Maternal and cord serum immunoglobulins in four Malaysian races

Immunoglobulin G, A and M levels were determined in paired maternal and cord sera of premature, full term and postmature newborns of urban dwelling Chinese, Indian, Malay and full term newborn of the forest dwelling Orang Asli (Malaysian aborigines). The mean serum IgC level in the full term Orang Asli newborns (1254±441 mg per 100 mil is comparable to that of the Indians (1211±282 mg per 100 ml) and Malays (1169±286 mg per 100 ml) but these levels are higher than those of the Chinese
newborns (1092±270 mg per 100 ml). Statistical analysis indicates a significant dependence of cord serum IgG level on maternal serum IgG level in the . Chinese, Indians and Malays. In addition, in Indians the cord serum IgG was significantly dependent at 5% level on the gestation age. The fetomaternal serum IgG level ratios at term were equal to or just less than one. The cord serum IgM levels of the Chinese, Indian, Malay and Orang Asli newborns at term were 11.6.±. 6.5, 12.5.±. 7.3, 10.9.±. 5.8 and
16.7±6.9 mg per 100 ml respectively. Statistical analysis showed absence of correlation between cord serum IgM level and birthweight, gestation age or maternal serum IgM level in Chinese and Malays. In Indians the cord sera IgM level showed a dependence on the birthweight. Immunoglobulin A was present in 34.6%, 40.5%, 31.6% and 62.5% of full term Chinese, Indian, Malay and Orang Asli newborns respectively. These observations are discussed in relation to the immunoglobulin levels observed in populations residing in temperate and other tropical regions.