Recurrent blocked duct(s) in a mother with immunoglobulin A deficiency

Abstract Secretory immunoglobulin A (sIgA) is the dominant immunoglobulin in human milk, and apart from the obvious contribution it makes towards the protection of the infant, sIgA may also form an important part of the defense of the mammary gland. This report involves a mother (M8) who participated in a research study investigating the relationships between symptoms and changes in the physiology of the lactating breast during mastitis. Breastmilk samples were collected on Days 14, 30, 60, and 90 postpartum, to establish the normal reference range of biochemical markers, and during periods of breast inflammation. M8 experienced seven episodes of blocked duct(s) during the first 19 weeks, five of which occurred within the 90-day reference sample collection period. On analysis, it was found there was no detectable sIgA present in her milk samples. Medical referral and further testing resulted in a diagnosis of selective IgA deficiency, of which the mother had not been previously aware. M8 showed little variation in her milk composition even when suffering with blocked duct(s), although there was an increase in the concentration of lactoferrin in both breasts at reference collection days 14-90. Lactoferrin concentration was also unusually high at Day 14 (15 g/L) in the left breast and continued to be increased in this breast until Day 60. The absence of sIgA in this mother's breastmilk may have been a contributing factor in her experiencing recurrent blocked ducts.