Predictors of persistent respiratory infections in patients with primary antibody deficiency, data from the US Immunodeficiency network (USIDnet)
Saturday, March 3, 2018
South Hall A2 (Convention Center)
Joud Hajjar, MD, Carleigh Kutac, MS, Jordan S Orange, MD PhD FAAAAI

Despite immunoglobulin replacement therapy (IgGRT), some primary antibody deficiency (PAD) patients have persistent respiratory infections; potentially leading to chronic lung disease. Our study objective is to determine the risk factors of developing persistent respiratory infections in PAD.


Common variable immunodeficiency, Agammaglobulinemia, Hypogammaglobulinemia and Specific Antibody Deficiency patients registered in the USIDnet were included. Frequency of respiratory infections before and after IgGRT and the causing pathogens were compared. Data on immune-phenotype and comorbidities were collected when available.


1961 PAD patients existed in the USIDnet database. Before initiation of IgGRT, 944(48.1%) of PAD patients had pneumonia, 1051(53.6%) had sinusitis and 709(36.2%) had otitis media (OM). IgGRT prevented further pneumonia in 690(73.1%) of pneumonia patients, 603(57.4%) of sinusitis patients and 451 (63.6%) of OM patients. 89.5% of those infections were due to an unknown bacteria or virus. Of reported pathogens, Haemophilus influenza 15(20.8%) and Streptococcus pneumonia 14(19.4%) were the most common pathogens causing pneumonia after IgGRT. Haemophilus influenza 11(25.5%) and Moraxella catarrhalis 9(20.9%) were the most common pathogens causing sinusitis. Viral infections were reported in 11(8.2%) of respiratory infections, mostly Respiratory Syncytial Virus 4(3%). When all respiratory infections were included, Haemophilus influenza 28(21.05%) and Streptococcus pneumonia 19(14.29%) were the most frequently reported pathogens. Analysis of patients’ comorbidities and immune-phenotyping is underway.


Respiratory infections are decreased but not eliminated by IgGRT. Haemophilus influenza and Streptococcus pneumonia caused most of the persistent respiratory infections. Further studies to identify the cause of susceptibility to those pathogens and provide targeted solutions to prevent those infections are warranted.