Severity of mastitis symptoms as a predictor of C-reactive protein in milk and blood during lactation.

OBJECTIVE To investigate the presence of C-reactive protein (CRP) in breast milk and any relationship between changes in CRP in breast milk and blood, and the severity of systemic and breast symptoms experienced during mastitis. METHODS Mothers (n = 26) were followed prospectively from day 5 postpartum to the end of their lactation. Milk from each breast, blood, 24-hour urine samples and data on breast and systemic pathologies were collected at reference intervals during the first 3 months postpartum, daily during the occurrence of any breast inflammation and at 7 days after resolution of symptoms. RESULTS CRP in blood was significantly increased during mastitis (p < 0.001, df:1,81; F = 31) and severity of systemic symptoms was a significant predictor for changes of CRP in blood (p < 0.01; df:3,42; F = 9.6). During mastitis both the symptomatic breast (p < 0.001; df:1,79; F = 19) and the contralateral asymptomatic breast (p < 0.004; df:1,75; F = 8.7) had a significantly higher milk CRP when compared with women with no mastitis. CONCLUSIONS Although an increasing severity of breast and systemic symptoms in mastitis was predictive of an increasing CRP in milk and blood, respectively, the presence of CRP in similar concentrations in the mastitis and asymptomatic breast suggests it is of little use in making a differential diagnosis between infective verses noninfective forms of mastitis.