Plasma amylase levels as a marker of disease severity in an isogenic murine model of paracoccidioidomycosis.

Survival patterns after peritoneal infection with Paracoccidioides brasiliensis vary according to the mouse strain and to the virulence of the fungal isolate. It has previously been observed that a significant increase in plasma amylase levels occurs only when susceptible mice (B10.A) were infected with a virulent isolate (Pb18). In order to verify if increased amylase levels correlate with susceptibility to P. brasiliensis infection, 12 mouse strains with different susceptibility patterns to this fungus were investigated after infection with Pb18. When compared with their respective controls, C57BI/6, B10D2/oSn, B10D2/nSn, C3H/HeJ, B10.A and BALB/c mice showed a conspicuous amylase increase and AKR, (NZB x NZW)F1, CBA/J, (A/Sn x B10.A)F1, A/Sn and DBA/2 absence of alteration. The influence of the infecting fungal isolate on this enzymatic parameter was investigated using B10.A mice and fungal isolates with diverse degrees of virulence. When compared with their non-infected controls, mice infected with Pb45 or Pb47 showed a very high amylase increase, with Pb44 or Pb18 a high one and with Pb50 or Pb265 a discrete increase. On the whole, there is an inverse correlation between survival times after infection and the increase in amylase levels. Thus, measurement of plasma amylase is a satisfactory parameter to evaluate the severity of paracoccidioidomycosis in mice.