Comparison of Two Different Criteria for Specific Antibody Deficiency in Patients With Chronic and Recurrent...

Specific antibody deficiency (SAD) is highly associated with chronic rhinosinusitis (CRS) and is defined by inadequate post-vaccination percentage of protective (≥1.3 ug/mL) pneumococcal antibody serotypes divided by total tested serotypes (post-pPA).

Although  < 70% post-pPA has been used commonly as the criterion for SAD, we sought to evaluate the clinical outcome of a different definition of SAD.

203 patients aged 6 to 70 years with CRS were classified, retrospectively by pre-vaccination pPA (pre-pPA) and post-pPA by two different criteria. Using 70% as the threshold for adequate pneumococcal antibody (PA) response, patients were classified as: Group A (adequate pre-pPA), Group B (inadequate pre-pPA, adequate post-pPA), Group C (inadequate pre-pPA, inadequate post-pPA, SAD). Using 50% as the threshold, patients were similarly classified as: Group A', B' and C'.

The recurrence rate of sinusitis during the next one year in Group A (pre-pPA ≥70%) was significantly less than that of Group A' (pre-pPA ≥50%) (10% vs. 34%, P = .03). Group A had lower incidence of sinusitis than Group B (pre-pPA < 70%, post-pPA ≥70%) (10% vs. 34%, P = .025). Among Group B' patients, the recurrence rate of sinusitis was significantly less among those with post-pPA of ≥70% than those with 50%-69% (28% vs. 69%, P < .01).

Employment of a 70% pPA threshold for SAD in comparison to a 50% threshold would decrease the incidence of sinusitis in the next one year by vaccinating patients in 51-69% pPA range. Pre-existing PAs (Group A) yielded a higher protection against sinusitis than vaccine-acquired antibodies (Group B).