Thyroxin binding globulin [TBG] and prealbumin [TBPA] levels in healthy subjects

This study was carried out on 120 carefully selected normal healthy subjects [56 males and 49 females in addition to 15 newborns]. Their ages ranged from newborn to Geriatric. Estimation of plasma TBG and prealbumin by RIA and immunoturbidimetric methods respectively was performed. Plasma TBG levels were nearly constant in females up to the age of 7.5 years and then showed progressive decrease, together with that of the male group, till the age of 16 years and then showed a slight gradual increase till the age of 65 years. The highest levels of TBG were observed at birth and at the age of 65 years and the lowest one was at age group of 15-18 years [about two thirds the highest levels]. No significant sex difference was encountered in TBC levels among all age groups. Pre albumin levels were nearly constant till the age of 8 years in males and decrease slightly in females. In both sexes, a marked increase was noted from 8-14 years, then the increase was much slower till the age of 24 years. The level started to decline slightly from age 24 to 40 years and markedly till age of 65 years. The highest level of prealbumin was in age of 15-35 years which was two and half folds that obtained for newborns and old age [65 years]. Prealbumin was significantly higher in male than females at the age range 15-50 years. Significant negative correlation was demonstrated between plasma TBC and prealbumin levels in all age groups

Transeferrin and haptoglobin, age and sex variations

Immunoturbidimetric technique was used to measure serum transferrin and haptoglobin levels in 120 subjects representing different age groups starting from birth till 80 years. Both sexes were represented almost equaly Plasma transferrin levels showed a gradual rise from birth till the age of 15 years and then dropped sharply at the age of 20 years. A slight decrease was then observed starting from the age of 24 to reach its lowest level at the age of 65 years. The highest level of transferrin was observed at 15 years which was significantly higher than in older age groups. Serum haptoglobin was absent in the newborn and started to appear at the age of one month. Then it showed marked increase from age of one month to the age of 30 Years, remaining relatively constant between 30 and 40 years then gradually increased to reach the highest level at the age of 65 years which was significantly different from other age groups. No sex difference was shown for either transferrin or haptoglobin at all age groups. So-age variations need more focusing to standardize normal levels which requires large number of cases, since it is limited by the high cost of kits in the present study