Beta Thalassaemia Trait as a Likely Link between Hyper-Reactive Malarial Splenomegaly and Myeloproliferative Disorders

Myeloproliferative Disorders (MPDs) is a term for describing a group of related disorders with the ability to transform to one another. This concept assumes that these disorders are an expression of excessive proliferation of any one of the cell lines, all of which are derived from a common haemopoietic cell. Primary Proliferative Polycythaemia (PPP) is an MPD with clinical stages which include the spent phase and postpolycythemic myeloid metaplasia; it could also terminate in acute leukemia or Chronic Myeloid Leukemia (CML). Hyperreactive Malarial Splenomegaly (HMS) is associated with massive splenomegaly as a result of exaggerated immune response to persistent exposure to malaria parasites. Though HMS is mostly a diagnosis of exclusion, it is thought to be a pre-malignant state with propensity to lymphoid malignancies [1,2]. It is therefore believed that HMS and lymphoproliferative disorders are indistinguishable [3]. There is also a genetic predisposition to HMS because of its association with HLA-DR2 haplotype and HLA heterozygosity [4,5]. Also, relatives of patients tend to have splenomegaly than is expected in the general population [6] Beta thalassaemia is a genetic disorder of hemoglobin synthesis which has ineffective erythropoiesis and marrow stress as an underlying pathology. Though there is no previous link between HMS and the MPDs nor BTT, the MPDs that have been reported in patients with beta thalassaemia include polycythaemia, [7-9] myelofibrosis, [10,11] and CML [12,13]. We describe here a patient with BTT who, over a period of about twenty years, after unsuccessful treatment for HMS developed features of polycythaemia, CML and myelofibrosis sequentially.