Purpose of the Study
The investigation was a prospective study to determine the long-term antibody levels of children initially diagnosed with hypogammaglobulinemia.
Thirty-five children, <4 years of age, who presented with immunoglobulin G (IgG) levels 2 standard deviations below the mean on 2 or more occasions and who had no clinical or laboratory evidence of cellular or other immunodeficiency states. There were 24 males and the mean age at presentation was 19.6 months.
Evaluation consisted of an assessment of overall health status and a panel of laboratory tests, including immunoglobulins, IgG subclasses, antibodies to polio virus (Normal ≥1:8) and tetanus (Normal >0.05 IU/mL), isohemagglutinin titers (Normal anti-A >1:16, anti B >1:8), and antipneumococcal antibodies, with the use of standard techniques. The children were followed for up to 120 months with many of the initial laboratory examinations being repeated at subsequent visits. Immunoglobulin was administered to 9 children for appropriate indications.
There were 3 distinct groups identified. 1) 29 children with full recovery and who never had any type of invasive infections. 2) 3 children continued to have low IgG levels and poor antibody titers to one or more immunization. 3) children whose IgG levels became normal but they were unable to mount an adequate response to antigenic challenge, eg, tetanus and/or pneumococcal vaccines.
The condition may well not be as benign as was thought and careful long-term follow-up is most certainly in order. Invasive infections and low antibody levels at presentation may well be the signals that indicate a permanent antibody deficiency state.
An excellent long-term follow-up of this not too uncommon immunological problem carried out at one of the North America's premier children's institutions. I'd recommend reading the full article either electronically or on paper.