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.
