COMPARISON OF DAMAGE TO KIDNEYS AND LIVER CAUSED BY LETHAL BABESIA-RODHAINI INFECTION AND NONLETHAL BABESIA-MICROTI INFECTION IN MICE

Two mouse babesioses, lethal Babesia rodhaini and non-lethal Babesia m icroti infections, were examined to determine if damage to kidneys and liver is correlated with the prognosis of these infections. All B. ro dhaini-infected mice died after a sudden increase of parasitemia, seve re hemolysis, and excretion of reddish hemoglobinuria. All B. microti- infected mice survived after a temporary moderate increase of parasite mia, moderate hemolysis, and excretion of greenish urine. B. rodhaini- infected mice showed immune complex-induced mesangiopathic glomerulone phropathy, moderate renal tubular necrosis, and extensive liver necros is. In the glomerulonephropathy, electron microscopy showed electron-d ense deposits in the mesangial matrix and along the glomerular basemen t membrane. Biochemical analysis of blood and urine from these mice co nfirmed renal damage in terms of increased BUN and of proteinuria that contained albumin and protein of more than 200 kDa molecular weight, and hepatic damage in terms of an increase in serum direct bilirubin. B. microti-infected mice had relatively mild immune complex-induced me sangiopathic glomerulonephropathy, mild renal tubular necrosis, and fo cal liver necrosis. BUN and serum direct bilirubin showed no increase, and proteinuria contained no detectable proteins of more than 200 kDa . These data suggest that the severity of damage in the kidneys and li ver is correlated with the prognosis of the two Babesia infections.