Serum immunoglobulins in a rural and an urban population of Greece with special reference to immunoglobulin A.

The serum concentration of immunoglobulins G, A, and M was studied in 390 inhabitants of a rural community and in 204 residents of an urban area of Greece. It was found that serum IgA levels were significantly higher in the rural area where intestinal infections were more prevalent. No significant difference in serum IgG was found between the two groups.