IgD in Human Colostrum

Abstract

ABSTRACT. Simultaneous colostrum (C) and plasma samples (P) from 14 women, 1 to 5 days postpartum, were examined. Total IgD and specific IgD antibodies to & lactoglobulin, bovine serum albumin, Bermuda grass, and a-gliadin were measured by solid phase radioimmunoassay. The geometric mean concentrations of IgD were 35.8 (range 2.2-410) &dl for colostrum and 591.3 (range 72-4100) pgldl for plasma. Six subjects had a specific IgD antibody C/P ratio more than 10-fold greater than the total IgD C/P ratio, suggesting enhancement of antibody to a specific antigen in the mammary gland. All six had C/P ratios suggestive of local enhancement of IgD antibody to Bermuda grass, and two met this criterion for enhancement of IgD antibodies to &lactoglobulin, bovine serum albumin, or a-gliadin. Specimens for these studies were obtained during the peak grass pollen season. Seventeen additional subjects were studied to compare total IgD in colostrum and plasma with total IgG and serum albumin. The mean C/P ratio for IgD (0.055 f 0.015) exceeded the C/P ratio for total IgG (0.015 f 0.003) or total albumin (0.020 f 0.002). For 14 of 17 subjects the colostrum/plasma ratio for IgD exceeded the C/P ratio for albumin or IgG. Data were transformed logarithmically and correlation coefficients calculated. For albumin versus IgG in colostrum, there was a strong correlation, r = 0.865, p = 0.001. This was different from albumin versus IgD, r = 0.489, p = 0.046 and from IgD versus IgG, r = 0.556, p = 0.020. These analyses support a different mechanism of entry of IgD into milk compared to I& or albumin. These studies also suggest that IgD antibodies may participate in responses of the mucosal immune system. (Pediatr Res 19: 122-126,1985) Abbreviations C, colostrum P, plasma C/P, colostrum/plasma ratio BG, Bermuda grass BLG, j3-lactoglobulin BSA, bovine serum albumin Recent interest in both animal and human breast milk immunology concerns homing of lymphoblasts from mucosal sites to the mammary gland with resultant local production of im-

Selective concentration of IgD class-specific antibodies in human milk

“…Consistent with published studies (Keller et al, 1985), neither albumin nor IgG showed evidence of local concentration in breast milk. This is indicated by the high serum/milk (S/M) ratios in individual samples (Table 1, Fig.…”

“…Certain disparities may be of importance. Keller et al, (1985) found more pronounced selective concentration of total IgD than we did, and marked individual differences between antibody ratios. Keller et al (1985) employed an entirely different panel of antigens including lactoglobulin, bovine serum albumin, Bermuda grass and alpha-gliadin in subjects who were presumptively exposed to the antigens naturally.…”

“…The present results can be critically compared with those of Keller et al (1985) who used colostrum rather than milk, plasma rather than sera and a colostrum/plasma ratio which is the reciprocal of the S/M ratio employed in the current study. The experimental approaches applied in both investigations are similar and a comparison of respective data, after recalculation for the different ratio, indicates that in general, the same basic findings are present; there is selective concentration of IgA, IgM and IgD in human breast fluids in certain subjects; further, there is selective concentration of specific antibody.…”

Human Milk

“…Investigations have failed to show local synthesis of IgE in the breast [118][119][120]. Although IgE may be detected in 40% of colostrum and milk samples, the concentrations are extremely low, and many samples of colostrum and milk contain no IgE activity when paired samples of serum contain high IgE levels.…”

“…It has been suggested that nursing women with high serum IgD levels are more likely to have high IgD concentrations in their milk. The possibility of some local production of IgE and IgD cannot be ruled out [120].…”