Postnatal IgG levels in very-low-birth-weight infants. Preliminary observations
Related Experiment Videos
1Department of Pediatrics, Milwaukee County Medical Complex, Medical College of Wisconsin 53226.
Insights
Extremely low immunoglobulin G (IgG) levels were observed in very low birthweight infants. These low levels correlated with prematurity and postnatal age, with some infants showing critically low IgG concentrations.
Area of Science:
- Neonatology
- Immunology
- Pediatric Research
Background:
- Infants born with very low birthweight (VLBW) are susceptible to infections.
- Immunoglobulin G (IgG) plays a crucial role in passive immunity.
- Understanding IgG kinetics in VLBW infants is vital for managing infection risk.
Purpose of the Study:
- To serially assess immunoglobulin G (IgG) levels in very low birthweight (VLBW) infants.
- To determine the correlation between IgG levels, prematurity, and postnatal age.
- To report previously undocumented extremely low IgG levels in this population.
Main Methods:
- Serial measurement of IgG levels in 42 VLBW infants (gestational age 23-31 weeks).
- Analysis of cord blood IgG levels in 16 of the infants.
- Correlation of IgG levels with birthweight, gestational age, and postnatal age.
Main Results:
- 42.8% of VLBW infants had IgG levels below 100 mg/dl by a mean postnatal age of 71.2 days.
- Mean cord blood IgG was 413.5 mg/dl, dropping by 66% to 140.3 mg/dl by 57 days.
- Extremely low IgG levels, as low as 22 mg/dl, were observed and correlated with prematurity.
Conclusions:
- VLBW infants experience significant drops in IgG levels postnatally.
- Prematurity and postnatal age are key determinants of critically low IgG levels.
- The reported extremely low IgG levels in VLBW infants are unprecedented and warrant further investigation.
Abstract:
We studied the gammaglobulin levels (IgG) postnatally, serially, in 42 infants of very low birthweight (mean +/- SD 971 +/- 225 g) with gestational ages ranging from 23 to 31 weeks. Eighteen infants (42.8%) had IgG levels of less than 100 mg/dl by a mean postnatal age of 71.2 +/- 16 days. The lowest level was 22 mg/dl in an infant whose birthweight was 700 g. Sixteen of the 42 infants (mean birthweight 946.8 +/- 260 g) also had cord blood IgG levels determined. The mean cord blood IgG was 413.5 +/- 163 mg/dl. This had dropped to 140.3 +/- 87 mg/dl by 57 days, a drop of 66 percent. As expected, the lowest IgG levels postnatally was a reflection of the degree of prematurity and the length of postnatal age. Such extremely low levels of IgG have not been reported previously.