The spleen in Sickle Cell Anemia and Sickle Cell Thalassemia is usually enlarged in the first years of life but the immune protection provided is considered insufficient. In homozygous Sickle cell patients the spleen usually developed recurrent infarcts and after the first decade of age become fibrotic. Acute splenic sequestration is also frequent in those patients and this is considered as an indication for splenectomy.

In comparison in Sickle cell thalassemia patients, hypersplenism is more frequent.

The purpose of this study is to compare the clinical and laboratory issues related to the spleen in two groups of Sickle cell patients.

Clinical and laboratory characteristics related to the spleen in SCA patients will be studied.

Two groups of patient will be compared, a group of Sickle cell patients (Homozygous) and a second group of patients with Sickle cell beta thalassemia.

In those patients that splenectomy was performed the incidence of infections will be recorded besides the indications for splenectomy and the incidence of thrombotic events or thrombocytosis.

Inclusion Criteria:

• All the patients followed up at the Pediatric Hematology Unit

Exclusion Criteria:

• Patients lost from follow up of with insufficient data

Two groups of patients: 25 patients with homozygous Sickle Cell Anemia and 25 patients with Sickle Cell Thalassemia