Clinical features identify primary immunodeficiency disease

Three clinical warning signs can accurately identify children with a primary immunodeficiency disease (PID), according to a report in Pediatrics.

Ten warning signs have been promoted to help identify children with PID, but there is little evidence to support their use. British researchers reviewed the clinical records of 563 children who presented to 2 tertiary pediatric immunodeficiency centers to determine which warning signs were the most helpful. Of the 563 children, 430 had a defined PID; in the 133 others, detailed investigations had failed to establish a specific PID.

A family history of immunodeficiency disease was found to be the strongest identifier of PID. Overall, a family history was 18-fold more frequent in children with a PID than in those without a definable PID. The next 2 most helpful warning signs were use of intravenous antibiotics for sepsis in children with neutrophil PID and failure to thrive in children with T-lymphocyte PID. These 3 clinical features correctly identified 96% of patients with neutrophil and complement deficiencies and 89% of those with T-lymphocyte immunodeficiencies. The only warning sign that identified children with B-lymphocyte PID was family history.

On the basis of these findings, the investigators developed a simple schema for identifying PIDs in children with severe, unusual, or recurrent infections. They advise that pediatricians treating children with infectious diseases should routinely inquire about a family history of PID. PID, particularly neutrophil defects, should be considered in children requiring intravenous antibiotics for sepsis, and a T-cell immunodeficiency should be considered in children with infections if failure to thrive is noted. Because B-lymphocyte PID is more difficult to diagnose based on the clinical features, when it is suspected, a lower threshold is required for requesting antibody testing.

If a PID is diagnosed or there is continuing clinical concern, referral to a pediatric immunologist is warranted, the researchers recommend.

Subbarayan A, Colarusso G, Hughes SM, et al. Clinical features that identify children with primary immunodeficiency diseases. Pediatrics. 2011. Epub ahead of print.