Rare T. evansi Infection Linked to Apolipoprotein Gene
Case study suggests that infection is due to mutations in the apolipoprotein L-I gene
THURSDAY, Jan. 4 (HealthDay News) -- Most humans are immune to the parasite Trypanosoma evansi, which most often causes disease in animals, but patients who have mutations in the apolipoprotein L-I (APOL1) gene may be susceptible, according to a case report in the Dec. 28 issue of the New England Journal of Medicine.
Etienne Pays, Ph.D., of the Universite Libre de Bruxelles in Gosselies, Belgium, and colleagues diagnosed a T. evansi infection in an Indian cattle farmer who presented with a five-month history of fluctuating trypanosome parasitemia associated with febrile episodes. They treated the patient with suramin, which led to a complete cure.
The researchers found that the patient's serum had no trypanolytic activity because of a lack of APOL1, which they attributed to frameshift mutations in both APOL1 alleles. They were able to restore trypanolytic activity with recombinant APOL1.
"This case of human infection with T. evansi could be due either to acquired resistance to normal human serum by the parasite or to deficient trypanolytic activity of the host," the authors write. "T. evansi-infected human serum did not affect the two T. evansi strains (from Morocco and from Vietnam) that we tested."