Case report on a defective antibody response against pneumococcal serotype 9V in a patient with a single episode of pneumonia

Abstract

BackgroundPatients with recurrent respiratory tract infections and an impaired response to pneumococcal polysaccharide vaccination are diagnosed with a specific antibody deficiency. In adult patients with pneumococcal pneumonia an impaired antibody response to the infecting pneumococcal serotype can sometimes be found. It is unknown whether these patients are unable to produce an adequate anti-polysaccharide antibody response to pneumococcal vaccination after recovery.Case presentationThe authors describe a case of invasive pneumonia caused by Streptococcus pneumoniae serotype 9V in a previously healthy 35-year-old female. This patient did not produce serotype-specific antibodies against the infecting serotype during disease. After pneumococcal polysaccharide vaccination 3 months after recovery, she responded adequately to most other pneumococcal serotypes, but still had no response to the infecting serotype 9V. However, after 9 years (and prior to pneumococcal-conjugate vaccination) normal antibody levels against 9V were found. These antibody levels further increased after pneumococcal-conjugate vaccination.ConclusionThe authors believe that this case is the first description of a temporary deficient response to the infecting pneumococcal serotype in adults, while other reports with similar observations all involved children.

Corrected and Republished from: A Nonfunctional Opsonic Antibody Response Frequently Occurs after Pneumococcal Pneumonia and Is Associated with Invasive Disease

“…Likewise, the impaired immune response observed in the current study might also have been influenced by exposure to a high level of circulating CPS, either during previous colonization or infection or during the studied CAP episode. This is in line with previous studies that suggest an association between antigenemia and a poor quantitative Ig response ( 8 , 10 ). Moreover, we found that the two patients with the highest pneumococcal DNA concentration in plasma (see Table S1 in the supplemental material) exhibited nonfunctional convalescent-phase responses.…”

“…Few previous studies on the dynamics of naturally acquired pneumococcal immunity related to an infection episode exist. An association of pneumococcal antigenemia with an attenuated convalescent-phase quantitative anti-CPS Ig response was, however, reported in 1976 ( 8 ), and decreased serotype-specific Ig concentrations following pneumococcal infection have been described in case reports ( 9 , 10 ). In one previous study ( 24 ), 88% of convalescent-phase sera from patients with nonbacteremic pneumonia had functional opsonic Ig compared to 50% of sera from bacteremic patients.…”

“…Episodes of asymptomatic nasopharyngeal colonization induce protective adaptive immunity, but studies on the dynamics of naturally acquired immunity related to episodes of clinically significant pneumococcal infection are scarce ( 7 ). Interestingly, a delayed or absent anti-CPS Ig increase has been described after pneumococcal bacteremia ( 8 – 10 ). This observation raises the question whether infection by pneumococci, unlike an episode of asymptomatic colonization, may fail to induce immunologic boosting.…”

A Nonfunctional Opsonic Antibody Response Frequently Occurs after Pneumococcal Pneumonia and Is Associated with Invasive Disease

“…Few previous studies on the dynamics of naturally acquired pneumococcal immunity related to an infection episode exist. An association of pneumococcal antigenemia to an attenuated convalescent-phase quantitative anti-CPS Ig response was, however, already reported in 1976 (8), and decreased serotype-specific Ig concentrations following pneumococcal infection have been described in case reports (9,10). In one previous study (24), 88% of convalescent-phase sera from patients with nonbacteremic pneumonia had functional opsonic Ig, compared to 50% of sera from bacteremic patients.…”

“…Episodes of asymptomatic nasopharyngeal colonization induce protective adaptive immunity, but studies on the dynamics of naturally acquired immunity related to episodes of clinically significant pneumococcal infection are scarce (7). Interestingly, a delayed or absent anti-CPS Ig increase has been described after pneumococcal bacteremia (8)(9)(10). This observation raises the question of whether infection by pneumococci, unlike with an episode of asymptomatic colonization, may fail to induce immunologic boosting.…”