Haematological profile and blood transfusion pattern of patients with sickle cell anaemia vary with spleen size
Background: The spleen serves critical haematological and immunological functions in the body. However it is also the first organ to be affected by the effects of sickling in sickle cell anaemia. While the splenic size has been evaluated in sickle cell anaemia, the spleen sizes of these patients has not been associated with any specific haematological pattern.
Objectives: To determine the haematological parameters of patients with sickle cell anaemia (SCA) in relation to spleen size.
Methods: The full blood count (FBC), the irreversibly sickled cells and blood transfusion use amongst SCA patients in steady state was evaluated. Abdominal ultrasound was also performed for all patients and HbAA control for splenic size categorization.
Results: Forty patients with SCA and 22 controls with HbAA were studied with mean age of 29.28 ± 8.10 years 28.23 ± 8.14 years respectively. The mean splenic longitudinal lengths in patients and controls were 6.3 ± 4.3cm and 8.9 ± 1.5 cm respectively (p-value < .05). The mean haematocrit and haemoglobin value were significantly lower in SCA cases than in controls (p < 0.001). Though the red cell indices were similar but the white blood cell and platelet count were significantly higher in patients than in controls. Among SCA cases, the spleen size showed significant positive correlation with haematocrit (r = 0.371, p = 0.019) and the age at 1st transfusion (r = 0.447, p = 0.013) but significant negative correlation with MCV, MCH, MCHC and platelet count. Above 80% of patients with severe, moderate and mild autosplenectomy had been transfused compared to 25% of patients with splenomegaly.
Conclusions: Similarities in red cell indices between patients and controls suggests an identical factor influencing the red cell indices which could be genetic such as thalassemia or environmental such as iron deficiency. The negative correlation of the spleen size with red cell indices, white cell count and platelet count and positive correlation with haematocrit suggest that spleen size can be used to determine clinical course of the disease. Earlier age at first transfusion, significantly higher frequency of blood transfusion and MCHC in patients with severe autosplenectomy suggest a more severe clinical course when compared with patients with splenomegaly, normal spleen, mild and moderate autosplenomegaly.
Keywords: Sickle cell anaemia, Splenic size, Autosplenectomy, Haematological parameters