Blood tumour necrosis factor-α and the pathogenesis of anaemia in <i>Trypanosoma brucei</i> infected rabbits

Abstract

Trypanosomosis is a protozoan infection of domestic and wild animals characterized by anaemia, however, the pathogenesis of trypanosomosis-induced anaemia is not fully understood. This study evaluated the possible roles of Tumour Necrosis Factor-alpha (TNF-α) in the pathogenesis of anaemia induced by Trypanosoma brucei in rabbits. Twelve adult rabbits of both sexes with mean weight of 2.1 ± 0.1kg were randomly assigned into two groups of six rabbits each. Group A rabbits were intraperitoneally (i.p) infected with blood containing 2 x 106/ml of T. brucei , while group B (control) rabbits were injected with one ml of normal saline i.p. Blood was collected from the ear vein before infection and weekly thereafter for six weeks post-infection (p.i), in order to determine the packed cell volume (PCV), haemoglobin (Hb) concentration, red blood cell (RBC) count, reticulocyte count (RC) and serum concentrations of TNF-α. The PCV, RBC count and Hb concentration were significantly (p<0.05) lower in group A than group B rabbits throughout the duration of the study. Serum concentration of TNF-α was significantly (p<0.05) higher in group A (227.5 ± 8.1 ng/ml) than group B (51.3 ± 8.2 ng/ml) at week four post-infection. The serum concentration of TNF-α negatively correlated with PCV (r=-0.513) and Hb (r=-0.769) in group A. The study concluded that anaemia observed during experimental infection in rabbits with trypanosomosis was associated with increased levels of TNF-α. Keywords : Anaemia, Rabbits, Pathogenesis, Trypanosomosis, Tumour Necrosis Factor-α