Serumimmunoglobulins inarural andanurban population ofGreece withspecial reference to immunoglobulin A

SUMMARY Theserum concentration ofimmunoglobulins G,A,andM was studied in390 inhabitants ofa rural community andin204residents ofan urban areaofGreece. Itwas found that serumIgAlevels weresignificantly higher intherural areawhereintestinal infections weremore prevalent. Nosignificant difference inserumIgGwasfound between thetwogroups.IgMwasfound tobelower among residents oftherural area.Thepresent findings suggest a possible ecological association between increased IgAandchronic exposuretointestinal infection. Thedemonstration that IgAistheprincipal class of immunoglobulin inexternal secretions andthatitis themainimmunoglobulin madebyplasma cells in mucousmembranes ofthegastrointestinal tract (Crabbd etal., 1965) hasstimulated great interest in recent years. Thedescription ofalpha chain disease (oi-CD) bySeligmann etal.(1968), whichpresents asa benign orneoplastic aberration oftheIgA secretary system, hasledtotheobservation that this disease affects mainly individuals living inareas with a highdegree ofintestinal infestations andlow socioeconomic background (Seligmann etal., 1971).