the disease differs among affected patients, elderly, patients with co-morbidities like hypertension, diabetes and cardiovascular diseases are at more risk for complication and worse clinical course than normal population[7].
Sickle cell disease (SCD) is an inherited hemoglobinopathy with main characteristic being the presence of Hemoglobin S (HbS). The inheritance might be in homozygous or heterozygous form with a disease severity that differs accordingly. This hemoglobin cause deformity in the structure of Red Blood Cells (RBCs) changing them to sickle-shaped, rigid as well dysfunctional RBCs. Clinical manifestations are Vaso-occlusive crisis (VOC), intra- and extra- vascular hemolytic anemia [2]. Complication of SCD can be categorized into acute and chronic.
Acute complications include: Acute chest syndrome (ACS), Vaso-occlusive crisis (VOC), hepatobiliary complications, stroke, splenic sequestration, priapism, acute anemia, and fever[8]. Chronic complications are pulmonary hypertension, hepatic iron overload, kidney disease, avascular necrosis, retinopathy, and legs ulcer [7,9–12]. Among the acute complications, the most common are VOC and ACS. VOC are episodes of severe pain due to microvascular occlusion with erythrocytes and leukocytes, thus preventing blood flow and causing organ ischemia. ACS is common lung insult in SCD patients, known as newly pulmonary infiltrate due to alveolar consolidation affecting one lung segment at least, in it is severe form it is similar to the acute respiratory distress syndrome (ARDS), along with the radiological findings, patients usually present with fever, chest pain, shortness of breath, cough and wheezing. Its considered the second most common cause of hospitalization and the main reason behind intensive care unit admission as well early death among those patients[3]. There are three previously mentioned causes of ACS; first: pulmonary infection, second: bone marrow fat embolization and thirdly, intra-vascular pulmonary sequestration. Among those causes, pulmonary infections are the most common one and it is usually due to community-acquired pathogen that cause over inflammatory response instead of mild upper respiratory picture[3]. The National Acute Chest Syndrome Study published by Vichinsky et al to defined the causes of ACS, their study showed that infections are the main cause with atypical bacteria and viruses being the major causes, and despite the splenic dysfunction in SCD encapsulated bacteria were rarely isolated[13].
Patients with hemoglobinopathies are considered high risk for developing severe complication from COVID-19 infection as per the Thalassemia international federation[14].However, no strong evidence is available, and it is not known in COVID-19 infection really increase the morbidity and mortality in SCD patients or not[4]. The overlap between the ACS and COVID-19 pneumonia has been described [15]. Thus, taking a final decision in this regard is hard because of the conflict in literature and variance of COVID-19 clinical course among SCD population, we summarize all previously published data in Table 2.
As we notice from the table above few published cases described the use of RBCs exchange to manage ACS in SCD patients. Whenever RBCs exchange was used it was because the patients deteriorated, interestingly all of them improved after the exchange that is why we should raise the following question “ is it necessary to leave this choice as a rescue option?” . The most similar published case to our patient was published by and described the role of early RBCs exchange in preventing further deterioration in their patient as once oxygen requirement started to increase RBCs exchange offered rather than simple transfusion or other medications[15]. The difference in our case is that we chose to offer our patient RBCs exchange even when he was stable due to the overlapping between ACS and COVID-19 pneumonia and by weighing the benefit and risk we believe that giving him RBCs exchange played an important role in alleviating the infection course as well the need of ICU admission and possible intubation.
Both pneumonia and acute chest syndrome are life-threatening condition. Red blood cell exchange is well known method to treat ACS and there are published data about using it in case of severe COVID-19 pneumonia, mostly after deterioration [1,5,15]. Here, we present the first case report for SCD patient infected with COVID-19 who received red blood cells exchange immediately after admission to avoid the deterioration and need of intubation giving him the benefit of doubt. We think offering RBCs exchange for patients with SCD and COVID-19 pneumonia upon diagnosis may have major benefits such as, avoiding ICU admission and intubation.