Acute Splenic Sequestration Crisis

Abstract

Acute splenic sequestration crisis (ASSC) is a life-threatening complication associated with sickle cell anemia (SCA) that consists of an acute fall in hemoglobin produced by red blood cell (RBC) sickling within the spleen. It is also one of the leading causes of death in children with SCA. Occlusion of the splenic vascular supply leads to parenchymal ischemia and tissue necrosis. ASSCs are considered an emergency because of their high morbidity and mortality. Untreated patients may die within 1-2 h due to circulatory failure. Management is supportive, sometimes with blood transfusion and total or partial splenectomy. The aim of this chapter is to bring the up-to-date knowledge of the epidemiology, pathophysiology, diagnosis, and treatment of ASCC. Other important items considered are the spleen dysfunction, susceptibility to infections, and its prevention, disease expression, and to address the different managements for improving prognosis.

Microfluidic study of retention and elimination of abnormal red blood cells by human spleen with implications for sickle cell disease

“…The mechanical retention of RBCs by the IESs in the spleen is influenced by the shape and mechanical properties of individual RBCs ( 34 – 37 ). Sickled or elongated RBCs have been found retained by IESs in SCD patients with ASSC ( 17 , 22 ). In order to differentiate morphologies of SS RBCs with those of AA RBCs, we studied both AA and SS RBCs under oxygenated (Oxy) and deoxygenated (DeOxy) conditions using a sickling kinetics assay developed in our earlier work ( 38 , 39 ).…”

“…No severe hypoxia or widespread sickling in the spleen would be expected in most cases. However, about 5 ~ 10% SCD infants develop a life-threatening crisis—ASSC, where significant sickling of SS RBCs can be found ( 17 , 22 , 23 ). Fig.…”

“…This process might involve a vicious cycle: the more RBCs the spleen traps, the larger the spleen grows, and the larger the spleen grows, the deeper the hypoxia is, resulting in more and more sickled SS RBCs that are consequently being trapped and destroyed. Indeed, following splenectomy in young SCD children with still functional spleen, sickled RBCs have been found retained and congested upstream of IESs during ASSC ( 17 , 22 , 23 ). On the other hand, surface modulations such as PS externalization ( 24 ), decreased levels of CD47 ( 25 ), and elevated binding of autologous immunoglobulin ( 26 ), as well as increased membrane rigidity of sickled RBCs may also promote the retention and elimination of SS RBCs by the splenic macrophages ( 27 – 29 ).…”

A review of the role of infections in the aetiology of haemolysis in patients with sickle cell diseases: pathogenesis, management, and prevention

“…Moreover, it should be noted that prominent enlargement of spleen or liver might as well be caused by sequestration crisis, which must be diligently ruled. In contradistinction to HLH, acute sequestration organomegaly is usually tender and the patient is typically in hypovolaemic shock (105). Therefore, the diagnosis of HLH in SCD requires careful interpretation because of the clinico-pathological overlap between the diagnostic criteria of HLH and clinical manifestations and/or side effects of treatment for SCD (102)(103)(104)(105).…”