CHARACTERIZATION OF HAEMOPHILUS-INFLUENZAE ISOLATES FROM THE RESPIRATORY-TRACT OF PATIENTS WITH PRIMARY ANTIBODY DEFICIENCIES - EVIDENCE FOR PERSISTENT COLONIZATIONS

A total of 117 consecutive patients with primary antibody deficiencies were followed for up to 5 years with regard to acute respiratory trac t infections. Nontypeable Haemophilus influenzae (NTHI) was the sole p athogen in 61% (202/330) of the samples from which a potential pathoge n was recovered. Common variable immunodeficiency (CVI) was the most p revalent condition (27/39 patients) in the group where H. influenzae w as isolated. In patients where H. influenzae was not found only 9/78 p atients had CVI. 49 of these 78 patients had isolated IgG3 or IgA defi ciency. Both of these entities seemed to be associated with a lower pr evalence of NTHI infections. 13 of 18 patients with at least 2 isolate s of NTHI were colonized with the same strain from 3 to 43 months as s hown by total genomic DNA-fingerprinting. Recurrent symptomatic infect ions occurred in these patients despite substitution therapy with gamm aglobulins and repeated antibiotic treatments. All but 2 of the 224 H. influenzae isolates were beta-lactamase negative and sensitive to amp icillin. The use of 10 lipopolysaccharide-specific monoclonal antibodi es in a whole cell ELISA showed that the LPS-epitopes on the 224 H. in fluenzae isolates from the hypogammaglobulinemic group were very simil ar to 499 NTHI isolates from immunocompetent patients with respiratory infections. One may therefore conclude that i) patients with CVI, wer e prone to be permanently colonized with NTHI, and ii) the colonizing bacteria were ordinary strains showing the same LES-phenotypes as thos e strains that cause acute respiratory tract infections in immunocompe tent individuals.