> > From: Joy Anderson <[log in to unmask]> >> >> regards to immunology (but did study it in my >> graduate diploma of medical technology many years ago), but my >> understanding is that IgG is the small immunoglobulin that passes >> across the placenta (as you stated - classic example is anti-Rh), but >> that IgA is the one for all 'secretory' purposes, such as milk, lung >> lining, etc - it has a J-chain joining the two parts that are each >> like IgG molecules, and this J-chain results in the whole molecule >> being resistent to degradation (hence it survives in 'hostile' >> environments like a baby's gut). >> >> IgM, on the other hand, is a *huge* molecule that I thought could not >> get into milk *or* across the placenta. >> >> I thought that milk contains nearly all IgA except for the people who >> are genetically IgA-deficient, and they seem to compensate by having >> IgG in their milk. (Still not IgM.) > >Thanks so much for contributing to this discussion. > >I've been doing a fair bit of research and have come across numerous >references to breastmilk containing mostly IgA but containing all five >classes of immunoglobin. (IgG, IgA, IgM, IgD and IgE.) The Latrobe U tables >detailing antibacterial and antiviral properties of breastmilk contain >references to IgM. http://www.latrobe.edu.au/microbiology/table1.html > >There are also lots of references to Secretory IgM, but I don't know enough >about immunology to know if this is relevant. > >-- Jodine Chase Thanks, Jodine. And thanks for the leads via the web. Very interesting. From the refs on the websites (La Trobe and Medscape - linked from the La Trobe site), there is no IgE, and only small amounts of anything other IgA. A part quote: >Breastfeeding: Unraveling the Mysteries of Mother's Milk >from Medscape Women's Health eJournal[TM] ><snip> >Secretory immunoglobulin A (sIgA), dimeric IgA coupled to the >secretory component, is the main immunoglobulin in human milk. IgG >and IgM are also present in milk, but at much lower concentrations. >The changing concentration of these immunoglobulins in milk provides >an example of the interaction between milk components and the >functional development of the infant: while IgG and IgM rise rapidly >after birth, the newborn maintains low levels of endogenous IgA >during the first year of life. IgA is produced in the mammary gland >in B cells, which originate at maternal sites of high environmental >pathogen exposure (eg, the small intestine or respiratory tract), >and therefore protects the infant against pathogens present in the >immediate environment. From this it may be assumed that IgM appearing in any significant quantity in the baby's serum would be of infant origin, not from milk - yes? You mention 'Secretory IgM'. Please can you give me refs for this? I am not familiar with this type at all, but admit that my immunology knowledge is many years old. ****************************************************************** Joy Anderson B.Sc. Dip.Ed. Grad.Dip.Med.Tech. IBCLC Australian Breastfeeding Association counsellor Perth, Western Australia. mailto:[log in to unmask] ****************************************************************** *********************************************** To temporarily stop your subscription: set lactnet nomail To start it again: set lactnet mail (or digest) To unsubscribe: unsubscribe lactnet All commands go to [log in to unmask] The LACTNET mailing list is powered by L-Soft's renowned LISTSERV(R) list management software together with L-Soft's LSMTP(TM) mailer for lightning fast mail delivery. For more information, go to: http://www.lsoft.com/LISTSERV-powered.html