American Journal of Clinical Nutrition, Vol 32, 1842-1846, Copyright © 1979 by The American Society for Clinical Nutrition, Inc

ORIGINAL RESEARCH COMMUNICATIONS

alpha 2-Macroglobulin in vitamin A-deficient children

TC Kiorpes, G Wolf, G Arroyave and TN Wai

Serum samples were obtained from 43 children 14 years old or younger in Malaysia and Guatemala. The levels of the serum glycoprotein alpha 2- macroglobulin (alpha 2-M) were assayed by two methods: the trypsin- binding assay of Ganrot (Clin. Chim. Acta 14:493, 1960) and a radial immunodiffusion assay against alpha 2-M antiserum. The two methods gave the same results. When serum alpha 2-M levels were plotted against serum vitamin A concentrations, they were significantly correlated (r = 0.505, P less than 0.001); children with serum vitamin A levels greater than 40 micrograms/100 ml had alpha 2-M levels of 3.71 +/- 0.79 mg/ml (mean +/- SD, n = 13), while those with level less than 40 micrograms/100 ml had alpha 2-M levels of 2.78 +/- 0.51 mg/ml (n = 30); the difference was significant (P less than 0.001). Normal, apparently healthy children had alpha 2-M levels of 3.90 +/- 0.39 mg/ml. Most of the children sampled suffered from a variety of infections; of these, measles appeared to counteract the effect of vitamin A deficiency by elevating alpha 2-M levels. Vitamin A-deficient children with measles had alpha 2-M levels not significantly lower than those of normal children. The difference between deficient and normal values of alpha 2- M was still significant (P less than 0.05) when expressed per milligram of serum protein, showing that the effect was not caused by lowered serum protein concentrations associated with protein-calorie malnutrition, from which most of the deficiency children suffered.