Circulating immune complexes and renal function in canine leishmaniasis.

A third component of complement (C3) capture enzyme-linked immunosorbent assay was used to determine the concentration of IgG circulating immune complexes (CIC) in 91 dogs with naturally acquired leishmania infection and in a control group of 24 healthy dogs. Results were expressed as a percentage of a reference standard. Mean concentrations of CIC were significantly (P < 0.001) higher in leishmania-infected dogs (228.725 +/- 14.283%) than in controls (74.542 +/- 12.614%). An increase in CIC concentration was found in 57.1% of the leishmania-infected dogs. No significant differences could be recorded in CIC levels between males and females in either group. Infected dogs showing hypercreatininemia rendered a statistically significant (P < 0.030) higher serum CIC concentration than sick dogs with normal creatininemia. When hypercreatininemia (> or = 1.30 mg/dl) was used as an indicator for CIC increase, the positive predictive value obtained was 0.9 indicating that renal function impairment was associated with high serum CIC concentration in 90% of the infected dogs.