C-reactive protein concentration in dogs with primary immune-mediated hemolytic anemia.

BACKGROUND

Canine primary immune-mediated hemolytic anemia (IMHA) is associated with a high-mortality rate. C-reactive protein (CRP) is the most important acute-phase protein in dogs and may have value as a marker of prognosis or response to treatment in IMHA.

OBJECTIVE

The objectives of this study were to evaluate serum CRP concentration in dogs with primary IMHA at presentation and during treatment, to assess potential differences based on survival time, and to compare CRP with other laboratory parameters of inflammation and prognosis.

METHODS

Inclusion criteria for primary IMHA were anemia (PCV<0.30 L/L), a positive Coombs' test or persistent autoagglutination of erythrocytes, and the exclusion of underlying diseases by other diagnostic tests. Dogs were divided into 2 groups based on survival: dogs that were still alive 14 days after start of treatment (group 1) and dogs that died or were euthanized before day 14 (group 2). Serum CRP concentration, a CBC, and a biochemistry profile were performed on days 0, 3, 8, and 14. Serum CRP also was determined in 25 clinically healthy dogs.

RESULTS

CRP concentration in the 25 clinically healthy dogs ranged from 0-8.9 microg/mL (median 2.2 microg/mL). Thirty dogs were diagnosed with primary IMHA, 24 in group 1 and 6 in group 2. On day 0, CRP concentration in dogs in both groups (median 224 microg/mL) was increased above the reference interval. In group 1 dogs, median CRP concentration was 242 microg/mL on day 0, 69 microg/mL on day 3, 35 microg/mL on day 8, and 2 microg/mL on day 14. In group 2 dogs, median CRP concentration was 194 microg/mL on day 0, 119 microg/mL on day 3, and 41 microg/mL on day 8; only 1 dog in group 2 survived to day 8. There was a significant correlation between CRP and total WBC concentrations on days 0 and 3 (r=-.598, P=.003).

CONCLUSIONS

Serum CRP concentration was markedly increased in dogs with primary IMHA. CRP concentration did not differ based on patient survival, but might be a marker for long-term monitoring of these patients.