Alterations of serum lipid, lipoprotein and inflammatory cytokine profiles of rabbits infected with Trypanosoma brucei brucei.

In the study to analyze the pathophysiology of chronic salivarian trypanosomosis, the infection of rabbits with Trypanosoma brucei brucei produced a three-phase alteration of serum lipid and lipoprotein profiles. In the earliest stages, during the first 2 weeks post-infection (p.i.), serum triglycerides and very low density lipoproteins (VLDL) began to increase, high density lipoproteins (HDL) began to decrease, while a more rapid increase was observed in low density lipoproteins (LDL). Serum phospholipids increased moderately at 2 weeks p.i. preceded by a transient decrease at 1 week p.i. In the second phase, from 2 weeks p.i., the infected animals developed a condition consisting of a gradual accumulation of VLDL together with high triglycerides, high LDL and low HDL. Serum cholesterols increased moderately from 2 weeks p.i. The third phase was a convalescent stage between 7 and 10 weeks p.i. The alterations of triglyceride, VLDL and LDL levels suggested that suppression of lipolytic enzymes in charge of hydrolysis of serum triglycerides was initiated by 2 weeks p.i., and then became seriously impaired corresponding with the progression of disease. Serum tumor necrosis factor alpha (TNFalpha) was continuously detected from 1 week p.i., and for at least 5 additional weeks in all the infected animals. Serum interleukin (IL)-1-like activity was occasionally detected, and IL-6-like activity increased in the middle stages of infection in some of the infected animals. The derangement of lipid metabolism appeared to be associated with the period of TNFalpha induction following infection.