Morbidity pattern and interferon gamma level in sickle cell anemia patients with autosplenectomy

In sickle cell anemia patients (SCA), the spleen suffers multiple occlusion of its microvasculature causing ischemia and subsequently autosplenectomy. Among the functions of the spleen is the production of gamma interferon (IFN-γ) which has several immunological roles. This function could be impaired in these patients. Therefore, this study aimed at determining the extent to which autosplenectomy affects the immunity of SCA patients as reflected by the level of IFN-γ, frequency of infections, and crises (vaso-occlusive, hemolytic, aplastic) in these patients.

Forty SCA patients in steady state condition were recruited into the study. A self-administered questionnaire was completed by all patients, and venous blood sample was analyzed for IFN-γ levels. All patients underwent abdominal ultrasound scan.

Autosplenectomy was observed in 20% of the sickle cell patients. Bone pain was the most frequent type of crisis in the study population; this occurred in 100% and 85% of patients with autosplenectomy and those without autosplenectomy, respectively. Infection rates of more than once a year was reported in 87.5% of SCA patients with autosplenectomy compared with 50% of SCA patients without autosplenectomy. There was no significant difference in IFN-γ plasma levels between SCA patients with autosplenectomy and those without autosplenectomy.

This study showed a higher prevalence of infection and bone pain crisis among SCA patients with autosplenectomy than in SCA patients without autosplenectomy. It also showed comparable level of IFN-γ in the 2 groups of patients. Patients with autosplenectomy may benefit from early institution of drugs such as hydroxyurea to improve quality of life.